Dissolution, bioactivity behavior, and cytotoxicity of 19.58Li₂O·11.10ZrO₂·69.32SiO₂ glass–ceramic

Abstract

Glass and bioactive glass–ceramic can be used in several applications. In bone growth where good bone/biomaterial adhesion was required, bioactive coatings for implants can improve bone formation. The glass and glass–ceramics of the LZS (Li2O‐ZrO2‐SiO2) system are very interesting because of their mechanical, electrical, and thermal properties. Very recently, their biological response in contact with human osteoblast has been evaluated. However, despite several initiatives, there are still no studies that systematically assess this system's bioactivity, dissolution, and cytotoxicity in vitro. This work aims to investigate the dissolution, bioactivity behavior, and cytotoxicity of LZS glass–ceramic. LZS glass–ceramics were produced from SiO2, Li2CO3, and ZrSiO4 by melting followed by quenching. The obtained glass frits were milled and uniaxially pressed and heat‐treated at 800 and 900°C and submitted to physical–chemical, structural and mechanical characterization. Their dissolution behavior was studied in Tris–HCl, while bioactivity was performed in simulated solution body fluid (SBF). The cytotoxicity test was performed using glass–ceramic in direct contact with mesenchymal stem/stromal cells (SC) isolated from human exfoliated deciduous teeth. Structural and microstructural analyzes confirmed bioactivity. The results show that it was possible to produce bioactive glass–ceramic from LZS, proven by the formation of new calcium phosphate structures such as hydroxyapatite on the surface of the samples after exposure to SBF. The SC viability test performed indicated that the materials were not cytotoxic at 0.25, 0.5, and 1.0 mg/ml. The glass–ceramic system under study is very promising for a medicinal application that requires bioactivity and/or biocompatibility for bone regeneration.

Antimicrobial characteristics of the Li2O–ZrO2–Si2O bioactive glass and glass‐ceramic for bone regeneration and wound healing

“…The bioactivity of LZS glass‐ceramic has been previously reported 17 . In summary, the microstructure of the glass‐ceramic after exposure to SBF showed the appearance of a layer of calcium phosphates in the hydroxyapatite phase, as confirmed using EDS (in terms of chemical elements) and FTIR (in terms of functional groups).…”

“…They can modulate the ion release rate and, consequently, the local pH, thereby influencing the physiological conditions around implants or grafts 21 . The results showing the physical characteristics, morphology, and bioactive glass and glass‐ceramic structure of the LZS system can be found elsewhere 17,22 . In summary, the LZS glass and glass‐ceramics were differentiated by the crystalline phases formed during heat treatment.…”

“…They comprised 31.3% zirconium silicate, 40.1% lithium disilicate, and 18.6% quartz. The remaining 10% was amorphous 17 …”

“…This study used a bioactive glass of 19.58Li 2 O•11.10ZrO 2 •69.32SiO 2 (LZS) system, obtained in previous work of our research group 17 . Briefly, the raw materials for the composition production lithium carbonate (Li 2 CO 3 , P.A, Exodo Científica), zirconium silicate (ZrSiO 4 , P.A Colorminas Colorificio e Mineração), and quartz (SiO 2 , P.A Colorminas Colorificio e Mineração), were homogenized and melted in a platinum crucible at 1500°C for 4 h, with a heating rate of 10°C/min, and the melted glass was poured into distilled water.…”

“…LZS glass systems (Li 2 O–ZrO 2 –SiO 2 ) are a new class of bioactive materials that have recently been studied 16,17 . The bioactivity and possibility of obtaining scaffolds have also been addressed 16,17 .…”