writer：Hu Xiong, Kejin Zhou, Yunfeng Yan, Jason B. Miller, and Daniel J. Siegwart
keywords：photodynamic therapy, photosensitizer, activatable nanoprobes, near-infrared, pH-responsive fluorescence imaging
source：期刊
specific source：Acs Applied Materials & Interfaces
Issue time：2018年

Current photosensitizers (PSs) for photodynamic therapy (PDT) are limited by their low water

solubility and tendency to aggregate, low near-infrared (NIR)

absorption, and low cancer selectivity. Here, we designed

iodinated, water-soluble NIR boron dipyrromethene-based PSs

to achieve image-guided and efficient PDT against cancer in

vivo that is enhanced by leveraging tumor-specific pHresponsive activation. PEG2k5c-I and PEG2k5c-OMe-I

localized to tumors and were activated by acidic pH in the

tumor microenvironment to produce 1O2 and fluorescence for

efficient PDT and effective cancer detection after intravenous administration. Upon NIR irradiation, these PSs exhibited strong

NIR absorption at 660 and 690 nm, stable NIR emission at 692 and 742 nm, and high 1O2 quantum yields of 0.78 and 0.72 in

acidic pH. PEG2k5c-I and PEG2k5c-OMe-I killed cancer cells upon irradiation of NIR light and were nontoxic without

irradiation. Light-activated PDT treatment of breast cancer tumors in mice resulted in suppression of tumor growth, DNA

damage, and necrosis selectively in tumors. This work thus introduces a versatile method to directly synthesize modular pHresponsive water-soluble PSs and provides a versatile strategy for activatable PDT against cancer.