Patent Application
20240216661
The present invention relates to the application of an agent to a target site. In a preferred form, the invention uses ultrasonic energy to transport an agent contained within an agent carrier body having a plurality of micro-scale structures within it to the target site non-invasively. In this preferred form, at the target site, penetration of the agent into the target site is enabled or enhanced through sonophoretic mechanisms.
WO 2007/143796 discloses a method of delivering a molecule and/or particle to a target site using a device that includes generating ultrasound for enhancing the penetration of a molecule and/or particle into the target tissue.
The device of WO 2007/143796 includes an electro-conductive polymeric gel material that is loaded with a molecule and/or particle such as a pharmaceutical or ink etc. Application of an electric field to the electro conductive polymer gel releases substantially bound molecules or particles within the polymer gel matrix and, ultimately, such molecules or particles are transported through such polymer gel by ultrasound to the target tissue surface. At the target tissue surface, penetration of the molecule and/or particle into the tissue is enabled or enhanced through sonophoretic mechanisms.
One difficulty relating to this delivery mechanism is that the structure of the polymer gel can degrade over time, for example due to loss of moisture, which results in reduced propagation of the molecule and/or particle by ultrasound. Additionally, gels are poor transmitters of ultrasound reducing the efficacy of the sonophoretic process.
Furthermore, it can be time consuming and non-trivial to properly load an applicator with small volumes of the molecule and/or particle loaded polymeric gel.
In light of these problems, an improved device and mechanism for delivering an agent to a target tissue is sought.
Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction, or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant, or combined with other prior art by a person skilled in the art.
In one aspect of the invention there is provided an agent carrier for non-invasive delivery of an agent to biological tissues. Delivery of the agent to the tissues can be by one or more modalities. The modality of delivery can be characterised by a transportation stimulus or stimuli that causes transportation of the agent through the agent carrier. In a preferred form, the transportation stimulus also enhances or permits penetration of the agent into the tissue. Preferred forms of the invention use only ultrasound as the transportation stimulus.
In preferred forms the agent carrier includes an agent carrier body configured to retain agent within the agent carrier body. The agent carrier body has a tissue contacting surface for engaging tissues under treatment, wherein application of the transportation stimulus causes transportation of the agent through the agent carrier body to the tissue contacting surface.
The agent to be delivered can include one or more molecules or particles or one or more molecules and particles in any combination. The agent can be a fluid or can be carried in a fluid medium, e.g. by being dissolved, suspended or dispersed in a fluid medium, such as water, oil, an emulsion, a gel or the like. To give but a few examples, the agent can include, proteins, vaccines, nucleic acids, monoclonal antibodies, nanoparticles or molecular machines. In preferred embodiments the agent is a pharmaceutical or pharmaceutical composition. The pharmaceutical or one or more active pharmaceutical components of a pharmaceutical composition may be, without limit, any one of: a synthesised compound; a naturally occurring compound; or a biopharmaceutical. The purpose of the delivery of the pharmaceutical or pharmaceutical
The transportation stimulus is the driving force for moving the agent through the agent carrier to the tissue-contacting surface, and may enhance and/or permit the penetration of the agent from the tissue-contacting surface into the tissue.
In some embodiments the tissue can be any human or animal biological tissue, including mucous membranes, skin and teeth. Preferably the tissue is ocular tissue or oral mucosa. In some embodiments the tissue is any plant tissue.
In an aspect there is provided an agent carrier body including a tissue contacting surface for non-invasively engaging tissues under treatment, the tissue contacting surface being at least partly defined by a plurality of protrusions. The protrusions may be in fluid communication with one or more reservoirs forming part of the agent carrier body. Each agent reservoir may comprise a void formed within the agent carrier body. The protrusions may extend outward from an inside of a void and terminate at said tissue contacting surface. The void may be formed by a peripheral structure, where at least part of said peripheral structure may terminate at the tissue contacting surface.
In some embodiments the peripheral structure terminates in a common plane with the protrusions. In others at least some of said protrusions defining the tissue contacting surface extend outward from the void beyond the peripheral structure. In some embodiments, the protrusions may terminate in a plane and the peripheral structure may terminate short of the plane such that the protrusions extend beyond the peripheral structure.
The agent carrier body may further include one or a multiplicity of micro channels extending at least partially through the agent carrier body to the tissue contacting
The agent carrier body of these aspects can include a stack of layers including a tissue-contacting layer, which includes the tissue-contacting surface, and at least one other layer. The tissue-contacting layer preferably has holes extending through it to define at least a portion of the micro channels in the body. In some embodiments a plurality of layers have holes formed therein to enable agent to be transported from one layer to the next. Preferably holes formed in one layer of the plurality of layers are aligned with holes in an adjacent layer so that a plurality of holes in a plurality of layers cooperate to form the micro channels. In some embodiments the holes decrease in diameter and increase in number from the first layer to the tissue-containing layer. The micro channels may have a varying cross-section along their length.
In some embodiments a reservoir for storing agent is at least partly (and optionally fully) formed in the agent carrier body.
The micro channels and/or agent reservoir(s) and/or protrusions are defined by internal exposed surfaces within the agent carrier body. Preferably these internal exposed surfaces are configured to possess predetermined hydrophilic, hydrophobic, and/or electro-conductive properties. In this case, at least part of the internal exposed surfaces could be modified or treated to configure their hydrophilic, hydrophobic, and/or electro-conductive properties.
The agent carrier body may include a port to enable loading of the agent carrier body and/or reservoir(s) with agent.
The agent carrier body can further include a stimulus generator, operable to generate transportation stimulus. The stimulus generator preferably includes an ultrasonic transducer.
In some embodiments, the agent carrier preferably includes a housing configured to mechanically support an agent carrier body, of any type described herein. The housing can include a mounting arrangement configured to be mounted to an applicator device. The mounting arrangement preferably enables selective attachment and removal of the agent carrier to and from the applicator device, such that the agent carrier can be replaced.
The agent carrier housing also may include a recess or other mounting formation formed therein for receiving the agent carrier body. In some embodiments the agent carrier body can be selectively attached to, or removed from, the recess or mounting formation such that the agent carrier body can be replaced.
The agent carrier can include a port to enable loading of the agent carrier body and/or reservoir(s) with agent.
The agent carrier can further include a stimulus generator, operable to generate a transportation stimulus. The stimulus generator preferably includes an ultrasonic transducer. At least part of the stimulus generator can be formed as part of the agent carrier body.
In a preferred embodiment the agent carrier or agent carrier body is a consumable applicator tip adapted for one-time use as part of an applicator device.
In another aspect of the invention there is provided a non-invasive applicator device comprising an agent carrier and/or an agent carrier body as described herein.
The agent carrier or agent carrier body can be coupled directly or indirectly to a handle unit to facilitate hand held operation of the applicator device. The handle unit preferably includes a mounting arrangement configured to cooperate with a complementary mounting arrangement of the agent carrier and/or agent carrier body.
The handle unit may include an ultrasonic generator to generate ultrasonic waves that are transmitted to the attached agent carrier and/or agent carrier body.
Preferably the agent carrier is a consumable applicator tip adapted for one-time use.
The agent carrier preferably includes an agent carrier body including a tissue contacting surface for non-invasively engaging tissues under treatment, the tissue contacting surface being at least partly defined by a plurality of protrusions.
The agent carrier may include one or more agent reservoirs for carrying said agent, wherein said protrusions are in fluid communication with one or more reservoirs forming part of the agent carrier. Each agent reservoir may at partly (or wholly) comprise a void formed within the agent carrier body.
Also disclosed herein is a method of dispensing an agent from an agent carrier described herein. The method comprises holding the agent within an agent carrier, said
In some forms the method further includes applying the transportation stimulus to the tissue via the agent carrier to enhance or permit penetration of the agent into the biological tissue.
Holding the agent within an agent carrier can include holding at least some agent within the carrier body.
In preferred embodiments the agent carrier body terminates at its tissue contacting surface in a plurality of protrusions. In this case, engaging a tissue contacting surface of the agent carrier body with a tissue surface of the biological tissue, includes engaging the tissue surface of the biological tissue with the protrusions of the agent carrier body. Such engagement preferably does not involve mechanically penetrating any layer of biological tissue with the protrusions.
In another aspect of the invention there is provided a method of dispensing an agent from an agent carrier, an agent carrier body, or an applicator device as described previously, the method including: contacting the tissue-contact surface of the agent carrier with a tissue surface; and dispensing agent from the agent carrier body to the tissue surface and into the target tissue.
In some embodiments of any of the above methods the step of dispensing the agent includes generating ultrasonic waves for agent transport to the tissue contact surface. Even more preferably the method includes propagating ultrasonic waves through the agent carrier to the tissue. This aids the delivery of the agent through the tissues via sonophoresis.
In some embodiments of any of the above methods the step of dispensing the agent can include applying an electrical voltage across the agent carrier body to cause agent transport to the tissue contact surface. The electric voltage can also provide for the transport of agent into and through the tissue via iontophoresis. Even more preferably the method includes propagating an electric current through the agent carrier to the tissue.
In yet another aspect of the present invention there is provided a method of dispensing an agent from an agent carrier, an agent carrier body or an agent applicator device as described herein. The method including, contacting the tissue contacting surface of the agent carrier body with a tissue surface; and dispensing agent from the agent carrier to the tissue surface. The step of dispensing the agent preferably includes generating ultrasonic waves to cause or facilitate agent transportation to the tissue-contacting surface. The method can include the application of ultrasonic waves to the tissue surface to non-invasively cause or facilitate agent penetration of the agent into and through the tissue via sonophoresis.
The method further includes propagating ultrasonic waves through the agent carrier or agent carrier body to the tissue.
In another aspect the present invention provides a method of loading agent into any one of an agent carrier, agent carrier body, an agent applicator device as described herein. The method includes, exposing the agent carrier body to the agent to enable filling either of both of, a reservoir or micro channels in fluid communication with said reservoir, with said agent.
The method can include applying a negative pressure to the agent carrier or agent carrier body to draw agent into the micro channels or agent reservoirs in fluid communication with the micro channels. The method can include applying a positive pressure to the agent carrier or agent carrier body to inject the agent into the micro channels or agent reservoirs in fluid communication with the micro channels.
The step of filling the micro channels or agent reservoirs with the agent can include the application of ultrasonic energy to the agent carrier or agent carrier body to draw agent into the agent carrier or agent carrier body.
In some embodiments, the voids and/or micro channels in the agent carrier body are loaded by virtue of capillary forces when the agent carrier is in contact with the agent.
In another aspect the present invention provides a method of delivering an agent to a biological tissue, including: applying said agent using an agent carrier, agent carrier body or applicator of any one of the aspects or embodiments described herein, wherein ultrasound is the transportation stimulus; and configuring the operational parameters of the application to enhance or cause delivery of said agent to a selected depth within
such tissue. The operational parameters configured may include (but are not limited to) any one or more of:
Preferably the operational parameters are selected to deliver a chosen amount of agent to a chosen depth within tissue.
The method may involve delivering the agent to or beyond any one or more of the following tissues or tissue layers:
As used herein, except where the context requires otherwise, the term “comprise” and variations of such term, such as “comprising”, “comprises” and “comprised”, are not intended to exclude further things, additives, components, integers or steps. Also, as used herein, except where there is express wording to the contrary, specifying anything after the words ‘include’ or ‘for example’ or similar expressions does not limit what else is included.
Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings. In the drawings:
In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessary obscuring.
This description follows the following outline:
The delivery of drugs, including macromolecules larger than approximately 500 Daltons and hydrophilic drugs, to the body without using hypodermic injections, ingestion or surgery has long been a desired goal in medicine.
A myriad of drug delivery devices using a variety of technologies have been developed to achieve this (“Drug delivery devices”), however, these have been unable to non-invasively deliver to the body a large range of drugs in a safe, practical, predicable and effective way. Historically, the transdermal route, has been the primary focus of non-invasive drug delivery applications.
The advantages of delivering drugs to the body without ingestion, includes bypassing the degradation of drugs by the acid and or alkaline regions of the gastrointestinal tract and enzymes in the gastro-intestinal tract and avoiding their metabolism by the liver enzymes as well as removal of the dyspeptic side effects of drugs. Advantages of delivering macromolecules or hydrophilic drugs to the body without hypodermic injections include decreased or elimination of pain, local trauma and side effects, increased patient compliance, and lowering the incidence of needle contamination, disease transmission and needle misuse. Delivering drugs to the body without surgery that is required to introduce implanted devices has advantages including decreased or elimination of pain, local trauma and side effects and elimination of any anaesthetic risk.
Drug delivery devices may be applied to skin for both targeted applications and as a portal for systemic drug delivery. The primary barrier for transdermal transport of hydrophilic molecules and/or molecules larger than approximately 500 Daltons is the outermost layer of the epidermis, the stratum corneum, which is typically 10-20 μm in thickness. The stratum corneum is a nonviable cell layer that is comprised of highly-crosslinked keratinocytes embedded in a continuous matrix of skin lipids. Drug delivery devices are needed to overcome these natural semipermeable barriers to deliver the drugs. Drug delivery devices for the skin commonly use microneedles and/or iontophoresis as the primary means of delivering drugs to such tissues.
Another application site for Drug Delivery devices, less commonly used as a portal for systemic drug delivery, is mucosal membranes. The primary barrier for trans-mucosal transport of hydrophilic molecules and macromolecules is the epithelial layer. Drug delivery devices for trans-mucosal delivery commonly use nasal sprays, inhalants and/or iontophoresis as the primary means of delivering drugs.
The following technology (either solely or in any combination) is presently used in Drug delivery devices:
Drug delivery devices that deliver an agent to the body using a process known as iontophoresis operate by generating an electric current that results from the application of electrodes which create and maintain a potential difference between the device and the target tissue. Ionic forms of the drug to be delivered are transported in the electric current and thereby gain access to the target tissue. Devices that deliver an agent to the body using iontophoresis commonly have a continuous layer of drug containing fluid in which the electrode within the device is bathed. The application time tends to be long, in many cases, hours.
Agents that can be delivered to the body using iontophoresis must be both hydrophilic and have an electrical charge. Iontophoresis is not capable of delivering neutral molecules and/or particles including large proteins and vaccines.
Microneedles are discrete protrusions that function to pierce one or more layers of tissue. Depending on their application, microneedles can be partly or fully hollow or solid. Microneedles used in Drug delivery devices commonly function as: 1) structures that can increase permeability within tissue when combined with certain external stimuli; 2) structures incorporating an agent that dissolves into tissue; 3) hollow conduits for injection of agent into tissue; and/or 4) structures designed to scrape surface tissue or expose internal tissue. Microneedles are commonly incorporated into patches that are applied to skin either with adhesives or are mechanically engaged. They may also contain compounds to enhance the penetration of agent through tissue or applied to tissue after it has been pre-treated with permeation enhancer compounds.
Drug delivery devices that deliver an agent to the body using a process known as sonophoresis operate through applying ultrasound to tissue that both increases the permeability of tissues and provides kinetic energy to the agent. The increase in permeability of tissues through ultrasound results from a number of phenomena including any one or more of the following: 1) cavitation though generation and oscillation of gas bubbles; 2) thermal effects from an increase in temperature causing induction of convective transport; or 3) mechanical effects through occurrence of stresses due to pressure variation induced by ultrasound. Low frequency ultrasound, generally in the range of 20-200 kHz, but preferably below 100 kHz, has been found to be more effective for sonophoresis than higher frequencies of ultrasound. The prime method of sonophoretic transport through skin requires power sufficient to create cavitation.
Drug delivery devices that deliver an agent to the body using sonophoresis commonly have a layer of fluid containing the agent in which the source of the ultrasound is bathed or is placed in close proximity. These devices also sometimes include various kinds of microneedles where the microneedles are bathed in such fluid. In each of the aforementioned devices, because fluids attenuate the power of ultrasound more than solid materials, and the volume of fluid on which the ultrasound acts is large with respect to solid structures within or around it, the ultrasound energy is considerably attenuated by the time the wavefront approaches the tissue surface. This ultrasonic wavefront is partially reflected from the tissue surface back into the fluid layer which further disrupts the efficiency of the ultrasound resulting in the need for more power to be applied to the fluid. These techniques have some potential drawbacks, for example, ultrasound applied to tissue can, depending upon the magnitude of power, cause localised damage from cavitation and thermal effects. The threshold for damaging tissue from ultrasonic power depends on a variety of factors including the type of tissue, the thickness of tissue, the health of the tissue and whether the tissue is intact. For example, the skin is capable of tolerating more ultrasonic power being applied to it than mucous membranes on the eye. Furthermore, ultrasound applied to an agent may, depending upon the magnitude of power, cause the agent, or molecules within it, to cleave or denature or otherwise be damaged from cavitation, thermal or mechanical effects. Agents which are known to have a low tolerance to ultrasonic cavitation, mechanical forces or temperatures above 40 degrees centigrade include vaccines, proteins and other biologics.
In summary, preferred embodiments of the present invention use low frequency ultrasound at low power to transport an agent, contained within an agent carrier body having micro-scale structures within it, for delivering the agent non-invasively to tissues.
As will be appreciated, ultrasound will be applied over one or more frequency bands or over a frequency spectrum having several bands. Preferably the band(s) correspond to a resonant frequency of the applicator device including the agent carrier body, and optionally one or more harmonics of the resonant frequency. In some forms of the present invention, the ultrasound applied is of a low frequency, between 20 kHz to 100 kHz, most preferably the frequency of the ultrasonic energy is between 20 kHz and 40 kHz. This is particularly preferred for use with the mucous membranes, eyes and other delicate tissues. However, in other embodiments the applicator device may have a resonant frequency lower than this, and the devices describe herein may be operated with a primary resonant frequency at the tip of the agent carrier body of around 10 kHz. In testing, applicators suitable for use with embodiments of the present invention have been operated at frequencies in any one or more of the following frequency bands, a band centered at or about 10 kHz; 20 kHz, 22 kHz, 28 kHz, 28.19 kHz, and 38 kHz and/or frequency bands of 20-25 kHz, 25-30 kHz, 38-40 kHz, 40-45 kHz, 40 to 60 kHz, 40-80 kHz, 140-160 KHz.
For other tissues, such as skin, the ultrasonic frequency may be outside these ranges. In preferred forms of the present invention, the ultrasonic power used is relatively low, typically in the range 0.05 to 3.5 Wcm−2. Higher intensity ultrasonic power may be needed in some applications. In these cases it may be necessary to pulse or otherwise control the duty cycle of the ultrasonic energy to prevent tissue damage, (e.g. from thermal effects) and/or to prevent damage to the agent.
The ultrasonic energy applied to the applicator causes reciprocating motion of the tissue contacting surface. In typical embodiments the displacement of the tissue contacting surface from its mean position may be between about 100 nm and 2200 nm. Embodiments may operate with a displacement more than 200 nm. Embodiments may operate with a displacement less than 2100 nm. Embodiments may operate with a displacement more than 400 nm. The embodiments used in the experiments operated with a displacement less than 500 nm, and more specifically less than 400 nm.
The studies of the devices were performed using a laser doppler vibrometer model MSA400 from Polytec instruments in Germany.
As can be seen by selecting the frequency (or frequency band) of operation desired oscillation parameters can be chosen. These parameters will vary depending on the particular agent carrier used. In preferred embodiments these devices will be operated in a frequency band that corresponds to one or more of the peaks in motion as illustrated in the plots.
In typical embodiments the velocity of motion of the tissue contacting surface may be between about 0.01 m/s and 0.4 m/s. Embodiments may operate with a velocity more than 0.03 m/s. Embodiments may operate with a velocity less than 0.36 m/s. Embodiments may operate with a velocity more than 0.06 m/s. The embodiments used in the experiments operated with a displacement less than 0.05 m/s.
Embodiments of the present invention may advantageously be used in the delivery of agent to delicate tissues, such as mucous membranes (including the conjunctiva, buccal mucosa and labial mucosa), the cornea and the external coats of the eye.
The ultrasonic power and/or frequency parameters in embodiments may be increased or decreased for a variety of reasons including to control the depth of penetration of the agent into tissue. As an example, the ultrasonic power and/or frequency parameters used for delivering agent to the epithelial surface cells of a mucus membrane, may be lower than power and/or frequency parameters used for delivering agent to the rich blood vessel capillary beds and deeper connective tissue layers that lie below the epithelial surface.
It is intended that the agent carrier body does not penetrate any layer of the tissue surface. Although some superficial cell damage may occur in using embodiments of the present invention, it is not intended and is not relied upon in order to achieve delivery of the agent to the target tissue. Maintaining an intact tissue surface as much as possible may serve to more accurately control the depth of penetration of the agent into tissue layers.
The various micro-scale structures within the agent carrier body described herein, amongst other things serves the purpose of making direct contact between the agent carrier body and the tissue surface to propagate ultrasonic energy, thereby minimizing the extent of any continuous layer fluid within the agent carrier body and between the agent carrier body and the target tissue (which tend to attenuate ultrasonic waves).
One group of embodiments first described in the Applicant's Australian patent application 2013901606, include an agent carrier body having microstructures that form a plurality of micro channels surrounded by rigid walls for delivery of various agents. The micro channels are typically in the range of approximately 25 to 100 μm across when measured transverse to the direction of delivery, may have a length of between approximately 0.5 mm to 2 mm. Any suitable cross-sectional and/or longitudinal geometry can be used.
In use, each channel contains the agent in a fluid column within the channel and the ultrasonic energy is directly applied to each fluid column and the walls surrounding the fluid column. The ultrasonic wave is generated to be longitudinal in nature, i.e. it propagates along the channel. In some embodiments, by using the micron scale architecture of the microstructures, the wave front that impacts the fluid column is concentrated within each micro channel thus reducing attenuation of ultrasound. Reflection of ultrasonic waves at tissue surface is minimized by having direct contact of the device, and most preferably the agent carrier body, with the tissue surface so as not to permit the presence of a fluidic space between them. This further assists molecules to efficiently move toward the target tissue under the influence of ultrasound along the ultrasonic wavefront path. The ultrasonic waves are also carried in the agent carrier body, and specifically in the walls defining the micro channels. Since they do not attenuate the ultrasonic energy as much as fluids do, they efficiently transmit the sonophoretic power to the target tissue directly.
In preferred embodiments, the tissue-contacting surface of the device is not separated from the tissue by a continuous layer of fluid. The tissue-contacting surface of the agent carrier body presents a surface that has areas of solid body and liquid agent (i.e. the openings of the micro channels), in some embodiments approximating a solid-liquid “checker board”-like array. This arrangement may facilitate the sonophoretic ability of the device since the faces of the solid walls directly contact the tissue. In such embodiments the device architecture might be conceptualized as a large number of individual micron-scale sonophoretic delivery devices tightly packed and joined together.
Another group of new embodiments include a plurality of micro-scale structures that is formed by micron-scale protrusions that together define the tissue contacting surface of the agent carrier body. These protrusions contact the target tissue and the agent to be delivered surrounds them. In preferred forms, the agent carrier body has a peripheral structure, typically a wall, that surrounds the protrusions and contains the agent in use. This embodiment has a lower ratio of microstructures to fluid within the agent carrier body compared to an agent carrier body comprised of micro-channels. Preferably these embodiments maintain direct contact between the ultrasonic source and the target tissue via the protrusions, and possibly also the peripheral structure. The longitudinally directed ultrasonic waves are conducted by the protrusions and the fluid between. The protrusions act by facilitating the transport of drugs toward the target tissue. Waveform interference from fluid in adjacent spaces between protrusions is minimised by the presence of the protrusions, which serve to at least block propagation of waveforms.
Another group of new embodiments present a hybrid device, having at least one region having multiple micron-scale protrusions and at least one other region having micro channels surrounded by rigid walls. Typically a region or regions having micro channels surrounded by rigid walls will form part of a peripheral structure bounding a region that has micron-scale protrusions.
Molecules that are known to the inventors to possibly be delivered to the body using sonophoresis include 1) molecules having any kind of electric charge or have a neutral (including overall neutral) electrical charge and 2) small or large molecules (including monoclonal antibodies of approximately 150,000 Daltons) and 3) molecules that are hydrophilic or hydrophobic or lipophilic.
Several exemplary embodiments of the various aspects of the invention are described with reference to an exemplary applicator device for delivering an agent non-invasively to a target tissue surface site via a transportation modality, which preferably uses only ultrasonic waves. In these exemplary embodiments, at the target tissue surface site, penetration of the agent into the target tissue surface site is enabled or enhanced through sonophoretic mechanisms. Preferably, target tissue surface sites are mucous membranes including, but not limited to, conjunctival, vaginal, urethral, inner ear, tracheal and bronchial mucosa, anal, oral, and nasal tissues. A target tissue surface can also include the cornea.
The system comprises an applicator device that is preferably hand-held and used for delivering an agent to a target tissue. The preferred form of applicator device includes a handle coupled to an applicator tip. The applicator tip includes an agent carrier body that has micro channels formed in it through which the agent is delivered from within the applicator tip to a target tissue surface. The agent carrier body may be integrated within the applicator tip, or may be a separate component (such as a cartridge) that is attachable to the applicator tip.
The applicator tip may include a reservoir that holds an agent. The reservoir may form part of the agent carrier body, or may be a separate component that is in fluid communication with the agent carrier body.
An ultrasonic transducer forming part of the handle or applicator tip generates ultrasonic energy (waves) which causes the agent to be moved through the micro channels in the agent carrier body, egress through terminal pores of the micro channels at a tissue contacting surface of the agent carrier body and onto the target tissue surface. The ultrasonic waves also enhance and/or permit agent uptake into the target tissue through sonophoresis.
In this example, the agent carrier body 104 may be of any type described generally herein, and as exemplified in any one of
In this example, ultrasound 110 is generated and conducted through the agent carrier body 104. This causes agent 118 stored within the channels 112 to be released from the channels 112 and on to the tissue surface 108. The penetration of agent into the tissue 108 is enhanced and/or permitted by the use of ultrasound, which provides a sonophoretic effect on the tissue.
In the embodiment of
It is preferred that the inner surface(s) of the channel 112 are functionalised. The inner surface 113 of the channels 112 may be functionalised with compounds or molecules having hydrophobic or hydrophilic properties or a combination of both moieties.
Alternatively, the surface 113 of the channels 112 may be functionalised by contacting the surface of the channels with small molecules that are adsorbed to the surface of the channels, exposing specific functional groups that have the desired physical and/or chemical properties. The small molecules may be adsorbed through chemisorption or physisorption to the internal surface of the channels. Alternatively, or in addition to changing the water/oil affinity, the inner surfaces of the micro-channels and/or agent reservoirs may be functionalised by enabling them to become electro-conductive.
The agent carrier body 400 is formed of a layer(s) of solid material and possesses a number or network of micro channels that may be a variety of geometric shapes and sizes. These micro channels can be used to store or retain an agent and also to deliver agent from within the agent carrier body 400 to a tissue-contacting surface 406 of the agent carrier body 400. The micro channels can be created by a micro-fabrication technique. For instance, in embodiments where the agent carrier body 400 is formed from silicon, the micro channels can be formed by lithography, etching and/or other processes. In embodiments made from metal, plastics or polymers the micro channels can be created by other techniques including the use of lasers of various types and wavelengths and molding and extrusion technologies. The use of these micro-fabrication techniques are particularly desirable as they provide the advantages of retained agent volume accuracy, the benefits of predicable micro-fluidics and further permits refinements such as specialised surface chemical treatment to either or both the exposed tissue-contacting surface and the internal walls lining the micron-scale cavities 402 of the agent carrier body 400. These benefits can be used, for example, to further enhance agent loading, retention and delivery to a target tissue.
The tissue-contacting surface 406 has a series of openings, fenestrations or pores 404. A wide variety of shapes and sizes of pores can be on the order of 10 to 100 μm, but other embodiments may have pore sizes up to 1000 μm. The micro channels 402 extend from the pores 404 in the tissue contact surface 406 at least partially through the agent carrier body 400. The micro channels 402 can be used for both retention of the agent and transportation of the agent to a tissue surface.
The pores 404 may have a patterned appearance and exhibit a range of geometries, for example: close packed hexagon structures, arrayed squares with assorted densities, mixed polygon mosaics, spirals, lines etc. The desired geometries are physically etched into the agent carrier body 400 so as to create arrays of micro channels 402 for retention and/or transport of an agent. The micro channels may be in a variety of shapes for example cylindrical, conical etc.
The walls of the micro channels 402 and/or other internal surfaces within the agent carrier body 400 may be treated such that: they have hydrophilic or hydrophobic characteristics that may be the same or opposite in nature to each other and/or the areas between the pores 404 of the tissue-contacting surface 406. The walls of the micro channels 402 and/or other internal surfaces within the agent carrier body 400 may be treated such that they conduct electric charge or can generate a local electric field that may have the same or opposite polarity to each other and/or the areas between the pores 404 of tissue contacting surface 406.
The agent carrier body 400 can be formed from a unitary piece of material. However, in alternative embodiments the agent carrier body may include a number of layers that are stacked. The use of micro-fabricated solid material as single or multiple layers to create an agent carrier body allows for improved acoustic transmission and thus improved delivery of agent to a target tissue site by ultrasound.
The dimensions and internal lining characteristics of the micro channels 402 and/or other internal surfaces within the agent carrier body 404, and the dimensions and number of layers comprising the agent carrier, will be tailored to suit the agent and the target tissues, and will vary as a consequence of agent properties, dose and formulation requirements, ultrasonic power and heat generation, and the duration of use.
In alternative embodiments, the agent carrier body has a stacked layer structure and includes at least two layers. More preferably, one or more layers have additional micro-reservoir volumes formed within them and which are in fluid communication with the micro-channels for holding agent prior to application to the tissues being treated. The micro-reservoir volume may be a single volume or a plurality of small volumes, e.g. each of which is contiguous with one or a group of micro-channels. There may be a single large reservoir volume in the layer furthest from the tissue-contacting layer that is fluidically connected with the channels. Alternatively, there may be multiple micro-reservoir volumes, with each of the micro-reservoir volumes being in fluid communication.
Agent carrier body 448 is another embodiment in which the reservoir consists of a number of concentric rings each fluidically connected to each other. It will be appreciated that other arrangements of the agent reservoir volumes within a layer are possible without departing from the invention.
Generally, the holes in a lower or intermediate layer of an agent carrier body extend through the whole thickness of that layer and in combination with subsequent fluidically connected holes in other layers, form a micro channel that extends from the tissue-contacting surface in the surface contact layer of the agent carrier. It will be appreciated that in certain instances the holes only extend partway into a particular layer; this can be the case for the first layer as illustrated for example in
As stated previously, it is preferred that the inner surface(s) of the micro channels and other internal surfaces of the agent carrier, such as those of the agent reservoirs, may be functionalised.
In the embodiments illustrated in
Micro protrusions, such as micro-needles and microtubules can be created by secondary fabrication consisting of etching the tissue contact surface 502 of a tissue-contacting layer 501.6 such that the areas between the pores are largely removed. This leaves a wall around each pore of the required protrusion to surround each pore. The micro-needles and microtubules can be of any shape desired. For example,
In a preferred embodiment each layer is disc shaped or cylindrical in shape. Preferably the layers have a thickness of from about 0.3 mm to about 1.0 mm, and even more preferably each layer has a thickness of about 0.5 mm. It is preferred that each layer has a diameter of from about 3 mm to about 10 mm, and even more preferably has a diameter of about 5 mm. The thickness dimension and the diameter dimension may vary between layers. While the layers and overall shape of the agent carrier body have been described as being disc shaped or cylindrical in cross sectional shape, as in
The embodiment of
The transportation modality may use an electric field to cause a charged agent to be transported. The electric field can be provided by applying a voltage to an electrode in the agent carrier using an internal battery in the applicator device or by an external power supply. In a preferred form an electrode is located within the applicator device, a second external electrode, also connected to the applicator device power supply, can be located in such a way that the target tissue effectively becomes an electrode opposite in polarity to that of the internal electrode. The polarity of the electrodes can be selected such that the internal electrode is of the same polarity as the electric charge on the agent. The voltage established between the two electrodes transports an electrically charged agent through the agent carrier to the tissue-contacting surface and can enhance and/or permit the transport of the charged agent into the tissue via iontophoresis. Embodiments of the invention can use multiple delivery modalities using ultrasonic waves and electric current used in combination either alternately or simultaneously. Accordingly, Layer 618 can additionally be modified to include, or alternatively be, a material that serves as an electrode. The electrode can be positively or negatively charged and is used to generate a static or dynamic electric field. In the case where the top surface of the adjacent agent carrier layer does not have pores and the adjacent agent carrier layer is made from a material that is not electro-conductive, there is no direct contact between the electrode and the ions or charged agents contained within the micro channels or reservoirs however, ions and charged agents of the same polarity as that existing on the electrode will be repelled. If the adjacent agent carrier layer is made from a material that is electro-conductive and the adjacent agent carrier layer does not have holes, there is electrical conductivity established with the ions or charged agents contained within the micro channels or reservoirs. This scenario is functionally equivalent to the case where the surface of the adjacent agent carrier layer does have pores (and is not dependent on the electro-conductivity of the adjacent agent carrier layer) and the electrode is in direct contact with the ions or charged agents contained within the micro channels or reservoirs, where a further electrode, opposite in polarity to layer 618 can be placed on, or adjacent to, the target tissue. To complete the electric circuit, the electrode placed on or adjacent to the target tissue may be connected to the agent carrier; applicator handle; or other component of the application device (not shown). An applied voltage can provide the energy required to cause an electrically charged agent of the same polarity as the electrode of layer 618, to flow in the fluid contained in the micro channels of an agent carrier body 601 to migrate through the agent carrier, out of the pores to the tissue surface to be delivered into the tissue by iontophoresis.
This provides an alternative embodiment whereby the agent carrier is able to generate an electric voltage to facilitate the flow of an electric current to transport electrically charged agents through the agent carrier and out of the pores to the tissue.
In some embodiments the agent carrier body includes (as with layer 618), or is itself an electrode to facilitate the transport of a charged agent through the agent carrier and out of the pores to the target tissue. The electrode may be located adjacent to the stack of layers, or may be an electrode layer that is integrated within the stack of layers (as with layer 618).
In the above embodiment, ultrasonic energy and/or electrical voltage provide the energy required to move the agent through the agent carrier to its tissue contact surface where sonophoresis and/or iontophoresis enable the agent to be delivered into the target tissue.
As will be appreciated in the above embodiments, a layer including the tissue contacting surface e.g. 422, 422′, 422″ 502, 610 can be a layer including a tissue contacting surface being at least partly defined by a plurality of protrusions, such as those described in any one of
Multiple layers can be arranged such that progressing from the top most layer, through the intermediate layers, to the surface contact layer, the diameter of the holes decreases and the number of holes may be increased. Each subsequent layer includes a cluster of holes that is in alignment with a hole in the adjacent subsequent layer. For example, a first layer (which may be the top most layer or an upper one of the intermediate layers) has a number of holes. This first layer overlies a second layer, wherein the second layer has clusters of holes that are arranged beneath the holes in the first layer. This second layer may overlie a third layer and each hole in each of the cluster of holes in the second layer overlies a further cluster of smaller holes in the third layer (additional layers may also be provided in this manner).
The channels define a flow path for the agent through the agent carrier body to the tissue surface. The channels are defined initially by the diameter of the holes in the first hole possessing layer. Subsequent layers have clusters of holes that are aligned with the holes in this first hole possessing layer. Therefore, progressing from the first hole possessing layer through subsequent layers, the channels become multi-furcated into numerous branches. It will be understood that these numerous branches all form a part of the channel.
The following series of embodiments include a plurality of microstructures formed from micron-scale protrusions that together define the tissue contacting surface of the agent carrier body. These micro-scale structures contact the target tissue and the agent to be delivered surrounds them. In preferred forms the agent carrier body has a peripheral structure, typically a wall, that surrounds the protrusions and contains the agent in use. This embodiment has a lower ratio of microstructures to fluid within the agent carrier body compared to an agent carrier body comprised of micro-channels. Preferably these embodiments maintain direct contact between the ultrasonic source and the target tissue via the protrusions, and possibly also the peripheral structure. As will be appreciated the application of ultrasound will be generally in accordance with the parameters set out in the overview above.
More specifically
In some embodiments the peripheral structure terminates in a common plane with the protrusions. In others at least some of said protrusions defining the tissue contacting surface extend outward from the void beyond the peripheral structure. In some embodiments, the protrusions may terminate in a plane and the peripheral structure may terminate short of the plane such that the protrusions extend beyond the peripheral structure.
In such embodiments is should be noted that the protrusions of the preferred embodiments do not act as microneedles. Unlike microneedles, the protrusions of the preferred embodiments are not intended to penetrate any layer of tissue. The function of protrusions includes engaging the target tissue by applying pressure resulting in a frictional force on the surface. This aids the positioning of the device (e.g. on the slippery surface of mucous membranes) and enhances the sonophoretic effect.
As will be appreciated, the agent carrier bodies exemplified in these figures, can be used in place of any agent carrier body illustrated herein e.g. agent carrier body 104, 810, 902, 903, 903′, 903″, 903′″, 903″″ and 1302, or with any of the agent carriers described herein, e.g. agent carriers 300, 800, 800′ and 900, 900′, 900″, 900′″, 900″″. In the preferred embodiments, protrusions include the following properties:
They do not have a needle-like tip, that is, they do not narrow to a point such that their width does not decrease to near zero at the tip.
The cross-section is relatively constant, at least near their tip, and most preferably along their whole length. In most cases the width will not narrow by more than 20%, and preferably less than 10% towards its tip.
They do not enter an intact epithelial surface of the target tissue.
They aid in stabilizing the device by the frictional force they apply when the device is placed in contact with the tissue. This is particularly advantageous on mucous membranes that tend to have a low friction surface due to local mucous secretions.
They generally have a height to width aspect ratio (across their shortest cross sectional width) of between 1:1 to 10:1. Whilst higher aspect ratios may be used it is difficult to achieve acceptable strength that they can withstand handling, loading and application of ultrasonic energy without damage. As will be appreciated cross sectional shape will greatly affect the strength of them and will be chosen accordingly.
In preferred embodiments the protrusions occupy more than 5% of the volume surrounding them in which agent is carried. This percentage needs to be high enough so that the capillary force or other forces retain the agent within the agent carrier body against gravity or other forces caused by normal handling. In embodiments used with water-like agents, will typically have a density of projections of greater than 5% and most preferably greater than 10%. It should also be appreciated that as the agents become thicker, e.g. protein rich agents, the density of protrusions, or their size and/or wall surface area, can be lowered.
In this embodiment the agent carrier body 750, can be used for delivery of an agent to a tissue via a transportation stimulus. The agent carrier body 750 includes a tissue contacting surface 752 for engaging tissues under treatment. In this example the tissue contacting surface is defined, at least partly by a plurality of protrusions 754.
The protrusions 754 may be of any shape, but in the present example are generally cylindrical. Preferably the protrusions have a constant cross sectional shape along their height. The protrusions 754 extend outward from an inside of a void 756 that is formed within the agent carrier body 750. The outward ends 758 at least partly define the define the tissue contacting surface of the agent carrier body 750, The void 756 is formed by a peripheral structure 760, which in this case takes the form or a peripheral wall or rim. The rim 760 also defines part of the tissue contacting surface 752.
The peripheral structure 760 in this embodiment terminates in a common plane with the protrusions, to define a planar tissue contacting surface 752. However, in other embodiments the at least some of said protrusions 754 can extend beyond, and/or stop short of the peripheral structure so that tissue contacting surface 752 is not planar. In some embodiments the protrusions 754 may all extend beyond the peripheral structure 760.
The void 754 acts as a reservoir to hold agent within the agent carrier body 750. However unlike previous embodiments this reservoir is located on the tissue contacting surface side of the agent carrier body.
The protrusions 754 are located within the reservoir so that they are in fluid communication with the agent in the reservoir. This allows the protrusions 754 to act on the agent within the agent carrier body 750 and transmit the transportation stimulus into the agent, whereas in the embodiments above the walls of the micro channels acted on the agent within the agent carrier body.
Embodiments of this type generally have more volume for holding agent than embodiments described above. By having a larger filling volume, the possibility of air entrapment may also be reduced. These improved filling properties may give certain embodiments improved filling accuracy and repeatability, which contributes to an increase in dose accuracy, that may be important in medical applications. Furthermore the improved filling may lead to better ultrasonic energy transmission as dampening by retained air spaces is reduced.
It is preferred that the inner surface(s) of the void 754 are functionalised. The inner surface of the void 754 and the protrusions 752 may be functionalised with compounds or molecules having hydrophobic or hydrophilic properties or a combination of both moieties. Alternatively, the surface of the void 754 and the protrusions 752 may be functionalised by contacting the surface of the channels with small molecules that are adsorbed to the surface of the channels, exposing specific functional groups that have the desired physical and/or chemical properties. The small molecules may be adsorbed through chemisorption or physisorption to the internal surface of the channels. Alternatively, or in addition to changing the water/oil affinity, the inner surfaces of the micro-channels and/or agent reservoirs may be functionalised by enabling them to become electro-conductive. In a preferred form loading of the agent carrier body is performed by virtue of capillary forces when the agent carrier is in contact with the agent.
In
In
It will be appreciated that these embodiments are not exhaustive in any way and many alternative embodiments, having different protrusion dimensions, separations, cross sectional shapes can be devised. It should also be noted that, whilst these embodiments are contained within a square rim designated by reference numeral 792, other shapes can be used. Furthermore, the array of protrusions need not be a regular array or have even density or distribution across the chip. All protrusions 794 used in an embodiment need not have the same cross sectional shape.
Examples (f) and (g) have cross shaped protrusions 794. The cross shaped protrusions have the advantage that they have an increased wall surface area compared to round protrusions, but a reduced cross sectional area, thus maximising agent storage volume. The geometry of cross shaped protrusions also have relatively good mechanical properties, insofar as each arm acts as a buttresses to support the transversely extending arm.
In this micrograph the protrusions also taper at their bottom. The tapering is a result of the etching process used during manufacturing, and is largely unintentional. However, in some embodiments, this tapering can be used to advantage as it increases the volume of the void in which agent is held.
An agent carrier having a plurality of agent carrier bodies, perhaps arranged in a pattern such as an array, could also be provided.
The loading mechanisms, generally illustrated in
In an alternative embodiment of a method for charging an agent carrier body with agent, an agent can be directly injected into the port so that the air in the agent carrier (i.e. in the micro channels and/or agent reservoirs) is expelled and replaced by the agent.
In an alternative embodiment of a method for charging an agent carrier or applicator tip having an agent carrier with agent, agent can be directly injected into a port so that the air in the agent carrier (e.g. in the micro channels and/or agent reservoirs) is expelled and replaced by the agent.
As will be appreciated, the loading techniques described above can be used with suitable micro-channel, hybrid or protrusion based agent carrier bodies described herein or devised. However, agent carrier bodies or agent carriers which permit direct access to an agent reservoir may be loaded by directly placing agent into the reservoir, e.g. by pipetting the agent onto the reservoir. One example of such a mechanism was used in the experiments described below. In this example the agent was pipetted into the void on the tissue contacting surface of the agent carrier body of a protrusion-based agent carrier body. In a similar manner, agent may be pipetted to a reservoir on the back of the agent carrier body for delivery via micro channels to the tissue contacting surface.
The agent carrier may be provided as either empty agent carriers or as charged agent carriers that are filled with an agent. Where empty agent carriers are provided, an end user will need to charge the agent carrier with agent prior to use.
The invention also relates to a method of charging the agent carrier with an agent and discharging agent from the agent carrier.
The method of discharging agent from the agent carrier or dispensing agent to a tissue surface includes applying the agent carrier to a tissue surface and dispensing agent from the agent carrier to the tissue surface. Preferably the process of dispensing the agent includes applying ultrasonic waves to the tissue surface to facilitate penetration of the agent into the tissue through sonophoresis.
As will be appreciated from the foregoing the agent carrier or an agent carrier body itself can be an item separable from the applicator device. In a preferred form the agent carrier or agent carrier body is a single use item that is removable or interchangeable. This aids in the sterility required for medical usage and facilitates among other things cleaning and sterilising of the hand-held applicator device between patients. The solid physical nature of the preferred embodiments facilitates mounting and handling of the agent carrier in circumstances where they are replaceable. Moreover, the use of a solid material for the agent carrier body to contain the agent facilitates loading of an agent into an agent carrier, packaging, handling of agent carrier bodies pre-loaded with agent.
Importantly, the use of solid materials for the agent carrier body facilitate the propagation of ultrasonic waves that are used to move an agent through the agent carrier and enhances and/or permits the entry of an agent into the target tissue by sonophoresis.
The agent carrier 1300 includes the following main components: An agent carrier body 1302, and a tip housing 1303 that includes a tip body 1304 and an agent carrier body retaining cap 1306.
The agent carrier body 1302 is generally rectilinear in plan view, and in this example it is square. The agent carrier body 1302 may be made in accordance with any one of the examples given above or aspects described herein. The agent carrier body 1302 has a tissue contacting surface 1304.
The tip body 1304 serves to both connect the agent carrier 1300 to an agent applicator device and conduct transmission stimulus, in the form of ultrasonic energy to the agent carrier body 1302. To achieve this, the tip body 1304 is provided, on a first end thereof, with a mounting mechanism 1305 in the form of a screw thread. The mounting mechanism 1305 is used to make a mechanical connection with a corresponding connector of a handle assembly. The second end of the tip body 1304 is shaped to operate as a horn to conduct ultrasonic energy, via mating surface 1307, to the agent carrier body 1302.
The agent carrier body retaining cap 1306 serves to retain the agent carrier body 1302 and hold it in contact with the mating surface 1307. The agent carrier body retaining cap 1306 has an aperture 1310 formed in it, through which the tissue contacting surface 1308 of the agent carrier body 1302 is exposed in use. The agent carrier body retaining cap 1306 is mounted to the tip body 1304 using a screw thread.
As will be appreciated there are many morphological and mechanical variations can be made in such a system. For example the shape of the components, including the agent carrier body, and its associated tissue contacting surface may be varied. The present square embodiment is particularly convenient when the agent carrier body is made from a semiconductor material and its manufacturing process most conveniently outputs square components. The shape of the tip body can be varied to optimise transmission of ultrasonic energy if ultrasonic energy is used as a transportation stimulus. The shape of the aperture thorough which the tissue contacting surface of the agent carrier body is exposed can be varied. In some cases it may differ from the shape of the tissue contacting surface of the agent carrier body.
The method of engagement of the agent carrier retaining cap with the tip body can be varied widely to use any convenient type of mechanism. In this example engagement is by screw thread, however the agent carrier retaining cap could be press fit onto the tip body, or engaged with snap fasteners, or a bayonet fitting, to give a non-exhaustive list or alternatives. Similarly the mounting mechanism of the agent carrier body can be varied to use any known coupling mechanism.
An agent carrier having a plurality of agent carrier bodies, perhaps arranged in a pattern such as an array, could also be provided.
In a further aspect of the present invention there is provided methods for delivering an agent to a living tissue, e.g. animal, plant or human. It is considered that by selectively choosing the operational parameters of the non-invasive agent applicator presently described, the amount of agent delivered to a selected depth within tissue may be controlled.
The controlled parameters may include one or more of:
In particularly preferred forms, the system parameters can be chosen to control the delivery of an agent to a desired depth in the target tissue. An example of this would be setting system parameters such that transepithelial delivery of an agent predominantly into the stroma of the cornea would occur. Advantageously, this presents the opportunity to deliver a drug, vaccine or other agent to a selected tissue depth where it is known to be most efficacious.
In this regard, the present invention in one form provides a method of controlling the amount of agent delivered to a selected depth within tissue using an agent carrier, agent carrier body or applicator of any one of the aspects or embodiments described herein.
A series of experiments were conducted using mice to determine if an agent can be successfully delivered to tissues using embodiments of the present invention. The transportation stimulus in each case was ultrasonic energy only. In the present experiments a vaccine virus was administered using an embodiment of the present invention, using ultrasonic energy only, applied to the inside of the lip to determine whether the agent was presented to the immune system, and may induce an immune response. Researchers noted that no damage occurred to the mucous membrane of the lip by the application of the device for the period required to achieve a systemic immune response in Experiment 2.
Mice were vaccinated with an embodiment of the present invention illustrated in
The proportion of antigen presenting cells taken up the vaccine antigen (0.025-0.068 vs 0.025-0.022), and the proportion of dendritic cells recruited to the draining lymph nodes (0.25-0.54 vs 0.22-0.49) were similar in immunised and unimmunised mice, respectively (
A full heterologous prime-boost vaccination using recombinant poxviruses expressing HIV antigens was conducted using three microchips per mouse prime, and the responses were compared to mice primed intranasally (i.n.) (positive control), and to mice not primed with any vaccine (negative control). All mice were given an intramuscular (i.m.) booster vaccination two weeks after the priming vaccination.
The magnitude of the systemic immune responses (responses in the blood compartment) induced by different vaccination routes were evaluated by determining the percent of HIV-specific CD8 T cells in spleen. One of the mice vaccinated using an embodiment of the present invention generated an immune response that exceeded the positive control thus demonstrating proof of concept.
In a further experiment a preliminary prime-boost vaccination experiment was conducted using embodiments of the present invention illustrated in
Full prime-boost vaccination experiment was performed using the microchips 1 and 2 of
Table 1 summarises the experimental parameters and outcomes of each of the experiments.
a(×3)-refers to the number of microchips of vaccine administered to each mouse, thus “×3” means that three microchips were applied;
bDose, is represented in plaque forming units (pfu) of the priming vaccine, fowl pox virus expressing HIV antigens (FPV-HIV) are provided. The route of vaccination delivery; is indicated as follows:
cThe booster vaccine is vaccinia virus expressing HIV antigens (VV-HIV), and in all cases this was delivered using intramuscular (i.m.) route
dIn both cases, systemic immune response was investigated. M# represents mouse number.
Aims: To determine whether the lip delivery system using the embodiment of
As can be seen, no differences in the antigen uptake and presentation (
In this next experiment an evaluation of the efficacy of lip delivery with the same microchip as experiment 1, using prime-boost vaccination was performed.
Aims: To test whether lip prime followed by intramuscular (i.m.) booster vaccination can induce effective HIV-specific CD8 T cell immunity compared to intranasal prime (i.n.)/i.m. booster vaccination strategy using:
1) Priming Vaccination with FPV-HIV
7-14 days post booster vaccination spleens were harvested from each mouse, and single cell suspensions were prepared as described in Ranasinghe et al (2006).
The magnitude of the HIV-specific CD8 T cell responses was assessed with tetramer staining and intracellular cytokine staining, using 4×106 spleen cells from each mouse according to the plate scheme in Tables 2 and 3 as follows:
The HIV-specific tetramer (
Data also revealed that 3× lip or 4× lip microchip delivery was more effective than 5× lip microchip delivery (data not shown). These experiments were performed twice and data were found to be very similar between the experiments (Experiments 4 & 5). Data are representative of one experiment.
A further experiment was performed to test prime-boost vaccination strategy to assess the efficacy of lip delivery using four protrusion-based embodiments of the present invention illustrated in
Aims: To test whether these microchips can load and deliver the vaccine more effectively to the lip compared to microchips of
1) Priming Vaccination with FPV-HIV
In this experiment vaccination using a 3× lip/i.m. vaccination strategy using microchips 1 & 2 was tested in a similar manner to previous experiments.
Aim: Test the efficacy 3× lip/i.m. vaccination strategy compared to 1× oral/i.m. prime-booster vaccination using:
Vaccination and analysis were performed exactly as in experiment 3 with 3 mice per group. 1× oral prime/i.m. booster vaccination was also performed as an additional control to assess whether the priming was related to oral delivery or lip delivery (oral dose=5×106 FPV-HIV). The HIV-specific CD8 T cell responses were measured in the spleen 14 days post booster vaccination using tetramer staining and intracellular IFN-γ staining. The experiments were performed two times.
As can be seen the HIV-specific splenic CD8 T cell responses observed with microchip 1—mouse 2 and microchip 2—mouse 3 (red arrows) were greatly elevated compared to oral delivery (bottom 3 mice
Data indicated that if the delivery was uniform/consistent the microchip 1 and 2 could induce good HIV-specific CD8 T cell immunity in the blood compartment.
The positive responses detected with the microchips made in accordance with
Data from experiments, suggest that if uniformity/consistency could be attained, lip delivery could be more effective than oral or intranasal delivery.
Molecules that are known to the inventors to possibly be delivered to the body using sonophoresis include 1) molecules of any kind of electric charge or have a neutral (including overall neutral) electrical charge and 2) small or large molecules (including monoclonal antibodies of approximately 149,000 Daltons) 3) molecules that are hydrophilic or hydrophobic or lipophilic.
It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/AU2014/050027 | May 2014 | WO | international |
| 2014904549 | Nov 2014 | AU | national |
This application is a continuation of U.S. application Ser. No. 16/939,796, filed Jul. 27, 2020, which is a continuation of U.S. application Ser. No. 15/308,220, filed Nov. 1, 2016, which is a National Stage Application of International Application No. PCT/AU2015/050218, filed May 6, 2015, which claims the benefit of International Patent Application No. PCT/AU2014/050027, filed May 6, 2014 and Australian Patent Application No. 2014904549, filed Nov. 12, 2014, the disclosures of which are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16939796 | Jul 2020 | US |
| Child | 18608706 | US | |
| Parent | 15308220 | Nov 2016 | US |
| Child | 16939796 | US |
