scholarly journals Challenges in Fabrication of Tissue-Engineered Cartilage with Correct Cellular Colonization and Extracellular Matrix Assembly

2018 ◽  
Vol 19 (9) ◽  
pp. 2700 ◽  
Author(s):  
Mikko Lammi ◽  
Juha Piltti ◽  
Juha Prittinen ◽  
Chengjuan Qu

A correct articular cartilage ultrastructure regarding its structural components and cellularity is important for appropriate performance of tissue-engineered articular cartilage. Various scaffold-based, as well as scaffold-free, culture models have been under development to manufacture functional cartilage tissue. Even decellularized tissues have been considered as a potential choice for cellular seeding and tissue fabrication. Pore size, interconnectivity, and functionalization of the scaffold architecture can be varied. Increased mechanical function requires a dense scaffold, which also easily restricts cellular access within the scaffold at seeding. High pore size enhances nutrient transport, while small pore size improves cellular interactions and scaffold resorption. In scaffold-free cultures, the cells assemble the tissue completely by themselves; in optimized cultures, they should be able to fabricate native-like tissue. Decellularized cartilage has a native ultrastructure, although it is a challenge to obtain proper cellular colonization during cell seeding. Bioprinting can, in principle, provide the tissue with correct cellularity and extracellular matrix content, although it is still an open question as to how the correct molecular interaction and structure of extracellular matrix could be achieved. These are challenges facing the ongoing efforts to manufacture optimal articular cartilage.

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Tongguang Xiao ◽  
Weimin Guo ◽  
Mingxue Chen ◽  
Chunxiang Hao ◽  
Shuang Gao ◽  
...  

The scaffold is a key element in cartilage tissue engineering. The components of Wharton’s jelly are similar to those of articular cartilage and it also contains some chondrogenic growth factors, such as insulin-like growth factor I and transforming growth factor-β. We fabricated a tissue-engineered cartilage scaffold derived from Wharton’s jelly extracellular matrix (WJECM) and compared it with a scaffold derived from articular cartilage ECM (ACECM) using freeze-drying. The results demonstrated that both WJECM and ACECM scaffolds possessed favorable pore sizes and porosities; moreover, they showed good water uptake ratios and compressive moduli. Histological staining confirmed that the WJECM and ACECM scaffolds contained similar ECM. Moreover, both scaffolds showed good cellular adherence, bioactivity, and biocompatibility. MTT and DNA content assessments confirmed that the ACECM scaffold tended to be more beneficial for improving cell proliferation than the WJECM scaffold. However, RT-qPCR results demonstrated that the WJECM scaffold was more favorable to enhance cellular chondrogenesis than the ACECM scaffold, showing more collagen II and aggrecan mRNA expression. These results were confirmed indirectly by glycosaminoglycan and collagen content assessments and partially confirmed by histology and immunofluorescent staining. In conclusion, these results suggest that a WJECM scaffold may be favorable for future cartilage tissue engineering.


2020 ◽  
Vol 35 (4-5) ◽  
pp. 471-484 ◽  
Author(s):  
Ângela Semitela ◽  
André F Girão ◽  
Carla Fernandes ◽  
Gonçalo Ramalho ◽  
Igor Bdikin ◽  
...  

Polycaprolactone (PCL) electrospun scaffolds have been widely investigated for cartilage repair application. However, their hydrophobicity and small pore size has been known to prevent cell attachment, proliferation and migration. Here, PCL was blended with gelatin (GEL) combining the favorable biological properties of GEL with the good mechanical performance of the former. Also, polyethylene glycol (PEG) particles were introduced during the electrospinning of the polymers blend by simultaneous electrospraying. These particles were subsequently removed resulting in fibrous scaffolds with enlarged pore size. PCL, GEL and PEG scaffolds formulations were developed and extensively structural and biologically characterized. GEL incorporation on the PCL scaffolds led to a considerably improved cell attachment and proliferation. A substantial pore size and interconnectivity increase was obtained, allowing cell infiltration through the porogenic scaffolds. All together these results suggest that this combined approach may provide a potentially clinically viable strategy for cartilage regeneration.


Author(s):  
Samuel C. Uzoechi ◽  
Kennedy O. Ejeta ◽  
Goddy C. Okoye ◽  
Gideon I. Ndubuka ◽  
Patrick Ugochukwu Agbasi ◽  
...  

Since articular cartilage is avascular, both nutrient supply and metabolic waste excretion depend on diffusion. However, the major cause of the progression of articular cartilage defect is the poor inherent regenerative capacity of chondrocytes which limits the process of cartilage tissue repair. Creation of nutrient gradients in in vitro cell culture, however, can provide a clue on zonal distributions of cells and glycosaminoglycan synthesis throughout the tissue engineered cartilage. We hypothesized that glucose gradient, in combination with growth factors, could induce differences in matrix distributions for articular cartilage regeneration. Chondrocytes were harvested from bovine cartilage and expanded in monolayers. First, either p0 or p2 chondrocytes were differentiated in serum-free chondrogenic medium containing different glucose concentrations supplemented with TGFβ3/dex or IGF-1under hypoxic or normoxic conditions for 7 days in monolayer. The results indicate that cellular metabolism, cell numbers and glycosaminoglycan (GAG) content increased with increase in glucose concentration in all conditions. Aggrecan (AGC) expression consistently increased with decreasing glucose concentration in both normoxic and hypoxic conditions. COL II and COL I expressions increased with increasing glucose concentration up to 5mmol/L. The expression of COMP increased with increasing glucose concentration under hypoxic conditions and interestingly showed an opposite trend under normoxic conditions. However, comparing the chondrogenic capacity of p0 and p2 cells in the different glucose concentrations did not show differences, but the potential of p2 cells was in general lower compared to p0. Hypoxia had stimulatory effects on matrix production compared to normoxia in both passages. Therefore, supplemented glucose concentration in monolayer could induce differences in matrix production, but the chondrogenic potential remained equal. Therefore, this information could be use to a create gradients through a tissue-engineered cartilage.


2020 ◽  
pp. 039139882095386
Author(s):  
Wenrun Zhu ◽  
Lu Cao ◽  
Chunfeng Song ◽  
Zhiying Pang ◽  
Haochen Jiang ◽  
...  

Articular cartilage repair remains a great clinical challenge. Tissue engineering approaches based on decellularized extracellular matrix (dECM) scaffolds show promise for facilitating articular cartilage repair. Traditional regenerative approaches currently used in clinical practice, such as microfracture, mosaicplasty, and autologous chondrocyte implantation, can improve cartilage repair and show therapeutic effect to some degree; however, the long-term curative effect is suboptimal. As dECM prepared by proper decellularization procedures is a biodegradable material, which provides space for regeneration tissue growth, possesses low immunogenicity, and retains most of its bioactive molecules that maintain tissue homeostasis and facilitate tissue repair, dECM scaffolds may provide a biomimetic microenvironment promoting cell attachment, proliferation, and chondrogenic differentiation. Currently, cell-derived dECM scaffolds have become a research hotspot in the field of cartilage tissue engineering, as ECM derived from cells cultured in vitro has many advantages compared with native cartilage ECM. This review describes cell types used to secrete ECM, methods of inducing cells to secrete cartilage-like ECM and decellularization methods to prepare cell-derived dECM. The potential mechanism of dECM scaffolds on cartilage repair, methods for improving the mechanical strength of cell-derived dECM scaffolds, and future perspectives on cell-derived dECM scaffolds are also discussed in this review.


2002 ◽  
Vol 50 (10) ◽  
pp. 1313-1323 ◽  
Author(s):  
Ghada A. Nofal ◽  
Cheryl B. Knudson

The proteoglycan-rich extracellular matrix (ECM) directly associated with the cells of articular cartilage is anchored to the chondrocyte plasma membrane via interaction with the hyaluronan receptor CD44. The cytoplasmic tail of CD44 interacts with the cortical cytoskeleton. The objective of this study was to determine the role of the actin cytoskeleton in CD44-mediated matrix assembly by chondrocytes and cartilage matrix retention and homeostasis. Adult bovine articular cartilage tissue slices and isolated chondrocytes were treated with latrunculin or cytochalasin. Tissues were processed for histology and chondrocytes were examined for CD44 expression and pericellular matrix assembly. Treatments that disrupt the actin cytoskeleton reduced chondrocyte pericellular matrix assembly and the retention of proteoglycan within cartilage explants. There was enhanced detection of a neoepitope resulting from proteolysis of aggrecan. Cytoskeletal disruption did not reduce CD44 expression, as monitored by flow cytometry, but detergent extraction of CD44 was enhanced and hyaluronan binding was decreased. Thus, disruption of the cytoskeleton reduces the anchorage of CD44 in the chondrocyte membrane and the capacity of CD44 to bind its ligand. The results suggest that cytoskeletal disruption within cartilage uncouples chondrocytes from the matrix, resulting in altered metabolism and deleterious changes in matrix structure.


Author(s):  
Yuta Takagi ◽  
Toshihiko Shiraishi ◽  
Shin Morishita ◽  
Ryohei Takeuchi ◽  
Tomoyuki Saito ◽  
...  

This paper describes the effects of vibration stimulation on chondrocytes in three-dimensional culture in relation to the production of regenerative cartilage tissue, using collagen artificial skin as a carrier and supplementation with hyaluronic acid (used in the conservative treatment of osteoarthritis), and the mechanism of the adaptive response of chondrocytes to mechanical loading. The experimental condition imitates an environment of articular cartilage in vivo that chondrocytes are completely surrounded by the extracellular matrix and receives mechanical stimulation for the weight-bearing mechanics. Chondrocytes were isolated from articular cartilage of porcine metatarsophalangeal joints. Experiments were performed under four different culture conditions: control condition, in which chondrocytes were cultured with atelocollagen gel and collagen artificial skins, and no vibration (HA−Vib−); HA−Vib+, in which chondrocytes were cultured in atelocollagen gel and collagen artificial skins with vibration treatment for 2 weeks; HA+Vib−, in which chondrocytes were cultured in medium containing 0.1% hyaluronic acid; and HA+Vib+, in which chondrocytes were cultured in medium containing 0.1% hyaluronic acid with vibration treatment for 2 weeks. Histologic analysis was conducted at 14 days of culture. The proliferation of chondrocytes was obtained by counting the number of cells with a hemocytometer after 3, 7, 10, and 14 days of culture. The expression of Sox 9 and β-catenin was detected by western blotting analysis. Sox 9 has been reported of involvement in transcription of type IX collagen that binds cartilage-specific type II collagen fibrils. β-catenin plays an important role of signaling pathways of cell proliferation although the relationship between β-catenin and mechanical vibration stimulation has not been clarified yet. The obtained results are as follows. The mechanical vibration enhanced the thickness of extracellular matrix of chondrocytes in histologic section at 14 days of culture and increased the expression of Sox 9. In addition, the mechanical vibration significantly increased the number of chondrocytes after 10 days of culture and promoted the expression of β-catenin. These results show that mechanical vibration promotes the matrix production and proliferation of chondrocytes and that a part of important signaling pathways in relation to mechanical vibration stimulation and proliferation of chondrocytes has been revealed.


2020 ◽  
Author(s):  
J E Dennis ◽  
G A Whitney ◽  
J Rai ◽  
R J Fernandes ◽  
T J Kean

AbstractCartilage tissue has been recalcitrant to tissue engineering approaches. In this study, human chondrocytes were formed into self-assembled cartilage sheets, cultured in physiologic (5%) and atmospheric (20%) oxygen conditions and underwent biochemical, histological and biomechanical analysis at one- and two-months. The results indicated that sheets formed at physiological oxygen tension were thicker, contained greater amounts of glycosaminoglycans (GAGs) and type II collagen, and had greater compressive and tensile properties than those cultured in atmospheric oxygen. In all cases, cartilage sheets stained throughout for extracellular matrix components. Type II-IX-XI collagen heteropolymer formed in the neo-cartilage and fibrils were stabilized by trivalent pyridinoline cross-links. Collagen cross-links were not significantly affected by oxygen tension but increased with time in culture. Physiological oxygen tension and longer culture periods both served to increase extracellular matrix components. The foremost correlation was found between compressive stiffness and the GAG to collagen ratio.SummaryTissue-engineered cartilage formed from human articular chondrocytes produces thicker, stiffer, more extracellular-matrix rich cartilage tissue when grown under physiological (5%) vs. atmospheric oxygen (20%) tension.


2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Eric Tong ◽  
Grace D. O'Connell ◽  
Terri-Ann N. Kelly ◽  
Clark T. Hung

Osteoarthritis, a chronic malady characterized by joint pain and swelling, is caused by damage to articular cartilage and is perpetuated by low-grade inflammation.  Treatments for osteoarthritis do exist, but many treatments focus on coping with the disease rather than curing it.  Surgical options that replace damaged cartilage tissue with that of donor cartilage tissue or cartilage tissue from other parts of articular joints face complications especially when the tissue is not of the correct size or does not have native-like properties. A more suitable treatment option for osteoarthritis is to develop an in vitro tissue-engineered cartilage construct that can be grown using the patient’s own cells and to surgically remove the patient’s damaged cartilage and replace it with the tissue-engineered cartilage. A challenge in developing such a treatment option is producing tissue-engineered cartilage with mechanical properties akin to those of native human articular cartilage. This challenge may be overcome by maximizing the production of type II collagen by the chondrocytes in vitro. One way to maximize collagen production is through the application of chondroitinase ABC, an enzyme which temporarily suppresses proteoglycans in the cartilage matrix to create more space for type II collagen to develop. In this study, two two levels of cABC treatment were applied (“high” and “low”) to cartilage tissue constructs. The “low” cABC treated group received daily feeding of 0.075 U/mL from day 14 to 21 followed by a replacement of chondrogenic media without cABC.  The “high” cABC treated group received a single addition of 0.15 U/mL from day 14 to 16 followed by a replacement of chondrogenic media without cABC.  At the end of 42 days, the constructs were subjected to mechanical testing and biochemical analyses. These analyses showed that the high cABC treatment yielded more native-like mechanical properties when compared to the low cABC treatment and the control results.  Biochemical and histological analyses confirmed that the proteoglycan and collagen II content were higher in the low and high cABC treated groups when compared to the control. All analyses show that the most efficient application of chondroitinase ABC is through a two day duration treatment of a higher concentration (0.15 U/mL).


2007 ◽  
Vol 35 (4) ◽  
pp. 677-679 ◽  
Author(s):  
M. Plainfossé ◽  
P.V. Hatton ◽  
A. Crawford ◽  
Z.M. Jin ◽  
J. Fisher

Low-friction surfaces are critical for efficient joint articulation. The tribological properties of articular cartilage have been studied extensively in native tissue and joints. Despite their importance, very few studies have examined the frictional properties of tissue-engineered cartilage. We have therefore reviewed the relationship between composition, structure and friction in tissue-engineered cartilage.


Author(s):  
Chen-Yuan Chung ◽  
Mostafa Motavalli ◽  
Joseph M. Mansour

Articular cartilage is a hydrated connective tissue consisting of a relatively small number of chondrocytes surrounded by a saturated extracellular matrix comprised mainly of type-II collagen fibrils and proteoglycans. As a deformable fluid saturated material, cartilage is most often modeled using biphasic or poroelastic theories [1,2]. The ultimate goal of this work is to evaluate biomechanical properties of native and tissue engineered cartilage under combined compression and shear. The purpose of this investigation was to determine stress and deformation fields in cartilage under compression and simple shear and relate these to measured results.


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