Porphyrin-terminated nanoscale fluorescent polyrotaxane as a biodegradable drug carrier for anticancer research

Drug delivery carriers hold tremendous promise for improving cancer treatment. The polyrotaxane has shown excellent value as a drug carrier. However, few references reported that water solution polyrotaxane with fluorescence as drug carrier is free of labeling with organic fluorescence dyes. Herein, we synthesized a drug-loaded fluorescent polyrotaxane with porphyrin terminating, which can be used as a tracer material in drug and gene delivery. The structure, morphology and zeta potential of the porphyrin-terminated polyrotaxane (PR-COOH) were characterized by nuclear magnetic resonance (NMR), high resolution transmission electron microscope (HR-TEM) and zeta potentiometer. In this research, the cisplatin (CDDP) is used as a model drug. The zeta potential, drug encapsulation efficiency and drug release of CDDP-loaded polyrotaxane (PR-COOH-Pt) were studied. Confocal laser scanning microscopy (CLSM) showed that PR-COOH could be internalized by HeLa cells and CT26 cells. The antitumor efficacy of PR-COOH-Pt was investigated in vitro by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and in vivo by a xenograft tumor model. The results showed that the PR-COOH-Pt could significantly inhibit tumor growth, thus the PR-COOH-Pt hold a promising role in cancer therapy.