Preparation of pH-Sensitive Astragalus Polysaccharide Nanoparticles Loaded with Paclitaxel and Evaluation of Antitumor Activity

Purpose Chinese medicine polysaccharide are considered as promising medical materials due to their good biocompatibility and safety. The aim of this study was to develop a novel amphiphilic drug carrier based on astragalus polysaccharide (APS) to optimise the delivery of paclitaxel. Methods The pH-sensitive histidine (His) and hydrophobic stearic acid (SA) were grafted onto astragalus polysaccharide and self-assembled into nanoparticles by ultrasonication. The nanoparticles were characterised by Fourier transform infrared (FTIR), dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), and X-ray diffraction, and tested for encapsulation efficiency (EE%), drug loading capacity(LC%) and in vitro release of paclitaxel. The effects of nanoparticles on the proliferation of immune cells RAW264.7 and breast cancer cells SUM149 were assessed by cck-8 assay, and their effects on SUM149 cell cycle block and apoptotic protein expression were detected. Results The EE% of nanoparticles on paclitaxel was 77.61% and the LC% was 9.96%. Under acidic conditions, the surface charge of nanoparticles was reversed and the structure was swollen to promote drug release. Cellular experiments showed that blank nanoparticles could promote the proliferation of immune cells, and the anticancer effect of drug-loaded nanoparticles was significantly better than that of paclitaxel alone. Conclusion The prepared pH-sensitive nanoparticles can effectively enhance the uptake of paclitaxel by tumour cells and induce apoptosis in breast cancer cells, making them a promising new type of paclitaxel drug carrier.