Template-free preparation of iron oxide loaded hollow silica spheres and their anticancer proliferation capabilities

Hollow silica spheres (HSS) exhibited high-specific surface area, low toxicity, low density, and good biocompatibility. The effectivity of HSS material can be improved further by loading nanoparticles for smart biological applications. In this work, magnetic nanoparticle (iron oxide; Fe₃O₄)-loaded pure HSS (c-HSS-Fe) were synthesized successfully using a template-free chemical route and investigated for their anticancer cell proliferation capabilities against cancerous cell lines: human colorectal carcinoma cells (HCT-116). The structure, morphology, chemical bonding, and thermal stability of the prepared HSS derivatives were studied using spectroscopic and microscopic techniques. Our analyses confirmed the successful preparation of Fe₃O₄ loaded HSS material (sphere diameter ∼515 nm). The elemental analysis revealed the existence of Fe along with Si and O in the Fe₃O₄ loaded HSS material, thus reaffirming the production of the c-HSS-Fe product. The effects of silica spheres on HCT-116 cells were examined microscopically and by MTT assays. It was observed that the c-HSS-Fe demonstrated dose-dependent behavior and significantly reduced the cancer cell proliferation at higher doses. Our results showed that c-HSS-Fe was more effective and profound in reducing the cancer cells' activities as compared to unloaded HSS material where the cancer cells have undergone nuclear disintegration and fragmentation. It is concluded that c-HSS-Fe is a powerful bio-active material against cancerous cells.