(593c) Serum Protein Adsorption Onto Functionalized Polyanhydride Nanoparticles Influences Particle Interactions with Dendritic Cells

Polyanhydride-based nanoparticles are of increasing interest for use as vaccine adjuvants and delivery vehicles. Recent work has demonstrated that nanoparticles, whose surface is chemically functionalized with carbohydrates, target C-type lectin receptors on antigen presenting cells (APCs) efficiently. This results in enhanced nanoparticle internalization and activation of APCs. The objective of this study was to analyze how mouse serum proteins adsorb onto the surface of carbohydrate-functionalized nanoparticles in vitro. Additionally, it was desired to determine the effects of protein adsorption on the uptake and activation of bone marrow-derived dendritic cells (DCs). Quantum dot (QD)-loaded nanoparticles based on sebacic anhydride (SA), 1,6-bis-(p-carboxyphenoxy)hexane (CPH) and 1,8-bis-(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) were fabricated by an anti-solvent nanoprecipitation method. Di-mannose, lactose, and galactose, were the three carbohydrates that were studied and glycolic acid was used as a linker. For each trial nanoparticle suspensions were incubated with mouse serum, and 2D gel electrophoresis was used to analyze the adsorbed proteins. Complement component 3 (C3)-specific ELISA measurements on adsorbed proteins resulted in the identification of C3 levels on the particle surface. Sham- and serum-coated nanoparticles were then incubated with DCs for 48 hours and flow cytometry was used to measure MHC I, MHC II, CD40, and CD86 expression. Multiplex cytokine assays were performed to analyze the total amount of IL-1β, IL-10, TNF-α, IL-6, and IL-12p40 secreted by the cells after stimulation with nanoparticles. Results indicated that less serum proteins were adsorbed on more hydrophilic polymers. In general, linker-functionalized particles were internalized more effectively and all the functionalized particles enhanced dendritic cell activation. These results provide new insights into the rational design of nanoparticles for use as adjuvants and as vaccine delivery vehicles.