Experiments with a biological material for the closure of incisional hernias

1987 ◽  
Vol 21 (3) ◽  
pp. 195-200 ◽  
Author(s):  
M. Walter ◽  
U. Brenner ◽  
W. Holzmüller ◽  
J. M. Müller

A new preparation process was studied which should allow the implantation of collagen type I in its native structure in reconstructive surgery, in this special case for closure of incisional hernias. As experimental animals we used 30 female Lewis rats. A defect of the anterior abdominal wall measuring 3 cm × 4 cm was closed with our collagen substitute. Biopsies taken after 4, 6 and 8 weeks were examined morphologically. As criteria for revitalization and revascularization we used the type of infiltrating cells, the depth and density of infiltration and the formation of new blood vessels. After 4 weeks the implants were infiltrated by fibroblasts that decreased in density towards the centre. Good revascularization could be seen on the muscle-implant interface. After 6 weeks the density of infiltrating cells had increased markedly even to the centre of the collagen implant. Sporadically small vessels could be seen. Eight weeks after implantation the density of infiltrated cells was at the same high level, and capillary bundles could be seen within the whole implant. We believe that this collagen implant is suitable for the closure of hernias as shown by its physical and morphological properties. In particular it appears to guarantee an earlier and tighter closure of hernias than other materials.

2019 ◽  
Author(s):  
G. Bahcecioglu ◽  
B. Bilgen ◽  
N. Hasirci ◽  
V. Hasirci

AbstractA PCL/hydrogel construct that would mimic the structural organization, biochemistry and anatomy of meniscus was engineered. The compressive (380 ± 40 kPa) and tensile modulus (18.2 ± 0.9 MPa) of the PCL scaffolds were increased significantly when constructs were printed with a shifted design and circumferential strands mimicking the collagen organization in native tissue (p<0.05). Presence of circumferentially aligned PCL strands also led to elongation and alignment of the human fibrochondrocytes. Gene expression of the cells in agarose (Ag), gelatin methacrylate (GelMA), and GelMA-Ag hydrogels was significantly higher than that of cells on the PCL scaffolds after a 21-day culture. GelMA exhibited the highest level of collagen type I (COL1A2)mRNA expression, while GelMA-Ag exhibited the highest level of aggrecan (AGG)expression (p<0.001, compared to PCL). GelMA and GelMA-Ag exhibited a high level of collagen type II (COL2A1) expression (p<0.05, compared to PCL). Anatomical scaffolds with circumferential PCL strands were impregnated with cell-loaded GelMA in the periphery and GelMA-Ag in the inner region. GelMA and GelMA-Ag hydrogels enhanced the production of COL 1 and COL 2 proteins after a 6-week culture (p<0.05). COL 1 expression increased gradually towards the outer periphery, while COL 2 expression decreased. We were thus able to engineer an anatomical meniscus with a cartilage-like inner region and fibrocartilage-like outer region.


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.


2021 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Rabia Nazir ◽  
Arne Bruyneel ◽  
Carolyn Carr ◽  
Jan Czernuszka

In addition to biocompatibility, an ideal scaffold for the regeneration of valvular tissue should also replicate the natural heart valve extracellular matrix (ECM) in terms of biomechanical properties and structural stability. In our previous paper, we demonstrated the development of collagen type I and hyaluronic acid (HA)-based scaffolds with interlaced microstructure. Such hybrid scaffolds were found to be compatible with cardiosphere-derived cells (CDCs) to potentially regenerate the diseased aortic heart valve. This paper focused on the quantification of the effect of crosslinking density on the mechanical properties under dry and wet conditions as well as degradation resistance. Elastic moduli increased with increasing crosslinking densities, in the dry and wet state, for parent networks, whereas those of interlaced scaffolds were higher than either network alone. Compressive and storage moduli ranged from 35 ± 5 to 95 ± 5 kPa and 16 ± 2 kPa to 113 ± 6 kPa, respectively, in the dry state. Storage moduli, in the dry state, matched and exceeded those of human aortic valve leaflets (HAVL). Similarly, degradation resistance increased with increasing the crosslinking densities for collagen-only and HA-only scaffolds. Interlaced scaffolds showed partial degradation in the presence of either collagenase or hyaluronidase as compared to when exposed to both enzymes together. These results agree with our previous findings that interlaced scaffolds were composed of independent collagen and HA networks without crosslinking between them. Thus, collagen/HA interlaced scaffolds have the potential to fill in the niche for designing an ideal tissue engineered heart valve (TEHV).


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 382
Author(s):  
Rubén Martín-Cabezuelo ◽  
José Carlos Rodríguez-Hernández ◽  
Guillermo Vilariño-Feltrer ◽  
Ana Vallés-Lluch

A novel procedure to obtain smooth, continuous polymeric surfaces from poly(glycerol sebacate) (PGS) has been developed with the spin-coating technique. This method proves useful for separating the effect of the chemistry and morphology of the networks (that can be obtained by varying the synthesis parameters) on cell-protein-substrate interactions from that of structural variables. Solutions of the PGS pre-polymer can be spin-coated, to then be cured. Curing under variable temperatures has been shown to lead to PGS networks with different chemical properties and topographies, conditioning their use as a biomaterial. Particularly, higher synthesis temperatures yield denser networks with fewer polar terminal groups available on the surface. Material-protein interactions were characterised by using extracellular matrix proteins such as fibronectin (Fn) and collagen type I (Col I), to unveil the biological interface profile of PGS substrates. To that end, atomic force microscopy (AFM) images and quantification of protein adsorbed in single, sequential and competitive protein incubations were used. Results reveal that Fn is adsorbed in the form of clusters, while Col I forms a characteristic fibrillar network. Fn has an inhibitory effect when incubated prior to Col I. Human umbilical endothelial cells (HUVECs) were also cultured on PGS surfaces to reveal the effect of synthesis temperature on cell behaviour. To this effect, early focal adhesions (FAs) were analysed using immunofluorescence techniques. In light of the results, 130 °C seems to be the optimal curing temperature since a preliminary treatment with Col I or a Fn:Col I solution facilitates the formation of early focal adhesions and growth of HUVECs.


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.


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