Three-dimensional composite aerogel scaffolds based on electrospun poly(lactic acid)/gelatin and silica-strontium oxide short fibers promote bone defect healing

Abstract

Background: Bone defect regeneration is a dynamic healing process that relies on the body’s innate repair mechanisms, yet natural healing capacity remains limited. To address this challenge, advanced biomaterials combining bioactive inorganic components with biocompatible polymers have emerged as a promising strategy to enhance osteogenesis and angiogenesis. Methods: In this study, a novel three-dimensional composite scaffold material was successfully fabricated using a combined electrospinning-freeze drying technique. The scaffold incorporates flexible silicon dioxide-strontium oxide (SiO₂-SrO) nanofibers as functional components, which are physically blended with a poly(lactic acid)/gelatin (PG) fibrous matrix to achieve composite construction. Results: The fabricated scaffolds exhibited an optimal well-ordered porous structure, excellent biocompatibility, and sustained release of therapeutic ions (Si⁴⁺ and Sr²⁺). Notably, they significantly upregulated osteogenic gene expression and enhanced angiogenic potential as demonstrated by improved tubulogenesis in HUVEC cultures. In vivo evaluation using a rat calvarial defect model confirmed their superior bone regeneration capability through simultaneous promotion of osteogenesis and angiogenesis. Conclusion: Leveraging the synergistic effects of SiO₂-SrO nanofibers and PG polymers, this study presents a multifunctional scaffold capable of promoting bone regeneration through dual osteogenic and angiogenic stimulation. Our findings highlight the potential of this composite system not only for bone tissue engineering but also for broader biomedical applications.

Keywords

Inorganic nanofiber / Composite scaffold / Calvarial repair / Electrospinning / Tissue engineering / Bone tissue engineering

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