Effects of Fiber Density and Strain Rate on the Mechanical Properties of Electrospun Polycaprolactone Nanofiber Mats

Conte, Adriano A.; Sun, Katie; Hu, Xiao; Beachley, Vince

doi:10.3389/fchem.2020.00610

Cited by 43 publications

(17 citation statements)

References 60 publications

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“…With a fixed high voltage (35 kV) and flow rate (3.6 mL per hour) [ 21 ], the decrease in the PLGA concentration in the solution yielded fibers of smaller diameter, mainly owing to the reductions in the polymer viscosity and the degree of chain entanglements [ 25 , 26 , 27 ]. Larger fibers have significantly higher ultimate tensile strength, independent of the strain rate [ 28 ]. Additionally, the tensile moduli of the electrospun PLGA-based saxagliptin and pristine PLGA fibers were similar to that of rat skin (approximately 3.2 MPa) [ 29 ].…”

Section: Resultsmentioning

confidence: 99%

Enhanced Diabetic Wound Healing Using Electrospun Biocompatible PLGA-Based Saxagliptin Fibrous Membranes

et al. 2022

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Delayed diabetic wound healing is an adverse event that frequently leads to limb disability or loss. A novel and promising vehicle for the treatment of diabetic wounds is required for clinical purposes. The biocompatible and resorbable poly (lactic-co-glycolic acid) (PLGA)-based fibrous membranes prepared by electrospinning that provide a sustained discharge of saxagliptin for diabetic wound healing were fabricated. The concentration of released saxagliptin in Dulbecco's phosphate-buffered saline was analyzed for 30 days using high-performance liquid chromatography. The effectiveness of the eluted saxagliptin was identified using an endothelial progenitor cell migration assay in vitro and a diabetic wound healing in vivo. Greater hydrophilicity and water storage were shown in the saxagliptin-incorporated PLGA membranes than in the pristine PLGA membranes (both p <0.001). For diabetic wound healing, the saxagliptin membranes accelerated the wound closure rate, the dermal thickness, and the heme oxygenase-1 level over the follicle areas compared to those in the pristine PLGA group at two weeks post-treatment. The saxagliptin group also had remarkably higher expressions of insulin-like growth factor I expression and transforming growth factor-β1 than the control group (p= 0.009 and p< 0.001, respectively) in diabetic wounds after treatment. The electrospun PLGA-based saxagliptin membranes exhibited excellent biomechanical and biological features that enhanced diabetic wound closure and increased the antioxidant activity, cellular granulation, and functionality.

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Section: Resultsmentioning

confidence: 99%

Enhanced Diabetic Wound Healing Using Electrospun Biocompatible PLGA-Based Saxagliptin Fibrous Membranes

et al. 2022

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“…The calculated cross‐sectional area did not take into account the spaces between inserted filaments which could have led to a variation in tension during tensile testing. [ 48 ] Since every test involved the same materials with the same inherent properties, we expected the strain to remain consistent, irrespective of the number of filaments that was inserted. Finally, Young's Modulus (Figure 4J) was calculated as σ / ε and since both these values were similar across the range of scaffolds tested, it naturally follows that this produced a graph with little differences as well.…”

Section: Resultsmentioning

confidence: 99%

Manufacture of Soft‐Hard Implants from Electrospun Filaments Embedded in 3D Printed Structures

Alkaissy

Richard

Morris

et al. 2022

Macromolecular Bioscience

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Rotator cuff tendon tears are common injuries of the musculoskeletal system that often require surgical repair. However, re‐tearing following repair is a significant clinical problem, with a failure rate of up to 40%, notably at the transition from bone to tendon. The development of biphasic materials consisting of soft and hard components, which can mimic this interface, is therefore promising. Here, a simple manufacturing approach is proposed that combines electrospun filaments and 3D printing to achieve scaffolds made of a soft polydioxanone cuff embedded in a porous polycaprolactone block. The insertion area of the cuff is based on the supraspinatus tendon footprint and the size of the cuff is scaled up from 9 to 270 electrospun filaments to reach a clinically relevant strength of 227N on average. The biological evaluation shows that the biphasic scaffold components are noncytotoxic, and that tendon and bone cells can be grown on the cuff and block, respectively. Overall, these results indicate that combining electrospinning and 3D printing is a feasible and promising approach to create soft‐to‐hard biphasic scaffolds that can improve the outcomes of rotator cuff repair.

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“…The use of a slow speed manifold makes the fiber system random. This fiber microstructure determines specific mechanical properties, different from those observed in unidirectional fiber systems [58][59][60][61]. By analyzing the course of the curves on the basis of the tensile-strength-elongation relationship, it can be concluded, based on theoretical considerations, that PCL_MMT membranes are characterized by the highest strength, and thus the strength of interfiber contacts (the so-called complete fusion).…”

Section: Discussionmentioning

confidence: 97%

Effects of Montmorillonite and Gentamicin Addition on the Properties of Electrospun Polycaprolactone Fibers

et al. 2021

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Electrospinning was used to obtain multifunctional fibrous composite materials with a matrix of poly-ɛ-caprolactone (PCL) and 2 wt.% addition of a nanofiller: montmorillonite (MMT), montmorillonite intercalated with gentamicin sulphate (MMTG) or gentamicin sulphate (G). In the first stage, the aluminosilicate gallery was modified by introducing gentamicin sulfate into it, and the effectiveness of the intercalation process was confirmed on the basis of changes in the clay particle size from 0.5 µm (for MMT) to 0.8 µm (for MMTG), an increase in the interplanar distance d001 from 12.3 Å (for MMT) to 13.9 Å (for MMTG) and altered clay grain morphology. In the second part of the experiment, the electrospinning process was carried out in which the polymer nonwovens with and without the modifier were prepared directly from dichloromethane (DCM) and N,N-dimethylformamide (DMF). The nanocomposite fibrous membranes containing montmorillonite were prepared from the same polymer solution but after homogenization with the modifier (13 wt.%). The degree of dispersion of the modifier was evaluated by average microarray analysis from observed area (EDS), which was also used to determine the intercalation of montmorillonite with gentamicin sulfate. An increase in the size of the fibers was found for the materials with the presence of the modifier, with the largest diameters measured for PCL_MMT (625 nm), and the smaller ones for PCL_MMTG (578 nm) and PCL_G (512 nm). The dispersion of MMT and MMTG in the PCL fibers was also confirmed by indirect studies such as change in mechanical properties of the nonwovens membrane, where the neat PCL nonwoven was used as a reference material. The addition of the modifier reduced the contact angle of PCL nonwovens (from 120° for PCL to 96° for PCL_G and 98° for PCL_MMTG). An approximately 10% increase in tensile strength of the nonwoven fabric with the addition of MMT compared to the neat PCL nonwoven fabric was also observed. The results of microbiological tests showed antibacterial activity of all obtained materials; however, the inhibition zones were the highest for the materials containing gentamicin sulphate, and the release time of the active substance was significantly extended for the materials with the addition of montmorillonite containing the antibiotic. The results clearly show that the electrospinning technique can be effectively used to obtain nanobiocomposite fibers with the addition of nonintercalated and intercalated montmorillonite with improved strength and increased stiffness compared to materials made only of the polymer fibers, provided that a high filler dispersion in the spinning solution is obtained.

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Effects of Fiber Density and Strain Rate on the Mechanical Properties of Electrospun Polycaprolactone Nanofiber Mats

Cited by 43 publications

References 60 publications

Enhanced Diabetic Wound Healing Using Electrospun Biocompatible PLGA-Based Saxagliptin Fibrous Membranes

Enhanced Diabetic Wound Healing Using Electrospun Biocompatible PLGA-Based Saxagliptin Fibrous Membranes

Manufacture of Soft‐Hard Implants from Electrospun Filaments Embedded in 3D Printed Structures

Effects of Montmorillonite and Gentamicin Addition on the Properties of Electrospun Polycaprolactone Fibers

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