Healing characteristics of electrospun polyurethane grafts with various porosities

Bergmeister, Helga; Schreiber, C; Grasl, Christian; Walter, Ingrid; Plasenzotti, Roberto; Stoiber, Martin; Bernhard, David; Schima, Heinrich

doi:10.1016/j.actbio.2012.12.009

Cited by 102 publications

(96 citation statements)

References 39 publications

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“…This decrease in pore diameter of the PLA/PLA composite scaffold might be due to the introduction of a small amount of nanofibers (20 wt%). However, a pore size of approximately 40 μ m is large enough to allow cells to freely migrate in many cases [25]. …”

Section: Resultsmentioning

confidence: 99%

Fabrication of Microfibrous and Nano-/Microfibrous Scaffolds: Melt and Hybrid Electrospinning and Surface Modification of Poly(L-lactic acid) with Plasticizer

Yoon

Park

Lee

et al. 2013

BioMed Research International

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Biodegradable poly(L-lactic acid) (PLA) fibrous scaffolds were prepared by electrospinning from a PLA melt containing poly(ethylene glycol) (PEG) as a plasticizer to obtain thinner fibers. The effects of PEG on the melt electrospinning of PLA were examined in terms of the melt viscosity and fiber diameter. Among the parameters, the content of PEG had a more significant effect on the average fiber diameter and its distribution than those of the spinning temperature. Furthermore, nano-/microfibrous silk fibroin (SF)/PLA and PLA/PLA composite scaffolds were fabricated by hybrid electrospinning, which involved a combination of solution electrospinning and melt electrospinning. The SF/PLA (20/80) scaffolds consisted of a randomly oriented structure of PLA microfibers (average fiber diameter = 8.9 µm) and SF nanofibers (average fiber diameter = 820 nm). The PLA nano-/microfiber (20/80) scaffolds were found to have similar pore parameters to the PLA microfiber scaffolds. The PLA scaffolds were treated with plasma in the presence of either oxygen or ammonia gas to modify the surface of the fibers. This approach of controlling the surface properties and diameter of fibers could be useful in the design and tailoring of novel scaffolds for tissue engineering.

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Section: Resultsmentioning

confidence: 99%

Fabrication of Microfibrous and Nano-/Microfibrous Scaffolds: Melt and Hybrid Electrospinning and Surface Modification of Poly(L-lactic acid) with Plasticizer

Yoon

Park

Lee

et al. 2013

BioMed Research International

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“…Significant differences exist even in how researchers analyze their samples based on shape. Some researchers use a tubular shape—representing a macroscopic view of a blood vessel – while others employ a square sample . Within these studies there has been some analysis as to how different properties affect the maximum attained SRS force.…”

Section: Discussionmentioning

confidence: 99%

Biomimetic microstructural reorganization during suture retention strength evaluation of electrospun vascular scaffolds

et al. 2015

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Suture retention strength (SRS) is commonly used as a measure the ability of sutures to adhere implants to surrounding tissue. While SRS is widely employed, surprisingly its effects on graft microstructure have not been characterized. This is particularly germane to the broad utilization of electrospun implants in tissue engineering. These implants need to retain their initial nanoscale topography while simultaneously preserving clinically critical mechanical properties. We examined the suture-driven microstructural deformation of polycaprolactone electrospun to form both square and tubular SRS samples. The impact of fiber orientation (generally parallel or random orientation, orthogonally aligned) on the SRS of these vascular tissue equivalents was analyzed and compared to native and decellularized porcine vasculature. The initial state of the fiber clearly dictates the overall efficiency of scaffold utilization. SRS values for as-spun fibers at a thickness of 300 μm were found to be in the range of 1.59-4.78 N for the three orientations. Unexpectedly, random fibers provided the optimal SRS values based on both resistance to suture motion and the percentage of scaffold involvement. A "V-shaped" failure morphology is observed for both electrospun scaffolds and native tissue during SRS testing. Post-test fiber alignment in the tensile direction was visible in all initial fiber orientations similar to that of native tissue. These findings are significant as they allow us to employ new, counterintuitive biomimetic design criteria for nanofiber-based scaffolds in which reliable mechanical integration with the surrounding tissues via suture-based methods is important. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1525-1534, 2016.

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“…7 In brief, data were acquired using a load frame fitted with a 50-pound load cell with a force resolution of 10 −4 pounds and a linear displacement resolution of 10 −8 inches. Compliance testing was performed using a displacement velocity of 1.5 mm/minute and an acquisition rate of 4 data points/second using Laplace’s Law 8,9 to correlate linear force and displacement to compliance. Burst pressure testing was performed using a displacement velocity of 50 mm/minute and an acquisition rate of 4 data points/second using Laplace’s Law 8,10 to correlate linear force and displacement to burst pressure.…”

Section: Methodsmentioning

confidence: 99%

Preclinical study of patient-specific cell-free nanofiber tissue-engineered vascular grafts using 3-dimensional printing in a sheep model

Fukunishi

Best

Sugiura

et al. 2017

The Journal of Thoracic and Cardiovascular Surgery

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Background Tissue-engineered vascular grafts (TEVGs) offer potential to overcome limitations of current approaches for reconstruction in congenital heart disease by providing biodegradable scaffolds on which autologous cells proliferate and provide physiologic functionality. However, current TEVGs do not address the diverse anatomic requirements of individual patients. This study explores the feasibility of creating patient-specific TEVGs by combining 3-dimensional (3D) printing and electrospinning technology. Methods An electrospinning mandrel was 3D-printed after computer-aided design based on preoperative imaging of the ovine thoracic inferior vena cava (IVC). TEVG scaffolds were then electrospun around the 3D-printed mandrel. Six patient-specific TEVGs were implanted as cell-free IVC interposition conduits in a sheep model and explanted after 6 months for histologic, biochemical, and biomechanical evaluation. Results All sheep survived without complications, and all grafts were patent without aneurysm formation or ectopic calcification. Serial angiography revealed significant decreases in TEVG pressure gradients between 3 and 6 months as the grafts remodeled. At explant, the nanofiber scaffold was nearly completely resorbed and the TEVG showed similar mechanical properties to that of native IVC. Histological analysis demonstrated an organized smooth muscle cell layer, extracellular matrix deposition, and endothelialization. No significant difference in elastin and collagen content between the TEVG and native IVC was identified. There was a significant positive correlation between wall thickness and CD68+ macrophage infiltration into the TEVG. Conclusions Creation of patient-specific nanofiber TEVGs by combining electrospinning and 3D printing is a feasible technology as future clinical option. Further preclinical studies involving more complex anatomical shapes are warranted.

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Healing characteristics of electrospun polyurethane grafts with various porosities

Cited by 102 publications

References 39 publications

Fabrication of Microfibrous and Nano-/Microfibrous Scaffolds: Melt and Hybrid Electrospinning and Surface Modification of Poly(L-lactic acid) with Plasticizer

Fabrication of Microfibrous and Nano-/Microfibrous Scaffolds: Melt and Hybrid Electrospinning and Surface Modification of Poly(L-lactic acid) with Plasticizer

Biomimetic microstructural reorganization during suture retention strength evaluation of electrospun vascular scaffolds

Preclinical study of patient-specific cell-free nanofiber tissue-engineered vascular grafts using 3-dimensional printing in a sheep model

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