Development of thermo/pH-responsive chitosan coated pectin-graft-poly(N,N-diethyl acrylamide) microcarriers.

Pectin based micro/nanocarriers display promising properties for biomedical applications. In this study, thermo/pH-responsive chitosan coated pectin-graft-poly(N,N-diethyl acrylamide) (Pec-g-PDEAAm/CS) microcarriers containing 5-Fluorouracil (5-FU) as a model drug were developed. The structure, thermal stability and surface morphology of 5-FU-loaded microcarriers were investigated using FTIR, XRD, DSC and SEM. Microcarrier formulations were fabricated by varying grafting yield, drug/copolymer ratio, chitosan, and crosslinking agent concentrations. The effect of these parameters on swelling degree and 5-FU release was explored. It was observed that the grafting of pectin with poly(N,N-diethyl acrylamide) ensured sustained/controlled and thermo/pH responsive release of 5-FU. Besides, in vitro cytotoxicity results displayed that Pec-g-PDEAAm/CS microcarriers had good biocompatibility. Results illustrated that 5-FU release and swelling degree of the microcarriers were greatly controlled by especially chitosan shell, 5-FU/copolymer ratio and crosslink density. Therefore, based on the findings the developed thermo/pH-responsive Pec-g-PDEAAm/CS microcarriers might be considered as a promising carrier for controlled drug delivery.