Co-delivery of plantamajoside and sorafenib by a multi-functional nanoparticle to combat the drug resistance of hepatocellular carcinoma through reprograming the tumor hypoxic microenvironment

Sorafenib (SOR) is a multi-kinase inhibitor that was approved as the first-line systematic treatment agent of hepatocellular carcinoma (HCC). However, the anti-cancerous effect of SOR is dramatically impaired by the drug resistance, insufficient accumulation at tumor tissues, and limited tumor inner penetration. To combat the above issues, the PLA-based nanoparticles were first fabricated and co-loaded with SOR and plantamajoside (PMS), natural herbal medicines that possess excellent anti-cancerous effect on many types of drug resistant cancers. Then, the polypeptide CT, which is tumor-homing and cell membrane penetrable, was further decorated on the dual-agents loaded nanoparticles (CTNP-PMS/SOR) to enhance tumor accumulation of drugs. Importantly, the CT peptide is a conjugate derived from the covalent conjugation of CVNHPAFAC peptide, a tumor-homing peptide, on the fourth lysine of TAT, namely cell membrane penetrating peptide, through a pH-sensitive hydrazone bond. By this way, the cell penetrating ability of TAT was dramatically sealed under the normal condition and immediately recovered once the nanoparticles reached tumor sites. Both in vivo and in vitro experiments demonstrated that the anti-cancerous effect of SOR on malignant HCC was significantly enhanced after co-loaded with PMS. Mechanisms studies revealed that the PMS is capable of reprograming the tumor hypoxic microenvironment, which represents the main cause of drug-resistance of tumor cells. Besides, functionalization of the NP-PMS/SOR with CT peptides signally improved the accumulation of drugs at tumor sites and penetration of agents into tumor cells, which in turn resulted in stronger capacity of tumor growth inhibition.