Sizable Scaffold-Free Tissue-Engineered Articular Cartilage Construct for Cartilage Defect Repair.

This study introduces an implantable scaffold-free cartilage tissue construct (SF) that is composed of chondrocytes and their self-produced extracellular matrix (ECM). Chondrocytes were grown in vitro for up to 5 weeks and subjected to various assays at different time points (1, 7, 21, and 35 days). For in vivo implantation, full-thickness defects (n = 5) were manually created on the trochlear groove of the both knees of rabbits (16-week old) and 3 week-cultured SF construct was implanted as an allograft for a month. The left knee defects were implanted with 1, 7, and 21 days in vitro cultured scaffold-free engineered cartilages. (group 2, 3, and 4, respectively). The maturity of the engineered cartilages was evaluated by histological, chemical and mechanical assays. The repair of damaged cartilages was also evaluated by gross images and histological observations at 4, 8, and 12 weeks postsurgery. Although defect of groups 1, 2, and 3 were repaired with fibrocartilage tissues, group 4 (21 days) showed hyaline cartilage in the histological observation. In particular, mature matrix and columnar organization of chondrocytes and highly expressed type II collagen were observed only in 21 days in vitro cultured SF cartilage (group 4) at 12 weeks. As a conclusion, cartilage repair with maturation was recapitulated when implanted the 21 day in vitro cultured scaffold-free engineered cartilage. When implanting tissue-engineered cartilage, the maturity of the cartilage tissue along with the cultivation period can affect the cartilage repair.

Correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction.

BACKGROUND: The purpose of this study was to evaluate correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction flatfoot under loading. METHODS: CT scans of 15 healthy feet and 15 feet with stage II posterior tibial tendon dysfunction flatfoot were taken both in non- and simulated weight-bearing condition. The CT images of the hindfoot and medial longitudinal arch bones were reconstructed into three-dimensional models with Mimics and Geomagic reverse engineering software. The three-dimensional complex mobility of each joint in the medial longitudinal arch and their correlation with the medial arch angle change were calculated. RESULTS: From non- to simulated weight-bearing condition, the medial arch angle change and the medial longitudinal arch joints mobility were significant larger in stage II posterior tibial tendon dysfunction flatfoot (p<0.05). The eversion of the talocalcaneal joint, the proximal translation of the calcaneus relative to the talus, the dorsiflexion of the talonavicular joint, the dorsiflexion and abduction of the medial cuneonavicular joint, and the lateral translation of the medial cuneiform relative to the navicular, and the dorsiflexion of the first tarsometatarsal joint were all significantly correlated to the medial arch angle change in stage II posterior tibial tendon dysfunction flatfoot (all r>0.5, p<0.05). CONCLUSIONS: There is increased mobility in the medial longitudinal arch joints in stage II posterior tibial tendon dysfunction flatfoot and the medial arch angle change under loading causes displacement not only at hindfoot joints but also involve midfoot and forefoot joint.

[Migration of PKH26-labeled mesenchymal stem cells in rats with Alzheimer's disease].

OBJECTIVE: To investigate the migration of fluorescent dye PKH26-labeled BM-MSC in the Alzheimer's model rats. METHODS: Normal human bone marrow extracted for isolation of BM-MSC was cultured in vitro. The 5th passaged BM-MSC was labeled with PKH26, and observed under a fluorescence microscope for PKH26 labeling efficiency, and using flow cytometry BM-MSC surface markers was checked. The PKH26 labeled BM-MSC injected into the tail vein of the normal control group and AD animal model group, 14 days after finding the PKH26-labeled BM-MSC cells in the rat hippocampus using fluorescence microscopy. Using the Morris water maze experiment comparison of AD model and BM-MSC transplantation group of spatial learning and memory ability. RESULTS: TFlow cytometry showed BM-MSC surface markers CD73 and CD105 were positive. In vitro, PKH26-labeled rate of BM-MSC was 100 %. The Morris water maze experiment comparison of BM-MSC transplantation group and AD group of animals, BM-MSC transplantation group at 13, 14 days of spatial learning and memory ability than AD animal group had significantly improved. 14 days after BM-MSCs in rat hippocampus could be found which were PKH26-positive, consistent with DAPI staining. PKH26-positive cells in animal models of AD were significantly more than those in the normal control group. CONCLUSION: BM-MSC in AD rats not only migrates through the blood-brain barrier, but also mainly survives in the hippocampus of AD rats, and it can improve AD rat model of learning disabilities.

Arthroscopic Rotator Cuff Repair With Graft Augmentation of 3-Dimensional Biological Collagen for Moderate to Large Tears: A Randomized Controlled Study.

BACKGROUND: Due to the highly organized tissue and avascular nature of the rotator cuff, rotator cuff tears have limited ability to heal after the tendon is reinserted directly on the greater tubercle of the humerus. Consequently, retears are among the most common complications after rotator cuff repair. Augmentation of rotator cuff repairs with patches has been an active area of research in recent years to reduce retear rate. HYPOTHESIS: Graft augmentation with 3D collagen could prevent retears of the repaired tendon and improve tendon-bone healing in moderate to large rotator cuff tears. STUDY DESIGN: Randomized controlled study; Level of evidence, 2. METHODS: A prospective, randomized controlled study was performed in a consecutive series of 112 patients age 50 to 85 years who underwent rotator cuff repair with the suture-bridge technique (58 patients, control group) or the suture-bridge technique augmented with 3-dimensional (3D) collagen (54 patients, study group). All patients were followed for 28.2 months (range, 24-36 months). Visual analog scale score for pain, University of California Los Angeles (UCLA) shoulder score, and Constant score were determined. Magnetic resonance imaging was performed pre- and postoperatively (at a minimum of 24 months) to evaluate the integrity of the rotator cuff and the retear rate of the repaired tendon. Three patients in each group had biopsies at nearly 24 months after surgery with histological assessment and transmission electron microscopy. RESULTS: A total of 104 patients completed the final follow-up. At the 12-month follow-up, the UCLA shoulder score was 28.1 ± 1.9 in the study group, which was significantly better than that in the control group (26.9 ± 2.1, P = .002). The Constant score was also significantly better in the study group (87.1 ± 3.2) than in the control group (84.9 ± 4.2, P = .003). However, at the final follow-up, no significant differences were found in the UCLA shoulder scores (29.4 ± 1.9 in the control group and 30.0 ± 1.6 in the study group, P = .052) or Constant scores (89.9 ± 3.2 in the control group and 90.8 ± 3.5 in the study group, P = .18). In terms of structural integrity, more patients in the study group had a favorable type I retear grade (18/51) than in the control group (10/53) ( P = .06). The postoperative retear rate was 34.0% in the control group and 13.7% in the study group, thus indicating a significantly lower retear rate in the study group ( P = .02). Biopsy specimens of the tendon-bone interface in 6 patients revealed more bone formation and more aligned fibers with larger diameters in the study group than in the control group. No intraoperative or postoperative complications were noted in either group. CONCLUSION: 3D collagen augmentation could provide effective treatment of moderate to large rotator cuff tears, providing substantial functional improvement, and could reduce the retear rate. This technique could also promote new tendon-bone formation, thus exerting a prominent effect on tendon-bone healing.

Clinical significance of microRNA-130b in osteosarcoma and in cell growth and invasion.

OBJECTIVE: To investigate clinical significance of microRNA-130b (miR-130b) in osteosarcoma and its role in cell growth and invasion. METHODS: miR-130b expression was detected in 68 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues by qRT-PCR. The expression of miR-130b was altered by corresponding vectors in osteosarcoma cells, and then Western blot was used to detect the expression of PPARγ. BrdU cell proliferation and Transwell assays were performed to determine cell proliferation and invasion. RESULTS: The expression of miR-130b in osteosarcoma tissues was significantly higher than that in normal tumor-adjacent tissues. Its expression in patients with metastasis was significantly higher than that in those without metastases. miR-130b expression in tumor tissues was significantly associated with tumor size, clinical stage and distant metastasis. And its expression was significantly correlated with overall survival and disease free survival. miR-130b overexpression obviously repressed the expression of PPARγ, and resulted in significant increase of Saos-2 cell proliferation and invasion. On the contrast, repressing miR-130b expression with its inhibitor significantly increased PPARγ expression, and inhibited MG-63 cell proliferation and invasion. CONCLUSIONS: The high-expression of miR-130b is correlated with the adverse clinicopathological features and poor prognosis in osteosarcoma. miR-130b may regulate proliferation and invasion of osteosarcoma cells by targeting PPARγ, suggesting miR-130b may play a key role in the progression of osteosarcoma.

Scaffold-free cartilage fabrication system using passaged porcine chondrocytes and basic fibroblast growth factor.

The scaffold-free cartilage fabrication system we have reported previously for human application with nonpassaged cells has a big limitation in securing the enough cell number. Therefore, autologous chondrocytes from small biopsy of cartilage tissue inevitably have to be expanded through multiple passages, which result in poor engineered cartilage in terms of quality and quantity. This study applied basic fibroblast growth factor (bFGF) to overcome the limitation and produce an engineered cartilage tissue with clinically applicable size and quality. Porcine articular chondrocytes were expanded until passage 2 in the absence or presence of 5 ng/mL bFGF, and then subjected to the two-stage scaffold-free cultures for 21 days again in the absence or presence of 5 ng/mL bFGF. The fabrication of cartilage tissues was evaluated along with time in comparison with the constructs from unpassaged chondrocytes. Expansion of chondrocytes in the presence of bFGF increased accumulation of cartilage extracellular matrices and resultantly fabricated the larger size of cartilage tissues in the subsequent stages, being comparable to those of unpassaged cells. In contrast, bFGF showed no positive, but adverse, effects on the cartilage tissue formation, when treated additionally during the scaffold-free fabrication stages. These results suggested that use of bFGF during the expansion stage of chondrocytes could overcome the limitation of previous two-stage scaffold-free cartilage fabrication system, and provided a novel three-stage system to construct a clinically applicable quality of cartilage tissues.