A pH-Responsive Drug-Delivery System Based on Apatinib-Loaded Metal-Organic Frameworks for Ferroptosis-Targeted Synergistic Anti-Tumor Therapy.

Purpose: The efficacy of systemic therapy for hepatocellular carcinoma (HCC) is limited mainly by the complex tumor defense mechanism and the severe toxic side-effects of drugs. The efficacy of apatinib (Apa), a key liver cancer treatment, is unsatisfactory due to inadequate targeting and is accompanied by notable side-effects. Leveraging nanomaterials to enhance its targeting represents a crucial strategy for improving the effectiveness of liver cancer therapy. Patients and Methods: A metal polyphenol network-coated apatinib-loaded metal-organic framework-based multifunctional drug-delivery system (MIL-100@Apa@MPN) was prepared by using metal-organic frameworks (MOFs) as carriers. The nanoparticles (NPs) were subsequently characterized using techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), zeta potential measurements, and particle size analysis. In vitro experiments were conducted to observe the drug release kinetics and cytotoxic effects of MIL-100@Apa@MPN on HepG2 cells. The in vivo anti-tumor efficacy of MIL-100@Apa@MPN was evaluated using the H22 tumor-bearing mouse model. Results: The formulated MIL-100@Apa@MPN demonstrates remarkable thermal stability and possesses a uniform structure, with measured drug-loading (DL) and encapsulation efficiency (EE) rates of 28.33% and 85.01%, respectively. In vitro studies demonstrated that HepG2 cells efficiently uptake coumarin-6-loaded NPs, and a significant increase in cumulative drug release was observed under lower pH conditions (pH 5.0), leading to the release of approximately 73.72% of Apa. In HepG2 cells, MIL-100@Apa@MPN exhibited more significant antiproliferative activity compared to free Apa. In vivo, MIL-100@Apa@MPN significantly inhibited tumor growth, attenuated side-effects, and enhanced therapeutic effects in H22 tumor-bearing mice compared to other groups. Conclusion: We have successfully constructed a MOF delivery system with excellent safety, sustained-release capability, pH-targeting, and improved anti-tumor efficacy, highlighting its potential as a therapeutic approach for the treatment of HCC.