Similar Hyaline-Like Cartilage Repair of Osteochondral Defects in Rabbits Using Isotropic and Anisotropic Collagen Scaffolds

Abstract

Lesions in knee joint articular cartilage (AC) have limited repair capacity. Many clinically available treatments induce a fibrous-like cartilage repair instead of hyaline cartilage. To induce hyaline cartilage repair, we hypothesized that type I collagen scaffolds with fibers aligned perpendicular to the AC surface would result in qualitatively better tissue repair due to a guided cellular influx from the subchondral bone. By specific freezing protocols, type I collagen scaffolds with isotropic and anisotropic fiber architectures were produced. Rabbits were operated on bilaterally and two full thickness defects were created in each knee joint. The defects were filled with (1) an isotropic scaffold, (2) an anisotropic scaffold with pores parallel to the cartilage surface, and (3) an anisotropic scaffold with pores perpendicular to the cartilage surface. Empty defects served as controls. After 4 (n=13) and 12 (n=13) weeks, regeneration was scored qualitatively and quantitatively using histological analysis and a modified O'Driscoll score. After 4 weeks, all defects were completely filled with partially differentiated hyaline cartilage tissue. No differences in O'Driscoll scores were measured between empty defects and scaffold types. After 12 weeks, all treatments led to hyaline cartilage repair visualized by increased glycosaminoglycan staining. Total scores were significantly increased for parallel anisotropic and empty defects over time (p<0.05). The results indicate that collagen scaffolds allow the formation of hyaline-like cartilage repair. Fiber architecture had no effect on cartilage repair.

Mesenchymal Stem Cells in Oriented PLGA/ACECM Composite Scaffolds Enhance Structure-Specific Regeneration of Hyaline Cartilage in a Rabbit Model

“…Obviously, the cartilage regeneration evident in the scaffold-alone group and the MSC-loaded scaffold group shows that autologous MSCs can engage in cartilage niche-specific redifferentiation and regeneration when the cells are stimulated by the surrounding ECM in vivo (thus, in the absence of specific growth factors). Previous studies have shown that an aligned scaffold can induce oriented cartilage regeneration [ 15 , 21 , 22 ], as confirmed by the alignment evident in the scaffold-alone group and the MSC-loaded scaffold group in this study. In particular, the better biomechanical capacity in the MSC-loaded scaffold group compared with the scaffold-alone group afforded better functional regeneration.…”

“…Notably, the structural alignment of deep cartilage tissue runs vertical to that of subchondral bone [ 20 ]. Some studies have shown that scaffold alignment may have major effects on the orientation of cartilage regeneration [ 21 , 22 ].…”

Induction of Articular Chondrogenesis by Chitosan/Hyaluronic-Acid-Based Biomimetic Matrices Using Human Adipose-Derived Stem Cells

“…They support the relevant ECM deposition and stratification, with improved cellular attachment, proliferation, differentiation to the desired phenotype, and integration into the corresponding bone or cartilage defect sites [28,29]. In cartilage-based tissue regeneration, various natural polymers exist, including synthetic alternatives that have been investigated to help in cartilage reformation such as compositions of fiber proteins (collagen, fibrin) [30,31], porous sponge polysaccharides (agarose, alginate, hyaluronic acid, and chitosan) [32,33,34,35], and synthetic hydrogel polymers (polyethylene glycol and polylactic acid) [36,37]. Although synthetic materials allow better control of mechanical, morphological, and physicochemical properties, they more often cause a substantial inflammatory response in vivo than natural materials [38,39].…”

Healing of Osteochondral Defects via Endochondral Ossification in an Ovine Model

“…Treatment strategies to heal chondral defects often utilize the bone marrow-derived stromal/ stem cell population by accessing the bone marrow through microfracture techniques, which provide cost-effective and functional healing in many cases. [2][3][4] The precise contribution of the stromal stem cell population to the healing of osteochondral defects, however, is not known, although they may have both a direct and/or indirect (modulatory) effect on the repair tissue.…”