Abstract
Bone tissue regeneration remains a critical challenge in clinical dentistry, particularly for patients with large or infection-prone defects. This study explores the development of an antimicrobial hydrogel scaffold that combines Gelatin Methacryloyl (GelMA) with alpha lipoic acid-capped silver nanoparticles (AgNPs) to address the limitations of traditional bone grafts, such as infection risk and insufficient angiogenesis. Silver nanoparticles, ranging from 1 to 13 nm in size, were synthesised and incorporated into the GelMA scaffold for their potent antimicrobial properties while preserving biocompatibility.
Mesenchymal stem cells (MSCs) were cultured on GelMA-AgNP constructs, and various biological assays, including PrestoBlue, ApoTox-Glo, and Alizarin Red S staining, were performed to assess cell viability, cytotoxicity, apoptosis, and osteogenic differentiation. The study investigated a range of AgNP concentrations (1 µg/ml, 5 µg/ml, 25 µg/ml, and 100 µg/ml) to determine the optimal concentration for effective bone regeneration. The results demonstrated that at an optimal concentration of 5 µg/ml, the GelMA-AgNP scaffold significantly enhanced MSC viability (up to 91% of control) and promoted osteogenic differentiation, as indicated by increased alkaline phosphatase activity and upregulation of key osteogenic genes such as COL1A1, RUNX2, and SPARC.
Higher AgNP concentrations (25 µg/ml and above) resulted in cytotoxic effects, reducing MSC viability and osteogenic gene expression, particularly at 100 µg/ml, where a marked decline in cell functionality was observed. At 25 µg/ml, MSC viability decreased to 26.4%, indicating that while AgNPs play a crucial role in bone healing, their concentration must be carefully managed to avoid cytotoxicity.
These findings suggest that GelMA scaffolds containing 5 µg/ml alpha lipoic acid-capped AgNPs provide an effective antimicrobial environment while simultaneously promoting bone regeneration, positioning this bioregenerative construct as a promising therapeutic approach for dental bone regeneration. This construct has the potential to improve outcomes in implantology and periodontal treatments by mitigating infection risks and supporting bone healing. Further studies, including in vivo trials, are necessary to validate these results and explore the broader clinical applications of this scaffold.