Current Status of Tissue-engineered Scaffolds for Rotator Cuff Repair

Abstract

Rotator cuff tears continue to be at significant risk for re-tear or for failure to heal after surgical repair despite the use of a variety of surgical techniques and augmentation devices. Therefore, there is a need for functionalized scaffold strategies to provide sustained mechanical augmentation during the critical first 12-weeks following repair, and to enhance the healing potential of the repaired tendon and tendon-bone interface. Tissue engineered approaches that combine the use of scaffolds, cells, and bioactive molecules towards promising new solutions for rotator cuff repair are reviewed. The ideal scaffold should have adequate initial mechanical properties, be slowly degrading or non-degradable, have non-toxic degradation products, enhance cell growth, infiltration and differentiation, promote regeneration of the tendon-bone interface, be biocompatible and have excellent suture retention and handling properties. Scaffolds that closely match the inhomogeneity and non-linearity of the native rotator cuff may significantly advance the field. While substantial pre-clinical work remains to be done, continued progress in overcoming current tissue engineering challenges should allow for successful clinical translation.

Fibrous structures in augmentation for rotator cuff repair: an experimental comparison

“…The fiber material, morphology of the scaffold (fiber type, diameter and alignment, pore size and total porosity), and the interactions between the fibers play critical roles in the proper function of the engineered scaffolds [23]. Cells tend to orientate and elongate themselves along the alignment of the fibers, depositing ECM components in that direction, so the directions of alignment of the ECM and the scaffold fibers should be the same [10,23]. Also, studies show that cells are able to organize around and grow mostly aligned along the axis of small diameter fibers, this way the type of filament used in the present structures provides a larger cell-material contact surface area [17,21,23].…”

“…The ultimate load for human supraspinatus tendon strips has been previously reported at 88 to 411N, according to the location, and the sum of the ultimate load of all strips, which is an estimation of the ultimate load of the whole tendon, averaged 800 N. However, taking into account the human supraspinatus tendon usually functions at only 25% to 30% of its ultimate tensile strength[7], it can be consider that all structures demonstrate sufficient tensile strength, since all structures demonstrated to have an ultimate load superior than 30% of the previously reported range for human RCT strips. The structure that exhibit the maximum load failure value was D (~ 270 N), which was more than 30% of the estimated ultimate load of the whole tendon.Scaffolds for RCT repair should aim to approximate the Young's modulus (50-170 MPa)[7] and stiffness (~ 200 N/mm) of human RCT[10]. In the obtained test results, stiffness values are far from the reference value.…”

Bone marrow mesenchymal stem cell-derived exosomes promote rotator cuff tendon-bone healing by promoting angiogenesis and regulating M1 macrophages in rats

“…The rate of re-tear after rotator cuff reconstruction can be as high as 20%-94% [4,5]. The most important reason for re-tears is that tendon-bone healing is not ideal [6]. Promoting tendon-bone healing is a key point in treating RCTs and preventing re-tears after reconstruction.…”

rhBMP-2-Coated Acellular Dermal Graft for Chronic Rotator Cuff Healing: Translational Tendon Repair Research

“…And a growth factor should induce host cell infiltration and new tissue formation. Those characteristics are strongly necessary for biological augmentation approaches [9][10][11][12]. The dermal graft, which has been used for wound coverage, maybe applicable for large rotator cuff tears.…”