Photodegradable Polymer Capsules Fabricated via Interfacial Photocross-linking of Spherical Polymer Particles
Yukiya Kitayama, Toshifumi Takeuchi
Abstract
Functional capsule polymer particles have a variety of interesting applications, including stimuli-responsive delivery systems; however, a major drawback is that conventional fabrication methods typically require the use of sacrificial templates, toxic solvents, and precision polymer synthesis. Herein, photodegradable hollow/capsule polymer particles were fabricated by the interfacial photocross-linking of spherical polymer particles possessing photoreactive coumarin groups, thereby circumventing the aforementioned issues. Using this interfacial photocross-linking approach, shell-cross-linked hollow polymer particles were obtained directly from simple spherical polymer particles via a facile procedure. Encapsulation of various molecules in the hollow polymer particles was achieved by postintroduction based on the solvent exchange procedure. Furthermore, the [2π + 2π] dimerization of coumarin groups is a photoreversible reaction, with the cycloaddition and cycloreversion reactions occurring under photoirradiation at longer and shorter wavelengths, respectively. As a result, the fabricated hollow/capsule polymer particles were photodegradable, and temporal control of this process was achieved.