PREPARATION AND CHARACTERIZATION OF A NEAR-INFRARED LIGHT RESPONSIVE MICROCAPSULE SYSTEM FOR CANCER THERAPY

A novel near-infrared light responsive microcapsule system, gold nanorod-covered DOX-loaded hollow CaCO3 microcapsule (AuNR-HM-DOX) is developed for cancer therapy. The hollow CaCO3 microcapsules were prepared based on the self-assembly between chitosan and sodium alginate on CaCO3 particles via layer-by-layer technique, and then covered with gold nanorods to obtain the microcapsule system. Upon near-infrared (NIR) irradiation, microcapsule with gold nanorods can convert the absorbed NIR light into heat. Meanwhile, doxorubicin (DOX), a chemotherapy drug, is loaded into the microcapsule system via electrostatic adsorption for combined photothermal therapy and chemotherapy. Properties of AuNR-HM-DOX including grain diameter, optical spectra were characterized. Confocal fluorescence imaging was performed to observe the morphology of the capsules and existence of DOX in the core, confirming the successful loading of DOX. The release of DOX from the capsules under continuous NIR irradiation was investigated to evaluate the temperature responsiveness of AuNR-HM-DOX. Results indicate that AuNR-HM-DOX microcapsules possess uniform particle size and high light responsiveness. The combination of chemical and physical therapy of AuNR-HM-DOX features great potential as an adjuvant therapeutic alternative material for combined cancer therapy.