Advances in photosensitizer-related design for photodynamic therapy.

Photodynamic therapy (PDT) is highly effective in treating tumors located near body surface, offering strong tumor suppression and low damage to normal tissue nearby. PDT is also effective for treating a number of other conditions. PDT not only provide a precise and selective method for the treatment of various diseases by itself, it can also be used in combination with other traditional therapies. Because PDT uses light as the unique targeting mechanism, it has simpler and more direct targeting capability than traditional therapies. The core material of a PDT system is the photosensitizer which converts light energy to therapeutic factors/substances. Different photosensitizers have their distinct characteristics, leading to different advantages and disadvantages. These could be enhanced or compensated by using proper PDT system. Therefore, the selected type of photosensitizer would heavily influence the overall design of a PDT system. In this article, we evaluated major types of inorganic and organic PDT photosensitizers, and discussed future research directions in the field.