Nanoliposomes Co-Encapsulating Photoswitchable Probe and Photosensitizer for Super-Resolution Optical Imaging and Photodynamic Therapy

Abstract

Photosensitizers (PSs) are ideal cancer theranostic drugs that can be administered as both fluorescence imaging reagents and photodynamic therapy (PDT) drugs. To improve the tumoritropic behavior of PSs, nanoliposomes are presently being considered as optimal PSs carriers. Although nanoliposomal PSs have been utilized in clinical therapy, PSs localization and photosensitive processing in nanoliposomal PSs are rarely observed on nanoscale. Investigating changes in the fine structure of nanoliposomes under photosensitive processing will further our understanding of the photosensitive effect on nanoliposomal PSs. In this study, nanoliposomes co-encapsulating the PSs benzoporphyrin derivative monoacid A (BPD) and the photoswitchable probe Cy5-927 were prepared to realize PDT and nanoscale super-resolution optical imaging. The fine structures of nanoliposomal BPD and Cy5-927 (LBC) were visualized by a home-built stochastic optical reconstruction microscopy (STORM). Our PDT results showed that the photorelease and PDT efficiency of BPD were not decreased by co-encapsulating with Cy5-927 in LBC. Taken together, LBC can be used as a new optical probe and PDT reagent for investigating changes in nanoliposomes fine structure and micro-interaction in the cellular process of PDT. Therefore, our results deepened our understanding of liposome-based PDT for optimizing cancer treatment. © 2019 International Society for Advancement of Cytometry.