Investigation on the antimicrobial properties of cerium‐doped bioactive glasses

Abstract

Cerium-doped bioactive glasses (Ce-BGs) are implant materials that present high biocompatibility, modulate the levels of reactive oxygen species, and exert antimicrobial activity. The potential of BGs, 45S5, and K50S derived glasses doped with CeO 2 (1.2, 3.6, and 5.3 mol%) to inhibit the growth of pathogen microbes was thoroughly investigated according to the ISO 22196:2011 method properly adapted. A significant reduction of the E. coli charge was detected in all glasses, including the BGs without cerium. The evolution of pH of the medium not inoculated following the immersion of the Ce-BGs was monitored. The presence of cerium did not affect markedly the pH trend, which increased rapidly for both compositions. The change of pH was strongly mitigated by the presence of 200 mM phosphate buffer pH 7.0 (PB) in the medium. In media buffered by PB, the growth of E. coli, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, and C. albicans was not affected by the presence of BGs doped or not with cerium, suggesting that the antibacterial activity of Ce-BGs is linked to the increase of environmental pH rather than to specific ion effects. However, Ce-BGs resulted promising biomaterials that associate low toxicity to normal cells to a considerable antimicrobial effect, albeit the latter is not directly associated with the presence of cerium.

Cerium-Containing Mesoporous Bioactive Glasses (MBGs)-Derived Scaffolds with Drug Delivery Capability for Potential Tissue Engineering Applications

“…Moreover, the bacterial viability was evaluated after cultivation in the presence of scaffolds loaded with VAN. The results obtained (Figure 9) suggested an intrinsic antimicrobial effect of the samples similar to the data reported in the literature [49]. It was interesting to note a strong decrease in the microbial cells viability and ability to develop colonies in the case of bacteria seeded on S1Ce and S3Ce.…”

“…Youness et al [48] reported that the increase in cerium content in phosphate glasses enhanced their antibacterial activity against E. coli and S. aureus. Raimondi et al [49] studied the antibacterial activity of cerium doped BGs up to a 5.3 mol% content and observed that this activity is not directly associated with the presence of cerium, and it is dependent on the change of pH due to glass dissolution. Goh et al [50] reported the lack of antibacterial activity of polylactic acid/chitosan nanofibers decorated with cerium-containing bioactive glasses against E. coli, probably due to the slow release of ions from the glass composition and/or the small quantity of the glass adsorbed onto the nanofibers.…”

Co‐doping of iron and copper ions in nanosized bioactive glass by reactive laser fragmentation in liquids

“…Similarly, various metal ions have been doped into BG to enhance their therapeutic behavior. For example, BG doped with Ag, 48 Cu, 49–51 Zn, 15 Ce 52 and Ga 17 showed antibacterial properties, Ga doping showed wound healing properties 53–54 and Ce doping revealed pro‐osteogenic potential 53 …”

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

“…Bioactive glasses (BGs) find application in medicine as bone fillers, scaffolds, and implant coatings due to their ability to stimulate bone regeneration; , since the development of the first BG (45S5 Bioglass), their therapeutic use has expanded significantly, supporting and/or generating many biomedical applications. BGs are particularly versatile materials, and a variation of their forms (powders, coatings, 3D-scaffolds, and fibers) and compositions (addition of therapeutic inorganic ions, TIIs) have been shown to improve a range of relevant properties such as osteogenesis, angiogenesis, antibacterial activity, and cementogenesis. , …”

“…Our research group has investigated the effect of the addition of TIIs to BGs, ,− with a focus on the antioxidant properties and therapeutic applications of cerium-doped BGs (Ce-BGs). ,− To elucidate the redox behavior (Ce 3+ /Ce 4+ ratio) of Ce-BGs, − we performed studies with X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption spectroscopy; the same study was also carried out on Ce-BGs after enzymatic-like or enzyme-mimetic tests were performed with the aim of accurately assessing the evolution of the Ce 3+ /Ce 4+ ratio. , Alginate-treated Ce-BGs were also studied to verify the maintenance of the Ce 3+ /Ce 4+ ratio . Ce-BGs present antioxidant, antibacterial, osteogenic, and angiogenic properties and are promising therapeutic options for wound healing and tissue repair. , …”