Chitosan bearing pendant cyclodextrin as a carrier for controlled protein release

The objective of this work was to investigate the possibility of chitosan bearing β-cyclodextrin (CDen-g-CS) nanocomplexes for controlled protein release. CDen-g-CS was synthesized by a one-step procedure with N-succinylated chitosan and mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin in the presence of the water-soluble carbodiimide. The amount of β-CD grafted was up to 62.1 wt%. In vitro cytotoxicity against NIH 3T3 cells showed that CDen-g-CS was not cytotoxic and no significant difference of cytotoxicity was found between CDen-g-CS groups. Self-assembled nanocomplexes between CDen-g-CS and insulin were in the size range of 190–328 nm, with positive electrical charge (+3.7 to +25.5 mV) and high loading efficiency (37.7%). Insulin release in vitro was affected by the medium pH and the composition of copolymer. These results demonstrated that CDen-g-CS copolymer was a new promising vehicle for controlled protein release.