One-pot controllable synthesis of carboxylic group functionalized hollow mesoporous silica nanospheres for efficient cisplatin delivery

Abstract

Biocompatible hollow porous materials, due to their high void volume and shell porosity, are favorable platforms for efficient drug delivery. In this study, carboxylic group functionalized hollow mesoporous silica nanospheres (HMSNs-COOH) were successfully synthesized in a simple and one-pot co-condensation method using polystyrene nanospheres as a hard template, and carboxyethylsilanetriol as a source of carboxyl groups and reaction catalyzer. The synthesized HMSNs-COOH were studied by characterizing their morphology, nanostructure, specific surface area, particle size distribution and chemical composition using FESEM, HRTEM, SAXRD, N₂-sorption, DLS, FTIR and TGA techniques. The large specific surface area measured (973 m² g⁻¹) for the prepared HMSNs-COOH was found to increase the loading capacity of cisplatin to ∼48%, as an anti-neoplastic agent. Furthermore, release tests performed at three different pH values of 7.4, 6.5 and 5.5 showed a sustained and pH dependent release of the drug from the prepared HMSNs-COOH. The cytotoxicity of the formulated drug was also examined in c26 colon carcinoma cell lines using the MTT assay. We demonstrate that the drug loaded HMSNs-COOH samples have a lower toxicity than the free drug, due to controlled and sustained drug release.