Tailoring in vitro drug delivery properties of titania nanotubes functionalized with (3-Glycidoxypropyl) trimethoxysilane

Abstract

Surface chemistry and the porous structure of porous materials play an important role to fabricate the drug delivery systems. In the present work, TiO2 nanotubes (TNTs) were fabricated via hydrothermal treatment from anatase TiO2 nanoparticles and then the surface of TNTs was chemically functionalized with (3-Glycidoxypropyl) trimethoxysilane (GPTMS). The BET experiments exhibited a significant increment of specific surface area for TNTs (from 78.485 m2 g−1 to 362.96 m2 g−1). FTIR analysis exhibited that dexamethasone (DEX) molecules interacted with surface grafted groups such as OH or epoxy ring through an electrostatic effect or a hydrogen effect. On the other hand, the shifting in the stretching frequency of phosphate anion of the drug provides strong evidence that the DEX is bonded to samples. Thermogravimetric analysis (TGA) was applied to determine the amount of loaded drug and UV–vis spectrophotometry to analyze in vitro drug release from the drug carriers. Differences in time of drug release (34–65 h) and loading capacity (38–96%) were observed by changing the morphology and surface modification of TiO2 nanoparticles. It was found that GPTMS- modified TNTs due to the presence of epoxy ring exhibited extended release of DEX. To explain the extent of interaction between the drug and the carriers, the release profiles were modelled with empirical Hill equation. In vitro cell viability experiments showed that surface modification of TNTs with GPTMS increased the biocompatibility and lower the cytotoxicity of TNTs nanomaterials to cells. GPTMS- modified TNTs has a large potential for fabricating drug delivery nanosystems with controllable and long drug effects due to unique structure of GPTMS.