Chitosan-Functionalized Selenium Nanoparticles for Targeted Cancer Therapy: Advances in Synthesis, Stability, and Tumor-Specific Delivery

Cell type-specific drug delivery is a straightforward strategy to achieve targeted cancer therapy and reduce side effects. Hyaluronic acid (HA), an U.S. Food and Drug Administration (FDA)-approved biocompatible carbohydrate polymer, has been extensively employed as a targeting ligand for a drug delivery system due to its natural ability to bind to tumor cells overexpressing cluster of differentiation 44 (CD44) receptors. Here, we report the preparation and antitumor efficacy of HA-coated bovine milk exosomes (HA-mExo) for tumor-specific delivery of microRNA-204-5p mimics (miR-204). The exosome-based delivery formulation was prepared with miR-204 encapsulated inside the lumen and HA displayed outside the membrane. The resultant formulation of HA-mExo-miR204 was able to specifically target CD44-positive cancer cells, with a concomitant increase in the intracellular uptake of miR-204. Compared to the uncoated mExo-miR204 formulation, HA-mExo-miR204 showed significantly increased antitumor efficacy both in vitro and in vivo. Importantly, HA-mExo-miR204 showed excellent biocompatibility and did not cause significant systemic toxicity. Given that both HA and bovine milk exosomes are low-cost and highly accessible biogenic materials with broad biomedical applications, HA-decorated bovine milk exosomes can be proven to be a practical drug delivery system of RNA drugs for targeted cancer therapy.

pH/ROS dual-responsive supramolecular polypeptide prodrug nanomedicine based on host-guest recognition for cancer therapy

Bispecific antibodies are an emerging class of therapeutics for immune-oncology applications. T cell engagers (TCEs) target tumor-associated antigens (TAA) to eradicate cancer cells. TCEs for solid tumors have demonstrated encouraging preclinical efficacy but development has been challenging with dose-limiting toxicities due to on-target/off-tumor effect. To overcome the issue, we have developed ON-BOARD, an ultra-pH sensitive nanoparticle platform for masked and targeted delivery of payloads to the acidic tumor microenvironment (TME). Herein we report efficacious masked delivery of a TCE to tumors in mice using ON-BOARD demonstrating significantly improved tolerability and potential for clinical translation. TCEs were encapsulated in ON-BOARD nanoparticles and characterized for particle properties. The formulations were assessed in vitro under neutral or acid-activated conditions in TDCC assays. In vivo studies were performed in mice bearing “immune desert” pancreatic cancer. ON-BOARD tumor localization was measured by fluorescence while unencapsulated TCE and ON-BOARD/TCE pharmacokinetics was evaluated. PD studies evaluated immune-phenotype changes in tumors and draining lymph nodes, and systemic cytokine levels. Efficacy studies were performed in tumor-bearing mice comparing unencapsulated TCE to ON-BOARD-TCE as monotherapy and in combination with anti-4-1BB agonist therapy. ON-BOARD encapsulated TCEs have high encapsulation efficiency (>88%) in uniformly distributed stable particles (Dh<100nm). pH-specific and target-specific killing were confirmed in vitro in TDCC killing assays using a human gastric cancer cell line and a genetically engineered mouse pancreatic cancer cell line with 20 to 200-fold activation window between the acid-activated and intact formulations. In vivo, fluorescently labeled ON-BOARD nanoparticles localized to tumors in mice while ON-BOARD/TCE formulations demonstrated minimal payload leakage and mitigated payload degradation. ON-BOARD/TCE formulations showed favorable immunophenotype changes in tumors including increased CD8+, CD8+/T reg ratio and PD-1+Ki67+CD8+. ON-BOARD encapsulation also significantly improved TCE tolerability showing reduced body weight loss nadir (3% vs 17%) and reduced systemic proinflammatory cytokine response (IL-6, TNF, IFNγ, etc). When dosed in combination with anti-4-1BB agonist therapy in tumor-bearing animals, unencapsulated TCE induced 100% treatment-related animal death while ON-BOARD/TCE prevented animal death with minimum body weight loss. Furthermore, ON-BOARD/TCE with a4-1BB combo therapy showed 61% tumor growth inhibition in the “immune desert” pancreatic cancer model. The ON-BOARD platform demonstrated potential as an effective tool for masked tumor-specific delivery and improved tolerability of bispecific TCEs for cancer therapy. Citation Format: Qingtai Su, Stephen Gutowski, Gaurav Bharadwaj, Austin Burcham, Bhargavi Allu, Irina Kalashnikova, Zirong Chen, Ruolan Han, Jason B. Miller, Tian Zhao. Improved tolerability and tumor specific delivery of a therapeutic bispecific T cell engager using a pH-sensitive nanoparticle platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 815.

The biggest challenge in colorectal cancer therapy is to avoid intestinal drug absorption before reaching the colon, while focusing on tumor specific delivery with high local concentration and minimal toxicity. In our work, thymoquinone (TQ)-loaded polymeric nanocapsules were prepared using the nanoprecipitation technique using Eudragit S100 as polymeric shell. Conjugation of anisamide as a targeting ligand for sigma receptors overexpressed by colon cancer cells to Eudragit S100 was carried out via carbodiimide coupling reaction, and was confirmed by thin layer chromatography and 1H-NMR. TQ nanocapsules were characterized for particle size, surface morphology, zeta potential, entrapment efficiency % (EE%), in vitro drug release and physical stability. A cytotoxicity study on three colon cancer cell lines (HT-29, HCT-116, Caco-2) was performed. Results revealed that the polymeric nanocapsules were successfully prepared, and the in vitro characterization showed a suitable size, zeta potential, EE% and physical stability. TQ exhibited a delayed release pattern from the nanocapsules in vitro. Anisamide-targeted TQ nanocapsules showed higher cytotoxicity against HT-29 cells overexpressing sigma receptors compared to their non-targeted counterparts and free TQ after incubation for 48 h, hence delineating anisamide as a promising ligand for active colon cancer targeting.

Extrusion of neutrophil extracellular traps (NETs), a fundamental host innate immune defense against pathogens, has recently been linked to cancer resistance to immunotherapy and distant metastasis. These findings highlight interesting areas of cancer-elicited inflammation and potential therapeutic strategies. Disrupting existing NETs with DNase I has been proved to enhance the therapeutic efficacy of tumor immunotherapy and attenuate metastatic spread. However, systemic biodistribution of DNase I raises safety issues, potentially impairing host defense against infection. Hence, tumor-specific delivery and metastatic niche-targeted effects are attractive options for localized degradation of NETs. We have engineered a nanoplatform with a plasmonic gold blackbody (AuPB) core with broad-spectrum photo activity and a mesoporous polydopamine (mPDA) shell for efficient loading and photoregulated release of DNase I. The on-demand released DNase I triggered by the second near-infrared (NIR-II) light irradiation breaks the "NET-mediated physical barrier", thereby increasing the contact of immune cytotoxic cells with tumor cells in living mice and sensitizing immune checkpoint therapy of primary colorectal cancer (CRC). Moreover, the deposition and light-controlled cargo release from systemically delivered AuPB@mPDA carriers in liver, the most frequent site of CRC metastasis, abolished NET-mediated capture of circulating tumor cells and hence metastatic seeding. Our findings indicate that the localized, light-regulated release of DNase I by photoactive carriers in the NIR-II window represent a translational route for immune-mediated tumor regression and metastasis inhibition.

To synthesize and evaluate the antitumor efficacy of double-targeted docetaxel (DTX)-carboxymethyl chitosan (CMCS)-PEG-NGR (DTX-CPN) conjugates that could target to CD13 over-expressed tumor neovascular endothelium cells and tumor cells. DTX was conjugated to CMCS via biodegradable linker and cNGR was applied to endow the conjugates with double targeting ability. The physiochemical properties and stability of this DTX-CPN conjugates were characterized. Cellular uptake study was carried out to evaluate the targeting ability of DTX-CPN conjugates. Cytotoxicity and apoptosis analysis were conducted to evaluate in vitro antitumor effects. In vivo antitumor efficacy was investigated in B16 murine melanoma model. DTX-CPN conjugates could self-assemble into nanoparticles in water and were stable in plasma. cNGR modification could promote the cellular uptake of DTX-CPN conjugates in CD13 positive HUVEC and B16 cells, leading to more significant cytotoxicity and apoptosis effect than non-targeted conjugates. DTX-CPN conjugates also exhibited better antitumor effect than non-targeted conjugates and Duopafei® in a B16 murine melanoma model. Double-targeted DTX-CPN conjugates could efficiently target to tumor neovascular cells and tumor cells, and achieve good antitumor effects. DTX-CPN conjugates may be promising candidate for one-double targeting cancer therapy.

Hyaluronan decoration of milk exosomes directs tumor-specific delivery of doxorubicin

Successful short interfering RNA (siRNA)-based therapy for cancers depends on functional siRNA delivery specific to tumors. In our previous report, we have shown systemic siRNA delivery specific to human prostate cancer cell line PC-3 subcutaneous tumors in nude mice by atelocollagen, a collagen derivative, for formulating a complex with siRNA. We used an siRNA for human Bcl-xL as a model target. In the present study, we examined the antitumor effect on PC-3 orthotopic tumors in nude mice, as these tumors resemble the human clinical situation. The systemic intravenous administration of the complex (siRNA, 50 μg/shot) significantly reduced Bcl-xL expression and induced apoptosis in the tumors, and suppressed their growth. Liver metastasis was also inhibited in the orthotopic model. We successfully showed tumor-specific accumulation of the siRNA by Cy3-labeled siRNA and the direct quantification of the siRNA via reverse-phase high-performance liquid chromatography. The tumor-specific delivery was achieved by the enhanced permeability and retention effect, which is characteristic of macromolecular drugs. The high expression of vascular endothelial growth factor-A in the tumors provided adequate conditions to promote the permeability in the tumors, and to finally form the enhanced permeability and retention effect. In conclusion, our siRNA delivery is specific to the PC-3 orthotopic tumors in nude mice, and is practically feasible to treat tumors.

PDGF receptor-β-targeted copper-gadolinium-oxide self-assembled nanoclusters suppress tumor growth and metastasis via copper overload-mediated apoptosis and anti-angiogenesis

Pancreatic cancer is one of the deadliest causes of cancer-related death in the United States, with a 5-year overall survival rate of 6 to 8%. These statistics suggest that immediate medical attention is needed. Gemcitabine (GEM) is the gold standard first-line single chemotherapy agent for pancreatic cancer but, after a few months, cells develop chemoresistance. Multiple clinical and experimental investigations have demonstrated that a combination or co-administration of other drugs as chemotherapies with GEM lead to superior therapeutic benefits. However, such combination therapies often induce severe systemic toxicities. Thus, developing strategies to deliver a combination of chemotherapeutic agents more securely to patients is needed. Nanoparticle-mediated delivery can offer to load a cocktail of drugs, increase stability and availability, on-demand and tumor-specific delivery while minimizing chemotherapy-associated adverse effects. This review discusses the available drugs being co-administered with GEM and the limitations associated during the process of co-administration. This review also helps in providing knowledge of the significant number of delivery platforms being used to overcome problems related to gemcitabine-based co-delivery of other chemotherapeutic drugs, thereby focusing on how nanocarriers have been fabricated, considering the modes of action, targeting receptors, pharmacology of chemo drugs incorporated with GEM, and the differences in the physiological environment where the targeting is to be done. This review also documents the focus on novel mucin-targeted nanotechnology which is under development for pancreatic cancer therapy.

An ideal cancer therapy enhances anti-tumor effects while minimizing side effects. iRGD, a non-cytotoxic peptide that activates a tumor-specific molecular transport machinery, promotes the penetration of co-injected drugs into tumor tissues. Clinical trials have demonstrated its potential as a tumor-specific delivery scaffold and potentiator of anti-cancer agents. In this study, we synthesized an iRGD conjugate containing monomethyl auristatin F (MMAF), a highly toxic antimitotic agent, and characterized its dual function as a tumor-specific cytotoxic agent and co-injected drug delivery scaffold. The iRGD-MMAF conjugate internalized and killed cultured tumor cells in an αv integrin-dependent manner. When injected systemically, iRGD-MMAF homed selectively to tumors in mice, and extensively spread in the extravascular tumor tissue in line with the tumor-penetrating capacity of iRGD. iRGD-MMAF also significantly enhanced tumor-specific entry of a co-injected molecule by serving as an effective drug delivery scaffold. The results indicate that a chemically modified iRGD peptide with an added therapeutic benefit retains its ability to deliver co-injected agents to tumors.

Skin carcinoma, which includes basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma, is influenced by various factors such as genetic predisposition, chemical exposures, immune system imbalances, and ultraviolet (UV)radiation. This review delves into the mechanisms behind the development of these cancers, exploring the therapeutic potential of microbial, plant derived compounds and nanoparticles in advancing skin cancer treatments. Special attention is given to the cytotoxic effects of anti-neoplastic agents from microbial sources on different cancer cell lines, particularly melanoma. Additionally, the review highlights the role of phytochemicals- such as quercetin, resveratrol, and curcumin alongside vitamins, terpenoids, and sulforaphane, in management of skin cancers through mechanisms like apoptosis induction and cell cycle regulation. Recent advancements in nanotechnology-based drug delivery systems, including NP and microemulsion formulations, are also discussed for their enhanced ability to specifically target cancer cells. The diverse roles of NPs in skin cancer therapy, especially in terms of targeted drug delivery and immune modulation, are reviewed. These innovative NPs formulations have showed improved skin penetration and tumor-specific delivery, reduced systemic toxicity and enhanced therapeutic effectiveness.

Advanced strategies in liposomal cancer therapy: Problems and prospects of active and tumor specific drug release

Magnetic nanoparticles with a pH-sheddable layer for antitumor drug delivery

Tumor specific drug delivery has become increasingly interesting in cancer therapy. Using Mild local hyperthermia for tumor-specific drug release with thermosensitive liposomes, has a significant advantage over other triggering concepts in that the liposome tumor accumulation is increased as a consequence of increased tumor blood flow and in creased microvascular permeability. A crucial problem in this modality is how to generate a conformal and comparatively uniform temperature field for drug release. A new modality of drug targeting of tumors, which is based on thermosensitive liposomes, followed by localized release at the tumor site triggered by heating from ultrasound phased arrays, is currently under development. Besides noninvasiveness and deep penetration, an important advantage of ultrasound phased arrays is that they are able to generate multiple foci or switch between various multi-focus patterns and may produce a conformal and comparatively uniform temperature field. Pilot study on a conformal and comparatively uniform temperature field generation using ultrasound phased arrays was done. Primary simulation results show that employing combinations of different multi-focus patterns, we can obtain comparatively uniform, cylindrical temperature fields with diameters from 1 cm to 5cm and heights of 1cm.