Flt3 ligand delivered in a pluronic formulation prolongs the survival of mice with orthotopic pancreatic adenocarcinoma

Engineered implantable vaccine platform for continuous antigen-specific immunomodulation

Cancer vaccines harness the host immune system to generate antigen-specific antitumor immunity for long-term tumor elimination with durable immunomodulation. Commonly investigated strategies reintroduce ex vivo autologous dendritic cells (DCs) but have limited clinical adoption due to difficulty in manufacturing, delivery and low clinical efficacy. To combat this, we designed the "NanoLymph", an implantable subcutaneous device for antigen-specific antitumor immunomodulation. The NanoLymph consists of a dual-reservoir platform for sustained release of immune stimulants via a nanoporous membrane and hydrogel-encapsulated antigens for local immune cell recruitment and activation, respectively. Here, we present the development and characterization of the NanoLymph as well as efficacy validation for immunomodulation in an immunocompetent murine model. Specifically, we established the NanoLymph biocompatibility and mechanical stability. Further, we demonstrated minimally invasive transcutaneous refilling of the drug reservoir in vivo for prolonging drug release duration. Importantly, our study demonstrated that local elution of two drugs (GMCSF and Resiquimod) generates an immune stimulatory microenvironment capable of local DC recruitment and activation and generation of antigen-specific T lymphocytes within 14 days. In summary, the NanoLymph approach can achieve in situ immunomodulation, presenting a viable strategy for therapeutic cancer vaccines.

Preparation and Evaluation of Physicochemical Properties of the Doxepin Mucoadhesive Gel

Background: Oral mucositis is a common debilitating complication of cancer chemotherapy and radiotherapy that can reduce the quality of patient’s lives. Hence, treating this condition plays an important role in increasing the patient’s tolerance. Objectives: Doxepin mucoadhesive gel is useful for treating oral mucosa inflammation caused by long-term effects of chemotherapy, which has low adverse effects. Methods: Doxepin gel’s formulation was prepared with various concentrations of poloxamer 407 and hydroxypropyl methylcellulose in deionized water. The prepared gels were evaluated for pH, appearance, viscosity, spreadability, stability, and drug release. Results: After providing gels containing doxepin, formulations 1, 2, 8, and 9 had low quality and, thus, were removed from the study. Based on qualitative evaluations, formulations 3 and 4 did not meet the criteria for mucoadhesive gel and were removed from the study. The best formulation contained 17% w/w poloxamer 407, 10% w/w hydroxypropyl methylcellulose, and 5% w/w doxepin. Conclusions: Suitable physicochemical properties of prepared doxepin mucoadhesive gel enable it to well cover inflamed and damaged oral mucosa. On the other hand, doxepin’s slow release from formulation (8 hours) can increase therapeutic effects and reduce side effects, which can heal and soothe inflammations of the oral mucosa and be useful in cancer patient’s treatment.

The effect of the nonionic block copolymer pluronic P85 on gene expression in mouse muscle and antigen-presenting cells

DNA vaccines can be greatly improved by polymer agents that simultaneously increase transgene expression and activate immunity. We describe here Pluronic P85 (P85), a triblock copolymer of ethylene oxide (EO) and propylene oxide (PO) EO(26)-PO(40)-EO(26). Using a mouse model we demonstrate that co-administration of a bacterial plasmid DNA with P85 in a skeletal muscle greatly increases gene expression in the injection site and distant organs, especially the draining lymph nodes and spleen. The reporter expression colocalizes with the specific markers of myocytes and keratinocytes in the muscle, as well as dendritic cells (DCs) and macrophages in the muscle, lymph nodes and spleen. Furthermore, DNA/P85 and P85 alone increase the systemic expansion of CD11c+ (DC), and local expansion of CD11c+, CD14+ (macrophages) and CD49b+ (natural killer) cell populations. DNA/P85 (but not P85) also increases maturation of local DC (CD11c+ CD86+, CD11c+ CD80 +, and CD11c+ CD40+. We suggest that DNA/P85 promotes the activation and recruitment of the antigen-presenting cells, which further incorporate, express and carry the transgene to the immune system organs.