Inhibition of Breast Cancer Cell Proliferation by 9-Hydroxycamptothecin-Loaded Zeolitic Imidazolate Nanoparticles

Novel drug delivery systems have been designed to enhance local drug concentrations while reducing side effects conducive to improved breast cancer treatment outcomes. This study aimed to identify the anti-cancer function of zeolite imidazole ester-based material loaded with camptothecin nanoparticles.

We utilized a zeolitic imidazolate backbone material to fabricate 9-hydroxycamptothecin nanoparticles and investigated their impact on breast cancer cell proliferation. Scanning electron microscopy and Fourier-transform infrared spectroscopy revealed changes in the carrier skeleton of the loaded 9-hydroxyl camptothecin, characterized by a reduction in surface smoothness, accompanied by slight collapses and folds on the particle surface. Notably, we detected vibration of the benzene ring in the 9-hydroxycamptothecin structure within the nanoparticles. Cell proliferation was tested by CCK-8. Protein expression was measured by Western blot. The efficacy of nanoparticles was evaluated by animal experiments.

In this study, we utilized a zeolitic imidazolate backbone material to fabricate 9-hydroxycamptothecin (9-HCPT) nanoparticles and investigated their impact on breast cancer cell proliferation. Scanning electron microscopy and Fourier-transform infrared spectroscopy revealed changes in the carrier skeleton of the loaded 9-hydroxyl camptothecin, characterized by a reduction in surface smoothness, accompanied by slight collapses and folds on the particle surface. Notably, we detected vibration of the benzene ring in the 9-HCPT structure within the nanoparticles. Using the CCK-8 method, we evaluated the inhibitory effect of these nanoparticles on breast cancer cells and observed a significant reduction in the cytotoxicity of camptothecin (CPT) when incorporated into the zeolite imidazole ester skeleton material. Immunoblot analysis showed upregulation of cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and NF-κB-p65 in response to the nanoparticles. These results showed that our nanoparticles might be a useful drug delivery strategy to overcome breast cancer drug resistance.

The findings of this study suggest that nanoparticles loaded with CPT and formed from zeolite imidazole ester backbone material possess immune-enhancing properties that could suppress breast cancer progression. Accordingly, these nanoparticles hold promise as potential lead compounds for combined immunotherapy in breast cancer treatment.