Calcium silicate biocomposites: effects of selenium oxide on the physico-mechanical features and their in-vitro biological assessments

Abstract

Bone tissue regenerative material serves as a prospective recovery candidate with self-adaptable biological properties of bio-activation, degradability, compatibility, and antimicrobial efficacy instead of metallic implants. Such materials are highly expensive due to chemical reagents and complex synthesis procedures, making them unaffordable for patients with financial constraints. This research produced an efficient bone tissue regenerative material using inexpensive naturally occurring source materials, including silica sand and limestone. The extracted SiO2 and CaO particles (75:25 wt%) were subjected to hydrothermal synthesis (water treatment instead of chemical solvents) to produce the CaSiO3 biomaterial (code: S). Selenium oxide was doped with calcium silicate at 3, 5, and 10 wt.% to enhance its properties, yielding biocomposite materials (i.e., S3, S5, and S10). The physico-mechanical properties of these materials were investigated with XRD, FTIR, FESEM-EDS, and micro-UTM. The results revealed that the synthesized biocomposites have a crystalline wollastonite phase with a porously fused rough surface. From structural parametric calculations, we found that the biocomposites have reduced particle size and enhanced surface area due to the influence of selenium oxide. The biocomposite S10, having high SeO2 content, attained the maximum compressive strength of 75.2 MPa. In-vitro studies of bioactivity, biodegradability, biocompatibility, and antibacterial activity were performed. At 7 and 14 days of bioactivity, the synthesized biocomposites are capable of dissolving their ions into SBF solution to precipitate HAp and a required Ca/P ratio of 1.69 was achieved by S3. A comparative analysis has been performed on the degradation activity in Tris-HCl and the consequent pH changes during SBF treatment. The bio-analysis revealed that the biocomposite S3 shows enhanced bioactivity through a controlled degradation rate and secured cell viability of 88% at a concentration of 100 μg/ml. It also offers significant bacterial inhibition potency against E.coli and S.aureus bacteria.