scholarly journals Combining Innovative Bioink and Low Cell Density for the Production of 3D-Bioprinted Cartilage Substitutes: A Pilot Study

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Christel Henrionnet ◽  
Léa Pourchet ◽  
Paul Neybecker ◽  
Océane Messaoudi ◽  
Pierre Gillet ◽  
...  

3D bioprinting offers interesting opportunities for 3D tissue printing by providing living cells with appropriate scaffolds with a dedicated structure. Biological advances in bioinks are currently promising for cell encapsulation, particularly that of mesenchymal stem cells (MSCs). We present herein the development of cartilage implants by 3D bioprinting that deliver MSCs encapsulated in an original bioink at low concentration. 3D-bioprinted constructs (10×10×4 mm) were printed using alginate/gelatin/fibrinogen bioink mixed with human bone marrow MSCs. The influence of the bioprinting process and chondrogenic differentiation on MSC metabolism, gene profiles, and extracellular matrix (ECM) production at two different MSC concentrations (1 million or 2 million cells/mL) was assessed on day 28 (D28) by using MTT tests, real-time RT-PCR, and histology and immunohistochemistry, respectively. Then, the effect of the environment (growth factors such as TGF-β1/3 and/or BMP2 and oxygen tension) on chondrogenicity was evaluated at a 1 M cell/mL concentration on D28 and D56 by measuring mitochondrial activity, chondrogenic gene expression, and the quality of cartilaginous matrix synthesis. We confirmed the safety of bioextrusion and gelation at concentrations of 1 million and 2 million MSC/mL in terms of cellular metabolism. The chondrogenic effect of TGF-β1 was verified within the substitute on D28 by measuring chondrogenic gene expression and ECM synthesis (glycosaminoglycans and type II collagen) on D28. The 1 M concentration represented the best compromise. We then evaluated the influence of various environmental factors on the substitutes on D28 (differentiation) and D56 (synthesis). Chondrogenic gene expression was maximal on D28 under the influence of TGF-β1 or TGF-β3 either alone or in combination with BMP-2. Hypoxia suppressed the expression of hypertrophic and osteogenic genes. ECM synthesis was maximal on D56 for both glycosaminoglycans and type II collagen, particularly in the presence of a combination of TGF-β1 and BMP-2. Continuous hypoxia did not influence matrix synthesis but significantly reduced the appearance of microcalcifications within the extracellular matrix. The described strategy is very promising for 3D bioprinting by the bioextrusion of an original bioink containing a low concentration of MSCs followed by the culture of the substitutes in hypoxic conditions under the combined influence of TGF-β1 and BMP-2.

Author(s):  
Christel Henrionnet ◽  
Océane Messaoudi ◽  
Léa Pourchet ◽  
Pierre Gillet ◽  
Damien Loeuille ◽  
...  

Background: 3D printing has become a promising tool for cartilage engineering, combining 3D deposition of cells seeded in supporting biomaterials. Objective: Our goal was to evaluate the chondrogenic properties of three different bioinks, seeded with human bone marrow mesenchymal stem cells (bMSCs). Methods: The three different tested bioinks are seeded with 2 × 106 cells/mL bMSCs. The bioink#1 is composed of gelatin, fibrinogen, and very low viscosity alginate. The bioink#2 has the same composition, excepted for the alginate that is a low viscosity one. The bioink#3 is manufactured by CELLINK®. The cartilaginous substitutes were cultivated for 28 days in the presence of ITS vs TGF-ß1. The extracellular matrix synthesis is evaluated at D28 by histology (Hematoxylin-Eosin-Saffron & Alcian Blue) and immunostaining (type II collagen). Results: The bioink#1 better promoted type II collagen synthesis, although the three bioink were equipotent in terms of proteoglycan content. Despite its universal characteristics, the bioink#3 failed to encourage the hyaline-like matrix synthesis. Conclusion: The bioink#1 containing gelatin, fibrinogen, and very low viscosity seems to be the fittest of the three bio-inks to obtain a cartilaginous substitute presenting a remarkable matrix synthesis. This study confirms the importance of the choice of bioink for cartilage engineering.


2018 ◽  
Vol 206 (1-2) ◽  
pp. 73-81 ◽  
Author(s):  
Xue Yin ◽  
Silvia  Gonzales ◽  
Somya Sha ◽  
Howard Levene ◽  
Chun-Yuh Huang

Compressive loading promotes adenosine triphosphate (ATP) production and release by intervertebral disc (IVD) cells. Extracellular ATP can be rapidly hydrolyzed by ectonucleotidases. Adenosine, one of the adenine derivatives of ATP hydrolysis, can modulate diverse cellular actions via adenosine receptors. The objectives of this study were to investigate the effects of exogenous adenosine on the production of extracellular matrix (ECM; i.e., collagen type II and aggrecan) and ATP of IVD cells and explore the underlying mechanism of action. It was found that adenosine treatment significantly upregulated aggrecan and type II collagen gene expression and the ATP level in IVD cells. Dipyridamole, an adenosine transport blocker, completely suppressed the effects of adenosine on the ATP production and ECM gene expression of the IVD cells, whereas antagonists of adenosine receptors did not significantly affect adenosine-treated IVD cells. The findings suggested that elevated intracellular ATP and upregulation of ECM gene expression by adenosine treatment are mainly due to adenosine uptake rather than receptor activation. Since ECM biosynthesis is a high ATP demanding process, supplementing adenosine could be beneficial as IVD cells are able to utilize it to replenish intracellular ATP and sequentially promote ECM production, which is constantly suppressed by limited nutrition supply due to the avascular nature of the IVD.


1999 ◽  
Vol 17 (6) ◽  
pp. 836-842 ◽  
Author(s):  
Paula M. Ragan ◽  
Alison M. Badger ◽  
Michael Cook ◽  
Vicki I. Chin ◽  
Maxine Gowen ◽  
...  

2005 ◽  
Vol 2005 (4) ◽  
pp. 364-373 ◽  
Author(s):  
Vega Villar-Suárez ◽  
B. Colaço ◽  
I. Calles-Venal ◽  
I. G. Bravo ◽  
J. G. Fernández-Álvarez ◽  
...  

Isolated chondrocytes dedifferentiate to a fibroblast-like shape on plastic substrata and proliferate extensively, but rarely form nodules. However, when dissociation is not complete and some cartilage remnants are included in the culture, proliferation decreases and cells grow in a reticular pattern with numerous nodules, which occasionally form small cartilage-like fragments. In an attempt to reproduce this stable chondrogenic state, we added a cartilage protein extract, a sugar extract, and hyaluronan to the medium of previously dedifferentiated chondrocytes. When protein extract was added, many cartilaginous nodules appeared. Hyaluronan produced changes in cell phenotype and behaviour, but not nodule formation. Protein extract has positive effects on the differentiation of previously proliferated chondrocytes and permits nodule formation and the extensive production of type-II collagen. A comparison with incompletely dissociated chondrocyte cultures suggests that the presence of some living cells anchored to their natural extracellular matrix provides some important additional factors for the phenotypical stability of chondrocytes on plastic surfaces. In order to elucidate if it is possible that the incidence of apoptosis is related to the results, we also characterized the molecular traits of apoptosis.


2009 ◽  
Vol 63 (9) ◽  
pp. 619-626 ◽  
Author(s):  
Maurizio Vertemati ◽  
Ernesto Minola ◽  
Claudia Dolci ◽  
Giordano Stabellini ◽  
Furio Pezzetti ◽  
...  

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Toru Tanaka ◽  
Takehisa Shimizu ◽  
Norimichi Koitabashi ◽  
Hiroki Matsui ◽  
Hiroshi Doi ◽  
...  

[Objective] Runx2, a key transcription factor in osteoblast differentiation, is expressed in calcified atherosclerotic plaques. We have recently shown that Runx2 represses vascular smooth muscle cells (VSMCs) differentiation and promotes their osteogenic differentiation. Connective tissue growth factor (CTGF) has been implicated in the progression to vulnerable plaque by inducing mononuclear cell chemotaxis and VSMCs apoptosis despite of its potent stimulatory effect on connective tissue cell the proliferation and extracellular matrix synthesis. To assess the role of Runx2 in the process of plaque development, we investigated the molecular mechanism of the CTGF gene expression by Runx2 in VSMCs. [Methods and Results] RT-PCR analyses showed that adenovirally overexpressed Runx2 significantly repressed the basal expression of the CTGF gene in human aortic SMCs (HASMCs). Consistent with this, knockdown of the Runx2 expression in HASMCs by small interfering RNA (siRNA) increased CTGF mRNA levels. Luciferase assays showed that Runx2 reduced the transcriptional activity of the CTGF promoter. Transfection of a series of 5′-deletion constructs revealed that Runx2 inhibited CTGF expression through the sequence element located at 5′ untranslated region of CTGF mRNA. We next examined the effects of Runx2 on the TGFβ-induced CTGF expression. Runx2 overexpression significantly repressed CTGF expression in HASMCs stimulated with TGFβ, and knockdown of Runx2 by siRNA enhanced the induction of CTGF expression in response to TGFβ. Runx2 repressed TGFβ-induced CTGF promoter activity through the sequence including Smad binding element (SBE). Overexpression of Runx2 significantly reduced TGFβ- and Smad3-mediated luciferase activity of Smad-dependent promoter which contains four copies of SBE. Biotinylated DNA pulldown assay using SBE of CTGF promoter showed that Runx2 formed a complex with Smad3 and Smad4. [Conclusion] Runx2 repressed basal and TGFβ-induced CTGF gene expression in VSMCs. Thus, in addition to the potential for inducing vascular calcification, Runx2 may affect plaque stability by modulating extracellular matrix synthesis through inhibiting CTGF gene expression and TGFβ signaling.


2019 ◽  
Vol 34 (4-5) ◽  
pp. 373-385
Author(s):  
Kuan Wei Lee ◽  
Tang-Ching Kuan ◽  
Ming Wei Lee ◽  
Chen Show Yang ◽  
Lain-Chyr Hwang ◽  
...  

Extracellular matrix has an important part of the role in tissue engineering and regenerative medicine, so it is necessary to understand the various interactions between cells and extracellular matrix. Type II collagen and hyaluronic acid are the major structural components of the extracellular matrix of articular cartilage, and they are involved in fibril formation, entanglement and binding. The aim of this study was to prepare type II collagen fibrils with surface grafted with hyaluronic acid modified at the reducing end. The topographic pattern of type II collagen fibrils showed a significant change after the surface coupling of hyaluronic acid according to atomic force microscopy scanning. The presence of hyaluronic acid on the type II collagen fibrillar surface was confirmed by the specific binding of nanogold labelled with lectin. No significant increase in cell proliferation was detected by a WST-1 assay. According to histochemical examination, the maintenance of the round shape of chondrocytes and increased glycosaminoglycan secretion revealed that these cell pellets with Col II- g-hyaluronic acid molecules contained un-dedifferentiated chondrocytes in vitro. In the mixture with the 220-kDa Col II- g-hyaluronic acid copolymer, the expression of type II collagen and aggrecan genes in chondrocytes increased as demonstrated by real-time polymerase chain reaction analysis. Experimental results show that the amount of hyaluronic acid added during culturing of chondrocytes can maintain the functionality of chondrocytes and thus allow for increased cell proliferation that is suitable for tissue repair of human cartilage.


2017 ◽  
Vol 46 (3) ◽  
pp. 713-727 ◽  
Author(s):  
Chin-Chean Wong ◽  
Chih-Hwa Chen ◽  
Li-Hsuan Chiu ◽  
Yang-Hwei Tsuang ◽  
Meng-Yi Bai ◽  
...  

Background: Insufficient cell numbers still present a challenge for articular cartilage repair. Converting heterotopic auricular chondrocytes by extracellular matrix may be the solution. Hypothesis: Specific extracellular matrix may convert the phenotype of auricular chondrocytes toward articular cartilage for repair. Study Design: Controlled laboratory study. Methods: For in vitro study, rabbit auricular chondrocytes were cultured in monolayer for several passages until reaching status of dedifferentiation. Later, they were transferred to chondrogenic type II collagen (Col II)–coated plates for further cell conversion. Articular chondrogenic profiles, such as glycosaminoglycan deposition, articular chondrogenic gene, and protein expression, were evaluated after 14-day cultivation. Furthermore, 3-dimensional constructs were fabricated using Col II hydrogel-associated auricular chondrocytes, and their histological and biomechanical properties were analyzed. For in vivo study, focal osteochondral defects were created in the rabbit knee joints, and auricular Col II constructs were implanted for repair. Results: The auricular chondrocytes converted by a 2-step protocol expressed specific profiles of chondrogenic molecules associated with articular chondrocytes. The histological and biomechanical features of converted auricular chondrocytes became similar to those of articular chondrocytes when cultivated with Col II 3-dimensional scaffolds. In an in vivo animal model of osteochondral defects, the treated group (auricular Col II) showed better cartilage repair than did the control groups (sham, auricular cells, and Col II). Histological analyses revealed that cartilage repair was achieved in the treated groups with abundant type II collagen and glycosaminoglycans syntheses rather than elastin expression. Conclusion: The study confirmed the feasibility of applying heterotopic chondrocytes for cartilage repair via extracellular matrix–induced cell conversion. Clinical Relevance: This study proposes a feasible methodology to convert heterotopic auricular chondrocytes for articular cartilage repair, which may serve as potential alternative sources for cartilage repair.


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