scholarly journals Elastic, Dynamic Viscoelastic and Model-Derived Fibril-Reinforced Poroelastic Mechanical Properties of Normal and Osteoarthritic Human Femoral Condyle Cartilage

2021 ◽  
Author(s):  
Mohammadhossein Ebrahimi ◽  
Mikko A. J. Finnilä ◽  
Aleksandra Turkiewicz ◽  
Martin Englund ◽  
Simo Saarakkala ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Computational Models ◽  
Human Subjects ◽  
Femoral Condyle ◽  
Cartilage Tissue Engineering ◽  
Cartilage Degradation ◽  
Cartilage Tissue ◽  
Joint Models ◽  
Patellar Cartilage ◽  
Relaxation Measurements

AbstractOsteoarthritis (OA) degrades articular cartilage and weakens its function. Modern fibril-reinforced poroelastic (FRPE) computational models can distinguish the mechanical properties of main cartilage constituents, namely collagen, proteoglycans, and fluid, thus, they can precisely characterize the complex mechanical behavior of the tissue. However, these properties are not known for human femoral condyle cartilage. Therefore, we aimed to characterize them from human subjects undergoing knee replacement and from deceased donors without known OA. Multi-step stress-relaxation measurements coupled with sample-specific finite element analyses were conducted to obtain the FRPE material properties. Samples were graded using OARSI scoring to determine the severity of histopathological cartilage degradation. The results suggest that alterations in the FRPE properties are not evident in the moderate stages of cartilage degradation (OARSI 2-3) as compared with normal tissue (OARSI 0-1). Drastic deterioration of the FRPE properties was observed in severely degraded cartilage (OARSI 4). We also found that the FRPE properties of femoral condyle cartilage related to the collagen network (initial fibril-network modulus) and proteoglycan matrix (non-fibrillar matrix modulus) were greater compared to tibial and patellar cartilage in OA. These findings may inform cartilage tissue-engineering efforts and help to improve the accuracy of cartilage representations in computational knee joint models.

Dynamic Culture Improves Mechanical Functionality of MSC-Laden Tissue Engineered Constructs in a Depth-Dependent Manner

2011 ◽  
Author(s):  
Megan J. Farrell ◽  
Eric S. Comeau ◽  
Robert L. Mauck
Keyword(s):  
Mechanical Properties ◽  
Local Equilibrium ◽  
Cartilage Tissue Engineering ◽  
Three Dimensional ◽  
Nutrient Supply ◽  
Cartilage Tissue ◽  
Dependent Manner ◽  
Depth Dependence ◽  
Dynamic Culture ◽  
The Impact

Limitations associated with the use of autologous chondrocytes (CH) for cartilage tissue engineering beget the need for alternative cell sources. Mesenchymal stem cells (MSC) are clinically attractive due to their ability to undergo chondrogenesis in three-dimensional culture [1,2]; however, when compared to CH, MSC fail to develop functional equivalence [2,3]. We have previously shown a marked depth-dependence in local equilibrium modulus of MSC-laden gels, with the superficial zones (where maximal media exchange occurs) considerably stiffer than regions removed from nutrient supply (center and bottom of construct); less dramatic depth-dependence was observed in CH-laden gels [4]. Similarly, other studies have shown depth-dependent properties in CH-laden gels with the construct edge generally stiffer than the center [5]. Given this apparent influence of nutrient supply, the objective of the current study was to assess the impact of dynamic culture (via orbital shaking) on the development of depth-dependent mechanical properties in both MSC and CH-laden hydrogels. Furthermore, we assessed cell viability and matrix content throughout the construct depth to determine the mechanism by which this depth-dependency arises. We hypothesized that improved nutrient transport would reduce construct inhomogeneity (particularly for MSC-laden constructs) and improve bulk mechanical properties.

Polyethylene glycol diacrylate scaffold filled with cell-laden methacrylamide gelatin/alginate hydrogels used for cartilage repair

2021 ◽  
pp. 088532822110448
Author(s):  
Xiang Zhang ◽  
Zhenhao Yan ◽  
Guotao Guan ◽  
Zijing Lu ◽  
Shujie Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Polyethylene Glycol ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
High Concentration ◽  
Polyethylene Glycol Diacrylate ◽  
Low Concentration ◽  
Glycol Diacrylate

Natural cartilage tissue has excellent mechanical properties and has certain cellular components. At this stage, it is a great challenge to produce cartilage scaffolds with excellent mechanical properties, biocompatibility, and biodegradability. Hydrogels are commonly used in tissue engineering because of their excellent biocompatibility; however, the mechanical properties of commonly used hydrogels are difficult to meet the requirements of making cartilage scaffolds. The mechanical properties of high concentration polyethylene glycol diacrylate (PEGDA) hydrogel are similar to those of natural cartilage, but its biocompatibility is poor. Low concentration hydrogel has better biocompatibility, but its mechanical properties are poor. In this study, two different hydrogels were combined to produce cartilage scaffolds with good mechanical properties and strong biocompatibility. First, the PEGDA grid scaffold was printed with light curing 3D printing technology, and then the low concentration GelMA/Alginate hydrogel with chondral cells was filled into the PEGDA grid scaffold. After a series of cell experiments, the filling hydrogel with the best biocompatibility was screened out, and finally the filled hydrogel with cells and excellent biocompatibility was obtained. Cartilage tissue engineering scaffolds with certain mechanical properties were found to have a tendency of cartilage formation in in vitro culture. Compared with the scaffold obtained by using a single hydrogel, this molding method can produce a tissue engineering scaffold with excellent mechanical properties on the premise of ensuring biocompatibility, which has a certain potential application value in the field of cartilage tissue engineering.

scholarly journals Injectable Thermosensitive Chitosan/Pullulan-Based Hydrogels with Improved Mechanical Properties and Swelling Capacity

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2514 ◽  
Author(s):  
Prakasit Panyamao ◽  
Warintorn Ruksiriwanich ◽  
Panee Sirisa-ard ◽  
Suporn Charumanee
Keyword(s):  
Mechanical Properties ◽  
Sol Gel ◽  
Cartilage Tissue Engineering ◽  
Viscoelastic Behavior ◽  
Cartilage Tissue ◽  
Solution Temperature ◽  
Scanning Electron Micrographs ◽  
Interpenetrating Networks ◽  
Swelling Capacity

Thermosensitive chitosan/β-glycerophosphate (CS/BGP) systems have been developed as injectable hydrogels. However, the hydrogels exhibited poor mechanical properties due to their physically crosslinked networks. In this work, CS/BGP hydrogels were reinforced by covalent crosslinking using genipin (GE) and concomitantly semi-interpenetrating networks using pullulan (PL). Based on response surface methodology, the optimized formulation was composed of CS (1.05%, w/v), PL (1%, w/v), BGP (6%, w/v), and GE (70.79 mcg/mL). The optimized hydrogels exhibited Young’s modulus of 92.65 ± 4.13 kPa and a percentage of equilibrium swelling ratio of 3259.09% ± 58.90%. Scanning electron micrographs revealed a highly porous structure with nanofibrous networks in the CS/PL/BGP/GE hydrogels. The chemical interactions between the compositions were investigated by Fourier-transform infrared spectroscopy. Rheological measurements illustrated that the optimized hydrogels displayed sol–gel transition within one minute at 37 °C, a lower critical solution temperature of about 31 °C, and viscoelastic behavior with high storage modulus. Furthermore, the optimized hydrogels demonstrated higher resistance to in vitro enzymatic degradation, compared to the hydrogels without GE. Our findings could suggest that the thermosensitive CS/PL/BGP/GE hydrogels with enhanced mechanical properties and swelling capacity demonstrate the potential for use as scaffolds and carriers for cartilage tissue engineering and drug delivery applications.

scholarly journals PLGA/COL I Composite Scaffold Printed by a Low-temperature Deposition Manufacturing Technique for Application to Cartilage Tissue Engineering

2020 ◽  
Author(s):  
Liangquan Peng ◽  
Yong He ◽  
Weimin Zhu ◽  
Wei Lu ◽  
Yong Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Low Temperature ◽  
Composite Scaffold ◽  
Cartilage Tissue Engineering ◽  
Three Dimensional ◽  
Cartilage Tissue ◽  
Composite Scaffolds ◽  
Low Temperature Deposition ◽  
Temperature Deposition

Abstract Background Composite scaffolds of poly(lactic-co-glycolic acid) (PLGA) and PLGA/COL I were developed by a low-temperature deposition manufacturing (LDM) technique using three-dimensional printing technology. Their physical properties were tested, and the scaffolds were then used as cell culture platforms to prepare an ideal scaffold for cartilage tissue engineering. Methods The LDM technique was used to fabricate PLGA and PLGA/COL I composite scaffolds. The macrostructure, micromorphology, porosity, hydrophobicity, mechanical properties, and chemical structure of these scaffolds were examined. Primary chondrocytes were isolated and identified, second-passage cells were seeded onto the two scaffolds, and the adhesion and proliferation of the cells were determined. Results Both the PLGA and PLGA/COL I scaffolds prepared by LDM displayed a regular three-dimensional structure with high porosity. The PLGA scaffold had better mechanical properties than the PLGA/COL I scaffold, while the latter had significantly higher hydrophilicity than the former. The PLGA/COL I scaffold cultured with chondrocytes exhibited a higher adhesion rate and proliferation rate than the PLGA/COL I scaffold. Conclusion The novel PLGA/COL I composite scaffold printed by the LDM technique exhibited favourable biocompatibility and biomechanical characteristics and could be a good candidate for cartilage tissue engineering.

scholarly journals A Hyaluronic Acid Based Injectable Hydrogel Formed via Photo-Crosslinking Reaction and Thermal-Induced Diels-Alder Reaction for Cartilage Tissue Engineering

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 949 ◽  
Author(s):  
Gang Wang ◽  
Xiaodong Cao ◽  
Hua Dong ◽  
Lei Zeng ◽  
Chenxi Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Hyaluronic Acid ◽  
Cell Activity ◽  
Cartilage Tissue Engineering ◽  
Diels Alder ◽  
Cartilage Tissue ◽  
Good Prospect ◽  
Crosslinking Reaction ◽  
Injectable Hydrogel

A hyaluronic acid (HA) based injectable hydrogel with gradually increasing mechanical properties was synthesized via photo-crosslinking reaction and thermal-induced Diels-Alder (DA) reaction. The injectable hydrogel can quickly gelate within 30 s by photo-crosslinking of HA-furan under the catalysis of lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP). This injectable property is beneficial to keep the encapsulated cell activity and convenient for clinical operation. And the mechanical properties can be control from 4.86 to 10.66 kPa by exposure time. Then, the thermal-induced DA click chemistry further occurs between furan groups and maleimide groups which gradually promoted the crosslinking density of the injectable hydrogel. The mechanical properties of the injectable hydrogel can be promoted to 21 kPa. ATDC-5 cells were successfully encapsulated in the injectable hydrogel and showed good activity. All the results suggested that the injectable hydrogel with gradually increasing mechanical properties formed by photo-crosslinking reaction and thermal-induced DA reaction has a good prospect of application in cartilage tissue engineering.

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