Hollow mesoporous ZSM-5 zeolite/chitosan ellipsoids loaded with doxorubicin as pH-responsive drug delivery systems against osteosarcoma.

The toxic risks and adverse effects of anticancer drugs on healthy tissues limit their wide clinical application. Herein, we for the first time fabricated hollow mesoporous ZSM-5/chitosan ellipsoids loaded with doxorubicin (HM-ZSM-5/CS/DOX) as pH-responsive drug delivery systems against osteosarcoma. The HM-ZSM-5 ellipsoids including a hollow core and a mesoporous shell could efficiently load DOX drugs with a loading efficiency of 95.8%. The CS layer was uniformly distributed on the HM-ZSM-5 ellipsoids that contributed to the pH-responsive release of DOX drugs. The controlled DOX release kinetics from the HM-ZSM-5/CS/DOX ellipsoids was fitted well with the Korsmeyer-Peppas model. The HM-ZSM-5/CS/DOX ellipsoids exhibited good biocompatibility due to the low DOX release rate in the neutral media that simulated healthy tissues or blood. Moreover, the cellular uptake of the HM-ZSM-5/CS/DOX ellipsoids took place in tumor cells, and the quick release of DOX significantly promoted the apoptosis of MG63 cells. The levels of MDA, LDH and CK markers for the HM-ZSM-5/CS/DOX group were lower than those for the free DOX group, suggesting no systemic toxicity to the heart. Therefore, the HM-ZSM-5/CS/DOX ellipsoids as novel pH-responsive drug delivery systems can effectively treat osteosarcoma without systemic toxicity.