Osteogenesis of aspirin microsphere-loaded tilapia collagen/hydroxyapatite biomimetic scaffolds

Scaffold materials that imitating functional extracellular matrix would be an achievement in bone tissue engineering. Based on the superiority of marine collagen, this article reports the fabrication of novel Tilapia Collagen/Hydroxyapatite(T-col/HAp)-based tissue engineering scaffold. In order to improve the osteoinductive activity of scaffold, we fabricated Aspirin-PLGA microspheres by the O/W emulsion solvent extraction and embedded Aspirin-PLGA microspheres (AM) in the T-col/HAp scaffold. T-col/HAp/AM exhibited an interpenetrating network with microspheres staying in porous microstructure. The average pore of scaffold was in the range of 100–150 μm with ideal mechanical strength and chemical stability characteristics. The release rate of aspirin from the microspheres that embedded scaffold was gradual and controlled. Also, the significantly enhanced cell proliferation and mineralization capacity were observed in T-col/HAp/AM and T-col/HAp exposed cell group suggesting that this scaffold based on tilapia collagen could be an ideal biomaterial for bone tissue engineering. Furthermore, a high alkaline phosphatase activity for T-col/HAp/AM exposed group after 14 days incubation indicates the bone regeneration capacity of BMSCs. Combined with the Western Blot results, we can infer that the inhibition of local inflammation and the regulation of OPG/RANKL signaling pathway by the sustained release of aspirin may be a credible way for the bone regeneration. The in vivo results further verify that a great deal of bone tissue, with the treatment of T-col/HAp/AM, has been generated at an early postsurgical stage in rat cranial bone defect models by histology and imaging. The results from our study demonstrate that the T-col/HAp/AM scaffold could be an appropriate scaffold for bone tissue engineering.