Adhesion of Endothelial Cells and Endothelial Progenitor Cells on Peptide-Linked Polymers in Shear Flow

Abstract

The initial adhesion of human umbilical vein endothelial cells (HUVECs), cord blood endothelial colony-forming cells (ECFCs), and human blood outgrowth endothelial cells (HBOECs) was studied under radial flow conditions. The surface of a variable shear-rate device was either coated with polymer films or covered by synthetic fibers. Spin-coating was applied to produce smooth polymer films, while fibrous scaffolds were generated by electrospinning. The polymer was composed of hexyl methacrylate, methyl methacrylate, poly(ethylene glycol) methacrylate (PEGMA), and CGRGDS peptide. The peptide was incorporated into the polymer system by coupling to an acrylate-PEG-N-hydroxysuccinimide comonomer. A shear-rate-dependent increase of the attached cells with time was observed with all cell types. The adhesion of ECs increased on RGD-linked polymer surfaces compared to polymers without adhesive peptides. The number of attached ECFCs and HBOECs are significantly higher than that of HUVECs within the entire shear-rate range and surfaces examined, especially on RGD-linked polymers at low shear rates. Their superior adhesion ability of endothelial progenitor cells under flow conditions suggests they are a promising source for in vivo seeding of vascular grafts and shows the potential to be used for self-endothelialized implants.

Evaluation of late outgrowth endothelial progenitor cell and umbilical vein endothelial cell responses to thromboresistant collagen‐mimetic hydrogels

“…One approach to promote rapid endothelialization of “off‐the‐shelf” vascular prostheses involves utilizing bioactive luminal coatings to support EOC adhesion, proliferation, and differentiation . As previously noted, PEG‐Scl2‐2 hydrogels have been shown to maintain the resistance to the platelet adhesion and activation characteristic of pure PEG hydrogels and the resistance to platelet aggregation and activation associated with pure Scl2‐2 proteins .…”

In Vitro Endothelialization of Biodegradable Vascular Grafts Via Endothelial Progenitor Cell Seeding and Maturation in a Tubular Perfusion System Bioreactor

“…Second, it has been shown that a low flow rate supports better cell adhesion on graft surfaces during in vitro culture. 34 Prolonged adhesion is crucial to cell proliferation and eventual endothelialization of a TEVG.…”

“…These include modifications such as heparin-coated scaffolds, VEGF, antibodies, and various peptides. 28,34,38,46 Such modifications may improve initial cell seeding, which, in turn, may expedite in vitro endothelialization and tissue formation on bioreactor-cultured TEVGs. In addition, there is still some controversy on the role of EPCs and the role of specific subsets of these cells.…”

Promoting Endothelialization of Polymeric Cardiovascular Biomaterials

“…The presence of the adsorbed protein layer can act to hide the ligands of interest from view of the adhering cells . Therefore, the peptides are often immobilized to a non‐fouling interface [usually poly(ethylene glycol)] that resist non‐specific adsorption of proteins yet enable adhesion of cells that possess the appropriate integrin receptors . Additionally, the generation of synthetic materials that bare cell‐adhesive peptides on the surface provide a researcher with control over the surface density of the ligand, and this jurisdiction over surface density enables a researcher to regulate various aspects of adherent cell behaviour including adhesion, proliferation, migration, etc .…”