Simple preparation of photothermal nanomaterial GNR@SiO2 with enhanced drug loading content.

With the rising threat of cancers, gold nanorods (GNRs) based photothermal-chemotherapy is becoming an increasingly important strategy to cure cancers. There are some challenges faced by GNRs system including complicated synthesis process and low drug loading capacity. In this study, GNRs assisted mesoporous silica nanoparticles (GNR@SiO2 NPs) are fabricated by a simple method. The mesoporous SiO2 can not only prevent the aggregation of GNRs but also provide large hollow mesoporous structure to enhance drug loading capacity. Moreover, GNRs absorb near-infrared (NIR) light and convert it into heat. The temperature of the GNR@SiO2 solution was increased to ∼60 (2 W) and 90°C (3 W) after NIR radiation. The photothermal conversion efficiency was 32.60% of GNR@SiO2 under NIR light irradiation at 2 W, while 39.01% under NIR light irradiation at 3 W. The drug loading content of GNR@SiO2 was 22.3 ± 2.5%, which was higher than that of most reported GNR drug delivery systems. The authors also found that the GNR@SiO2@ doxorubicin may have a higher drug release rate under the conditions of the tumour microenvironment. The in vitro cytotoxity of GNR@SiO2 was demonstrated on HeLa cells. The experimental results indicate that GNR@SiO2 has great potential for synergistic treatment to kill cancer cells.