Applying Physiologically Relevant Strains to Tenocytes in an In Vitro Cell Device Induces In Vivo Like Behaviors

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Jung Joo Kim ◽  
David S. Musson ◽  
Brya G. Matthews ◽  
Jillian Cornish ◽  
Iain A. Anderson ◽  
...  

We have developed a novel cell stretching device (called Cell Gym) capable of applying physiologically relevant low magnitude strains to tenocytes on a collagen type I coated membrane. We validated our device thoroughly on two levels: (1) substrate strains, (2) cell level strains. Our cell level strain results showed that the applied stretches were transferred to cells accurately (∼90%). Our gene expression data showed that mechanically stimulated tenocytes (4%) expressed a lower level of COL I gene. COX2 gene was increased but did not reach statistical significance. Our device was then tested to see if it could reproduce results from an in vivo study that measured time-dependent changes in collagen synthesis. Our results showed that collagen synthesis peaked at 24 hrs after exercise and then decreased, which matched the results from the in vivo study. Our study demonstrated that it is important to incorporate physiologically relevant low strain magnitudes in in vitro cell mechanical studies and the need to validate the device thoroughly to operate the device at small strains. This device will be used in designing novel tendon tissue engineering scaffolds in the future.

2021 ◽  
Vol 8 (3) ◽  
pp. 39
Author(s):  
Britani N. Blackstone ◽  
Summer C. Gallentine ◽  
Heather M. Powell

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.


Author(s):  
Michel Haagdorens ◽  
Elle Edin ◽  
Per Fagerholm ◽  
Marc Groleau ◽  
Zvi Shtein ◽  
...  

Abstract Purpose To determine feasibility of plant-derived recombinant human collagen type I (RHCI) for use in corneal regenerative implants Methods RHCI was crosslinked with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to form hydrogels. Application of shear force to liquid crystalline RHCI aligned the collagen fibrils. Both aligned and random hydrogels were evaluated for mechanical and optical properties, as well as in vitro biocompatibility. Further evaluation was performed in vivo by subcutaneous implantation in rats and corneal implantation in Göttingen minipigs. Results Spontaneous crosslinking of randomly aligned RHCI (rRHCI) formed robust, transparent hydrogels that were sufficient for implantation. Aligning the RHCI (aRHCI) resulted in thicker collagen fibrils forming an opaque hydrogel with insufficient transverse mechanical strength for surgical manipulation. rRHCI showed minimal inflammation when implanted subcutaneously in rats. The corneal implants in minipigs showed that rRHCI hydrogels promoted regeneration of corneal epithelium, stroma, and nerves; some myofibroblasts were seen in the regenerated neo-corneas. Conclusion Plant-derived RHCI was used to fabricate a hydrogel that is transparent, mechanically stable, and biocompatible when grafted as corneal implants in minipigs. Plant-derived collagen is determined to be a safe alternative to allografts, animal collagens, or yeast-derived recombinant human collagen for tissue engineering applications. The main advantage is that unlike donor corneas or yeast-produced collagen, the RHCI supply is potentially unlimited due to the high yields of this production method. Lay Summary A severe shortage of human-donor corneas for transplantation has led scientists to develop synthetic alternatives. Here, recombinant human collagen type I made of tobacco plants through genetic engineering was tested for use in making corneal implants. We made strong, transparent hydrogels that were tested by implanting subcutaneously in rats and in the corneas of minipigs. We showed that the plant collagen was biocompatible and was able to stably regenerate the corneas of minipigs comparable to yeast-produced recombinant collagen that we previously tested in clinical trials. The advantage of the plant collagen is that the supply is potentially limitless.


2017 ◽  
Vol 312 (3) ◽  
pp. G219-G227 ◽  
Author(s):  
Leonie Beljaars ◽  
Sara Daliri ◽  
Christa Dijkhuizen ◽  
Klaas Poelstra ◽  
Reinoud Gosens

WNT-5A is a secreted growth factor that belongs to the noncanonical members of the Wingless-related MMTV-integration family. Previous studies pointed to a connection between WNT-5A and the fibrogenic factor TGF-β warranting further studies into the functional role of WNT-5A in liver fibrosis. Therefore, we studied WNT-5A expressions in mouse and human fibrotic livers and examined the relation between WNT-5A and various fibrosis-associated growth factors, cytokines, and extracellular matrix proteins. WNT-5A gene and protein expressions were significantly increased in fibrotic mouse and human livers compared with healthy livers. Regression or therapeutic intervention in mice resulted in decreased hepatic WNT-5A levels paralleled by lower collagen levels. Immunohistochemical analysis showed WNT-5A staining in fibrotic septa colocalizing with desmin staining indicating WNT-5A expression in myofibroblasts. In vitro studies confirmed WNT-5A expression in this cell type and showed that TGF-β significantly enhanced WNT-5A expression in contrast to PDGF-BB and proinflammatory cytokines IL-1β and TNF-α. Additionally, TGF-β induces the expression of the WNT receptors FZD2 and FZD8. After silencing of WNT-5A, reduced levels of collagen type I, vimentin, and fibronectin in TGF-β-stimulated myofibroblasts were measured compared with nonsilencing siRNA-treated controls. Interestingly, the antifibrotic cytokine IFNγ suppressed WNT-5A in vitro and in vivo. IFNγ-treated fibrotic mice showed significantly less WNT-5A expression compared with untreated fibrotic mice. In conclusion, WNT-5A paralleled collagen I levels in fibrotic mouse and human livers. WNT-5A expression in myofibroblasts is induced by the profibrotic factor TGF-β and plays an important role in TGF-β-induced regulation of fibrotic matrix proteins, whereas its expression can be reversed upon treatment, both in vitro and in vivo. NEW & NOTEWORTHY This study describes the localization and functional role of WNT-5A in human and mouse fibrotic livers. Hepatic WNT-5A expression parallels collagen type I expression. In vivo and in vitro, the myofibroblasts were identified as the key hepatic cells producing WNT-5A. WNT-5A is under control of TGF-β and its activities are primarily profibrotic.


2010 ◽  
Vol 21 (13) ◽  
pp. 1737-1760 ◽  
Author(s):  
Cédryck Vaquette ◽  
Saïd Slimani ◽  
Cyril J. F. Kahn ◽  
Nguyen Tran ◽  
Rachid Rahouadj ◽  
...  

2018 ◽  
Vol 41 (8) ◽  
pp. 467-473 ◽  
Author(s):  
Rethinam Senthil ◽  
Robert Berly ◽  
Thimmiah Bhargavi Ram ◽  
Nallathambi Gobi

Purpose: In this study, a blend of synthetic polymer (poly(vinyl) alcohol), natural polymer (collagen type I from fish bone), and graphene oxide nanoparticles is used to fabricate a composite nanofibrous scaffold, by electrospinning, for their potential application in accelerated wound healing. Methods: The scaffold was characterized for its physicochemical and mechanical properties. In vitro studies were carried out using human keratinocyte cell line (HaCaT) which proved the biocompatibility of the scaffold. In vivo study using mice model was carried out and the healing pattern was evaluated using histopathological studies. Results: Scaffold prepared from poly(vinyl) alcohol, collagen type I from fish bone, and graphene oxide possessed better physicochemical and mechanical properties. In addition, in vivo and in vitro studies showed its accelerated wound healing properties. Conclusion: The scaffold with required strength and biocompatibility may be tried as a wound dressing material in large animals after getting necessary approval.


2020 ◽  
Author(s):  
Zhao Li ◽  
Yue Du ◽  
Xin Wang

Abstract Background: To evaluate the potential differentiation ability of bone mesenchymal stromal cells(BMSCs) to pancreatic line Cells on rat acellular pancreatic bioscaffold(APB) and the effect of differentiated BMSCs for chronic pancreatitis(CP) in vivo. Methods: After BMSCs were isolated and identified, they were dynamic cultured on the APB and static cultured in tissue culture flask(TCF),with or without the growth factors (GF) in both the culture system. The cytological behavior such as the proliferation and differentiation of BMSCs in all the above kinds of culture system were assessed by morphological observation, flow cytometry, ELASA analysis, qRT-PCR assay and western blot analysis. For the in vivo study, the pancreatic fibrosis and pathological score were evaluated. And also the expression of α-SMA, collagen type I and III, IL-10 in pancreas tissue were detected by ELASA. Results: 4ml/min was the most appropriate flow rate for the dynamic culture of BMSCs. The proliferation rate of BMSCs in the APB groups were significantly increased compared to TCF system. During the pancreatic line cell differentiation process, APB could induce BMSCs express markers such as PDX-1 and PTF-1 at higher mRNA levels. In contrast, the marker Oct 4 was expressed at a lower level in APB group. For the pancreatic functional cytoketatins including α-Amy, CK7, Flk-1, and C-peptide, they were all expressed at higher level in APB group. And metabolic enzymes secretion such as amylase and insulin were promoted significantly in APB system. By scanning electron microscope(SEM) and transmission electron microscopy(TEM), the ultrastructure of BMSCs in the APB group could further demonstrated the morphological characteristics of pancreatic-like cells. In vivo study,the expression of α-SMA, collagen type I and III in tissues were less in differentiated BMSCs treatment group, while the level of IL-10 in pancreatic tissue were higher in differentiated BMSCs treatment group with significant difference (P<0.05). In addition, in both in vitro and in vivo study, GF could significantly facilitate the function of proliferation, differentiation and pancreatic cell therapy. Conclusion: Together our data show the capacity of APB , 3D pancreatic biomatrix, promoting BMSCs differentiate toward pancreatic line phenotypes, and the considerable potential of using these cells for pancreatic cell therapies and tissue engineering.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Haniel A Araujo ◽  
Leonardo Y Tanaka ◽  
Gustavo K Hironaka ◽  
Thais L Araujo ◽  
Celso K Takimura ◽  
...  

INTRODUCTION: Vascular remodeling orchestrates a complex network of signaling pathways responsible for pathological changes in many vascular diseases such as atherosclerosis. We investigated the role of endoplasmic reticulum chaperone Protein Disulfide Isomerase (PDI) and the extracellular PDI (ecPDI) pool in vascular caliber and architecture during vascular repair and remodeling after injury (AI). METHODS AND RESULTS: After rabbit iliac artery balloon injury, PDI is markedly increased at mRNA and protein levels (25-fold vs. basal 14 days AI), with increase in both intracellular and ecPDI. Silencing PDI by siRNA in vitro induced ER stress markers upregulation and apoptosis (assessed by TUNEL assay). PDI knockdown also upregulated proliferation marker PCNA and decreased differentiation marker calponin-C. Furthermore, ecPDI inhibition prevents injury-increased hydrogen peroxide generation and decreases arterial nitrate (NO3-) level. EcPDI neutralization in vivo with PDIAb-containing perivascular gel from days 12-14AI promoted 25% decrease in vascular caliber at arteriography and similar decreases in total vessel circumference at optical coherence tomography, without changing neointima, indicating increased constrictive remodeling. EcPDI neutralization promoted striking changes in collagen, with switch from circumferential to radial fiber orientation towards a more rigid fiber type. Collagen type I and III were decreased after ecPDI inhibition in arteries 14 days AI. Cytoskeleton architecture was also disrupted, with loss of stress fiber coherent organization and switch from thin to medium-thickness actin fibers. In human coronary atheromas, PDI expression inversely correlated with constrictive remodeling. There was decreased PDI expression in media and intima from plaques exhibiting constrictive remodeling and, conversely, enhanced PDI expression in media of plaques depicting outward remodeling. CONCLUSIONS: Thus, PDI is highly upregulated after injury and reshapes matrix and cytoskeleton architecture to support an anticonstrictive remodeling effect. Such findings suggest an important role for PDI in lumen maintenance during vascular remodeling.


1981 ◽  
Author(s):  
L Balleisen ◽  
J Rauterberg

To get close information about the characteristics of collagen induced MDA formation, platelet aggregation was induced by collagen type I, III a. V in dissolved and fibrillar form and by methylated type I collagen. The MDA formation was measured in the course of aggregation. In case of Meth.c. MDA production is induced also if under certain incubation conditions no aggregation is detectible.During the pl.aggr. induced by dissolved c. some MDA production was seen before the slope of the aggregation curve increased. Parallel to the increasing slope MDA increased fast, and some further increase over a 30 min. period was observed. For fibrillar and meth.c. MDA formation begins just with the increasing slope and reaches a stable plateau. In case of meth.c. the plateau is reached immediately after the maximum of aggregation occurred, in that of fibrillar c. some min. after maximal aggregation. For meth.c. the results obtained in the incubation system were comparable to that in the aggregation system.For meth.c. the kinetics of MDA formation in both systems were further defined. In both systems a concentration dependent saturation kinetic was obtained. In the aggregation system the concentration dependent increase of MDA formation was somewhat faster as in the incubation system and reached its saturation level at a lower collagen concentration.From the increasing and long lasting MDA formation induced by the interstitial collagens we might speculate that in vivo the stimulating activity of the collagens may work for a long time in conditions where the prostacyclin production of the vessel wall is decreased. The characteristics of MDA formation induced by meth.c. suggest that this c. may be a good tool for in vitro studies.


Author(s):  
Spencer L. York ◽  
Ahmad R. Arida ◽  
Karan S. Shah ◽  
Palaniappan Sethu ◽  
Marnie M. Saunders

In the body, osteocytes reside in lacunae, lenticular shaped cavities within mineralized bone. These cells are linked to each other and surface-residing osteoblasts via physical channels known as gap junctions. It has been suggested that osteocytes sense mechanical load applied to bone and relay that signal to osteoclasts and osteoblasts. Currentin vitroandin vivomodels of mechanotransduction face temporal and spatial barriers. Recent advances in polydimethylsiloxane (PDMS) based microfabrication techniques may be able to overcome some of these hurdles. However, before the bone research field can effectively utilize microsystems techniques, fundamental groundwork must be completed. This study characterized the behaviour of osteocytes on PDMS coated with collagen type I (CTI) and provides the framework for bone cell mechanotransduction studies using microsystems. The goal was to determine whether osteocytes were adversely affected by the substrate material by comparing their behaviour to a standard glass substrate. In addition, optimal culture conditions and time points for growing osteocytes on PDMS substrates were determined. Results of this study suggested that use of PDMS does not adversely affect osteocyte behaviour. Furthermore, the results demonstrated that osteocytes should be cultured for no less than 72 hours prior to experimentation to allow the establishment and maintenance of phenotypic characteristics. These results completed essential groundwork necessary for further studies regarding osteocytes in microsystems modelling utilizing PDMS.


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