LZS bioactive glass-ceramic scaffolds: Colloidal processing, foam replication technique and mechanical properties to bone tissue engineering

Abstract

Scaffolds are used in bone replacement because present biocompatibility, three-dimensional structure, and high porosity. However, despite the efforts, there are still significant barriers to the development of reliable, synthetic scaffolds to repair large defects is one of the challenges of regenerative medicine. Therefore, innovative solutions are needed better to meet the requirements of a minimally invasive approach while providing adequate vascularity and strength and mechanical reliability. In this sense, the obtainment of a material that satisfies all these requirements is very important. This work aims to evaluate the mechanical properties of glass-ceramic scaffolds of the LZS (Li2O–ZrO2–SiO2) system produced by the replica method. For this, detailed colloidal processing was carried out to identify the solids content, amount of dispersant, and the binder most suitable to produce scaffolds. Finally, the mechanical reliability of the most suitable composition was evaluated by Weibull statistics. Suspensions containing 47 vol% of LZS relative to glass and 0.2 wt % of dispersant were used. In addition, dispersion times and the amount of binder were adjusted. Scaffolds of bioactive glass-ceramics were obtained at 900 °C, replicating polyurethane foams. Then they were morphologically, structurally, and mechanically characterized. The obtained bioactive glass-ceramic scaffolds presented porosity up to 83%, compressive strengths comparable to those of trabecular bone, up to 1.3 MPa, in addition to pore size >300 μm, desirable to favor biological interests destined to the regeneration and formation of bone tissue, demonstrating the possibility of its use as a material for bone replacement or filling. The Weibull modulus found for the glass-ceramic scaffolds produced is 4.18: within the expected range of mechanical reliability for application in bone regeneration.