Embodiments of this disclosure relate generally to novel nanoparticle and cytokine compositions, and constructs and to methods for making and using the same.
Focused delivery of therapeutic agents to targeted areas of the body, without diminishing the potency or efficacy of such therapeutic agents, would allow for the improvement of treatment regimens. For example, current treatments for cancer include administration of chemotherapeutic agents and other biologically active factors such as cytokines and immune factors that impact the entire organism. The side effects of non-specific delivery include organ damage, loss of senses such as taste and feeling, as well as hair loss. While such currently available therapies provide treatment for a particular condition, they also require adjunct therapies to treat resulting side effects.
Formulations comprising therapeutic payloads having potentially toxic side-effects when administered systemically, would benefit from technological advancements that improve site-specific delivery and the stability of the formulations while diminishing the indiscriminate release of the payload, and thereby improve the overall therapeutic effect of the drug.
An additional deficiency of currently available treatments relates to ability to preserve or increase the potency of the therapeutic agents being administered. While delivering such agents to the site of a disease such as a tumor is a priority, it is also important to preserve the activity of such agents such that they are able to have maximum effect.
What is needed are compositions and methods for delivery systems of agents that affect the desired cells or site, while preserving or improving the therapeutic efficacy of such agents. Such systems may be used for delivery to specific cells of agents of all types. What is also needed are delivery systems that facilitate the targeted delivery of the therapeutic payload and do not cause unwanted side effects in the entire organism.
In an embodiment, the present disclosure relates to compositions and methods related to constructs comprising colloidal gold particles and cytokines, optionally combined with one or more therapeutic agents, one or more polyethylene glycol molecules. In certain embodiments, the colloidal gold particles comprise nanoparticles, and in certain embodiments the nanoparticles consist of colloidal gold nanoparticles. In certain embodiments, the gold nanoparticles are bound to two types of cytokines, either Tumor Necrosis Factor alpha (TNFα) (1) and interferon gamma (IFNγ), TNFα and Interleukin-2 (IL-2) (2) or TNFα and Interleukin-12 (IL-12) (3). The polyethylene glycol molecules may comprise a polyethylene glycol derivative covalently bound to the colloidal gold nanoparticle.
The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not necessarily to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Like reference numerals denote like features throughout specification and drawings.
The following detailed description is exemplary and explanatory and is intended to provide further explanation of the present disclosure described herein. Other advantages, and novel features will be readily apparent to those skilled in the art from the following detailed description of the present disclosure. Texts and references mentioned herein are incorporated in their entirety, including U.S. Pat. Nos. 7,387,900, 7,790,167, 7,951,614, 7,960,145, RE42524, 8,435,801, 8,486,666, and 8,785,202.
As used herein, the term “subject” should be construed to include subjects, for example medical or surgical subjects, such as humans and other animals requiring therapeutic intervention.
In the present disclosure the singular forms “a,” “an,” and “the” include the plural reference, and reference to a particular numerical value includes at least that particular value, unless the context clearly indicates otherwise. Thus, for example, a reference to “a bead” or “a nano structure” is a reference to one or more of such structures and equivalents thereof known to those skilled in the art, and so forth. When values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. As used herein, “about X” (where X is a numerical value) preferably refers to ±10% of the recited value, inclusive. For example, the phrase “about 8” preferably refers to a value of 7.2 to 8.8, inclusive; as another example, the phrase “about 8%” preferably (but not always) refers to a value of 7.2% to 8.8%, inclusive. Where present, all ranges are inclusive and combinable. For example, when a range of “1 to 5” is recited, the recited range should be construed as including ranges “1 to 4”, “1 to 3”, “1-2”, “1-2 & 4-5”, “1-3 & 5”, “2-5”, and the like. In addition, when a list of alternatives is positively provided, such a listing can be interpreted to mean that any of the alternatives may be excluded, e.g., by a negative limitation in the claims. For example, when a range of “1 to 5” is recited, the recited range may be construed as including situations whereby any of 1, 2, 3, 4, or 5 are negatively excluded; thus, a recitation of “1 to 5” may be construed as “1 and 3-5, but not 2”, or simply “wherein 2 is not included.” It is intended that any component, element, attribute, or step that is positively recited herein may be explicitly excluded in the claims, whether such components, elements, attributes, or steps are listed as alternatives or whether they are recited in isolation.
The term “cytokine” as used herein refers to a broad class of small proteins such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system and have an effect on other cells. Cytokines in this disclosure include interferon gamma (IFNγ), TNFα, interleukin-2 (IL-2), and interleukin-12 (IL-12).
The term “cytotoxicity” as used herein refers to the degree to which a substance can cause damage to a cell. A substance or process that causes cell damage or death is referred to as cytotoxic. Treating cells with the cytotoxic compound can result in a variety of cell fates. Cells may undergo apoptosis or necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. Cells can also stop actively growing and dividing (leading to a decrease in cell viability), or the cells can activate pathway-controlled cell death (i.e., apoptosis).
The term “paclitaxel” as used herein refers to a type of chemotherapy drug that is used to treat cancer. Paclitaxel is a taxane chemotherapeutic. A “paclitaxel prodrug” comprises a compound with little or no pharmacological activity that converts into a pharmacologically active paclitaxel drug compound in an area of interest in vivo. Such a prodrug may comprise a thiol derivatized paclitaxel prodrug.
For purposes of the description hereinafter, it is to be understood that the embodiments described below may assume alternative variations and embodiments. It is also to be understood that the specific articles, compositions, and/or processes described herein are exemplary and should not be considered as limiting.
Tumor necrosis factor alpha (TNFα) (1) is a pleiotropic cytokine that impacts nearly every aspect of human health. Its discovery in the 1970s had profound implications for treating solid tumors as a single injection of the protein resulted in hemorrhagic necrosis of solid tumors regardless of whether the cancer cells were sensitive to the protein. With continued research, TNFα has been found to selectively destroy the tumor vasculature (5), reduce tumor interstitial fluid pressure (6), increase the uptake of follow-on chemotherapy (7), and recruit immune system cells to the site of the tumor. Collectively, these effects may result in significant anti-tumor responses.
Not long after its discovery a recombinant form of the cytokine was produced to support clinical trials in cancer patients. Unfortunately, in nearly 200 clinical trials, systemically delivered TNFα was shown to be highly toxic and thus limited the dose that could safely be administered to cancer patients. The major dose-limiting toxicity of TNFα is hypotension and hepatoxicity (6). In all of these clinical trials no durable anti-tumor responses were observed.
Moreover, it was discovered in early phase 1 clinical trials of TNFα that many of the potentially dangerous side effects caused by TNFα occur at even low doses. Some of these, including severe fever and chills, can be pharmaceutically controlled, and therefore do not represent significant barriers to patient treatment or compliance with treatment. Other adverse effects such as tachycardia are potentially disqualifying AEs (8). This condition can lead to stroke and heart attack in at-risk patients. Notably, many cancer therapies, such as doxorubicin (9), which might be given in combination with CYT-6091 (described below), are known to be cardiotoxic.
Given these data, the use of TNFα in cancer treatment has been relegated to a limb-sparing procedure known as Isolated Limb Perfusion (ILP) (10). In the procedure, patients presenting with melanoma or sarcoma on their extremities will have the blood vessels of the affected limb connected to a heart-lung machine that perfuses the limb with TNFα followed by chemotherapy through the limb. ILP achieves two major goals: first, the localized delivery of TNF increases the concentration of the cytokine at the site of disease; secondly, the regional perfusion of the cytokine within the limb reduces systemic exposure to the cytokine and thus avoids most of the toxic side effect. However, the remarkable anti-tumor responses (60-75% complete and durable (10-years)) led the inventor to the development of the first patented gold nanoparticle, CYT-6091.
CYT-6091 (11-12) is comprised of a 27 nm gold nanoparticle that is covalently linked, via the formation of coordinate covalent bonds, with TNFα and PEG-THIOL.
Novel cytokine constructs comprising gold nanoparticles and TNFα are disclosed herein. In an embodiment, provided herein are constructs comprising gold nanoparticles bound to two types of cytokines, wherein the two types of cytokines comprise Tumor Necrosis Factor alpha (TNFα) and a cytokine selected from the group consisting of Interferon gamma (IFNγ) and Interleukin-12 (IL-12) or Interleukin-2 (IL-2). One embodiment consists of a gold nanoparticle bound to TNFα and IFNγ, and in certain embodiments, the ratio of TNFα to IFNγ is about 20:1 (w/w). Another embodiment consists of a gold nanoparticle bound to TNFα and Interleukin-2 (IL-2) or TNFα and Interleukin-12 (IL-12).
In certain embodiments the cytokine constructs of the disclosure comprise cytokines that may be bound to the surface of the gold nanoparticles using one or more binding chemistries including thiol or other covalent binding, ionic binding, or hydrophobic interactions.
In certain embodiments, the cytokine constructs may further comprise polyethylene glycol, polyethylene glycol derivatives, or polyethylene glycol-thiol.
Cytokine constructs of the disclosure comprising Tumor Necrosis Factor alpha (TNFα) and Interferon gamma (IFNγ) may further comprise paclitaxel, paclitaxel analogue or paclitaxel prodrug.
In an embodiment, provided herein are methods for increasing cytokine cytotoxicity, comprising the steps of combining a gold nanoparticle with two types of cytokines to create a construct, wherein the cytokines consist of Tumor Necrosis Factor alpha (TNFα) and IFN gamma (IFNγ), introducing the construct to a biological sample containing cells and assessing the cytotoxicity of the construct on the cells, wherein the cytotoxicity is increased compared to introduction of (a) native cytokines and/or (b) an individual cytokine bound to a gold nanoparticle. Such methods may be carried out on biological samples comprising cancer cells, and more specifically on thyroid cancer cells. Cytotoxicity may be measured using a cell viability assay.
In an embodiment, provided herein are methods for increasing cytokine potency, comprising the steps of combining a gold nanoparticle with two types of cytokines to create a construct, wherein the cytokines consist of Tumor Necrosis Factor alpha (TNFα) and Interleukin-12 (IL-12), introducing the construct to a biological sample containing cells and assessing the potency of the construct on the cells, wherein potency is increased compared to introduction of native cytokines. Potency may be measured using a HEK bioassay for assessing receptor activation. HEK bioassays, as used herein, are HEK cell-based functional assays to study receptor activity through a fluorescent output.
In an embodiment, provided herein are methods for inducing MHC-1 (13) expression in cancer cells, comprising introducing a cytokine construct to cancer cells, wherein the cytokine construct comprises Tumor Necrosis Factor alpha (TNFα) and IFN gamma (IFNγ) bound to a gold nanoparticle. Cancer cells may comprise lung cancer cells or thyroid cancer cells.
In an embodiment, provided herein are methods for activating naïve lymphocytes in a biological sample containing cancer cells comprising introducing a cytokine construct to the biological sample to induce MHC-1 (HLA-A-C) expression, followed by the addition of lymphocytes; wherein the cytokine construct consists of Tumor Necrosis Factor alpha (TNFα) and IFN gamma (IFNγ) bound to a gold nanoparticle, wherein the cytokine construct has a cytotoxic effect on the cancer cells and an activating effect on the lymphocytes.
In an embodiment, provided herein are methods for treating cancer in a subject in need thereof, comprising administering a cytokine construct to the subject, wherein the cytokine construct comprises Tumor Necrosis Factor alpha (TNFα) and IFN gamma (IFNγ) bound to a gold nanoparticle. In such an embodiment, the construct may further comprise polyethylene glycol, polyethylene glycol derivatives, or polyethylene glycol-thiol and the ratio of TNFα to IFNγ is about 20:1 (w/w). In such an embodiment, the construct may further comprise paclitaxel, or a paclitaxel analogue or prodrug.
Provided herein are compositions and methods related to constructs comprising colloidal gold nanoparticles and cytokines, optionally combined with one or more therapeutic agents, and optionally polyethylene glycol molecules. The types of cytokines consist of Tumor Necrosis Factor alpha (TNFα), and interferon gamma (IFNγ) or Interleukin-12 (IL-12) or Interleukin-2 (IL-2). The polyethylene glycol molecules may comprise a polyethylene glycol derivative covalently bound to the colloidal gold nanoparticle.
In an embodiment of the invention, methods for treating diseases and disorders comprising the administration of a cytokine construct is provided. In such an embodiment, methods for treating a solid tumor, comprise administering a composition to an organism having the solid tumor, wherein the composition comprises cytokine constructs consisting of colloidal gold particles and two types of cytokines, optionally combined with one or more therapeutic agents, one or more polyethylene glycol molecules; wherein the colloidal gold particles consist of gold nanoparticles and wherein the two types of cytokines bound to the gold nanoparticles consist of TNFα and IFNγ.
In certain embodiments, the cancer is melanoma. In certain embodiments, the cancer is a solid tumor. In certain embodiments, methods for treating solid tumors comprise the administration of novel cytokine construct compositions to an organism having a solid tumor, wherein the novel cytokine constructs comprise a gold nanoparticle bound to two types of cytokines, wherein the two types of cytokines comprise Tumor Necrosis Factor alpha (TNFα) and Interferon gamma (IFNγ).
The following examples are given to illustrate exemplary embodiments of the present disclosure. It should be understood, however, that the present disclosure is not to be limited to the specific conditions or details described in these examples. Examples are provided below to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention.
Two methods were used to produce CYT-IFNγ-TNFα. The first involves the simultaneous binding of TNFα, IFNγ and PEG-THIOL to the surface of the gold nanoparticles.
The second involves the sequential binding of TNFα followed by the simultaneous binding of IFNγ and PEG-THIOL.
For these studies, the pH of the colloidal gold solution was adjusted to approximately 8.0 by the stepwise addition of a 50 mM solution of sodium borate (NaBo). Similarly, the binding buffer (BB), the solution used to dilute TNFα (CytImmune Sciences, Inc.), IFNγ (R&D Systems) and 20 kDa form of PEG-THIOL (SunBio, Inc.) was similarly adjusted to 8.0 with NaBo. TNFα, IFNγ and PEG-THIOL were diluted into the BB to final concentrations of 0.25, 5.0 and 15 μg/mL, respectively. Equal volumes of both the gold nanoparticles and BB (containing the various reagents) were combined, by the rapid addition of the BB solution to the gold nanoparticle solution, under a strong vortex. The solutions were incubated for a minimum of 3 hours.
Subsequently, particle-bound vs free reagents were separated by centrifugation, although one skilled in the art could easily employ ultrafiltration with an appropriate apparatus, such as a UF cartridge or hollow fiber assembly. The concentrated nanoparticles were washed two times using an isotonic solution and upon the final concentration step, the gold nanoparticles were aliquoted and frozen at −80° C. Alternatively, a lyophilization cycle for the long-term storage of the nanodrugs at −20° to +4° C. may be used.
Cytokine-specific sandwich ELISAs were used to measure both the particle-bound and free fractions of TNFα and IFNγ. Both ELISAs use commercially available cytokine-specific neutralizing monoclonal antibodies (R&D Systems) to capture either TNFα or IFNγ bound to the particles or free in solution. Once captured, cytokine-specific rabbit polyclonal antibodies (CytImmune Sciences, Inc.) were added to the wells and the complex was detected with alkaline phosphatase conjugated goat-anti-rabbit antibodies (Sigma). The concentration of each cytokine was determined by regression analysis against known standards. Depending on the scale TNFα and IFNγ concentrations typically ranged from 2 to 40 μg/mL, respectively, with 90-95% of the cytokine measured as being bound to the gold nanoparticles.
Cross Antibody ELISA: A Qualitative Demonstration that Both IFNγ and TNFα are on the Same Gold Nanoparticle
Although the ELISAs described in Example 1 are useful to quantitate the relative amounts of both IFNγ and TNFα on the particle surface they do not demonstrate the presence of both cytokines on the same particle.
To address this need, a cross-antibody (XAb) ELISA was developed (
In one version of the XAb ELISA we used the murine monoclonal antibody against TNFα to capture the CYT-IFNγ-TNFα or the single-agent controls which were bound solely with TNFα. Once the nanoparticles were captured by the mAb (following and incubation at RT for 4-24 H), the plates were washed and the rabbit polyclonal antibody against human IFNγ was used as the detection system. As shown in
For these studies 5,000-10,000 FTC-133 cells were plated in 6-well tissue culture clusters in 2 mL of complete DMEM. The cells were maintained under standard tissue culture conditions (37° C., 95% relative humidity). 24-48 hours later, CYT-IFNγ-TNFα (between 0.05-2.0 μg of IFNγ) was added to the media and the uptake of the nanoparticle by the cells was imaged under bright field or phase contrast microscopy at various times after the addition of the nanoparticle.
As shown in
Given the uptake of the nanoparticle and the fact that both TNFα and IFNγ are known to induce cytotoxicity in certain cancer cell lines the experiments were repeated but the growth of the cells was determined after an additional incubation period of 5-7 days. Additionally, additional nanoparticles, such as CYT-6091 (see below) and the single-agent interferon gamma nanoparticle were also included.
Shown in
In this study we compared the potency of CYT-IFNγ-TNFα vs the same dose of IFNγ and TNFα in solution. Small scale batches of the nanoparticle were produced as described above and the concentration of the particle bound cytokines was determined by quantitative ELISA. Subsequently, increasing concentrations of IFNγ and TNFα, added as CYT-IFNγ-TNFα, were added to FTC-133 cells growing in 96 well tissue culture clusters. In another group of wells, the same doses of native IFNγ and TNFα were added at the same concentration as CYT-IFNγ-TNFα. The native cytokines were added as a single solution.
The cells were incubated for an additional 2-3 days at 37° C. and at 95% relative humidity. Subsequently, the incubation media was removed, and the cells were gently washed 3times in serum free DMEM. After the final wash, 100 μL of complete DMEM was added back to the cells followed by the addition of 10 μL of Alamar Blue™. The plates were incubated at 37° C. until the fluorescence for untreated/control wells obtained a value of 104 relative fluorescence units.
As shown in
HEK-IFNγ (InvivoGen, California, USA) is an engineered HEK cell line which has been stably transfected with the IFNγ receptor/signaling machinery. In this cell line, the binding of IFNγ to its receptor induces expression and secretion of an alkaline phosphatase reporter gene. The amount of alkaline phosphatase produced is directly proportional to the amount of IFNγ present in the sample. The amount of the reporter gene that is released can be assayed by adding tissue culture supernatants to fixed volumes of the PNPP (p-Nitrophenyl Phosphate; Sigma Aldrich, Missouri, USA) substrate.
To evaluate whether CYT-IFNγ-TNFα induced similar increases in potency, as demonstrated in cytotoxicity studies, these cells were used in similar studies as described in
The combination of native IFNγ/TNFα induced dose dependent increases in the relative amounts of the alkaline phosphatase secreted by the HEK-INFg cells. Unlike the FTC-133, wherein the native cytokine combination exhibited marginal activity, the HEK-IFNγ data are anticipated as the cells are engineered to secrete the reporter protein in a dose dependent manner. However, the data presented in
The increase in potency observed in CYT-IFNγ-TNFα may in part be due to mechanisms by which the gold nanoparticles improve the stability of the cytokine. To test this in a simple matrix, equal concentrations of both native IFNγ and TNF or CYT-IFNγ-TNFα were added to FTC-133 cells which were subsequently cultured at 37° C. for 2 days. On the second day aliquots of each set of samples were collected, frozen at −80° C. and analyzed by ELISA.
The data shown in
Though not wishing to be bound by the following theory, it is hypothesized that the increased potency reported in
To test this hypothesis, the imaging studies outlined in Example 1 were repeated with the cells imaged between 90 minutes and 8 hours following the addition of CYT-IFNγ-TNFα. The cells were imaged by both bright field and phase contrast microscopy to identify the trafficking of the nanoparticles.
The data presented in
Unlike the near transparent image of control FTC-133 cells (top left panel), many of the cells exhibit a pink color highlighting the presence of the nanoparticle on the cell surface. Similarly, all of the CYT-IFNγ-TNFα treated FTC-133 cells exhibited perinuclear localization of the particles, evidenced as black precipitates around the nucleus. Additionally, in several cells, highlighted by the arrows in the bright field (bottom left panel) and the phase contrast images (bottom right panel), the pattern of nanoparticle uptake was punctate in nature. While mechanism of action studies are not presented, these initial data support that CYT-IFNγ-TNFα induced clustering of their target receptor.
Many tumors escape detection and elimination by the immune system by either poorly or not expressing the major histocompatibility antigen (13-14). In humans, this complex has been designated HLA A-C with the murine equivalent termed MHC-1. IFNγ is known to upregulate MHC-1 expression (12). To test this hypothesis, we evaluated both baseline (untreated) and CYT-IFNγ-TNFα -induced expression of the histocompatibility complexes in both human and murine cancer cells lines.
For these studies numerous cell lines including FTC-133 (human thyroid cancer), H460 and A549 (human lung cancer), Colo26 (murine colon carcinoma isolated from Balb C mice) and B16F10 (melanoma cell line isolated in C57B1/6 mice) were used. Approximately 20,000 cells for each cell line were plated in 6-well tissue culture plates and incubated under standard culture conditions for 48 hours. Subsequently the cells were incubated with either the human nanoparticle CYT-IFNγ-TNFα or the murine equivalent, CYT-mIFNγ-hTNFα.
Generating a murine nanoparticle was required since, unlike human TNFα, human IFNγ is not cross-reactive in mice. This variant was produced and interrogated by the methods outlined in the above examples.
For these studies, between 0.0625 to 1 μg of the CYT-IFNγ-TNFα (the human nanoparticle) or CYT-mIFNγ-TNFα (the murine nanoparticle) were incubated with FTC-133, H460, and A549 cells or Colo 26 or B16F10 cancer cells, respectively. 48 hours later, the cells were washed 2 times with incomplete DMEM and 1 μg of a mouse monoclonal antibody (Sigma Aldridge) that recognizes both the HLA-A-C and the murine MHC-1 complexes was added to the cultures. The antibody was diluted in complete DMEM and incubated with the cells for 1 hour. Subsequently, the cells were once again washed 2 times with incomplete DMEM, and a FITC-conjugated goat anti-mouse polyclonal antibody (Sigma Aldrich) was added to the cultures. The antibody was incubated for an additional hour. The cells were washed one final time with incomplete DMEM, and the presence of the HLA-A-C or MHC-1 complex was documented by fluorescent microscopy.
Shown in
Furthermore, both human lung cancer cell lines exhibited similar pattern of CYT-IFNγ-TNFα uptake as evidenced by the pink/black staining of the cells to highlighting binding and internalization of the nanoparticle and subsequent expression of HLA-complex (
In the following study we determined whether the induction of MHC-1 by CYT-IFNγ-TNFα would lead to a de novo anti-cancer immune response. For this study either Colo 26 or B16F10 cancer cells were plated and treated with the murine variant of CYT-IFNγ-TNFα (CYT-mIFNγ-hTNFα) as described above. Controls were cancer cells receiving no treatment. After MHC-1 induction was confirmed, approximately 106 splenocytes from naïve Balb/c were added to the Colo 26 cultures. A similar number of splenocytes harvested from C57B1/6 mice were added to either control or nanoparticle treated cultures and the induction of an anti-cancer immune response was confirmed by the proliferation of the splenocytes.
The data presented in
Similar data were obtained in CYT-mIFNγ-hTNFα treated B16F10 cancer cell cultures. As shown in
CYT-6091 (11-12) and CYT-21625 (16) are tumor targeting nanoparticles that target the delivery of TNFα, as a single agent (CYT-6091) or TNFα plus a paclitaxel prodrug (CYT-21625) to solid tumors. Both nanoparticles are engineered on 27 nm particles of PEGylated colloidal gold. Pharmacokinetic and tumor uptake studies reveal that CYT-6091 and CYT-21625, by virtue of PEGylation, increase pharmacokinetic exposure, as measured by terminal half-life (T1/2) and Area Under the Curve (AUC), when compared to native preparations (11 and 16).
In the following experiments, the ability of the particle bound PEG-THIOL moiety to similarly increase pharmacokinetic exposure and tumor uptake of IFNγ was evaluated. Thus, after compounding and analytical interrogation of the nanoparticle, both TNFα and IFNγ in a single solution or the same dose of cytokines formulated as CYT-IFNγ-TNFα were injected into naïve or Colo-26 tumor-burdened Balb/c mice. Given that the currently approved form of IFNγ is injected subcutaneously, the PK profile was determined by injecting the drugs either intravenously or intraperitoneally.
At various times after the injection, the animals were sacrificed and whole blood was collected and spiked (10% v/v) with an 18 mg/mL solution of EDTA. The samples were measured for both TNFα and IFNγ content by a cytokine specific ELISA. To demonstrate that CYT-IFNγ-TNFα remained stable in the circulation, blood samples were collected after injection and analyzed using the XAb assay described in Example 1.
The data presented in
CYT-IFNγ-TNFα Does not Undergo Burst Release Upon its Injection into the Circulation
A common obstacle faced in nanoparticle development is burst release which refers to the near immediate release of the nanoparticle constituents upon injection. For both TNFα and IFNγ this may result in toxicity such as hypotension and may result in hepatotoxicity in the case of TNFα. Thus, to test the stability of CYT-IFNγ-TNFα in the circulation samples collected early in the pharmacokinetic study were analyzed in the cross-antibody (XAb) ELISA described in Example 1. Briefly, if either the TNFα or IFNγ constituents underwent burst release in the circulation one would predict that the blood samples would fail to generate a signal in the XAb ELISA as the particles would either not be captured or detected.
The data presented in
In the following study, the accumulation of the human or murine form of CYT-IFNγ-TNFα in two murine tumor models was tracked. In the first study, the presence of the nanoparticle was tracked by imaging control or nanoparticle treated animals. In
Shown in
For this study B16F10 tumors were established on the ventral surface of C57B1/6 mice as described in Paciotti et. al. (14). Once the tumors were established mice (n=5/group) received an intraperitoneal injection of CYT-IFNγ-TNFα or the same cytokine dose administered in solutions. The animals were sacrificed 4 hours later and the tumors harvested and frozen at −80° C. The samples were later homogenized using a glass homogenizer. The homogenates were analyzed for intra-tumor IFNγ content by ELISA.
Consistent with the data reported for CYT-6091 (10) and CYT-21625 (14), the data shown in
The data presented in the previous examples support that binding highly potent immune molecules such as INFγ and TNFα to the surface of PEGylated gold nanoparticles increases the potency of the cytokine(s) and improves their pharmacokinetic profiles to favor accumulation in solid tumors.
Using the methods described in Example 1, the development of additional follow-on nanoparticles with the potential of inducing and driving potent anti-cancer vascular and immune responses was pursued. Once manufactured, the nanoparticles were interrogated using the analytical methods described above.
Saturation binding curves were conducted for Interleukin-2 (IL-2) or Interleukin-12 (IL-12) by adding increasing amounts of the cytokine to a fixed volume of gold. After a 1-hour incubation, the particles were centrifuged at 14000 rpm and the supernatant was collected and set aside. The particles were reconstituted to 0.1X of their original volume and both the particle bound and free (supernatant) fractions were assayed by in-house IL-2 or IL-12 ELISAs.
The data shown in
Adopting the method described in Example 1 a dual agent IL-12-TNFα designated, CYT-IL-12-TNFα was manufactured. The potency of CYT-IL-12-TNFα was tested using a HEK-12 bioassay. Similar to the HEK-IFNγ cells, the HEK-IL-12 cells respond to IL-12 by secreting the same alkaline phosphatase reporter protein. Thus, for this study, equal doses of either native IL-12 or CYT-IL-12 were incubated with the HEK-IL-12 cells per the manufacturer's instructions. 48 hours later, a 10 μL sample from each of the replicate wells was added to 200 μL of the PNPP substrate. Similar to the data reported for the CYT-IFNγ-TNFα nanomedicine, CYT-IL-12-TNFα induced a significant increase in the potency of IL-12, which was nearly 70-fold higher (
In the next series of studies, 5 μg of Interleukin-2 (IL-2), 0.25 μg of TNF and 15 μg PEG-THIOL were introduced to a single solution of gold nanoparticles. Single agent controls containing only one of the cytokines were also generated. Bound and free cytokine fractions were isolated by centrifugation. To demonstrate the presence of both cytokines on the same particle, single agent and dual agent nanoparticles were serially diluted and tested in both forms of the cross-antibody ELISA. For these assays, the dual or single agent nanoparticles were captured using either a TNFα or IL-2 monoclonal antibody. The monoclonal antibody captured material was detected using the rabbit polyclonal antibodies (Cytimmune Sciences, Inc. Maryland, USA) utilizing alkaline phosphatase conjugated goat-anti-rabbit to detect the complimentary cytokine.
The data presented in
There exists long-standing evidence suggesting that many chemotherapies activate the immune system as part of their anti-tumor efficacy (17-18). Conceptually, chemotherapy may generate the cancer antigens needed to initiate and drive cancer immunotherapy. This is supported by the fact that many of the current clinical trials focused on immuno-oncology have added a chemotherapy arm (19-20). Other therapies including precision medicines have the potential to restore or block biologic pathways that could enhance or drive anti-cancer efficacy in combination with cytokines and to those ends there is an increasing list of small molecule immuno-oncology drugs that are in development.
To demonstrate the ability to generate such drugs a multimodal immuno-oncology nanoparticle comprised of both TNFα and IFNγ was developed, to which a small molecule prodrug was added. A schematic of the new nanoconstruct is shown in
Using the methods outlined in Example 1, 2.5 μg of the thiolated paclitaxel analog was added to the existing formulation. Free drugs were separated from the particle bound constituents by centrifugation and the nanoparticle was analyzed for cytokine concentration.
To gain an initial understanding of the impact of adding the paclitaxel prodrug to CYT-IFNγ-TNFα FTC-133 cells were incubated with similar doses of IFNγ and TNFα added as either CYT-IFNγ-TNFα or CYT-IFNY-TNFα-Paclitaxel nanoparticles. Significant morphologic changes were noted within two days of incubation. For example, for CYT-IFNγ-TNFα perinuclear localization of the particles, previously described, were observed. In the case of CYT-IFNY-TNFα-Paclitaxel the nuclei became segmented with particles localized around each segment.
The micrographs presented in
The nanoparticles discussed within this document suggest a possible treatment strategy for solid tumors. Shown in
Shown in