Polysorbasome: A Colloidal Vesicle Contoured by Polymeric Bioresorbable Amphiphiles as an Immunogenic Depot for Vaccine Delivery.

To accomplish an innovative vaccine design, there are two key challenges: developing formulations that avoid cold chain shipment and finding a delivery vehicle that is absorbable in vivo. Here, we explored the design and performance of a colloidal vesicle that enabled us to consider both challenges. We used polymeric bioresorbable amphiphiles as surface-active agents for stabilizing oily/aqueous interfaces and formed a colloidal vehicle named polysorbasome (PSS, polymeric absorbable vesicle), without using conventional emulsifiers such as sorbitan esters or their ethoxylates. Homogenizing the oil/water compartments forms a colloid containing an aqueous solution in its core and provides an oily barrier that isolates the encapsulated material from external materials. In this form, the PSS serves as a depot for sustained delivery of vaccine antigens. Following vaccination, the antigen-specific antibodies and the cell-mediated immunity can be manipulated after the antigen being formulated with PSS particles. Then, the degradability intrinsic to the polymeric bioresorbable amphiphiles complies with the destruction and further absorbance of the vehicles in vivo. The structural features of these versatile vesicles based on bioresorbable amphiphilic engineering may provide new insights into vaccine delivery.