A review of cytotoxicity testing methods and in vitro study of biodegradable Mg-1%Sn-2%HA composite by elution method

In recent years, magnesium alloys and their composites, a new generation of biodegradable metals, have become biomedical materials for orthopedic bone implants because of their adequate strength and high biocompatibility. Good biocompatible material should lead to low cytotoxicity, hemolysis, bleeding, and inflammation and must not be at risk for carcinogenic reactions. The medical equipment was tested for cell growth, reproduction, and morphology using in vitro tissue cells in the cytotoxicity test. This research examines the cytotoxicity of a Mg-1%Sn-2%HA composite, produced using powder metallurgy methods, utilizing an in vitro mammalian cell culture system in accordance with ISO 10993-5 criteria. Extracts were generated utilizing the elution technique in Dulbecco's Modified Eagle Medium (DMEM) supplemented with fetal bovine serum (FBS) and evaluated on L-929 mouse fibroblast cells. The cells were cultured at 37 °C with 5% CO₂ for 7 days, after incubation, the monolayers were evaluated microscopically for aberrant cell morphology and degeneration, followed by quantitative cell toxicity using the MTT method. The results indicated a high cell viability of 71.51% with the undiluted extract preparation, confirming the non-cytotoxic properties of the Mg-1%Sn-2%HA composite. Furthermore, cell viability improved with dilution, attaining 84.93%, 93.20%, and 96.52% at concentration of 50%, 25%, and 12.5%, respectively. No notable morphological alterations or indications of cellular deterioration were seen. The results support the viability of the Mg-1%Sn-2%HA composite as a biodegradable material for orthopedic applications. The research offers essential insights into the formulation and assessment of magnesium-based biomaterials for enhanced safety and efficacy in medical implants. The novelty of this study lies in combining a critical review of cytotoxicity evaluation methods with an experimental investigation of Mg-1%Sn-2%HA composite. This work is the first to systematically evaluate the cytotoxicity of Mg-1%Sn-2%HA composite, thereby filling a key research gap. Unlike earlier reports that focused solely on Mg-Sn alloys or Mg-HA composites, this work integrates both alloying and reinforcement strategies, thereby offering new insights into their collective role in biocompatibility assessment.