Heparin/chitosan nanoparticle carriers prepared by polyelectrolyte complexation.

In this study, novel nanoparticles were prepared by polyelectrolyte complexation between heparin and chitosan on simple and mild conditions. The size, polydispersity, zeta potential, and morphology of the nanoparticles were characterized. Entrapment studies of the nanoparticles were conducted using bovine serum albumin (BSA) as a model protein. Specifically, the effects of the pH value of chitosan solution, chitosan molecular weight (MW), chitosan concentration, heparin concentration, and BSA concentration on the nanoparticle size, the nanoparticle yield, and BSA entrapment were studied in detail. We found that, the size and the yield of the nanoparticles were affected by the above factors. The nanoparticle yield played a crucial role in BSA entrapment, namely, more nanoparticles could encapsulate more BSA. At length, suitably high pH value of chitosan solution, moderate chitosan MW, increasing both heparin concentration and chitosan concentration at an optimal concentration ratio favored more nanoparticles formed and consequently a higher BSA entrapment efficiency.