A photo-responsive membrane for tailored drug delivery with spatially and temporally controlled release.

Accurate delivery of therapeutics to tumor regions and effective sparing of normal tissue structures are important principles for the treatment of widespread metastases or malignant lesions in close proximity to vital organs. However, the currently available drug delivery techniques do not support precise drug release within the identified disease margins. We propose a tailored drug delivery strategy that utilizes a photo-responsive material in combination with tumor margin imaging for automated and tailored release of therapeutics. As a proof of concept, a poly(ethylene oxide)-b-PSPA (PEO-b-PSPA) diblock copolymer is synthesized by spiropyran (SP) polymerization. A photo-responsive membrane (PRM) is formed and irradiated with light sources of different wavelengths. Switching irradiation between ultraviolet light (UV) and green light (Vis) controls the permeability of the PRM in coincidence with the programmed irradiation patterns. The dynamic process of photo-switchable drug permeation through the PRM is modeled and compared with the experimental results. The strategy of tailored drug release is verified using both regular geometric shapes and metastatic cancer images. The therapeutic effect of this tailored drug release strategy is demonstrated in vitro in human breast cancer cells. Our pilot study implies the technical potential of using photo-responsive carriers for image-guided chemotherapy with precisely controlled drug release patterns.