Design of hydrophilic photocleavage o-nitrobenzyl acrylate-modified nanogels with outstanding biocompatibility prepared by RAFT polymerization for drug carrier

Abstract

Three kinds of hydrophilic photocleavage o-nitrobenzyl acrylate-modified nanogels with different particle size and narrow particle size distribution (1.8–0.24) were designed and synthesized by reversible addition-fragmentation chain transfer radical (RAFT) polymerization based on methoxy polyethylene glycol methacrylate (MPEGMA) and UV-light responsive crosslinker 5-(acryloyloxy)-2-nitrobenzyl acrylate (ONB) prepared with acryloyl chloride and 2-hydroxy-5-nitrobenzyl alcohol. The influences of particle size and distribution of the nanogel on its loading, encapsulation and photo-responsive release properties were investigated via the measurements of the final drug loading, the encapsulation efficiency and final cumulative release of coumarin 102 in the nanogel. The final drug loading, the encapsulation efficiency and the final cumulative release of coumarin 102 in the nanogel NG-ONB-300 with narrow particle size distribution were nearly twice more than those in the nanogel NG-ONB-300AIBN with wide particle size distribution (0.33) at the same concentration of coumarin 102 and reached 8.31%, 39.5% and 67%, respectively. With the increase of the particle size of the nanogel, the drug loading and encapsulation efficiency of the nanogel were decreased. Significantly, the in vitro cytotoxicity of the nanogel was also evaluated against HeLa cervical cancer cells by the MTT cell viability assay and its cell viability at different concentrations was greater than 91%, demonstrating that the photocleavage nanogel has an excellent biocompatibility and great potential in drug delivery fields.