Microcapsules obtained from complex coacervation of collagen and chondroitin sulfate

Microcapsules composed of collagen and chondroitin sulfate were obtained by complex coacervation and characterized by DSC, optical microscopy, SEM, and UV-Vis spectroscopy. Composition of the microcapsules could be adjusted by the feed ratio and the pH of the solution. Prepared under low temperature and aqueous solution, the process is most suitable for encapsulating delicate bioactive agents. Albumin as a model protein was encapsulated with a loading level of up to 95% by weight. Degradation rate of the microcapsules decreased with the concentration of the crosslinking agent glutaraldehyde and increased with the bacterial collagenase level. Correspondingly the release of albumin could also be varied by the cross-linking degree of the microcapsules.