Cell Proliferation to Evaluate Preliminarily the Presence of Enduring Self-Regenerative Antioxidant Activity in Cerium Doped Bioactive Glasses

Abstract

(1) Background: a cell evaluation focused to verify the self-regenerative antioxidant activity is performed on cerium doped bioactive glasses. (2) Methods: the glasses based on 45S5 Bioglass®, are doped with 1.2 mol%, 3.6 mol% and 5.3 mol% of CeO2 and possess a polyhedral shape (~500 µm2). Glasses with this composition inhibit oxidative stress by mimicking catalase enzyme (CAT) and superoxide dismutase (SOD) activities; moreover, our previous cytocompatibility tests (neutral red (NR), 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Bromo-2-deoxyUridine (BrdU)) reveal that the presence of cerium promotes the absorption and vitality of the cells. The same cytocompatibility tests were performed and repeated, in two different periods (named first and second use), separated from each other by four months. (3) Results: in the first and second use, NR tests indicate that the presence of cerium promotes once again cell uptake and viability, especially after 72 h. A decrease in cell proliferation it is observed after MTT and BrdU tests only in the second use. These findings are supported by statistically significant results (4) Conclusions: these glasses show enhanced proliferation, both in the short and in the long term, and for the first time such large dimensions are studied for this kind of study. A future prospective is the implantation of these bioactive glasses as bone substitute in animal models.

Cerium Containing Bioactive Glasses: A Review

“…The cell lines selected for these assays are then typically chosen to model the response likely observed in vivo upon the surgical implant of BGs. 122 , 124 Accordingly, the cell types commonly employed to assess the cytocompatibility of BGs have a role in wound healing (fibroblasts), 81 , 93 , 115 , 125 , 126 bone structure (osteocytes), 96 , 127 , 128 and bone maintenance and formation (osteoclasts and osteoblasts). 108 , 111 , 116 , 129 As cell cultures are sensitive to changes in variables such as temperature, pH, and nutrient concentration, careful control of the experimental conditions is crucial in correlating cell death to toxicity of the biomaterial rather than to changes in the culture conditions.…”

“… 130 Among the latter, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT) is the method of choice for the quantification of metabolically active cells upon incubation with BG eluates. 81 , 96 , 108 , 125 , 127 , 131 MTT is a rapid colorimetric test based on the cleavage of a yellow tetrazolium salt to purple formazan crystals by mitochondrial enzymes in metabolically active cells. 122 Another indirect assay reported on BG extracts is the alamarBlue assay for cell viability (applicable both as a direct and indirect test).…”

“…Direct cytocompatibility has been assessed by a range of assays, including MTT, 83 , 93 , 111 , 115 , 125 , 126 , 129 , 131 alamarBlue, 116 and neutral red (NR) 96 , 127 , 128 for cell viability, bromo-2-deoxyuridine (BrdU) for cell proliferation, 96 , 127 and LDH activity for cytotoxicity. 81 , 116 Remarkably, all the BGs investigated show little 93 , 115 or no 83 , 96 , 111 , 126 , 127 , 129 effect on cell viability and are cytotoxic regardless of the amount of cerium in the glass composition; 81 , 116 , 128 in some instances, the amount of cerium in the glass composition increases the biocompatibility of the materials. 93 , 115 , 128 , 129 At very long (14 days) culture times, cell viability is reported to decrease, and BGs with a higher amount of cerium show better cytocompatibility.…”

<p>The Advances of Ceria Nanoparticles for Biomedical Applications in Orthopaedics</p>

“…109,110 Recently, 45S5 bio-glass with ceria has been developed with a polyhedral shape and large size, and the cellular uptake capacity, survivability, and proliferate ability have been demonstrated. 111 CeO 2 -NPs doped in MBG with MgO could decrease the degradation rate and enhance chemical durability. Meanwhile, the tests verified that the "sol-gel" synthesis technique promoted hydroxyapatite growth rate over the conventional "melt quenching" route.…”

Anti-inflammatory and antibacterial activities of cerium-containing mesoporous bioactive glass nanoparticles for drug-free biomedical applications

“…A considerable amount of literature has been published on cerium-containing BGs [ 20 , [26] , [27] , [28] , [29] , [30] , [31] ]. For example, Shruti et al.…”