Responsive ZIF-90 nanocomposite material: targeted delivery of 10-hydroxycamptothecine to enhance the therapeutic effect of colon cancer (HCT116) cells

Abstract

There is significant value in developing multifunctional drug delivery systems with high therapeutic efficiency for diagnosing and treating tumors. In this study, we synthesized the ATP-triggered and pH-sensitive material ZIF-90 using the liquid-phase diffusion method. This was done to load 10-hydroxycamptothecin (HCPT), and the FA-PEG-NH₂ conjugate was synthesized through an amidation reaction. We further modified the HCPT@ZIF-90 nanocomposite by employing the Schiff base reaction to create the HCPT@ZIF-90-PEG-FA nanomaterial. Drug loading test results revealed a high HCPT drug loading of up to 22.3% by weight. In the drug release experiment, the cumulative drug release of HCPT@ZIF-90 nanomaterials in pH 5.4 and ATP solutions was the highest after 72 hours. The active targeted delivery of FA and the dual-responsive release of HCPT by ZIF-90 significantly enhanced the therapeutic effect of HCPT@ZIF-90-PEG-FA on human colon cancer cells (HCT116). In the cytotoxicity test, when 100 μg mL⁻¹ of HCPT@ZIF-90-PEG-FA was incubated with cells, the cell survival rate was 16.61 ± 1.19%, significantly lower than that of the other experimental groups. This result indicates that HCPT@ZIF-90-PEG-FA exhibits excellent anti-tumor activity. Cell cycle experiments have shown that HCPT@ZIF-90-PEG-FA may inhibit the proliferation of cancer cells by blocking DNA synthesis and halting cell cycle progression. Cell uptake experiments showed that HCPT@ZIF-90-PEG-FA was mainly present in the cytoplasm of HCT1116 cells, indicating successful cellular entry of the drug to exert its therapeutic effect. In vivo experiments also demonstrated that HCPT@ZIF-90-PEG-FA nanomaterials can effectively eradicate HCT116 tumors. The utilization of the nano-drug carrier ZIF-90, along with the modification with PEG-FA, notably improved the therapeutic efficacy of HCPT. These results suggest that the system, with its active targeted delivery of FA and dual-responsive release of HCPT, could present a novel strategy for treating human colorectal cancer.