Nano-aggregates using thermosensitive chitosan copolymers as a nanocarrier for protein delivery

Polymeric micelle or self-aggregate formations have received much attention as carriers for drug delivery systems because of their high efficiency for drug delivery. Our recent results in the formation of nano-aggregates using chemically modified chitosan encouraged us to investigate the possibility of applying them as drug carriers. Therefore, we investigated a novel chitosan-based nano-aggregate as a drug carrier for sustained protein release. Thermosensitive chitosan-Pluronic (CP) was prepared by grafting monocarboxy Pluronic F127 onto the chitosan using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide. Bovine serum albumin (BSA)-loaded CP nano-aggregate was prepared by the direct dissolution method based on thermosensitive property of the CP copolymer. The physico-chemical properties of CP nano-aggregates were characterised by critical aggregate concentration, dynamic light scattering, and -potential. In vitro release studies were investigated with BSA as a model protein at 37 degrees C. BSA released from the CP nano-aggregates for about 6 h. The results suggest that CP nano-aggregates can potentially be efficient nanocarriers for protein delivery.