scholarly journals BENEFICIAL EFFECTS OF EXOGENOUS CROSSLINKING AGENTS ON SELF-ASSEMBLED TISSUE ENGINEERED CARTILAGE CONSTRUCT BIOMECHANICAL PROPERTIES

2011 ◽  
Vol 11 (02) ◽  
pp. 433-443 ◽  
Author(s):  
BENJAMIN D. ELDER ◽  
ARVIND MOHAN ◽  
KYRIACOS A. ATHANASIOU

Background. As articular cartilage is unable to repair itself, there is a tremendous clinical need for a tissue engineered replacement tissue. Current tissue engineering efforts using the self-assembly process have demonstrated promising results, but the biomechanical properties remain at roughly 50% of native tissue. Methodology/Principal Findings. The objective of this study was to determine the feasibility of using exogenous crosslinking agents to enhance the biomechanical properties of a scaffoldless cartilage tissue engineering approach. Four crosslinking agents (glutaraldehyde, ribose, genipin, and methylglyoxal) were applied each at a single concentration and single application time. It was determined that ribose application resulted in a significant 69% increase in Young's modulus, a significant 47% increase in ultimate tensile strength, as well as a trend toward a significant increase in aggregate modulus. Additionally, methylglyoxal application resulted in a significant 58% increase in Young's modulus. No treatments altered the biochemical content of the tissue. Conclusions/Significance. To our knowledge, this is the first study to examine the use of exogenous crosslinking agents on any tissue formed using a scaffoldless tissue engineering approach. In particular, this study demonstrates that a one-time treatment with crosslinking agents can be employed effectively to enhance the biomechanical properties of tissue engineered articular cartilage. The results are exciting, as they demonstrate the feasibility of using exogenous crosslinking agents to enhance the biomechanical properties without the need for increased glycosaminoglycan (GAG) and collagen content.

2021 ◽  
Vol 57 (4) ◽  
pp. 166-180
Author(s):  
Maria-Minodora Marin ◽  
Madalina Georgiana Albu Kaya ◽  
George Mihail Vlasceanu ◽  
Jana Ghitman ◽  
Ionut Cristian Radu ◽  
...  

Type II collagen has been perceived as the indispensable element and plays a crucial role in cartilage tissue engineering. Thus, materials based on type II collagen have drawn farther attention in both academic and research for developing new systems for the cartilage regeneration. The disadvantage of using type II collagen as a biomaterial for tissue repairing is its reduced biomechanical properties. This can be solved by physical, enzymatic or chemical cross-linking processes, which provide biomaterials with the required mechanical properties for medical applications. To enhance type II collagen properties, crosslinked collagen scaffolds with different cross-linking agents were prepared by freeze-drying technique. The present research work studied the synthesis of type II collagen biomaterials with and without crosslinking agents. Scaffolds morphology was observed by MicroCT, showing in all cases an appropriate microstructure for biological applications, and the mechanical studies were performed using compressive tests. DSC showed an increase in denaturation temperature with an increase in cross-linking agent concentration. FTIR suggested that the secondary structure of collagen is not affected after the cross-linking; supplementary, to confirm the characteristic triple-helix conformation of collagen, the CD investigation was performed. The results showed that the physical-chemical properties of type II collagen were improved by cross-linking treatments.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Stefano Focaroli ◽  
Gabriella Teti ◽  
Viviana Salvatore ◽  
Isabella Orienti ◽  
Mirella Falconi

Articular cartilage is a highly organized tissue with complex biomechanical properties. However, injuries to the cartilage usually lead to numerous health concerns and often culminate in disabling symptoms, due to the poor intrinsic capacity of this tissue for self-healing. Although various approaches are proposed for the regeneration of cartilage, its repair still represents an enormous challenge for orthopedic surgeons. The field of tissue engineering currently offers some of the most promising strategies for cartilage restoration, in which assorted biomaterials and cell-based therapies are combined to develop new therapeutic regimens for tissue replacement. The current study describes thein vitrobehavior of human adipose-derived mesenchymal stem cells (hADSCs) encapsulated within calcium/cobalt (Ca/Co) alginate beads. These novel chondrogenesis-promoting scaffolds take advantage of the synergy between the alginate matrix and Co+2ions, without employing costly growth factors (e.g., transforming growth factor betas (TGF-βs) or bone morphogenetic proteins (BMPs)) to direct hADSC differentiation into cartilage-producing chondrocytes.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4199
Author(s):  
Mahshid Hafezi ◽  
Saied Nouri Khorasani ◽  
Mohadeseh Zare ◽  
Rasoul Esmaeely Neisiany ◽  
Pooya Davoodi

Cartilage is a tension- and load-bearing tissue and has a limited capacity for intrinsic self-healing. While microfracture and arthroplasty are the conventional methods for cartilage repair, these methods are unable to completely heal the damaged tissue. The need to overcome the restrictions of these therapies for cartilage regeneration has expanded the field of cartilage tissue engineering (CTE), in which novel engineering and biological approaches are introduced to accelerate the development of new biomimetic cartilage to replace the injured tissue. Until now, a wide range of hydrogels and cell sources have been employed for CTE to either recapitulate microenvironmental cues during a new tissue growth or to compel the recovery of cartilaginous structures via manipulating biochemical and biomechanical properties of the original tissue. Towards modifying current cartilage treatments, advanced hydrogels have been designed and synthesized in recent years to improve network crosslinking and self-recovery of implanted scaffolds after damage in vivo. This review focused on the recent advances in CTE, especially self-healing hydrogels. The article firstly presents the cartilage tissue, its defects, and treatments. Subsequently, introduces CTE and summarizes the polymeric hydrogels and their advances. Furthermore, characterizations, the advantages, and disadvantages of advanced hydrogels such as multi-materials, IPNs, nanomaterials, and supramolecular are discussed. Afterward, the self-healing hydrogels in CTE, mechanisms, and the physical and chemical methods for the synthesis of such hydrogels for improving the reformation of CTE are introduced. The article then briefly describes the fabrication methods in CTE. Finally, this review presents a conclusion of prevalent challenges and future outlooks for self-healing hydrogels in CTE applications.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Er-Yuan Chuang ◽  
Chih-Wei Chiang ◽  
Pei-Chun Wong ◽  
Chih-Hwa Chen

The treatment of articular cartilage damage is a major task in the medical science of orthopedics. Hydrogels possess the ability to form multifunctional cartilage grafts since they possess polymeric swellability upon immersion in an aqueous phase. Polymeric hydrogels are capable of physiological swelling and greasing, and they possess the mechanical behavior required for use as articular cartilage substitutes. The chondrogenic phenotype of these materials may be enhanced by embedding living cells. Artificial hydrogels fabricated from biologically derived and synthesized polymeric materials are also used as tissue-engineering scaffolds; with their controlled degradation profiles, the release of stimulatory growth factors can be achieved. In order to make use of these hydrogels, cartilage implants were formulated in the laboratory to demonstrate the bionic mechanical behaviors of physiological cartilage. This paper discusses developments concerning the use of polymeric hydrogels for substituting injured cartilage tissue and assisting tissue growth. These gels are designed with consideration of their polymeric classification, mechanical strength, manner of biodegradation, limitations of the payload, cellular interaction, amount of cells in the 3D hydrogel, sustained release for the model drug, and the different approaches for incorporation into adjacent organs. This article also summarizes the different advantages, disadvantages, and the future prospects of hydrogels.


Cartilage ◽  
2020 ◽  
pp. 194760352097324
Author(s):  
Wassif Kabir ◽  
Claudia Di Bella ◽  
Peter F.M. Choong ◽  
Cathal D. O’Connell

Objectives Recapitulating the mechanical properties of articular cartilage (AC) is vital to facilitate the clinical translation of cartilage tissue engineering. Prior to evaluation of tissue-engineered constructs, it is fundamental to investigate the biomechanical properties of native AC under sudden, prolonged, and cyclic loads in a practical manner. However, previous studies have typically reported only the response of native AC to one or other of these loading regimes. We therefore developed a streamlined testing protocol to characterize the elastic and viscoelastic properties of human knee AC, generating values for several important parameters from the same sample. Design Human AC was harvested from macroscopically normal regions of distal femoral condyles of patients ( n = 3) undergoing total knee arthroplasty. Indentation and unconfined compression tests were conducted under physiological conditions (temperature 37 °C and pH 7.4) and testing parameters (strain rates and loading frequency) to assess elastic and viscoelastic parameters. Results The biomechanical properties obtained were as follows: Poisson ratio (0.4 ± 0.1), instantaneous modulus (52.14 ± 9.47 MPa) at a loading rate of 1 mm/s, Young’s modulus (1.03 ± 0.48 MPa), equilibrium modulus (7.48 ± 4.42 MPa), compressive modulus (10.60 ± 3.62 MPa), dynamic modulus (7.71 ± 4.62 MPa) at 1 Hz and loss factor (0.11 ± 0.02). Conclusions The measurements fell within the range of reported values for human knee AC biomechanics. To the authors’ knowledge this study is the first to report such a range of biomechanical properties for human distal femoral AC. This protocol may facilitate the assessment of tissue-engineered composites for their functionality and biomechanical similarity to native AC prior to clinical trials.


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