Conventional treatments for tumors were frequently accompanied by drawbacks and side effects. It might be useful to use the revolutionary microneedle technology which combines photothermal therapy with tumor immunotherapy. In this study, we created a microneedle drug delivery system with mercapto-modified gold nanorods and immune checkpoint blocker anti-PD-1 polypeptide. With good mechanical strength, the microneedle system can efficiently penetrate the skin and deliver drugs. When inserted into human skin, anti-PD-1 peptides and gold nanorods can be released, boosting the capacity of cytotoxic T lymphocytes to destroy tumor cells. Additionally, the elimination of the tumor is aided by the production of heat while being exposed to near-infrared light. This microneedle drug delivery system can enhance the immunological reaction and prolong the survival time of mice. Moreover, it has been demonstrated that the system has mild toxic and side effects on normal tissues and can effectively inhibit the growth of tumors, indicating a bright prospect for the treatment of cancers.
Keywords: Cancer immunotherapy; dissolving microneedles; photothermal therapy; transcutaneous immunization.