Preparations and Drug Controlled Release of pH and Reduction Dual Sensitive Nano Gels Based on Chitosan

Chitosan(CS) nano gels were prepared using N,N-bis(3-carboxy-acryloyl) cystamine (BCCy) containing disulfide bonds as crosslinker and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-Hydroxysuccinimide (EDC/NHS) as catalyst in aqueous solution. The structures and morphologies of the nano gels were characterized by FT-IR, elemental analysis, nano particle size analyzer and SEM. The effect of pH and reduction environment on particle size was studied. As a model drug, camptothecin(CPT) was loaded on the nano gels for investigating the controlled release. Results showed that the particle size decreased as the amount of crosslinking agent increased. The nano gels had good biocompatibility and significant pH and reduction sensitivities.