scholarly journals Vascular Tissue Engineering: Effects of Integrating Collagen into a PCL Based Nanofiber Material

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ulf Bertram ◽  
Dominik Steiner ◽  
Benjamin Poppitz ◽  
Dirk Dippold ◽  
Katrin Köhn ◽  
...  

The engineering of vascular grafts is a growing field in regenerative medicine. Although numerous attempts have been made, the current vascular grafts made of polyurethane (PU), Dacron®, or Teflon® still display unsatisfying results. Electrospinning of biopolymers and native proteins has been in the focus of research to imitate the extracellular matrix (ECM) of vessels to produce a small caliber, off-the-shelf tissue engineered vascular graft (TEVG) as a substitute for poorly performing PU, Dacron, or Teflon prostheses. Blended poly-ε-caprolactone (PCL)/collagen grafts have shown promising results regarding biomechanical and cell supporting features. In order to find a suitable PCL/collagen blend, we fabricated plane electrospun PCL scaffolds using various collagen type I concentrations ranging from 5% to 75%. We analyzed biocompatibility and morphological aspectsin vitro. Our results show beneficial features of collagen I integration regarding cell viability and functionality, but also adverse effects like the loss of a confluent monolayer at high concentrations of collagen. Furthermore, electrospun PCL scaffolds containing 25% collagen I seem to be ideal for engineering vascular grafts.

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.


1991 ◽  
Vol 274 (2) ◽  
pp. 615-617 ◽  
Author(s):  
P Kern ◽  
M Menasche ◽  
L Robert

The biosynthesis of type I, type V and type VI collagens was studied by incubation of calf corneas in vitro with [3H]proline as a marker. Pepsin-solubilized collagen types were isolated by salt fractionation and quantified by SDS/PAGE. Expressed as proportions of the total hydroxyproline solubilized, corneal stroma comprised 75% type I, 8% type V and 17% type VI collagen. The rates of [3H]proline incorporation, linear up to 24 h for each collagen type, were highest for type VI collagen and lowest for type I collagen. From pulse-chase experiments, the calculated apparent half-lives for types I, V and VI collagens were 36 h, 10 h and 6 h respectively.


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 23 (06) ◽  
pp. 417-423 ◽  
Author(s):  
J. M. Cissell ◽  
S. C. Milton ◽  
L. A. Dahlgren

Summary Objectives: To evaluate the effects of pros-taglandin E2 (PGE2) treatment on the metabolism of equine tendon fibroblasts in vitro to aid in investigating the response of tendon fibroblasts to injury and novel therapeutics. Methods: Superficial digital flexor tendon fibroblasts isolated via collagenase digestion from six young adult horses were grown in monolayer in four concentrations of PGE2 (0, 10, 50, 100 ng/ml) for 48 hours. Cells and medium were harvested for gene expression (collagen types I and III, cartilage oligomeric matrix protein [COMP], decorin, and matrix metalloproteinase-1, –3, and –13), biochemical analysis (glycosaminoglycan, DNA, and collagen content), and cytological staining. Results: Gene expression for collagen type I was significantly increased at 100 ng/ml PGE2 compared to 10 and 50 ng/ml. There were not any significant differences detected for gene expression of collagen type III, COMP or dec-orin or for biochemical content and cell morphology. Clinical significance: Under the conditions investigated, exogenous treatment of equine tendon fibroblasts with PGE2 failed to alter cell metabolism in a manner useful as a model of tendon injury. A model that applies cyclic strain to a three dimensional construct seeded with tendon fibroblasts may prove to be a more useful model and merits further investigation for this purpose. The ability to assess cellular responses in an environment where the cells are supported within the extracellular matrix may prove beneficial.


2019 ◽  
Vol 14 (17) ◽  
pp. 1469-1475
Author(s):  
Pavle Banović ◽  
Ivan Čapo ◽  
Dejan Ogorelica ◽  
Nenad Vranješ ◽  
Verica Simin ◽  
...  

The majority of suggested mechanisms of Borrelia spreading inside erythema migrans (EM) are developed from in vitro studies and animal models. This report is the first to describe pathomorphological substrate of EM caused by Borrelia spielmanii in humans, addressing the hypothesis of enhanced Borrelia penetration through extracellular matrix. In the process of ruling out of atypical Masters’ disease, we conducted a punch biopsy of suspected EM and a two-tier serology testing for Lyme borreliosis, where we registered antibodies against B. spielmanii. Skin biopsy showed CD4+ and CD8+ lymphocyte involvement and high activity of matrix metalloproteinase 9. No alterations were detected in distribution and morphology of collagen type I and IV. Therefore, it is suggested that other mechanisms should be considered as major contributing factors to local spreading of B. spielmanii.


2010 ◽  
Vol 63 (7-8) ◽  
pp. 459-464 ◽  
Author(s):  
Zoran Milosavljevic ◽  
Biljana Ljujic

Introduction. Human dermal tissue is composed of loose and dense connective tissue. Main cell populations are fibroblasts and the dominant fibers are built from collagen type I. The aim of our study was to determine the precise method and time frame for the in vitro production of human dermal equivalent and to investigate the effects of ratio of structural elements and vitamin C on characteristics of the engineered tissue. Material and methods. Primary isolation of the foreskin fibroblasts was performed by explant method and enzymatic dissociation. Various collagen gels were obtained by mixing cells (from 25x103 to 200x103/ml) and neutralized collagen type I (from 2 to 4 mg/ml), with or without vitamin C. The routine histological and morphometrical examination was performed. Results. Enzymatic dissociation of the foreskin proved to be a faster method for production of desired number of fibroblasts (7.5x105 for 4 days). The contraction of collagen-gels started from day one through day seven and was dependent on cell and collagen concentration with higher density gels being contracted to a greater extent, except for the lowest/highest values. The best result was achieved with 100x103 cells and 2 mg/ml collagen. Vitamin C at 50 ?g/ml had no effect on speed of tissue formation. Conclusion. A precise approach that mimic the in vivo conditions is needed for the in vitro production of the dermal equivalent suitable for the possible treatment of tissue defects. Nearly ten days are necessary from the donor tissue dissociation to the final product.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 687 ◽  
Author(s):  
Sam G. Edalat ◽  
Yongjun Jang ◽  
Jongseong Kim ◽  
Yongdoo Park

In vitro maturation of cardiomyocytes in 3D is essential for the development of viable cardiac models for therapeutic and developmental studies. The method by which cardiomyocytes undergoes maturation has significant implications for understanding cardiomyocytes biology. The regulation of the extracellular matrix (ECM) by changing the composition and stiffness is quintessential for engineering a suitable environment for cardiomyocytes maturation. In this paper, we demonstrate that collagen type I, a component of the ECM, plays a crucial role in the maturation of cardiomyocytes. To this end, embryonic stem-cell derived cardiomyocytes were incorporated into Matrigel-based hydrogels with varying collagen type I concentrations of 0 mg, 3 mg, and 6 mg. Each hydrogel was analyzed by measuring the degree of stiffness, the expression levels of MLC2v, TBX18, and pre-miR-21, and the size of the hydrogels. It was shown that among the hydrogel variants, the Matrigel-based hydrogel with 3 mg of collagen type I facilitates cardiomyocyte maturation by increasing MLC2v expression. The treatment of transforming growth factor β1 (TGF-β1) or fibroblast growth factor 4 (FGF-4) on the hydrogels further enhanced the MLC2v expression and thereby cardiomyocyte maturation.


2020 ◽  
Vol 133 (23) ◽  
pp. jcs248278 ◽  
Author(s):  
Ana M. Diaz-Espinosa ◽  
Patrick A. Link ◽  
Delphine Sicard ◽  
Ignasi Jorba ◽  
Daniel J. Tschumperlin ◽  
...  

ABSTRACTMatrix resorption is essential to the clearance of the extracellular matrix (ECM) after normal wound healing. A disruption in these processes constitutes a main component of fibrotic diseases, characterized by excess deposition and diminished clearance of fibrillar ECM proteins, such as collagen type I. The mechanisms and stimuli regulating ECM resorption in the lung remain poorly understood. Recently, agonism of dopamine receptor D1 (DRD1), which is predominantly expressed on fibroblasts in the lung, has been shown to accelerate tissue repair and clearance of ECM following bleomycin injury in mice. Therefore, we investigated whether DRD1 receptor signaling promotes the degradation of collagen type I by lung fibroblasts. For cultured fibroblasts, we found that DRD1 agonism enhances extracellular cleavage, internalization and lysosomal degradation of collagen I mediated by cathepsin K, which results in reduced stiffness of cell-derived matrices, as measured by atomic force microscopy. In vivo agonism of DRD1 similarly enhanced fibrillar collagen degradation by fibroblasts, as assessed by tissue labeling with a collagen-hybridizing peptide. Together, these results implicate DRD1 agonism in fibroblast-mediated collagen clearance, suggesting an important role for this mechanism in fibrosis resolution.This article has an associated First Person interview with the first author of the paper.


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