Fabrication and characterisation of biomimetic, electrospun gelatin fibre scaffolds for tunica media-equivalent, tissue engineered vascular grafts

Smooth muscle tissue engineering in crosslinked electrospun gelatin scaffolds

“…Below the collector, a stainless steel knife‐edged plate, at a 45° angle in line with the needle, was maintained at −3 kV. After electrospinning and drying, the scaffolds were vapor crosslinked in a vacuum desiccator containing 25% wt/vol glutaraldehyde in water (solution, grade II, Sigma Aldrich) for 2 h. The scaffolds were characterized microstructurally in both dry and wet state (swollen in deionized water for 24 h) . Figure (a) displays the scanning electron microscope (SEM) image of an example of such a scaffold.…”

“…Furthermore, the electrospinning set up induces preferential fiber orientation in 45° (oblique fiber orientation) as is illustrated in the fiber orientation distribution for each tubular scaffold in Table . As porosity and pore size increased, the wet, crosslinked electrospun tubular scaffolds S1, S2, S3, and S4 exhibited lower mechanical performance, with a Young's modulus (same in both axial and circumferential directions) varying from 1.2 to 0.1 MPa, tensile strength in the circumferential direction varying from 2 to 0.4 MPa, tensile strength in the axial direction varying from 0.8 to 0.4 MPa, and suture retention strength varying from 1.94 to 1.81 MPa, respectively …”

“…However, cell migration through the gel was very slow for mouse SMCs and has been thought to be even slower for the larger human SMCs. Crosslinked, electrospun multi‐layer gelatin fiber, tubular scaffolds with ±45 degree fiber orientation in acellular and wet state (gelatin swollen with water) exhibited improved suture strength in the range of 1.8–1.94 N, and also strength and Young's modulus equivalent to the tunica media of the coronary artery …”

Modeling, simulations, and optimization of smooth muscle cell tissue engineering for the production of vascular grafts

“…Table presents the value of the input parameters used for the computational simulations to simulate experiments presented by Elsayed et al (a, b). In the experiments, gelatin fiber scaffolds were electrospun as stacks of alternating +45 and −45° unidirectional fiber layers, forming a bidirectional fiber assembly to optimize the mechanical properties of the scaffold (Elsayed et al, ). The scaffold gelatin fibers were, subsequently, crosslinked using glutaraldehyde, as is described by Elsayed et al (a).…”

“…All initial scaffold microstructural parameters used as input data in the model and presented in Table refer to the measured mean values across the scaffold (mean fiber diameter, mean pore diameter, mean porosity; Elsayed et al, a). The permeability measurements for these scaffolds and other electrospun scaffolds of different porosity, pore and fiber size (Elsayed et al, a) were found to follow the Carman–Kozeny equation (Carman, ): with a Kozeny constant, K = 0.032 (Elsayed et al, a). Although the Carman–Kozeny equation has been derived for viscous flow through tubular porous paths and was intended for flow through granular beds, over the years its applicability has been well proven for flows through fiber media (Amico & Lekakou, ), which is, in fact, the case for the scaffolds of this study.…”