DTX-loaded star-shaped TAPP-PLA-b-TPGS nanoparticles for cancer chemical and photodynamic combination therapy

A novel multifunctional material consisting of a four-armed star-shaped porphyrin-cored poly(lactide)-b-D-α-tocopheryl polyethylene glycol 1000 succinate amphiphilic copolymer (TAPP-PLA-b-TPGS) was synthesized through an arm-first approach and was characterized by 1H NMR and gel permeation chromatography (GPC). This porphyrin-functionalized material has potential applications in both drug-delivery systems and photodynamic therapy (PDT). Docetaxel (DTX)-loaded or coumarin 6-loaded nanoparticles (NPs) were prepared by a modified nanoprecipitation technique. The resulting NPs were characterized through determination of their size and size distribution data, surface charge and surface morphology, drug loading content, drug encapsulation efficiency, as well as differential scanning calorimetry (DSC) experiments. In drug release assays, the DTX-loaded NPs showed excellent pH-dependent drug-release behavior. The NPs were also found to generate singlet oxygen (1O2) species and exhibit significant phototoxicity in HeLa cervical cancer cells after irradiation with light of 660 nm wavelength. The drug-loaded NPs demonstrated superior performance compared to the commercial drug, Taxotere®, which is likely due to synergistic effects between phototherapy and chemotherapy in the destruction of HeLa cells. This novel functionalized drug-delivery system shows considerable potential in providing a new multi-modality treatment approach for cancer.