Tendon-Tissue Derived Monofilaments by Electrochemical Compaction: Production and Characterization

Repair of tendon tissues remains a complex problem in orthopedic surgery. Tendon auto- and allografts are not utilized to the full extent of their capabilities due largely to the lack of porosity and availability of properly processed tendon stock. Cryomilling is often utilized to maximize surface area-to-volume while limiting alterations to native protein/gene structure. In this study, native tendons were isolated, cryomilled, and decellularized using a truncated protocol. The resulting decellularized tendon powder exhibited reduced DNA content of less than 15 ng/mg, indicating effective removal of cellular components. The resulting decellularized tendon "powder" was then subjected to mild acidic conditions to partially solubilize the collagen within the extracellular matrix to produce a solution that could be electrochemically compacted to generate aligned fibers. Proteomic analyses revealed the presence of tendon-related proteins (cartilage oligomeric protein, fibromodulin, lumican, biglycan, and tenascin c). Proteoglycans were present in tendon-derived thread (TDT) and largely absent in pure collagen threads, as visualized by safranin O and quantified by dimethylmethylene blue staining. Mesenchymal stem cells seeded and cultured for up to 14 days on collagen threads and TDTs exhibited similar expression of genes related to tendon tissue.