An Experimental In Vitro and In Vivo Study on Achilles Tendon Regeneration Using Ostrich Eggshell Membrane Combined with Platelet-Rich Plasma

Research Type: Level 5 - Case report, Expert opinion, Personal observation Introduction/Purpose: Tendon injuries pose substantial medical, social, and economic challenges worldwide. Despite advancements in repair techniques, outcomes remain suboptimal due to poor tissue quality and function. Tissue engineering presents a promising solution, with biocompatible scaffolds playing a key role in regeneration. Ostrich eggshell membrane (ESM), distinguished by its organized calcite crystal structure and superior mechanical properties compared to other avian membranes, has emerged as a potential natural scaffold. When combined with platelet-rich plasma (PRP), known for its regenerative benefits, ESM offers a promising approach to enhancing tendon repair. Methods: Ostrich ESM was prepared from pathogen-free ostrich eggs, sterilized with UV radiation and prepared in desired dimensions before implantation (1.5 x 1 cm). High-resolution scanning electron microscopy (HRSEM) was utilized to visualize the sample morphology and fiber bonding. In vitro biocompatibility was assessed using the MTT assay and DAPI staining, while in vivo biocompatibility was evaluated in a rat model. For the in vivo Achilles tendinopathy assay, rats were divided into groups and subjected to AT rupture followed by treatment with ESM, PRP, or a combination. SEM was employed to evaluate tendon morphology, and real-time PCR was conducted to analyze gene expression levels. Results: The in vivo assay indicated that the ESM scaffold was safe for an extended period of 8 weeks, showing no signs of inflammation based on histopathological analysis. In the Achilles tendon rupture model, combining ESM with PRP enhanced tendon healing after 14 weeks post-surgery. Histopathological, morphological, and mechanical assessments confirmed this finding by comparing tendon tissues to normal tendons, untreated tendinopathy, and injured tendons treated with the ESM scaffold. Gene expression analysis revealed significantly increased expression of Col1a1, Col3a1, bFGF, Scleraxis (Scx), and tenomodulin in the ESM-PRP groups. Conclusion: The combination of Ostrich ESM with PRP significantly enhances AT repair and is a biocompatible scaffold for the application in living organisms.