Photothermal therapy.

Microneedles (MNs), as an effective minimally invasive delivery route, when used to puncture the skin, can bypass the skin's stratum corneum (SC) to enter the skin microcirculation and achieve systemic administration. Additionally, the MN route has obvious advantages over other routes of administration, including simplicity, non-pain, readily-permitted transport of drugs (including DNA and metformin) and macromolecules (such as antibodies and proteins), good repeatability, and wide range of clinical applications and safety. MNs have been combined with various therapy strategies including photodynamic therapy (PDT) and photothermal therapy (PTT) to treat many diseases, and hold great promise for improving the diagnosis and treatment of diseases. Both MN-assisted PDT and PTT are light-mediated phototherapy methods and have unique advantages, including improved selectivity, and minimal invasiveness and side effects. MN-assisted PDT or PTT has been studied for various applications by many research groups and pharmaceutical companies worldwide. Therefore, this review summarizes recent advances in MNs for PDT or PTT.