Synthesis, characterization, and drug delivery application of carboxymethyl chitosan-CTAB self-assembling

In this study, self-assembly vesicles based on carboxymethyl chitosan (CMCS) were prepared for insulin delivery. The self-assembly behavior of mixed systems consisting of CMCS and the cetyl trimethyl ammonium bromide (CTAB) was investigated. The resulting CMCS/CTAB vesicles were nearly spherical in shape, with the majority ranging around 100 nm in diameter. The toxicity profile of CMCS/CTAB vesicles was evaluated in vitro via methyl thiazolyl tetrazolium (MTT) assay. The results indicated that the stability of CMCS/CTAB vesicles was enhanced by increasing the degree of substitution (DS) of CMCS or by reducing the molecular weight (MW) of CMCS. Additionally, we observed that vesicle stability improved with decreased temperature. The insulin loading capacity and encapsulation efficiency decreased as the MW increased. Moreover, the loading capacity and encapsulation efficiency increased with the increase of the DS. The release of insulin slowed as the insulin content increased. The increase of MW or DS of CMCS could slow the release of insulin.