The Issue of Tissue: Approaches and Challenges to the Light Control of Drug Activity

摘要

Many of the major challenges associated with drug delivery can potentially be addressed by linking drug action to light irradiation. These challenges include the spacing, timing and amount of a drug’s activity. Once a drug’s activity is linked to light, this activity can be more easily manipulated, because light itself is easy to manipulate. One of the main issues that light control can address is off-target toxicity. This has the potential to be limited if drugs are activated only in target tissues using light. For drugs that are needed at varying concentrations through the day, varying light has the potential to temporally modulate drug release. Because of these and other advantages, a range of mechanisms for using light to manipulate drug activity has been developed, including photocleavage control, photoconformational control, photothermal control and photo- degradation control. These major themes of light control will be described in this minireview, and illustrated with examples. In addition, the issue of tissue light permittivity, arguably the major challenge for the discipline, will be described and analyzed.