Internal Targeting and External Control: Phototriggered Targeting in Nanomedicine.

The photochemical control of structure and reactivity bears great potential for chemistry, biology, and life sciences. A key feature of photochemistry is the spatiotemporal control over secondary events. Well-established applications of photochemistry in medicine are photodynamic therapy (PDT) and photopharmacology (PP). However, although both are highly localizable through the application of light, they lack cell- and tissue-specificity. The combination of nanomaterial-based drug delivery and targeting has the potential to overcome limitations for many established therapy concepts. Even more privileged seems the merger of nanomedicine and cell-specific targeting (internal targeting) controlled by light (external control), as it can potentially be applied to many different areas of medicine and pharmaceutical research, including the aforementioned PDT and PP. In this review a survey of the interface of photochemistry, medicine and targeted drug delivery is given, especially focusing on phototriggered targeting in nanomedicine.