LAUSR

Nanotheranostics with comprehensive diagnostic and therapeutic capabilities show exciting cancer treatment potentials. Here, we develop an excipient-free drug delivery system for cancer diagnosis as well as therapy, in which a near infra-red photosensitizer and a chemotherapeutic drug can be self-delivered without any carriers. The building block of the drug delivery system was synthesized by covalently conjugating four anticancer drugs (7-ethyl-10-hydroxy-camptothecin, SN-38) with a photosensitizer (porphyrin) via hydrolyzable ester linkage, which endows the drug delivery system with 100% active pharmaceutical ingredients, excellent imaging, and therapeutic functionalities. The conjugates can readily self-assemble into nanosheets (PS NSs) and remain stable for at least 20 days in aqueous solution. In PS NSs, fluorescence resonance energy transfer (FRET) dominates the fluorescence of SN-38 and enables to monitor the drug release fluorescently. The PS NSs also show excellent anticancer activity in vitro , due to the increased cell uptake with the synergistic effect of photodynamic therapy and chemotherapy.