Catechin Nanoparticle Intranasal Vaccine Platform with Resiquimod Adjuvant Encapsulated

Nanoparticle(NP) drug delivery systems are an emerging nanomedicine technology used to improve the efficacy of subunit vaccines. Nanoparticles are engineered ex vivo to present protein antigens on their surfaces and encapsulate immune-stimulatory adjuvants, then injected into the patient. Although NP platforms enhance subunit vaccine efficacy, low encapsulation of expensive adjuvants presents major challenges to clinical translation. The binding of antigens and degraded NP can damage antigens and thus limit subsequent the immune response. Many current NP delivery systems use synthetic materials, such as Polyethylene glycol (PEG), that may elicit immune responses and encounter degradation issues. This project aims to develop an intranasal subunit vaccine platform with the unique capacity of eliciting both protective mucosal and systemic immune responses by overcoming the transport barriers presented by the nasal mucosa and targeting antigens to and activating APCs. Catechin NPs can encapsulate Resiquimod, an immune stimulatory vaccine adjuvant. Previous work on this project has demonstrated the benefits of Catechin NP in drug delivery applications. Catechin, a tea extract, is a natural biomaterial and has proven antioxidant properties stemming from its OH groups. Resiquimod, a Toll-like receptor 7(TLR7) agonist, has proven anti-tumor properties in vivo and elicits CD8+ T cell activation. Several criteria limit the efficacy of NP delivery systems, such as the size of NP, encapsulation efficiency, and aggregation. Therefore, these aspects are carefully controlled. In this study, the Catechin polymers synthesized have a M_w of 18.5 kDa and Catechin NP have a diameter of 108nm. Catechin NPs had a dye encapsulation efficiency of 60% and a Resiquimod encapsulation efficiency of 15%. Further testing involving DC 2.4 cellular uptake of encapsulated NP will be conducted.