Engineering Gallium-Silk Fibroin-Gelatin Porous Scaffolds for Tissue Regenration

The increasing demand for effective materials in tissue regeneration has positioned bone tissue engineering (BTE) as a critical area for innovation beyond conventional bone repair strategies. BTE seeks to develop scaffolds capable of promoting osteointegration through enhanced cell adhesion, proliferation, and tissue regeneration. Natural polymers such as gelatin and silk fibroin have emerged as attractive scaffold candidates due to their inherent biocompatibility, biodegradability, low cost, and abundance. However, their limited mechanical strength necessitates reinforcement with functional nanomaterials. Among emerging candidates, gallium-based liquid metal nanoparticles (GaLM NPs) have gained attention for their favorable conductivity, antimicrobial activity, and cytocompatibility. In this study, porous scaffolds composed of a gelatin-silk fibroin matrix reinforced with GaLM NPs were fabricated using a freeze-drying process, following homogeneous nanoparticle dispersion via probe sonication. Structural characterization confirmed successful nanoparticle incorporation without disrupting the secondary structures of the native proteins. The resulting scaffolds exhibited an interconnected porous architecture with variable pore sizes, although the majority were <50 μm-smaller than ideal for optimal bone ingrowth. Short-term swelling studies in phosphate-buffered saline (PBS) over 3 days revealed minimal dimensional changes, indicating good initial aqueous stability. Moreover, the scaffolds exhibited electrical conductivity, a property increasingly recognized for its positive influence on osteogenesis. These preliminary findings suggest that GaLM NP-reinforced gelatin-silk fibroin scaffolds are promising candidates for BTE applications. However, further optimization is required. Future work should focus on tailoring pore size distribution to meet bone ingrowth thresholds (>100 μm), assessing long-term structural integrity in physiologically relevant conditions, evaluating mechanical performance under load, and conducting comprehensive in vitro assays to determine cytocompatibility, cell attachment, and proliferation behavior.