In this work, a composite of microRNA-124-5p mimics (miR-124-5p) and
gold nanoparticle (AuNP) aggregates was fabricated to combine the gene therapy and
photothermal therapy for effective
tumor medicine. The AuNP aggregates cross-linked by
cystamine not only serve as photothermal therapeutic agents but are able to condense miR-124-5p as nanocarrier for gene delivery because of the coulomb interaction. The release of miR-124-5p could be initiated by the cleavage of
cystamine when the nanocarrier enter the cytoplasm of
tumor cells through endocytosis, where contains high concentration of
glutathione (GSH). Moreover, the size of the AuNP aggregates did not change after the GSH-triggered miR-124-5p release because of the coinstantaneous disruption of
disulfide bond and reformation of the
thiol-
gold bond, resulting in sustained photothermal property of the nanocarrier for
tumor therapy. In vitro experiments showed that the
miRNA@AuNAs (miR-124-5p) composite under near-infrared radiation performed great cytotoxicity to
tumor cells, which is two and three times higher than the group of pure AuNP aggregates under near-infrared radiation and
miRNA@AuNAs composite without near-infrared radiation, respectively. All experiment statistics show that the
miRNA@AuNAs composite with combination of
photothermal therapy and gene therapy has great potential for effective
tumor treatment.