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The fusion of tissue spheroids attached to pre-stretched electrospun polyurethane scaffolds.

Beachley V, Kasyanov V, Nagy-Mehesz A, Norris R, Ozolanta I, Kalejs M, Stradins P, Baptista L, da Silva K, Grainjero J, Wen X, Mironov V - J Tissue Eng (2014)

Bottom Line: Tissue spheroids attached, spread, and fused after being placed on pre-stretched polyurethane electrospun matrices and formed tissue constructs.Efforts to eliminate hole defects with fibrogenic tissue growth factor-β resulted in the increased synthesis of collagen and periostin and a dramatic reduction in hole size and number.In control experiments, tissue spheroids fuse on a non-adhesive hydrogel and form continuous tissue constructs without holes.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Rowan University, Glassboro, NJ, USA.

ABSTRACT
Effective cell invasion into thick electrospun biomimetic scaffolds is an unsolved problem. One possible strategy to biofabricate tissue constructs of desirable thickness and material properties without the need for cell invasion is to use thin (<2 µm) porous electrospun meshes and self-assembling (capable of tissue fusion) tissue spheroids as building blocks. Pre-stretched electrospun meshes remained taut in cell culture and were able to support tissue spheroids with minimal deformation. We hypothesize that elastic electrospun scaffolds could be used as temporal support templates for rapid self-assembly of cell spheroids into higher order tissue structures, such as engineered vascular tissue. The aim of this study was to investigate how the attachment of tissue spheroids to pre-stretched polyurethane scaffolds may interfere with the tissue fusion process. Tissue spheroids attached, spread, and fused after being placed on pre-stretched polyurethane electrospun matrices and formed tissue constructs. Efforts to eliminate hole defects with fibrogenic tissue growth factor-β resulted in the increased synthesis of collagen and periostin and a dramatic reduction in hole size and number. In control experiments, tissue spheroids fuse on a non-adhesive hydrogel and form continuous tissue constructs without holes. Our data demonstrate that tissue spheroids attached to thin stretched elastic electrospun scaffolds have an interrupted tissue fusion process. The resulting tissue-engineered construct phenotype is a direct outcome of the delicate balance of the competing physical forces operating during the tissue fusion process at the interface of the pre-stretched elastic scaffold and the attached tissue spheroids. We have shown that with appropriate treatments, this process can be modulated, and thus, a thin pre-stretched elastic polyurethane electrospun scaffold could serve as a supporting template for rapid biofabrication of thick tissue-engineered constructs without the need for cell invasion.

No MeSH data available.


Related in: MedlinePlus

Pre-stretched electrospun polyurethane scaffold: (a) scanning electron microscopy of the electrospun scaffold (small magnification); (b) scanning electron microscopy of the electrospun scaffold (large magnification); and (c) hole formation in the pre-stretched electrospun polyurethane scaffold after rupture—white arrows indicate the centrifugal direction of stretch.
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fig2-2041731414556561: Pre-stretched electrospun polyurethane scaffold: (a) scanning electron microscopy of the electrospun scaffold (small magnification); (b) scanning electron microscopy of the electrospun scaffold (large magnification); and (c) hole formation in the pre-stretched electrospun polyurethane scaffold after rupture—white arrows indicate the centrifugal direction of stretch.

Mentions: The biomechanical properties of the tissue-engineered construct (force–elongation relationship) with and without TGF-β1 treatment were estimated. Tissue specimens were glued between two fine waterproof sandpaper 1500-b frames (Figure 1) using rubber cement (acid free). Two cuts were made along each side of each specimen. The length and width of the each specimen in the frame was 10 and 5 mm, respectively. Tissue specimens were gripped at both ends with two-piece clamps that were lined with sandpaper such that the edges of the frame aligned with the end of the grips. Tensile tests were performed at room temperature (20°C ± 1°C) using a Bose ElectroForce® 3200 Test System with load cell 50 N (Figure 2(b)). The frame improved traction of the tissue within the grips and prevented slippage during the test. The side faces of the frame were cut after the specimens were placed between the grips and the testing machine (Figure 1). Each specimen was loaded at a rate of 0.2 mm/s until they ruptured (this elongation rate usually is used for quasi-static tensile testing of soft biological tissue and biomaterials), and the force-elongation curves were recorded.


The fusion of tissue spheroids attached to pre-stretched electrospun polyurethane scaffolds.

Beachley V, Kasyanov V, Nagy-Mehesz A, Norris R, Ozolanta I, Kalejs M, Stradins P, Baptista L, da Silva K, Grainjero J, Wen X, Mironov V - J Tissue Eng (2014)

Pre-stretched electrospun polyurethane scaffold: (a) scanning electron microscopy of the electrospun scaffold (small magnification); (b) scanning electron microscopy of the electrospun scaffold (large magnification); and (c) hole formation in the pre-stretched electrospun polyurethane scaffold after rupture—white arrows indicate the centrifugal direction of stretch.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4229054&req=5

fig2-2041731414556561: Pre-stretched electrospun polyurethane scaffold: (a) scanning electron microscopy of the electrospun scaffold (small magnification); (b) scanning electron microscopy of the electrospun scaffold (large magnification); and (c) hole formation in the pre-stretched electrospun polyurethane scaffold after rupture—white arrows indicate the centrifugal direction of stretch.
Mentions: The biomechanical properties of the tissue-engineered construct (force–elongation relationship) with and without TGF-β1 treatment were estimated. Tissue specimens were glued between two fine waterproof sandpaper 1500-b frames (Figure 1) using rubber cement (acid free). Two cuts were made along each side of each specimen. The length and width of the each specimen in the frame was 10 and 5 mm, respectively. Tissue specimens were gripped at both ends with two-piece clamps that were lined with sandpaper such that the edges of the frame aligned with the end of the grips. Tensile tests were performed at room temperature (20°C ± 1°C) using a Bose ElectroForce® 3200 Test System with load cell 50 N (Figure 2(b)). The frame improved traction of the tissue within the grips and prevented slippage during the test. The side faces of the frame were cut after the specimens were placed between the grips and the testing machine (Figure 1). Each specimen was loaded at a rate of 0.2 mm/s until they ruptured (this elongation rate usually is used for quasi-static tensile testing of soft biological tissue and biomaterials), and the force-elongation curves were recorded.

Bottom Line: Tissue spheroids attached, spread, and fused after being placed on pre-stretched polyurethane electrospun matrices and formed tissue constructs.Efforts to eliminate hole defects with fibrogenic tissue growth factor-β resulted in the increased synthesis of collagen and periostin and a dramatic reduction in hole size and number.In control experiments, tissue spheroids fuse on a non-adhesive hydrogel and form continuous tissue constructs without holes.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Rowan University, Glassboro, NJ, USA.

ABSTRACT
Effective cell invasion into thick electrospun biomimetic scaffolds is an unsolved problem. One possible strategy to biofabricate tissue constructs of desirable thickness and material properties without the need for cell invasion is to use thin (<2 µm) porous electrospun meshes and self-assembling (capable of tissue fusion) tissue spheroids as building blocks. Pre-stretched electrospun meshes remained taut in cell culture and were able to support tissue spheroids with minimal deformation. We hypothesize that elastic electrospun scaffolds could be used as temporal support templates for rapid self-assembly of cell spheroids into higher order tissue structures, such as engineered vascular tissue. The aim of this study was to investigate how the attachment of tissue spheroids to pre-stretched polyurethane scaffolds may interfere with the tissue fusion process. Tissue spheroids attached, spread, and fused after being placed on pre-stretched polyurethane electrospun matrices and formed tissue constructs. Efforts to eliminate hole defects with fibrogenic tissue growth factor-β resulted in the increased synthesis of collagen and periostin and a dramatic reduction in hole size and number. In control experiments, tissue spheroids fuse on a non-adhesive hydrogel and form continuous tissue constructs without holes. Our data demonstrate that tissue spheroids attached to thin stretched elastic electrospun scaffolds have an interrupted tissue fusion process. The resulting tissue-engineered construct phenotype is a direct outcome of the delicate balance of the competing physical forces operating during the tissue fusion process at the interface of the pre-stretched elastic scaffold and the attached tissue spheroids. We have shown that with appropriate treatments, this process can be modulated, and thus, a thin pre-stretched elastic polyurethane electrospun scaffold could serve as a supporting template for rapid biofabrication of thick tissue-engineered constructs without the need for cell invasion.

No MeSH data available.


Related in: MedlinePlus