Biodegradable Viral Nanoparticle/Polymer Implants Prepared via Melt-Processing

Viral nanoparticles have been utilized as a platform for vaccine development and are a versatile system for the display of antigenic epitopes for a variety of disease states. However, the induction of a clinically relevant immune response often requires multiple injections over an extended period of time, limiting patient compliance. Polymeric systems to deliver proteinaceous materials have been extensively researched to provide sustained release, which would limit administration to a single dose. Melt-processing is an emerging manufacturing method that has been utilized to create polymeric materials laden with proteins as an alternative to typical solvent-based production methods. Melt-processing is advantageous because it is continuous, solvent-free, and 100% of the therapeutic protein is encapsulated. In this study, we utilized melt-encapsulation to fabricate viral nanoparticle laden polymeric materials that effectively deliver intact particles and generate carrier specific antibodies in vivo. The effects of initial processing and postprocessing on particle integrity and aggregation were studied to develop processing windows for scale-up and the creation of more complex materials. The dispersion of particles within the PLGA matrix was studied, and the effect of additives and loading level on the release profile was determined. Overall, melt-encapsulation was found to be an effective method to produce composite materials that can deliver viral nanoparticles over an extended period and elicit an immune response comparable to typical administration schedules.