Papers by Keyword: Endothelialization

Abstract: Forming an endothelial cell (EC) monolayer on the surface of blood-contacting devices is an ideal way to improve their blood compatibility, this process is known as endothelialization. Heparin is a proteoglycan with a strong negative charge, which is a commonly used antithrombotic agent. Heparin coatings also has been successfully used to improve the hemocompatibility of various biomaterials. In this study, a short peptide Arg-Glu-Asp-Val (REDV) with specific affinity for endothelial cells was covalently conjugated with maleimide-functionalized heparin. The conjugate retains the negative charge of heparin and can be directly immobilized on the surface of positively charged poly-L-lysine. This specific reaction to the carboxyl group of heparin could potentially reduce the shedding and steric hindrance effects of REDV peptide and enhancing the affinity and selectivity of heparin for EC.

Abstract: An extracellular matrix-like poly (ε-caprolactone) (PCL)/gelatin core-shell nanofibrous scaffold with high hydrophilicity was developed by coaxial-elecrospinning. However, the behavior of vascular endothelial cells (ECs) on the modified scaffold remains limited. In this study, human umbilical vein ECs (HUVECs) were seeded onto PCL scaffolds with or without gelatin. Morphological changes of HUVECs were observed under confocal laser scanning microscopy (LSCM). HUVECs’ adhesion, proliferation and apoptosis were detected by MTT assay and flow cytometry (FCM). Our results showed that HUVECs on PCL/gelatin scaffolds with identical polygonal and cobblestone-like characteristics reached confluence after 7 days. Modification of PCL nanofibers significantly promoted the attachment of HUVECs onto scaffolds within 1 hour. Compared to pristine PCL, a two-fold increase in proliferation of HUVECs was also observed after 7 days, whereas the apoptosis of HUVECs was obviously reduced by 40% on the modified scaffolds. In summary, these results indicated modified PCL/gelatin scaffold developed by coaxial-elecrospinning can increase the adhesion, proliferation, and suppress apoptosis of HUVECs, suggesting it has a great potential and promising vascular graft in tissue engineering applications.

Abstract: The biological modification of biomaterials surface was an important means for surface endothelialization. In this work, an extracellular matrix-like (ECM-like) surface modification was developed for inducing endothelialization on titanium cardiovascular implant surface. To solve the problem of antibody denaturing caused in the randomly immobilizing, cluster of differentiation 34 (CD34) antibody was directly immobilized on titanium surface using a layer-by-layer self-assembly (LBL) technique. The biological behaviors of the endothelial progenitor cells (EPCs) on modified titanium surface were investigated by in vitro cell culture experiment. The results showed that the avidin, biotinylated protein A and the CD34 antibody were successfully assembled onto the NaOH etched titanium surface. The results of cells experiment suggested that the CD34 antibody immobilized surfaces promoted EPCs attachment and capture in vitro. It was believed that the response of adhesion, proliferation, differentiation of EPCs to titanium surface was regulated by modifying the surface chemistry which controlled the cell-biomaterial interactions. This work provided a surface biomodification means to increase the biocompatibility of titanium-based vascular implant surfaces.

Abstract: A new technique for micropatterning surfaces for cell growth support is described and characterized. This technique allows covering of large three-dimensional surfaces at low cost with controllable micropatterns. This method takes advantage of the random properties of aerosols and the principles of liquid atomization. Parameters of interest were the pressure of atomization air, the flow rate and volume of the atomised liquid, and the distance between the spray nozzle and the surface of the sample. The experimental setup permitted to obtain mean diameters of spots between 10 and 20 microns with a maximum surface coverage of 20%. In an initial step, polytetrafluoroethylene (PTFE) films were treated with ammonia plasma to insert amino groups on the surface. The ammonia plasma treated films were immersed in a solution containing sulfosuccinimidyl 4-(N-maleidomethyl)cyclohexane-1-carboxy-late (SSMCC) to permit the introduction of maleimido groups on the PTFE surface to subsequently conjugate peptides through a sulfhydryl containing N-terminal cystein residue. Plasma/S-SMCC pretreated surfaces were then sprayed with peptide sequences CGRGDS and CWQPPRARI. Our data showed that spots of CGRGDS peptides over a background of CWQPPRARI peptides were the most effective combination to enhance endothelialization.