Antioxidant-Loaded Mesoporous Silica—An Evaluation of the Physicochemical Properties

Abstract

The dangerous effects of oxidative stress can be alleviated by antioxidants—substances with the ability to prevent damage caused by reactive oxygen species. The adsorption of antioxidants onto nanocarriers is a well-known method that might protect them against rough environ-mental conditions. The aim of this study was to investigate the adsorption and desorption of gallic acid (GA), protocatechuic acid (PCA), chlorogenic acid (CGA), and 4-hydroxybenzoic acid (4-HBA) using commercially available mesoporous silica materials (MSMs), both parent (i.e., SBA-15 and MCM-41) and surface functionalized (i.e., SBA-NH2 and SBA-SH). The MSMs loaded with active compounds were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermoporometry (TPM), and powder X-ray diffraction (XRD). High-performance liquid chromatography (HPLC-CAD) was used to evaluate the performance of the adsorption and desorption processes. The antioxidant potential was investigated using the Folin–Ciocalteu (FC) spectrophotometric method. Among the studied MSMs, the highest adsorption of GA was observed for amine-modified SBA-15 mesoporous silica. The adsorption capacity of SBA-NH2 increased in the order of PCA, 4-HBA < GA < CGA. Different desorption effectiveness levels of the adsorbed compounds were observed with the antioxidant capacity preserved for all investigated compounds.

Improvement of Thermal Protection in Recycled Polyolefins through Hybrid Mesoporous Silica–Antioxidant Particles

“…The inclusion of low-molecular-weight substances in the nanometric pores of the mesoporous silica is described in the literature [21,22], along with the incorporation of segments of macromolecular chains [23][24][25] or metals like silver [26,27], leading to their confinement [28,29]. This capability of mesoporous silica for the amorphization of antioxidants and poorly soluble drugs is a feature already reported [30][31][32].…”

Increasing Bioavailability of Trans-Ferulic Acid by Encapsulation in Functionalized Mesoporous Silica

“…The structure of mesoporous silica allows it to be loaded with drugs, polyphenols or more complex natural agents such as natural extracts [ 27 , 28 , 29 ]. Polyphenols are given special attention due to their pharmacological properties and because they are extremely numerous found in various plants, fruits and vegetables [ 30 , 31 , 32 , 33 , 34 ] while their biological activity is very wide.…”