Loading with Biomolecules Modulates the Antioxidant Activity of Cerium-Doped Bioactive Glasses

Abstract

In order to identify new bioactive glasses (BGs) with optimal antioxidant properties, we carried out an evaluation of a series of cerium-doped BGs [Ce-BGsH, K, and mesoporous bioactive glasses (MBGs)] loaded with different biomolecules, namely, gallic acid, polyphenols (POLY), and anthocyanins. Quantification of loading at variable times highlighted POLY on MBGs as the system with the highest loading. The ability to dismutate hydrogen peroxide (catalase-like activity) of the BGs evaluated is strongly correlated with cerium doping, while it is marginally decreased compared to the parent BG upon loading with biomolecules. Conversely, unloaded Ce-BGs show only a marginal ability to dismutate the superoxide anion (SOD)-like activity, while upon loading with biomolecules, POLY in particular, the SOD-like activity is greatly enhanced for these materials. Doping with cerium and loading with biomolecules give complementary antioxidant properties to the BGs investigated; combined with the persistent bioactivity, this makes these materials prime candidates for upcoming studies on biological systems.

Ce-MBGs Loaded with Gentamicin: Characterization and In Vitro Evaluation

“…As described previously [ 15 , 16 ], MBGs containing different amounts of cerium (0, 1.2, 3.6 and 5.3 mol%) were synthetized by sol–gel evaporation induced self-assembly (EISA) modified method, ground and sieved to produce size of about 250 µm. Cerium percentage was optimized to add beneficial properties without compromising the glassy system properties and the MBGs’ bioactivity [ 14 ].…”

“…A significant amount of research is now involving cerium doping to produce potent antioxidant and anti-inflammatory materials, able to tune the ROS level within the microenvironment [ 10 , 12 , 13 ]. For instance, we have included cerium into melt-derived BGs [ 14 ] and MBGs [ 15 , 16 ], and other researchers have worked on cerium-doped fibers [ 17 ], scaffolds [ 18 ] and nanoparticles [ 19 ]. The antioxidant properties of Ce-BGs are undisputed, but their antibacterial effect is controversial [ 12 ].…”

“…Gen has already been included in other bioactive glasses-based systems, such as MBG particles [ 24 ], scaffolds [ 22 , 27 ] and fibers [ 28 ]. Starting from our optimized Ce-MBGs compositions [ 15 , 16 ], this study investigates the effect of Gen loading on the bioactivity, the antioxidant properties and the antibacterial activity of these Ce-MBGs to obtain multifunctional DDSs. The influence of Ce doping on the loading process is also examined.…”

Antioxidant Effects of Bioactive Glasses (BGs) and Their Significance in Tissue Engineering Strategies

“…In addition, to incorporate antioxidant elements, MBGs can be loaded with antioxidant natural or synthetic macromolecules for modulating oxidative stress and accelerating tissue healing. On this matter, gallic acid, polyphenols (POLY), and anthocyanins were successfully loaded into Ce-doped MBGs to enhance their antioxidant activity [ 17 ]. The results clarified that unloaded Ce-MBGs have only a marginal capability of SOD-like activity, while the samples loaded with the biomolecules, especially POLY, revealed a substantial improvement in the SOD-like activity.…”

“…For instance, doping the BG composition with cerium (Ce) leads to the production of antioxidant materials with potent catalase mimetic activity [ 16 ]. Moreover, the loading of antioxidant substances (e.g., phytochemicals) to specific types of BGs, e.g., mesoporous BGs (MBGs), was successfully performed for imparting this special activity to the material [ 17 , 18 , 19 ]. The surface of BGs has also been recognized as a suitable place for grafting bioactive macromolecules [ 20 ]; antioxidants (e.g., polyphenols) have been successfully grafted onto BGs for potential use in tissue engineering applications [ 21 ].…”