Vascular tissue engineering: Fabrication and characterization of acetylsalicylic acid‐loaded electrospun scaffolds coated with amniotic membrane lysate

Abstract

As the incidence of small‐diameter vascular graft (SDVG) occlusion is considerably high, a great amount of research is focused on constructing a more biocompatible graft. The absence of a biocompatible surface in the lumen of the engineered grafts that can support confluent lining with endothelial cells (ECs) can cause thrombosis and graft failure. Blood clot formation is mainly because of the lack of an integrated endothelium. The most effective approach to combat this problem would be using natural extracellular matrix constituents as a mimic of endothelial basement membrane along with applying anticoagulant agents to provide local antithrombotic effects. In this study, we fabricated aligned and random electrospun poly‐L‐lactic acid (PLLA) scaffolds containing acetylsalicylic acid (ASA) as the anticoagulation agent and surface coated them with amniotic membrane (AM) lysate. Vascular scaffolds were structurally and mechanically characterized and assessed for cyto‐ and hemocompatibility and their ability to support endothelial differentiation was examined. All the scaffolds showed appropriate tensile strength as expected for vascular grafts. Lack of cytotoxicity, cellular attachment, growth, and infiltration were proved using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay and scanning electron microscopy. The blood compatibilities of different scaffolds examined by in vitro hemolysis and blood coagulation assays elucidated the excellent hemocompatibility of our novel AM‐coated ASA‐loaded nanofibers. Drug‐loaded scaffolds showed a sustained release profile of ASA in 7 days. AM‐coated electrospun PLLA fibers showed enhanced cytocompatibility for human umbilical vein ECs, making a confluent endothelial‐like lining. In addition, AM lysate‐coated ASA‐PLLA‐aligned scaffold proved to support endothelial differentiation of Wharton's jelly‐derived mesenchymal stem cells. Our results together indicated that AM lysate‐coated ASA releasing scaffolds have promising potentials for development of a biocompatible SDVG.

Fabrication and Plasma Surface Activation of Aligned Electrospun PLGA Fiber Fleeces with Improved Adhesion and Infiltration of Amniotic Epithelial Stem Cells Maintaining their Teno-inductive Potential

“…Different working gases such as air, oxygen (O 2 ), nitrogen (N 2 ), ammonium (NH 3 ), argon (Ar), or helium (He) have been used for this purpose [29,[43][44][45][46][47][48]. Most of studies concerning plasma activation of electrospun scaffolds have focused on PCL [29,46,47,[49][50][51] and PLLA [52][53][54][55][56][57][58] while those concerning PLGA [48,[59][60][61][62] are few and still neglected in the literature although its wide application range in the field of tissue engineering [63]. Despite the known cytocompatibility of PLGA [10,11,13,25,64], its poor hydrophilic properties and the rather low ability to interact with cells restrict the natural cell recognition sites on its surface, which may lead to poor overall cell adhesion [65].…”

Metagenomic discovery and functional validation of L-asparaginases with anti-leukemic effect from the Caspian Sea

“…In vitro hemolysis test was also performed according to available protocols with minor modi cations [42,43]. The test was done based on standard phlebotomy procedures.…”

Improved efficacy of bio‐mineralization of human mesenchymal stem cells on modified PLLA nanofibers coated with bioactive materials via enhanced expression of integrin α2β1

“…[8][9][10] and synthetic ceramics such as poly-L-lactide acid (PLLA), poly caprolactone (PCL), and poly lactide acid (PLA), etc. [11][12][13][14] The compatibility issue can be avoided by using electrospinning technology, in which the polymeric solutions are transformed into nanofibers by electrostatic forces. 15 Currently, the electrospun PLLA nanofibers have been widely used in tissue engineering, bone regenerative medicine, and bone grafting due to their high surface-to-volume ratio along with an adjustable porosity and porous structures.…”