pH-responsive paclitaxel prodrug encapsulated in a polypeptide-chitosan polymer delivery system for osteosarcoma...

Osteosarcoma, a highly invasive and metastatic primary bone malignancy, remains a significant clinical challenge due to the limited improvement in overall survival despite advances in treatment strategies. This highlights the urgent need for the development of more effective therapeutic options. In response, we have developed a novel paclitaxel (PTX)-loaded nanodrug system, PLGA-CS-1@PTX, by incorporating a synthesized epoxy-tetrapeptide derivative (compound 1) with poly(lactic-co-glycolic acid) (PLGA) and chitosan (CS), forming the PLGA-CS-1 composite system. The system was thoroughly characterized for its physicochemical properties, including morphology, particle size, and in vitro release behavior. Scanning electron microscopy (SEM) confirmed the nanostructure of the particles, with particle sizes around 170 nm and a narrow PDI (<0.15), indicating a uniform distribution. In vitro release studies showed a pH-responsive release profile, with 84.8 % of PTX released at pH 5.4 after 65 h of incubation, compared to 68.1 % at pH 6.4 and 14.8 % at pH 7.4, demonstrating good drug release control in acidic environments. Biological assays demonstrated significant inhibition of osteosarcoma cell proliferation in both HOS and U2OS cell lines, with a dose-dependent reduction in SPICE1 expression, suggesting that PLGA-CS-1@PTX can effectively suppress the proliferative activity of osteosarcoma cells by modulating SPICE1 levels. The hydrophobic segment of the peptide enhanced the drug loading capacity and minimized side effects, improving the overall safety profile of the system. This composite system effectively integrates the strengths of each component, offering a promising, safe, and efficient strategy for osteosarcoma treatment with great potential for clinical application.