Chitosan-dextran Sulfate Nanoparticles for Delivery of an Anti-angiogenesis Peptide

Abstract

A novel nanoparticle delivery system has been developed by employing the oppositely charged polymers chitosan (CS) and dextran sulfate (DS), and a simple coacervation process. Under the conditions investigated, the weight ratio of the two polymers is identified as a determining factor controlling particle size, surface charge, entrapment efficiency and release characteristics of the nanoparticles produced. Particles of 223 nm mean diameter were produced under optimal conditions with a zeta potential of approximately −32.6 mV. A maximum of 75 anti-angiogenesis peptide entrapment efficiency was achieved with a CS:DS weight ratio of 0.59:1. The same nanoparticle formulation also showed slow and sustained peptide release over a period of 6 days. In contrast, the formulation containing a lower ratio of CS:DS (0.5:1) was found to have reduced entrapment efficiency and more rapid peptide release characteristics. The results of this study suggest that physicochemical and release characteristics of the CS–DS nanoparticles can be modulated by changing ratios of two ionic polymers. The novel CS–DS nanoparticles prepared by the coacervation process have potential as a carrier for small peptides.