Preparation, characterization, and in-vitro evaluation of liposome-coated chitosan nanoparticle as immune adjuvant candidate in RAW 264.7 cells

Abstract

Chitosan has been explored for various biological applications due to its biodegradability and biocompatibility. In this research, we prepared, characterized, and evaluated liposome-coated chitosan nanoparticles for immune adjuvant against bovine serum albumin (BSA) as a vaccine model. The liposome was formulated using DPPC, cholesterol, and DSPE-PEG with a molar ratio of 9.5:9.5:1. The BSA-chitosan nanoparticle was generated using the ionic gelation method prepared at pH 2.8, 5.5, and 8.7 before it was encapsulated with the liposome. The adjuvant was evaluated for its degree of encapsulation efficiency by Bradford reagent, and the particle size was determined using Zetasizer. Cell viability and nitric oxide release assays were carried out in RAW 264.7 cells. It was found that encapsulation efficiency was in the range of 72% to 85%, and the smallest particle size of the adjuvant-BSA was approximately ∼ 200 nm with a polydispersity index of ∼ 0.04. MTT assays have shown that cell viability was around 80%-90% compared to the control and capable of inducing nitric oxide release (p<0.05). Further exploration should be carried out in order to further discover cytokine release, humoral, and cellular immune responses.