scholarly journals Hydrogels with differentiation inducers-loaded nano-boxes for simultaneous subchondral bone and cartilage regeneration

2020 ◽  
Vol 28 ◽  
pp. S524
Author(s):  
A.S. Mao ◽  
X. Liu ◽  
X. Shi
2008 ◽  
Vol 36 (12) ◽  
pp. 2379-2391 ◽  
Author(s):  
Karin Schlichting ◽  
Hanna Schell ◽  
Ralf U. Kleemann ◽  
Alexander Schill ◽  
Andreas Weiler ◽  
...  

Background In osteochondral defects, subchondral bone, as a load-bearing structure, is believed to be important for bone and cartilage regeneration. Hypothesis A stiff scaffold creates better conditions for bone formation and cartilage regeneration than does a softer one. Study Design Controlled laboratory study. Methods Critical osteochondral defects were created in the femoral condyles of 24 sheep. Subchondral bone was reconstructed with a stiff scaffold or a modified softer one, with untreated defects serving as controls. The repair response was evaluated with mechanical, histological, and histomorphometrical techniques at 3 and 6 months postoperatively. Results The elastic modulus of regenerated fibrocartilage over the stiff scaffold tended to be higher than in the soft scaffold group (61 % vs 46% of healthy cartilage) at 3 months. No difference was determined at 6 months; all were well below healthy cartilage. Treated defects showed substantial degradation of the soft scaffold with surrounding sclerotic bone at 3 and 6 months. In contrast, degradation of the stiff scaffold was slower and occurred together with continuous osseous replacement. Conclusion Stiff scaffolds were found to improve bone regeneration. In contrast, soft scaffolds provided less support, and consequently subchondral bone became sclerotic. Although regenerated cartilage formed over the stiff scaffolds at 3 months, and these exhibited better mechanical properties than did the soft scaffold group, the mechanical properties in both treated groups were the same at 6 months, not dissimilar to that of tissue formed in the untreated specimens and inferior to native articular cartilage. Clinical Relevance The results imply that subchondral defect filling in clinical settings advances bone regeneration and should have a comparable stiffness to that of healthy subchondral bone rather than being too flexible. Degradation of resorbable materials and consequently the loss of stiffness may compromise the healing of critical defects.


Cartilage ◽  
2020 ◽  
pp. 194760352098016
Author(s):  
Sampath Samuel Joshua Pragasam ◽  
Vijayalakshmi Venkatesan

Objective The present study aims to assess for temporal changes in tibial subchondral bone and cartilage in WNIN/Gr-Ob rats (portraying obesity, insulin resistance, dyslipidemia, impaired glucose tolerance, hypertension) in comparison with Wistar controls (WNIN) using anthropometry, micro-computed tomography (micro-CT), scanning electron microscopy (SEM), histopathology, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence. Design Body weight, abdominal circumference, body mass index (BMI), lean/fat mass, serum tumor necrosis factor (TNF)-α levels were measured (ELISA), followed by ultrastructural analysis of tibial subchondral bone (micro-CT) and cartilage architecture (histopathology and SEM) in WNIN/Gr-Ob and WNIN rats with age (3, 6 and 9 months). Additionally, primary cultures of articular chondrocytes isolated from 6-month-old WNIN/Gr-Ob and WNIN rats were assessed for matrix metalloproteinase (MMP)-13 and Collagen type II (COL2A1) by immunofluorescence. Results WNIN/Gr-Ob rats exhibited frank obesity with increased BMI, lean and fat mass vis-à-vis significantly higher levels of serum TNF-α (6>9>3 months) as compared with the controls. With an increase in BMI, WNIN/Gr-Ob rats presented with tibial cartilage fibrillation, erosion, osteophyte formation (6 months) and subchondral bone cyst (9 months) confirmed by histology and SEM. An increase in subchondral trabecular bone volume (sclerosis with decreased plate porosity) was observed in all ages in WNIN/Gr-Ob rats compared to their Control. Gaining insights, primary cultures of articular chondrocytes complemented with altered cellular expressions of COL2A1 and MMP-13 from WNIN/Gr-Ob rats, indicating osteoarthritis (OA) progression. Conclusion Multiple metabolic perturbations featured in WNIN/Gr-Ob rats were effective to induce spontaneous OA-like degenerative changes affecting knee joints akin to human OA.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wei Lin ◽  
Huijun Kang ◽  
Yike Dai ◽  
Yingzhen Niu ◽  
Guangmin Yang ◽  
...  

Abstract Background Patellar instability (PI) often increases the possibility of lateral patellar dislocation and early osteoarthritis. The molecular mechanism of early articular cartilage degeneration during patellofemoral osteoarthritis (PFOA) still requires further investigation. However, it is known that the NF-κB signaling pathway plays an important role in articular cartilage degeneration. The aim of this study was to investigate the relationship between the NF-κB signaling pathway and patellofemoral joint cartilage degeneration. Methods We established a rat model of PI-induced PFOA. Female 4-week-old Sprague-Dawley rats (n = 120) were randomly divided into two groups: the PI (n = 60) and control group (n = 60). The distal femurs of the PI and control group were isolated and compared 4, 8, and 12 weeks after surgery. The morphological structure of the trochlear cartilage and subchondral bone were evaluated by micro-computed tomography and histology. The expression of NF-κB, matrix metalloproteinase (MMP)-13, collagen X, and TNF-ɑ were evaluated by immunohistochemistry and quantitative polymerase chain reaction. Results In the PI group, subchondral bone loss and cartilage degeneration were found 4 weeks after surgery. Compared with the control group, the protein and mRNA expression of NF-κB and TNF-ɑ were significantly increased 4, 8, and 12 weeks after surgery in the PI group. In addition, the markers of cartilage degeneration MMP-13 and collagen X were more highly expressed in the PI group compared with the control group at different time points after surgery. Conclusions This study has demonstrated that early patellofemoral joint cartilage degeneration can be caused by PI in growing rats, accompanied by significant subchondral bone loss and cartilage degeneration. In addition, the degeneration of articular cartilage may be associated with the activation of the NF-κB signaling pathway and can deteriorate with time as a result of PI.


2018 ◽  
Vol 39 (8) ◽  
pp. 908-915 ◽  
Author(s):  
Tomoyuki Nakasa ◽  
Yasunari Ikuta ◽  
Mikiya Sawa ◽  
Masahiro Yoshikawa ◽  
Yusuke Tsuyuguchi ◽  
...  

Background: In the evaluation of osteochondral lesions of the talar dome (OLT), bone marrow lesions (BML) are commonly observed in the subchondral bone on magnetic resonance imaging (MRI). However, the significance of BML, such as the histology of the overlying cartilage, is still unclear. The purpose of this study was to investigate the relationship between the BML and cartilage degeneration in OLT. Methods: Thirty-three ankles with OLT were included in this study. All ankles underwent CT and MRI and had operative treatment. The ankles were divided into 2 groups, depending on the presence of bone sclerosis (ie, with or without) in the host bone just below the osteochondral fragment (nonsclerosis group and sclerosis group). The area of BML was compared between the 2 groups. Biopsies of the osteochondral fragment from 20 ankles were performed during surgery, and the correlation between the BML and cartilage degeneration was analyzed. The remaining 13 ankles had the CT and MRI compared with the arthroscopic findings. Results: The mean area of BML in the nonsclerosis group was significantly larger than that in the sclerosis group. In the histologic analysis, there was a significant and moderate correlation between the Mankin score and the area of BML. The mean Mankin score in the nonsclerosis group was significantly lower than that in the sclerosis group. Conclusions: This study revealed that a large area of BML on MRI exhibited low degeneration of cartilage of the osteochondral fragment, while a small area of BML indicated sclerosis of the subchondral bone with severe degeneration of cartilage. The evaluation of BML may predict the cartilage condition of the osteochondral fragment. Level of Evidence: Level III, comparative series.


Author(s):  
Nynke B. Rooks ◽  
Marco T. Y. Schneider ◽  
Ahmet Erdemir ◽  
Jason P. Halloran ◽  
Peter J. Laz ◽  
...  

Abstract Accurately capturing the bone and cartilage morphology and generating a mesh remains a critical step in the workflow of computational knee joint modeling. Currently there is no standardized method to compare meshes of different element types and nodal densities, making comparisons across research teams a significant challenge. The aim of this paper is to describe a method to quantify differences in knee joint bone and cartilages meshes, independent of bone and cartilage mesh topology. Bone mesh-to-mesh distances, subchondral bone boundaries and cartilage thicknesses from meshes of any type of mesh are obtained using a series of steps involving registration, resampling, and radial basis function fitting after which the comparisons are performed. Subchondral bone boundaries and cartilage thicknesses are calculated and visualized in a common frame of reference for comparison. The established method is applied to models developed by five modeling teams. Our approach to obtain bone mesh-to-mesh distances decreased the divergence seen in selecting a reference mesh (i.e. comparing mesh A-to-B vs. mesh B-to-A). In general the bone morphology was similar across teams. The cartilage thicknesses for all models were calculated and the mean absolute cartilage thickness difference was presented, the articulating areas had the best agreement across teams. The teams showed disagreement on the subchondral bone boundaries. The method presented in this paper allows for objective comparisons of bone and cartilage geometry that is agnostic to mesh type and nodal density.


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