Fabrication of Highly Oriented Cylindrical Polyacrylonitrile, Poly(lactide-co-glycolide), Polycaprolactone and Poly(vinyl acetate) Nanofibers for Vascular Graft Applications

Abstract

Small-diameter vascular grafts fabricated from synthetic polymers have found limited applications so far in vascular surgeries, owing to their poor mechanical properties. In this study, cylindrical nanofibrous structures of highly oriented nanofibers made from polyacrylonitrile, poly (lactide-co-glycolide) (PLGA), polycaprolactone (PCL) and poly(vinyl acetate) (PVAc) were investigated. Cylindrical collectors with alternate conductive and non-conductive segments were used to obtain highly oriented nanofibrous structures at the same time with better mechanical properties. The surface morphology (orientation), mechanical properties and suture retention of the nanofibrous structures were characterized using SEM, mechanical tester and universal testing machine, respectively. The PLGA nanofibrous cylindrical structure exhibited excellent properties (tensile strength of 9.1 ± 0.6 MPa, suture retention strength of 27N and burst pressure of 350 ± 50 mmHg) when compared to other polymers. Moreover, the PLGA grafts showed good porosity and elongation values, that could be potentially used for vascular graft applications. The combination of PLGA nanofibers with extracellular vesicles (EVs) will be explored as a potential vascular graft in future.

Optimization of Electrospun Bilayer Vascular Grafts through Assessment of the Mechanical Properties of Monolayers

“…On the other hand, since the adhesion behavior of the fibers to each other has been enhanced with the orientation, there has been a significant improvement, especially in the longitudinal elongation. Malik et al produced electrospun vascular grafts with axially oriented fibers and achieved higher tensile strength values in the direction of the orientation when compared with randomly oriented samples . Besides, the tensile strength values of the oriented samples showed a slight decrement in longitudinal test direction in most cases when compared with the samples with randomly distributed fibers, as the number of fibers reduced in the longitudinal direction by the effect of radial fiber orientation.…”

A Flexible Multifunctional PAN Piezoelectric Fiber with Hydrophobicity, Energy Storage, and Fluorescence

“…Figure 9 a is the stress–strain curve of PAN composite fibers, and Table 1 shows the specific parameters of the dielectric properties and mechanical properties. Polyacrylonitrile nanofibers certainly exhibited mechanical strength and stretchability [ 47 , 48 ]. The addition of ILs made the PAN nanofibers exhibit a certain orientation under the action of electrostatic force.…”

Fibrous hydrogels by electrospinning: Novel platforms for biomedical applications

“…Typically, diameters of electrospun fibers, controlled by electrospinning setup (voltage applied to a needle, flow rate of precursors, and distance between a needle and a collector) 32 – 35 and viscosity of precursors, 36 vary from some 10 nm to 10 µm, 37 and various approaches (rotating collector, gap electrospinning, and magnetic field-assisted electrospinning) were developed to manipulate alignment of fibers. 38 – 41 These micro/nanofibers were electrospun with various materials such as poly (ε-caprolactone) (PCL), 42 – 44 polylactic acid (PLA), 45 , 46 poly (D, L-lactic-co-glycolic) acid (PLGA), 47 – 50 polyurethane (PU), 51 – 53 and polyacrylonitrile (PAN) 54 , 55 and used for drug delivery, wound dressings, and vascular graft applications.…”