Phototriggered release of photolabile drugs via two‐photon absorption‐induced cleavage of polymer‐bound dicoumarin

Abstract 7‐( tert ‐Butyldimethylsiloxy)‐7′‐(methacryloxy)dicoumarin (TBS‐Cum‐ D ‐MA) is introduced as a versatile polymerizable and photocleavable linker system for drug attachment to acrylic polymers. Following the copolymerization of the TBS‐Cum‐ D ‐MA with monomeric methylmethacrylate, a model drug chlorambucil was attached in a simple reaction. Phototriggered drug release via single‐ and two‐photon absorption induced cycloreversion of the cyclobutane of the dicoumarin part was investigated. The bound drug chlorambucil is sensitive to UV light being required for single‐photon induced cleavage of the dicoumarin linker and decomposes upon UV exposure. However, under the conditions of two‐photon absorption induced drug release, no photodegradation of chlorambucil was observed. As the only effective two‐photon absorber in the molecule is the cyclobutane structure, even high energies of visible light do not cause any degradation of the drug. This suggests that two‐photon‐triggered drug release may be successfully accomplished even with UV light sensitive drugs. The concept introduced here may be a powerful strategy in polymer design for photocontrolled drug delivery devices.