pH-Sensitive silica-based core–shell nanogel prepared via RAFT polymerization: investigation of the core size effect on the release profile of doxorubicin

Abstract

In cancer therapy, one of the most well-known treatments is chemotherapy (CT); however, the efficiency of chemotherapy is restricted by numerous factors. To improve the therapeutic index of CT, nanoparticles were used as a target drug delivery. In this work, a pH-responsive core–shell system based on various sizes of silica nanoparticles (SiNPs) as the core and polymethacrylic acid (PMAA) hydrogel as the shell was synthesized. To compare the effect of the nanoparticle size on the drug delivery, a uniform shell was prepared using reversible addition–fragmentation chain transfer (RAFT) polymerization on the surface of the nanoparticle. The synthesized nanocarriers were characterized using TGA, FT-IR, SEM, TEM, and DLS techniques. Doxorubicin (DOX) was used as the model drug. An in vitro drug-release procedure at physiological pH (7.4) and under cancer-cell conditions (pH 4.8) illustrates the pH-controlled release of the nanocarriers over 15 days. The DOX-release kinetic study from the nanocarriers showed that the release mechanism follows the Gompertz model. In addition, the DOX-loaded nanocarriers have notable cytotoxicity against human breast cancer MCF-7 cells. The obtained results demonstrate that the prepared core–shell hydrogel with a size of 120 nm has a high capability to be employed as a prolonged and sustained pH-sensitive drug-release system.