A claimed invention relates to the field of medicine or biology, namely the methods using nanotechnology objects, in particular colloidal solutions of gold nanoparticles which demonstrate a strongly marked effect on cellular proteins and can be used to restore the contractile function of mammalian vascular smooth muscle cells. Further, the invention relates to medicinal products which comprise gold nanoparticles and may be used for remote opening of voltage-gated ion channels in mammalian vascular smooth muscle cells.
Many types of nanomaterials are now extensively used in medicine and biology, such as biosensors, biomaterials, drug delivery systems and the like (Yang et al, 2010); however they are not used as medicinal products. It is apparent that properties of nanoparticles (NPs) may substantially vary from those of the same material when it is available in a macroform. These new physical and/or chemical properties are found in unexpected biological or even cytotoxic effects (Seaton et al, 2010). Because of high reactive ability of nanoparticles to interact with cellular proteins combined with their extremely small size and, therefore, better ability to penetrate cell structures, it becomes clear that understanding of how nanoparticles interact with living cells is important for theoretical and clinical medicine and biology.
The contractile function of smooth muscle (SM) cells is very important in all aspects of human physiology since these cells are the main element of effector hollow organs, including blood vessels. Therefore, SMs play a key role in supporting human life in a normal and pathological condition because they provide adequate supply of blood and oxygen.
The most important and widespread cardiovascular diseases, such as hypertension (Cox, Folade, Swanson, 2001; Novokhatska, Tishkin, Dosenko et al, 2013) ionizing radiation-induced (Soloviev, Tishkin, Kyrychenko, 2009) and diabetes-induced angiopathies (Klymenko, Novokhatska, Kizub et al, 2014), were supposed to be associated with excessive reactive oxygen intermediates (ROIs) and consequent protein kinase C activation. Basic mechanisms include disorder of vasodilating potential caused by reducing endothelium-dependent vasorelaxation (Soloviev et al, 2003; Ivanova et al, 2012) and/or inhibiting ion currents through potassium (K+) channels (Soloviev, Tishkin, Ivanova et al, 2009; Soloviev, Tishkin, Kyrychenko et al, 2009; Kizub et al, 2010; Kyrychenko et al, 2010). Finally, all these factors taken together contribute to vascular insufficiency and reduce blood supply to tissues. SM contractility is known to closely relate to their membrane potential, which in turn is determined preferably by K+ membrane conductivity. Therefore, K+ conductivity is generally thought to play an important role in regulation of SM cell membrane potential and, therefore, regulation of vascular tone. Four basic types of K+ channels in SM cells have been described: voltage-gated K+ channels (Kv) encoded by Kv gene family, inwardly(abnormally)-rectifying K+ channels (KIR) encoded by Kir2.0 gene, atropine-sensitive K+ channels (KATP encoded by Kir6.0 and genes encoding sulfonylurea receptor expression, and high-conductivity Ca2+-dependent K+ channels (BKCa) encoded by gene Slo1 (KNCMA1). At the molecular level, BKca channels comprise pore-forming alpha subunits and regulatory B1 subunits. The presence of B1 subunits provides higher Ca2+ sensitivity to BKca channel, making said channel an effective modulator of SM vascular function in healthy and sick subjects. The role of ion channels in SM contraction is usually assessed by pharmacological tools and patch-clamp technique recording membrane potential in various modifications. As was shown, BKca channels play an important role in the treatment of hypertension (Kyrychenko, Tishkin, Dosenko et al, 2012) and radiation-induced vascular hypertension (Kizub et al, 2010). The available data clearly indicates that reduction of outgoing current density in endothelial cells and SM cells combined with reduced BKCa mRNA expression led to vascular hypercontractility and the development of hypertension (Soloviev, Tishkin, Ivanova et al, 2009). It is important to note that, despite widespread use of nanoparticles including gold NPs (Au NPs), evidence of any direct effect of NPs on effector and regulatory elements of the vascular system, i.e. SM cells and endothelium, is not known in biology and medicine.
The object of this invention was to achieve the effect of relaxation in mammalian vascular smooth muscle cells using Au NPs and to establish mechanisms of changing outgoing ion currents and contractility in SM cells.
The prior art discloses a method of SM cell relaxation in a subject, the method comprising administration of a complex containing choline conjugated Au NPs to a subject. The complex interacts with acetylcholine receptors of SM cells in a subject, and Au NPs in the complex bind to sulfhydryl receptor groups, thereby blocking the transmission of nerve impulses in subject's neuromuscular junction (U.S. Pat. No. 8,357,719 B2 published on Jan. 22, 2013).
The prior art also discloses a method of achieving the relaxing effect on muscles and treating atrium fibrillation using a complex containing negatively charged Au NPs having anionic bonds with choline or spermidine. Complexes migrate to an acetylcholine receptor with subsequent rupture of ionic bonds in the complex for stimulation of Au NP bond with Cys-loop acetylcholine receptors (Application U.S. 20120295969 A1 published on Nov. 22, 2012).
The prior art also discloses a method of remote control over neuronal activity using quantum dots (QDs) sensitive to optical excitation and nanoparticles of a semiconductor material. The method comprises activating voltage of closed ion channels using optically excited QDs. Fields formed by photogenerated QD dipoles excite cell membrane potential and create action potentials that control communication and signals between neurons. Such remote method for switching cell activity allows orienting specific cells by changing QD surface chemistry and interacting with specific proteins in cells (Lih Lin, Quantum dot optical switches for remote control of neurons, 30.04.2012, SPIE Newsroom).
Closer to the invention are the methods and compositions for remote control over cell functions which are based on the use of radio frequency waves from excitation of nanoparticles, in particular magnetite NPs targeted to specific types of cells. Magnetite NPs can be applied to a target cell ex vivo and/or for intracellular expression. Types of target cells have a sensitive temperature channel wherein excitation of nanoparticles leads to localised temperature rise causing cellular response. Such cellular responses may include, for example increased gene expression resulting from production by one or more physiologically active proteins. Expression of such proteins may be used to treat a variety of inherited or acquired diseases or disorders in a subject, in particular any disease associated with protein deficiency (publication of the international application WO 2013 029025 A1 dd. Feb. 28, 2013).
The object of the invention is to provide remote activation of voltage-gated ion channels in mammalian vascular smooth muscle cells, in particular potassium channels, using gold nanoparticles. A further object is to enhance activation of voltage-gated ion channels in mammalian vascular smooth muscle cells which is obtained using gold nanoparticles through laser irradiation.
This object is achieved so that according to the invention the claimed method for remote opening of voltage-gated ion channels in mammalian vascular smooth muscle cells comprises extracellular application of the colloidal solution of gold nanoparticles in population of mammalian vascular smooth muscle cells.
According to one embodiment of the invention, the method may use high-conductivity potassium channels as voltage-gated ion channels.
According to an additional embodiment of the invention, the method may use the colloidal solution of gold nanoparticles 4 . . . 7 nm in size.
According to yet another additional embodiment of the invention, the method may use the colloidal solution of gold nanoparticles 5 nm in size.
According to yet another additional embodiment of the invention, the method may use the colloidal solution of gold nanoparticles having electrokinetic potential of at least 35 mV.
According to yet another additional embodiment of the invention, the method may use the colloidal solution of gold nanoparticles with maximum plasmon resonance absorption band within 510 . . . 570 nm.
According to yet another additional embodiment of the invention, the method may use the colloidal solution of gold nanoparticles at a concentration within 10−6 . . . 3×10−4 M.
According to yet another additional embodiment of the invention, the method may use the colloidal solution of gold nanoparticles stabilised with sodium ascorbate.
According to yet another additional embodiment of the invention, the method may further use laser irradiation of population of mammalian vascular smooth muscle vascular cells after extracellular application of the colloidal solution of gold nanoparticles.
According to yet another additional embodiment of the invention, the method may use laser irradiation having power of 5 mW and wavelength of 532 nm.
According to yet another additional embodiment of the invention, the method may use laser irradiation for at least 5 seconds.
Further, the said object may be achieved so that, according to the invention, the claimed medicinal product opening voltage-gated ion channels in mammalian vascular smooth muscle cells comprises the colloidal solution of gold nanoparticles at a concentration required for remote opening of voltage-gated ion channels in mammalian vascular smooth muscle cells.
According to one embodiment of the invention, the colloidal solution of gold nanoparticles may contain nanoparticles 4 . . . 7 nm in size.
According to the additional embodiment of the invention, the colloidal solution of gold nanoparticles may contain nanoparticles 5 nm in size.
According to the additional embodiment of the invention, the colloidal solution of gold nanoparticles may contain nanoparticles having electrokinetic potential of at least 35 mV.
According to the additional embodiment of the invention, the colloidal solution of gold nanoparticles may contain nanoparticles having maximum plasmon resonance absorption band within 510 . . . 570 nm.
According to the additional embodiment of the invention, the colloidal solution of gold nanoparticles may contain nanoparticles at a concentration within 10−6 . . . 3×10−4 M.
According to the additional embodiment of the invention, the medicinal product opening voltage-gated ion channels in mammalian vascular smooth muscle cells contains the colloidal solution of gold nanoparticles stabilised with sodium ascorbate.
The claimed invention is illustrated by the following exemplary embodiment of the method and a means of remote opening of voltage-gated ion channels in mammalian vascular smooth muscle cells as well as by drawings and images where:
Designation*−P <0.05 compared to the combined influence of Au NPs and laser irradiation.
Designation*−P<0.05 compared to control, #−P<0.05 compared to Au NPs.
The effect of remote opening of voltage-gated ion channels in mammalian vascular smooth muscle cells by extracellular application of the colloidal solution of gold nanoparticles in the population of mammalian vascular smooth muscle cells was studied in 6-8 week old male rats Wistar (body weight: 250-350 g) which are held under controlled environmental conditions (+21° C., day-night cycle: 12 h/12 h) and have free access to water and standard food for rats.
For the purposes of the study, smooth muscle cells isolated from rat thoracic aorta using collagenase and pronase were taken. Rats were anesthetised with ketamine (37.5 mg/kg body weight, intraperitoneally) and xylazine (10 mg/kg body weight, intraperitoneally), and thoracic aorta about 1.0 . . . 1.5 cm long was removed and denuded to make it free from connective tissue. Aorta was cut into small pieces (1.5×1.5 mm) in the cooled low Ca2+ ion content solution comprising (in mM): NaCl 140, KCl 6, MgCl2 3, D-glucose 10, HEPES 10 (pH 7.4) for 15 minutes. Vascular tissues were placed in fresh low Ca2+ ion content solution comprising collagenase type IA 2 mg/mL (417 U/mg), pronase type E XXV 0.5 mg/ml, and bovine albumin serum 2 mg/ml. Then tissues were incubated for 30 minutes at a temperature of +37 ° C. After incubation, tissues were washed (for 2-3 minutes) twice in fresh low Ca2+ ion content solution to remove enzymes. Cells were dispersed by stirring using a glass pipette and then placed in modified Krebs bicarbonate buffer. A certain number of muscle cells was maintained at a temperature of +40° C. and remained functional for at least 4 hours.
The studies were conducted using Au NP colloidal solutions with different NP size and various stabilisers; however ascorbate-stabilised Au NPs 4 . . . 7 nm in size, more preferably ≈5 nm in size, demonstrated strongly marked ability to relax vascular smooth muscle cells in rats by remote control (see Table 1 below).
After that, various components of total potassium current activated by action of Au NPs were determined pharmacologically (
It is known that the relationship between potential applied to the channel and its current (conductivity) is described by Boltzmann equation. Thus, the standard Boltzmann equation can be used for static assessment of the impact of Au NPs on aortic Ik of SM cells before and after administration of Au NPs (
This effect was studied experimentally using single channel recordings, the most direct approach to establish a mechanism of channel modulation by Au NPs. In supracellular areas formed on rat aortic myocytes, activity of 3-5 BKCa channels typically occurs at potentials ranging from −20 to +40 mV. Depending on the extent of channel activity in each separate membrane segment, the optimal confining potential was set within this range so that the initial channel activity (typically expressed in NPo) would not be too high, for example about 0.05-0.1. Adding Au NPs potentiates BKCa activity with a delay for 1-2 minutes (
The mechanism of interaction Au NPs with potassium channels and strengthening of the achieved effect by exposing cells to laser irradiation may be associated with plasmon resonance effect, i.e. excitation of surface plasmons on the surface of Au NPs, which may be increased by irradiation with light at a resonance frequency. Au NPs, as nanosized structures of a noble metal, are known to have a distinctive feature, such as collective oscillation of electronic “gas” on NP surface (surface plasmon resonance) leading to photo-induced local electric fields near the surface of nanoparticles. In case of laser irradiation, this local electric field can be significantly enhanced by local plasmon resonance, which in turn affects ion channel voltage sensor, increases outgoing current, and leads to SM relaxation. In the absence of external irradiation, such plasmon may be excited by chemiluminescence of natural tissue.
The strength of an electric field in a cell membrane depends on Au NP concentration, and K+ channels may be activated when threshold Au NP concentration is reached.
Therefore, channel recordings shown on
The medicinal product opening voltage-gated ion channels in mammalian vascular smooth muscle cells containing the colloidal solution of gold nanoparticles may prepared as follows. The Au NP colloid solution with maximum plasmon resonance absorption band within 532 nm is synthesised by reducing sodium tetrachloroaurate with sodium ascorbate in aqueous solutions at a room temperature. Colloidal solutions thus prepared are then neutralised with acetic acid to pH 6-7. Dynamic light scattering spectroscopy of the Au NP colloidal solution thus obtained (200 mg/l, i.e. ˜10−3 M or 6.02×1020 particles/l) shows that the average hydrodynamic size of Au NPs is approximately 5 nm (
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Number | Date | Country | Kind |
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A201508753 | Sep 2015 | UA | national |