Photodynamic and Photothermal therapy via human serum albumin delivery

Phototherapy, which mainly includes photodynamic therapy (PDT) and photothermal therapy (PTT), is a new type of tumor therapy that uses a specific light source to irradiate enriched phototherapy drugs at the tumor site and produce reactive oxygen species or induce a photothermal action to kill the tumor. Human serum albumin (HSA)—the most abundant carrier protein in serum—has diverse binding domains; thus, it can be used as a carrier to bind various photosensitizers and photothermal converting agents (PTCAs) to improve the therapeutic efficacy of PDT and PTT. Compared to traditional tumor therapy, phototherapy administered via HSA delivery has the advantages of strong targeting and less trauma and has been widely studied to date. However, this interesting topic has not yet been systematically reviewed. Herein, we focus on the recent research progress on photosensitizers and PTCAs in HSA-delivered PDT and PTT, including their design and synthesis, tumor-targeting mechanisms, and tumor therapeutic applications. Furthermore, as clinical tumor treatment methods, PDT and PTT still have several drawbacks and limitations, such as the inability to spread to metastatic tumors, the dependence on the dose of photosensitizers and PTCAs, low light tissue penetration, and the requirement to avoid light for patients during treatment. This important review may facilitate the development of enhanced photosensitizers and PTCAs to provide highly powerful research tools for basic medical studies aimed at improving the diagnosis and treatment of clinical cancer.