Enhancing Bovine Hydroxyapatite: The Role of Crosslinker and Secretome in Biomechanical Properties and Toxicity

Abstract

Background: Advancements in biomaterials aid in hard tissue repair. Hydroxyapatite (HAP) similar to natural bone and used in bone grafts. Crosslinking agents like poly-vinyl alcohol (PVA) and glutaraldehyde (GTA), combined with bone marrow-derived mesenchymal stem cell (BM-MSC) secretome, are being explored for their potential to enhance HAP's biomechanical properties and minimize toxicity. This study investigates how crosslinkers and secretomes affect the toxicity and biomechanical characteristics of bovine hydroxyapatite (BHA). Methods: This in vitro laboratory study employed a comparative design. HAP was crosslinked with PVA at a 0.5% concentration and with GTA at 0.1% and 1% concentrations, both with and without BM-MSC secretome. Mechanical properties, including compressive and bending strength, were measured. Toxicity levels and water content were also analyzed using MTT Assay. Data were analyzed descriptively and statistically using ANOVA dan Tukey’s Method for Post Hoc Analysis. Results: Addition of crosslinker and secretome significantly impacted bending strength (p=0.004), but not compressive strength (p=0.648). The HAP + PVA 0.5% + secretome group had the highest compressive and bending strength compared to the control, HAP + GTA 0.1% + secretome, and HAP + GTA 1% + secretome groups. While addition crosslinker and secretome tended to reduce HAP toxicity and water content, differences were not statistically significant (p > 0.05 and p > 0.05, respectively). Conclusion: The biomechanical properties of HAP are improved by the addition of 0.5% PVA, to enhanced compressive and bending strengths. GTA's effectiveness is concentration-dependent, with higher concentrations causing toxicity. Determining optimal concentration is crucial for safe clinical application.