Atelocollagen Scaffold Enhances Cartilage Regeneration in Osteochondral Defects: A Study in Rabbits.

BACKGROUND: To enhance articular cartilage healing, microfractures (Mfx) and bone marrow aspirate concentrate (BMAC) are commonly used, and some form of scaffold is often used together to increase its efficacy. Herein, we compared the efficacy of atelocollagen scaffold to that of collagen scaffold when used with Mfx or BMAC on osteochondral defect of animal. METHODS: This experiment was designed in two stages, and therapeutic effects of Mfx and BMAC were respectively evaluated when used with atelocollagen or collagen scaffold. Femoral condyle defects were artificially created in male New Zealand White rabbits, and in each stage, 12 rabbits were randomly allocated into three treatment groups: test group with additional atelocollagen scaffold, the positive control group with collagen scaffold, and the negative control group. Then, for 12 weeks, macroscopic and histological evaluations were performed. RESULTS: At 12 weeks, defects in the test group were fully regenerated with normal cartilage-like tissue, and were well integrated with the surrounding cartilage at both stages experiment, whereas defects in the control groups were not fully filled with regenerated tissue, and the tissue appeared as fibrous tissue. Histologically, the regenerated tissue in the test group showed a statistically significant improvement compared to the positive and negative control groups, achieving a similar structure as normal articular cartilage. CONCLUSION: The results showed that implantation of the atelocollagen scaffold enhanced cartilage regeneration following osteochondral defects in rabbits. This suggests that the atelocollagen scaffold can be used with Mfx or BMAC for effective regeneration of osteochondral defects.

Intra-Articular Atelocollagen Injection for the Treatment of Articular Cartilage Defects in Rabbit Model.

BACKGROUND: Atelocollagen is widely recognized as a biomaterial for regenerative medicine because of its good compatibility and low antigenicity. Injury of the outermost layer of articular cartilage, known as the lamina splendens, can lead to osteoarthritis (OA) and eventually full-thickness cartilage loss. The intra-articular injection of atelocollagen has been designed to restore the cartilage layer and cartilage defects in OA joints. In this study, we investigated the efficacy of atelocollagen as a cartilage supplement for joint defects. METHODS: In this study, we evaluated the therapeutic effects of atelocollagen in animals with cartilage defects. Femoral groove defects were artificially created in 12 male New Zealand white rabbits, which were treated with intra-articular injection of either atelocollagen (experimental) or normal saline (control). The results were observed 3, 6, 9, and 12 weeks following macroscopic and histological evaluations. RESULTS: At 3 weeks, cartilage tissue was restored in the experimental group, whereas the control group did not show signs of restoration. At 12 weeks, defects in both groups were filled with regenerated tissue, but the experimental group displayed a morphologically better appearance. Histologically, the regenerated tissue in the experimental group showed statistically significant improvement compared to the control group, with a structure similar to that of normal articular cartilage. CONCLUSION: The results showed that the intra-articular injection of atelocollagen enhanced cartilage regeneration following rabbit patellar groove defects. Therefore, intra-articular injection of atelocollagen can be used as an effective supplement for joint defects.

Atelocollagen Enhances the Healing of Rotator Cuff Tendon in Rabbit Model.

BACKGROUND: Failure of rotator cuff healing is a common complication despite the rapid development of surgical repair techniques for the torn rotator cuff. PURPOSE: To verify the effect of atelocollagen on tendon-to-bone healing in the rabbit supraspinatus tendon compared with conventional cuff repair. STUDY DESIGN: Controlled laboratory study. METHODS: A tear of the supraspinatus tendon was created and repaired in 46 New Zealand White rabbits. They were then randomly allocated into 2 groups (23 rabbits per group; 15 for histological and 8 for biomechanical test). In the experimental group, patch-type atelocollagen was implanted between bone and tendon during repair; in the control group, the torn tendon was repaired without atelocollagen. Each opposite shoulder served as a sham (tendon was exposed only). Histological evaluation was performed at 4, 8, and 12 weeks. Biomechanical tensile strength was tested 12 weeks after surgery. RESULTS: Histological evaluation scores of the experimental group (4.0 ± 1.0) were significantly superior to those of the control group (7.7 ± 2.7) at 12 weeks ( P = .005). The load to failure was significantly higher in the experimental group (51.4 ± 3.9 N) than in the control group (36.4 ± 5.9 N) ( P = .001). CONCLUSION: Histological and biomechanical studies demonstrated better results in the experimental group using atelocollagen in a rabbit model of the supraspinatus tendon tear. CLINICAL RELEVANCE: Atelocollagen patch could be used in the cuff repair site to enhance healing.