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. 2018 May 10;13(5):e0196779.
doi: 10.1371/journal.pone.0196779. eCollection 2018.

Effects of Collagen Matrix and Bioreactor Cultivation on Cartilage Regeneration of a Full-Thickness Critical-Size Knee Joint Cartilage Defects With Subchondral Bone Damage in a Rabbit Model

Free PMC article

Effects of Collagen Matrix and Bioreactor Cultivation on Cartilage Regeneration of a Full-Thickness Critical-Size Knee Joint Cartilage Defects With Subchondral Bone Damage in a Rabbit Model

Kuo-Hwa Wang et al. PLoS One. .
Free PMC article

Erratum in


Cartilage has limited self-repair ability. The purpose of this study was to investigate the effects of different species of collagen-engineered neocartilage for the treatment of critical-size defects in the articular joint in a rabbit model. Type II and I collagen obtained from rabbits and rats was mixed to form a scaffold. The type II/I collagen scaffold was then mixed with rabbit chondrocytes to biofabricate neocartilage constructs using a rotating cell culture system [three-dimensional (3D)-bioreactor]. The rabbit chondrocytes were mixed with rabbit collagen scaffold and rat collagen scaffold to form neoRBT (neo-rabbit cartilage) and neoRAT (neo-rat cartilage) constructs, respectively. The neocartilage matrix constructs were implanted into surgically created defects in rabbit knee chondyles, and histological examinations were performed after 2 and 3 months. Cartilage-like lacunae formation surrounding the chondrocytes was noted in the cell cultures. After 3 months, both the neoRBT and neoRAT groups showed cartilage-like repair tissue covering the 5-mm circular, 4-mm-deep defects that were created in the rabbit condyle and filled with neocartilage plugs. Reparative chondrocytes were aligned as apparent clusters in both the neoRAT and neoRBT groups. Both neoRBT and neoRAT cartilage repair demonstrated integration with healthy adjacent tissue; however, more integration was obtained using the neoRAT cartilage. Our data indicate that different species of type II/I collagen matrix and 3D bioreactor cultivation can facilitate cartilage engineering in vitro for the repair of critical-size defect.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.


Fig 1
Fig 1. Experimental design.
Chondrocytes were isolated from rabbit cartilage and proliferated in an RCCS. The cell-matrix constructs gradually formed neocartilage, and each was then embedded into a surgically created wound in the knee.
Fig 2
Fig 2. Various size bone defects at 3 months.
(A) Self-repair was identified in the 3-mm circular, 3-mm-deep bone defects. Dotted box indicates the defect site. Note the surface disruption. (B) Fibrous cartilage repair with superficial fragmentation was apparent in the 4-mm circular, 3-mm-deep defects. Dotted box indicates the defect site. (C) Incomplete healing with fibrous tissue coverage was observed in the 5-mm circular, 4-mm-deep bone defects. Dotted box indicates the defect site. Note the fibrosis penetrating into the new bone formation region (indicated by arrow). All images: HE staining, magnification 20×.
Fig 3
Fig 3. Rotating cell culture of chondrocytes for neocartilage constructs.
Chondrocytes cultured in type II/I collagens from different species formed neocartilage constructs at 2 and 4 weeks (HE staining, magnification 200×). GAG expression of neoRBT and neoRAT cartilage at 4 weeks is displayed in the right-most column. Note the moderate GAG accumulation at 4 weeks in both the neoRBT and neoRAT cartilage. GAG accumulation around the lacuna of chondrocytes was observed in both neocartilage types.
Fig 4
Fig 4. Neocartilage plug implantation.
(A), (B) Neocartilage plugs of diameter 5 mm were implanted into the rabbit condyles. Condyles containing (C) neoRBT and (D) neoRAT cartilage at 3 months after surgery.
Fig 5
Fig 5. Cartilage regeneration using different neocartilage constructs.
Black arrow in each graph indicates the defect site with or without implantation. In 2 months, less fragmentation and more integration with adjacent tissue were identified in neoRAT cartilage sites (A) compared with neoRBT cartilage sites (B). In 3 months, both (C) neoRAT and (D) neoRBT cartilage groups exhibited hyaline-like cartilage characterized by well-defined chondrocytes. Magnification of the labeled area in (C) and (D) revealed abundant aligned clusters in the (E) neoRAT and (F) neoRBT cartilage. The autograft group showed abundant hyaline-like cartilage penetration at 3 months. Well-defined wound healing was observed in the autograft group (G), whereas a gap was found between the base of the defect and the graft at 3 months in the allograft group (H). The allograft did not integrate with the adjacent normal tissue. In the surgery without implantation control group, the defect was filled with severe fibrosis, no cartilage was found in the defect area, the subchondral bone in the wound was denuded, no union had occurred, and pannus formation was noted in the defect area (I). All images: HE staining, magnification 20×.

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    1. Buckwalter JA. Articular cartilage injuries. Clin Orthop Relat Res. 2002;(402):21–37. . - PubMed
    1. Seol D, McCabe DJ, Choe H, Zheng H, Yu Y, Jang K, et al. Chondrogenic progenitor cells respond to cartilage injury. Arthritis Rheum. 2012;64(11):3626–37. doi: 10.1002/art.34613 ; PubMed Central PMCID: PMCPMC4950521. - DOI - PMC - PubMed
    1. Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L. Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Engl J Med. 1994;331(14):889–95. doi: 10.1056/NEJM199410063311401 . - DOI - PubMed
    1. Hoikka VE, Jaroma HJ, Ritsila VA. Reconstruction of the patellar articulation with periosteal grafts. 4-year follow-up of 13 cases. Acta Orthop Scand. 1990;61(1):36–9. . - PubMed
    1. Kimura T, Yasui N, Ohsawa S, Ono K. Chondrocytes embedded in collagen gels maintain cartilage phenotype during long-term cultures. Clin Orthop Relat Res. 1984;(186):231–9. - PubMed

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Grant support

This study was funded by the Ministry of Science and Technology, Taiwan ( (grants NSC-101-2120-M-038-001 to Prof. Wen-Fu Thomas Lai, MOST 104-2622-B-038 -006 -CC1 to Prof. Wen-Fu Thomas Lai, and MOST 104-2917-I-564-006 to Dr. Li-Hsuan Chiu). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.