Preparation of diatomite silica nanoparticles with dual-targeting and controlled drug release for cancer treatment

Abstract

Diatomite, a natural porous biomaterial, holds great potential for biomedical applications due to its biocompatibility, eco-friendliness, and structural properties. In this study, we fabricated diatomite silica nanoparticles (DSNs) through mechanical grinding, followed by thermal and acid treatments to remove surface impurities. These DSNs were further functionalized with folic acid (FA) and glucose molecules to enable dual-targeting capabilities toward cancer cells, enhancing the specificity of drug delivery. We developed a controlled release system using disulfide bonds, where the anticancer drug camptothecin (CPT) was conjugated to the DSNs. The release mechanism relies on the intracellular and extracellular glutathione (GSH) concentration gradient, where a high concentration of GSH inside cancer cells cleaves the disulfide bonds, thereby releasing CPT. Our results demonstrate the successful functionalization and drug release behavior of DSN-Glu-SS-CPT-FA. Confocal microscopy confirmed effective cellular uptake by HeLa cancer cells. These findings suggest that DSNs with dualtargeting and controlled release properties hold promise as effective nanocarriers for cancer treatment (see Scheme 1).