Amphiphilic copolymer and TPGS mixed magnetic hybrid micelles for stepwise targeted co-delivery of DOX/TPP–DOX and image-guided chemotherapy with enhanced antitumor activity in liver cancer

Recently, several targeted drug delivery systems have shown promising antitumor activity towards different types of cancer. However, targeting the tumor microenvironment, cellular surface and/or only one organelle may not achieve the expected therapeutic effects. Herein, a targeted drug delivery with stepwise targeting and image-guided strategy was obtained for enhancing antitumor therapy and overcoming various problems caused by the random drug distribution of traditional medicine. In this design, a multifunctional nanoplatform, TPGS/PPG2L@IONPs@DOX/TPP–DOX, based on poly(ethylene glycol)-poly(ε-caprolactone)-poly(amidoamine)-lactose acid (mPEG-PCL-G2.0 PAMAM-LA, PPG2L) copolymer and D-α-tocopherol polyethylene glycol 1000 succinate (TPGS), as a co-carrier, incorporates iron oxide nanoparticles (IONPs) as imaging agents and loads a DOX/triphenylphosphonium (TPP)–DOX drug for chemotherapy. In this nanoplatform micelle, the LA as targeting moieties to hepatocarcinoma cells is the first targeting step. After the drug is released from the hybrid micelles, the incorporated DOX and TPP–DOX target delivery to nuclei and mitochondria for the next targeting step. Furthermore, with the help of MRI contrast agents of IONPs, the distribution of hybrid micelles was monitored. As a result, the hybrid micelles demonstrated enhanced antitumor cell activity in both HepG2 and HepG2/DOX cells. The results indicated that the multifunctional hybrid micelles showed great potential in enhancing antitumor activity under image-guided and stepwise targeted chemotherapy.