Preparation of Peptide Microspheres Using Tumor Antigen-Derived Peptides

Abstract

Due to its distinct biological attributes, poly(D,L lactide-co glycolide) (PLGA) is one of the most preferred methods for DNA/protein/peptide encapsulation for therapeutics. Importantly, PLGA acts as an adjuvant for weakly immunogenic antigens and mimics booster responses after a single dose of administration, thereby serving as a single-shot vaccine delivery vehicle. Efficient delivery of antigens to antigen-presenting cells (APC) has been made possible by the use of a PLGA particle-based vaccine delivery system. Also, the plasma half-life of the PLGA-encapsulated vaccine increases as it is protected from degradation, prior to its further release. PLGAs are reported to be catabolized into individual nontoxic units once inside the host and further degraded via normal metabolic pathways. In this chapter, we have described the preparation and characterization of tumor peptide encapsulated PLGA microparticles as a model for controlled-release peptide delivery system.

Peptide/protein vaccine delivery system based on PLGA particles

“…7 Co-delivery of both the antigen and immunostimulant (IS) may lead to enhanced potency, adjuvant dose reduction, and consequently minimizing toxicity of the IS. 8,9 However, the application of PLGA particles faces some challenge such as acidic feature of PLGA microenvironment, protein exposure to water-oil interface, harsh parameters during particle preparation, and protein instability during encapsulation that may affect protein integrity and immunogenicity. 10 Many strategies, including the addition of stabilizing excipients, the optimization of process conditions, chemical modifications such as glycosylation and pegylation have been developed to overcome antigen instability during encapsulation and release process.…”