Atelocollagen exhibits superior performance compared to growth factors in upregulating proteins associated with tendon healing.

PURPOSE: We aimed to compare the effects of atelocollagen (AC) and individual growth factors on the expression of key molecular markers associated with tendon healing. METHODS: C2C12 myoblasts were cultured in Dulbecco's Modified Eagle Medium (DMEM) containing 5% fetal bovine serum (FBS) and treated with 1 nM or 10 nM of Atelocollagen (AC), bone morphogenetic protein-2 (BMP-2), transforming growth factor-beta 1 (TGF-β1), insulin-like growth factor-1 (IGF-1), or vascular endothelial growth factor (VEGF) for 5 days. After 5 days of treatment, cells were harvested from the culture medium, and Western blot analysis was performed to quantify the expression of phosphorylated extracellular signal-regulated kinase (p-ERK), Collagen type I (Col I), Collagen type ⠢ (Col ⠢), and Tenascin C (TnC). Additionally, immunofluorescence staining was conducted to qualitatively assess cytoskeletal organization and cell adhesion, which are key factors in tendon healing. RESULTS: In the AC-treated groups, the expression levels of p-ERK, Col I/Col ⠢, and TnC were significantly higher compared to the groups treated with individual growth factors (BMP-2, IGF, VEGF, and TGF-β1) (p < 0.05). These changes were dose-dependent, as there was no significant difference in protein expression between AC and the growth factors at 1 nM, whereas at 10 nM, AC treatment resulted in a significant increase (p < 0.05). In the cell proliferation assay, C2C12 myoblasts treated with AC at 10 nM exhibited significantly higher proliferation rates compared to those treated with individual growth factors (p < 0.05). Additionally, immunofluorescence analysis revealed greater cytoskeletal alignment in AC-treated cells, suggesting enhanced cell adhesion, structural organization, and mechanical stability. CONCLUSIONS: AC significantly upregulated key molecular markers involved in cell proliferation, extracellular matrix remodeling, and tendon structural integrity more effectively than individual growth factors. The increased expression of these genes in myoblasts suggests AC's potential role in promoting tendon healing. CLINICAL RELEVANCE: Through the modulation of key molecular pathways critical to tendon healing, AC presents strong potential as an effective biological augmentation strategy for improving tendon-to-bone interface healing after surgical repair.