Theranostic nanomedicine is capable of diagnosis, therapy, and monitoring the delivery and distribution of drug molecules and has received growing interest. Herein, a self-monitored and self-delivered photosensitizer-doped FRET nanoparticle (NP) drug delivery system (DDS) is designed for this purpose. During preparation, a donor/acceptor pair of perylene and 5,10,15,20-tetro (4-pyridyl) porphyrin (H2TPyP) is co-doped into a chemotherapeutic anticancer drug curcumin (Cur) matrix. In the system, Cur works as a chemotherapeutic agent. In the meantime, the green fluorescence of Cur molecules is quenched (OFF) in the form of NPs and can be subsequently recovered (ON) upon release in tumor cells, which enables additional imaging and real-time self-monitoring capabilities. H2TPyP is employed as a photodynamic therapeutic drug, but it also emits efficient NIR fluorescence for diagnosis via FRET from perylene. By exploiting the emission characteristics of these two emitters, the combinatorial drugs provide a real-time dual-fluorescent imaging/tracking system in vitro and in vivo, and this has not been reported before in self-delivered DDS which simultaneously shows a high drug loading capacity (77.6%Cur). Overall, our carrier-free DDS is able to achieve chemotherapy (Cur), photodynamic therapy (H2TPyP), and real-time self-monitoring of the release and distribution of the nanomedicine (Cur and H2TPyP). More importantly, the as-prepared NPs show high cancer therapeutic efficiency both in vitro and in vivo. We expect that the present real-time self-monitored and self-delivered DDS with multiple-therapeutic and multiple-fluorescent ability will have broad applications in future cancer therapy.
Keywords: FRET; combination therapy; in vitro; in vivo; self-delivery; self-monitoring.