Figure 2. The hierarchical architecture of tendon. Collagen triple-helices self-assemble into fibrils. Bundles of fibrils form fibers, which constitute tendon fascicle. Tendon fibroblasts (tenocytes) reside between collagen fibers. Fascicles are wrapped by endotenon, a layer of connective tissue containing blood vessels, nerves and lymphatics. Multiple fascicles are further surrounded by another connective tissue layer, epitenon, to form the tendon tissue.
Figure 3. An overview of approaches for repair of tendon injuries. Briefly, surgical interventions and biophysical stimulation are currently employed in clinical care. Meanwhile, tissue engineering strategies are the cutting-edge of tendon healing and regeneration. Engineered replacement of injured tendon using a combination of cells, bioactive molecules, and scaffolds is under intensive investigation