Table 5.

List of latest development of enthesis in tendons/ligaments

	Tendons	Ligaments	Ref.
Compositions and structure	Connective tissue mainly including collagen and specialized cells tenocytes. Collagen constitutes 65–80% of the dry mass of healthy tendons, including collagens types I, II, III, V, VIII, IX, X, XI, XII, XIV and XIX–XXI. The basal membrane is composed of type IV collagen.	Dense connective tissue consists of fibroblasts, fibrocartilage and mainly collagen type I or elastin. Directly or indirectly attached to the bone tissue, with the indirect attachment through Sharpey fibers.	[126, 127]
Mechanical properties	Different due to various elements including classification and methodological factors. The strongest tendon in human body is the Achilles tendon, with the ultimate stress of 100 MPa, and the ultimate strain of 4–10%. The attachment side of the soft and hard tissue is a weak point in deformation.	Different due to various elements including classification and methodological factors. The attachment side of the soft and hard tissue is a weak point in deformation.	[126, 127]
Development of enthesis in tendons/ligaments	Constructing scaffolds with appropriate biomaterials, hierarchical organized architecture and specially designed structures in vitro. Cultivation of cells and integration of factors on scaffolds. Enhancing mechanical properties and testing engineering enthesis in vitro. Performing in vivo implantation with histological evaluation but finding limitations in mechanical behavior.	Leveraging the advancements from biomaterials to replicate the native features of enthesis in vitro. Finding cells leading to accelerated healing. Improving mechanical properties including gradient in stiffness, shear loading and stress. Injecting cells/biomaterials in animal models, but without scaffold grafting.	[59, 122, 128–132]