Assessment of magnesium-based components for intraocular drug delivery by <i>in vitro</i> biocompatibility and drug-device interaction

The development of magnesium-based intraocular drug delivery devices holds significant promise for biomedical applications, particularly in treating wet age-related macular degeneration (AMD) using vascular endothelial growth factor inhibitors such as bevacizumab. Magnesium's rapid degradation, which can be finely tuned to achieve the controlled release required for AMD treatment, along with its well-established biocompatibility and biodegradable properties, positioning it as an ideal material for these applications. The study aimed to evaluate magnesium's potential as a carrier for ocular drug delivery systems by demontrating the stability of monoclonal antibodies, specifically bevacizumab, in the presence of magnesium corrosion products and the biocompatibility of these products with various cell lines, including murine fibroblasts (3T3), rat retinal Müller cells, and human retinal pigment epithelial cells (ARPE19). The stability of bevacizumab with pure magnesium (Mg) was investigated through an indirect enzyme-linked immunosorbent assay protocol, developed and customized for this specific aim. The biocompatibility of Mg corrosion products was assessed by toxicological evaluations through MTT and Trypan Blue Viability assays, along with cell cycle analysis. Results demonstrated no significant impact of Mg corrosion products on bevacizumab stability, with changes in mean values consistently below or equal to 10%. Furthermore, Mg extracts showed minimal cytotoxicity, as metabolic activity exceeded 80% across all cell lines, classified as Grade 0/1 cytotoxicity under ISO 10993-5 standards. Cell viability, proliferation, and morphology remained unaffected for up to 72 h of exposure. This study provides the first<i>in vitro</i>evaluation of bevacizumab's stability in the presence of magnesium corrosion products and its biocompatibility with retinal cell lines, laying the foundation for future ophthalmic research and underscoring magnesium's potential as a material for intraocular drug delivery systems.