Photodynamic therapy with smart nanomedicine.

For several decades, clinical demands for utilization of photodynamic therapy (PDT) have been increasing. Notably, PDT was mainly applied for cancer therapy, and most photosensitizers (PSs) were developed to treat cancer. The advantages of PDT, such as minimal invasiveness and local treatment by topical light irradiation, have made it possible to widen the range of target diseases. Thus, PDT has been clinically used for treatment of various diseases (e.g., cancer, acne, and age-related macular degeneration). However, PS, which is the main component of PDT, exhibits several shortcomings such as low solubility, low bioavailability, and lack of lesion selectivity for use as a therapeutic agent. Therefore, many research projects have been performed to develop smart PS. To increase therapeutic efficacy and to decrease adverse effects in normal tissue at the same time, PS incorporation within nanoscaled delivery systems is evolving. This review provides a comprehensive explanation of PDT in smart nanomedicine, which is academically and clinically utilized in the treatment of various diseases.