Unlike Bone, Cartilage Regeneration Remains Elusive

Abstract

Articular cartilage was predicted to be one of the first tissues that could successfully be regenerated, but this proved not to be the case. In contrast, bone but also vasculature and cardiac tissues have seen numerous successful reparative approaches, despite consisting of multiple cell and tissue types and thus possessing more complex design requirements. Here, we use bone regeneration successes to highlight cartilage regeneration challenges, namely selecting appropriate cell sources and scaffolds, creating biomechanically suitable tissues, and integrating to native tissue. Also discussed are technologies addressing hurdles of engineering a tissue possessing mechanical properties unmatched in man-made materials and functioning in environments unfavorable to neotissue growth.

Enhanced Mechanical Properties in Cellulose Nanocrystal–Poly(oligoethylene glycol methacrylate) Injectable Nanocomposite Hydrogels through Control of Physical and Chemical Cross-Linking

“…9,11,12 However, injectable hydrogels are often limited by a relatively low elastic modulus, [13][14][15][16] limiting their utility in applications demanding at least a degree of mechanical strength (e.g. engineering of stiffer tissues such as cartilage, 17 implantation in high-shear environments, 18 or spinal applications 19 ).…”

Hybrid Hydrogels with Extremely High Stiffness and Toughness

“…10 Hydrogels for cartilage replacement, for instance, require high stiffness and toughness to retain shape and to resist fracture, respectively. 5 Several approaches have been reported to improve the toughness of hydrogels, [11][12][13][14] but simultaneously achieving high stiffness and toughness remains a challenge. Stiffness and toughness of polymer networks are often inversely related.…”

Biological Augmentation and Tissue Engineering Approaches in Meniscus Surgery

“…62 With this strategy, cells are seeded densely in nonadherent molds and manipulated to enhance cell-cell interactions, which initiates a process akin to a developmental one, allowing the formation of a matrix with adequate mechanical properties. 63 Cells naturally form a bioactive microenvironment that may increase the likelihood of integration with host tissue because of its biocompatibility.…”