Spatiotemporal responsive hydrogel microspheres for the treatment of gastric cancer

The development of tumor drug microcarriers has attracted considerable interest due to their distinctive therapeutic performances.Current attempts tend to elab-orate on the micro/nano-structure design of the microcarriers to achieve multiple drug delivery and spatiotemporal responsive features.Here,the desired hydrogel microspheres are presented with spatiotemporal responsiveness for the treatment of gastric cancer.The microspheres are generated based on inverse opals,their skele-ton is fabricated by biofriendly hyaluronic acid methacrylate(HAMA)and gelatin methacrylate(GelMA),and is thenfilled with a phase-changing hydrogel composed offish gelatin and agarose.Besides,the incorporated black phosphorus quantum dots(BPQDs)within thefilling hydrogel endow the microspheres with outstanding pho-tothermal responsiveness.Two antitumor drugs,sorafenib(SOR)and doxorubicin(DOX),are loaded in the skeleton andfilling hydrogel,respectively.It is found that the drugs show different release profiles upon near-infrared(NIR)irradiation,which exerts distinct performances in a controlled manner.Through both in vitro and in vivo experiments,it is demonstrated that such microspheres can significantly reduce tumor cell viability and enhance the efficiency in treating gastric cancer,indicating a promising stratagem in thefield of drug delivery and tumor therapy.