Mesoporous silica coated gold nanorods loaded doxorubicin for combined chemo-photothermal therapy

Abstract

The efficacy of the combined chemo-photothermal therapy, using a mesoporous silica-coated gold nanorods loaded DOX (pGNRs@mSiO2-DOX), was consistently tested both in vitro and in vivo. The prepared nanoparticles that were characterized using transmission electron microscopy (TEM), UV-vis absorption spectroscopy and zeta potential showed high doxorubicin loading capacity in addition to its pH-responsive release. The pGNRs@mSiO2-DOX photo-heat conversion characteristic found to be stable for several repeated NIR irradiated doses was tested in simulated body fluid. In vitro results showed that pGNRs@mSiO2-DOX causes a significant damage in breast cancer cell line MCF-7 compared to free DOX. Contrary to this, it showed low toxicity to human amnion wish cells compared to CTAB coated GNRs and free DOX. In vivo results showed that intravenous administration of pGNRs@mSiO2-DOX (1.7 mg/kg) markedly suppresses the growth of subcutaneous Ehrlich carcinoma in female Balb mice (p<0.0001). Consistently, histopathological examination revealed a complete loss of tumor cellular details for mice that received the combined treatment. Based on the obtained results, this passively targeted pGNRs@mSiO2-DOX could specifically deliver drug and excessive local heat to tumor sites achieving high combined therapeutic efficacy.

Keywords: Combined chemo–photothermal therapy; Drug delivery; Gold nanorods; MCF-7 cell line; Mesoporous silica; pH responsive drug release.