Adhesion Of Human Endothelial Cells Research Articles

Flexible and Stretchable Photoelectrochemical Sensing toward True-to-Life Monitoring of Hydrogen Peroxide Regulation in Endothelial Mechanotransduction.

Hydrogen peroxide (H2O2) levels play a vital role in redox regulation and maintaining the physiological balance of living cells, especially in cell mechanotransduction. Despite the achievements on strain-induced cellular H2O2 monitoring, the applied voltage for H2O2 electrooxidation possibly gave rise to an abnormal expression and inadequate accuracy, which was still an inescapable concern. Hence, we decorated an interlaced CuO@TiO2 nanowires (NWs) semiconductor meshwork onto a polydimethylsiloxane film-supported gold nanotubes substrate (Au NTs/PDMS) to construct a flexible photoelectrochemical (PEC) sensing platform. Under white light irradiation, CuO@TiO2 NWs synergistically exhibited great stretchability and the PEC platform enabled stable photocurrent responses from the reduction of H2O2 even during mechanical deformation. Moreover, the admirable biocompatibility and an almost negligible open circuit voltage of +0.18 V for the CuO@TiO2 NWs/Au NTs/PDMS sensor guaranteed human umbilical vein endothelial cells (HUVECs) adhesion tightly thereon even under continuous illumination for 30 min. Finally, the as-proposed stretchable PEC sensor achieved sensitive and true-to-life monitoring of transient H2O2 release during HUVECs deformation, in which H2O2 release was positively correlated to mechanical strains. This investigation opens a new shade path on in situ cellular sensing and meanwhile greatly expands the application mode of the PEC approach.

Facile design of biofunctionalized nanocomposite hydrogel to potentiate angiogenesis and osteogenesis for the skull regeneration

The clinical treatment of cranial defect reconstruction using hydrogels faces challenges such as inadequate biomechanical strength and limited biofunctional effects. In this study, we have addressed these issues by developing a novel hydrogel. This hydrogel composes desferrioxamine-modified laponite nanoplatelets (LAP/DFO) combined with tannin-modified poly(vinyl alcohol) (PVA/TA), aiming to closely emulate the natural organic-inorganic bony matrix. Our results indicated that the multifunctional hydrogel system, particularly when incorporating LAP/DFO (referred to as PL10), could form a highly ordered porous structure, achieve appropriate biomechanical strength, and release bioactive factors as expected. This system enhanced the adhesion and proliferation of human umbilical vein endothelial cells (HUVECs) for angiogenesis and promoted mesenchymal stem cells (MSCs) osteogenic differentiation for osteogenesis in vitro. Moreover, in vivo investigations confirmed the efficacy of the multifunctional hydrogels, particularly PL10, in enhancing bone regeneration compared to blank PVA. Collectively, this study contributes valuable insights into the design of bioactive factor delivery systems and offers efficient therapeutic strategies for promoting the repair of cranial defects.

Circulating cluster miR-99b/let-7e/miR-125a expression associates with endothelial function, cytokine, and chemokine levels in myocardial infarction patients

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Ministry of Science and Innovation (ISCIII) co-financed by the European Regional Development Fund (ERDF), and by the Generalitat Valenciana Introduction During vascular remodelling following a myocardial infarction, miRNAs can modulate endothelial function in a post-transcriptional manner. Our study is focused on the cluster miR-99b/let-7e/miR-125a, examining its serum expression during the acute phase of a Non-ST-segment Elevation Myocardial Infarction (NSTEMI) and its expression one year later. Purpose All the miRNA miR-99b/let-7e/miR-125a cluster is hypothesized to impact endothelial function, specifically influencing cellular adhesion, proliferation, and vasculogenesis. Furthermore, it is hypothesized an association exists between the levels of miRNAs from this cluster during the acute phase of myocardial infarction and the serum levels of inflammatory cytokines and chemokines implicated in the pathology. Methods Serum RNA was extracted from control (n=41), acute NSTEMI phase (n=46), and one-year follow-up (n=24) patients. miRNA expression was quantified by qRT-PCR and miR-484 was used as endogenous control. Endothelial function was assessed by analyzing adhesion, proliferation, and vasculogenesis in human umbilical vein endothelial cells (HUVEC) and transfected with miRNA inhibitors and mimics. Serum levels of proinflammatory cytokines (IL-1β, IL-6, TNF-α, and VEGF-A), anti-inflammatory cytokines (IL-10 and IL-13), and chemokines (MCP-3, MDC, IL-8, and MIP-1α) were determined. Results The miRNA cluster components exhibited decreased expression during the acute phase of the infarction (p< 0.05) and returned to control levels after one year of follow-up. All the cluster components were high expressed in endothelial cells, and we determined the effect of these miRNAs or their inhibition on endothelial function. let-7e mimic increased (p< 0.05) cell adhesion, as well as the formation of tubular networks (p< 0.001). miR-125a inhibitor decreased cell proliferation (p< 0.05). Neither the mimic nor the inhibitor of miR-99b had effects on this endothelial function. let-7e exhibited a negative correlation with the proinflammatory cytokine TNF-α (r= -0.19, p= 0.0386) and a positive correlation with the levels of the anti-inflammatory cytokine IL-13 (r= 0.22, p= 0.0416). miR-99b showed a positive association with the chemokine MDC (r= 0.22, p= 0.0195), while the levels of miR-125a did not correlate with any of the analysed mediators. Conclusions miR-99b/let-7e/miR-125a cluster is implicated in NSTEMI and exhibits a consistent expression pattern in patients' serum, decreasing during the acute phase and returning to control levels one year after. Each of these miRNAs, especially let-7e and miR-125a, differentially affects cellular processes such as endothelial proliferation and angiogenesis. Additionally, let-7e and miR-99b miRNAs differentially impact the inflammation generated in NSTEMI. These results suggest the involvement of miRNAs from the same cluster in various processes that are coordinately activated in inflammatory situations, such as acute coronary syndrome.

In situ densification and heparin immobilization of bacterial cellulose vascular patch for potential vascular applications

Nowadays, developing vascular grafts (e.g., vascular patches and tubular grafts) is challenging. Bacterial cellulose (BC) with 3D fibrous network has been widely investigated for vascular applications. In this work, different from BC vascular patch cultured with the routine culture medium, dopamine (DA)-containing culture medium is employed to in situ synthesize dense BC fibrous structure with significantly increased fiber diameter and density. Simultaneously, BC fibers are modified by DA during in situ synthesis process. Then DA on BC fibers can self-polymerize into polydopamine (PDA) accompanied with the removal of bacteria in NaOH solution, obtaining PDA-modified dense BC (PDBC) vascular patch. Heparin (Hep) is subsequently covalently immobilized on PDBC fibers to form Hep-immobilized PDBC (Hep@PDBC) vascular patch. The obtained results indicate that Hep@PDBC vascular patch exhibits remarkable tensile and burst strength due to its dense fibrous structure. More importantly, compared with BC and PDBC vascular patches, Hep@PDBC vascular patch not only displays reduced platelet adhesion and improved anticoagulation activity, but also promotes the proliferation, adhesion, spreading, and protein expression of human umbilical vein endothelial cells, contributing to the endothelialization process. The combined strategy of in situ densification and Hep immobilization provides a feasible guidance for the construction of BC-based vascular patches.

Electrospun silk fibroin/polylactic acid conduit filled with proangiogenic carboxylated silk fibroin/chitosan hydrogel facilitates peripheral nerve regeneration

Angiogenesis plays a crucial role in peripheral nerve regeneration after injury. We introduce a proangiogenic hydrogel-filled nerve conduit, designed to promote peripheral nerve regeneration. The hydrogel was synthesized by chemically crosslinking carboxylated silk fibroin (cSF) and chitosan (CS), enriched with vascular endothelial growth factor (VEGF) to initiate angiogenesis. Complementarily, a nerve conduit was fabricated using coaxial electrospinning of poly-lactic acid (PLA), silk fibroin (SF), and ibuprofen (IBU) was incorporated to further support nerve regeneration. The hydrogel exhibited optimal properties including rapid gelation, uniform porosity and full biodegradation within four weeks. The nerve conduit, on the other hand, displayed enhanced mechanical strength, elasticity, and controlled biodegradability. In vitro assays demonstrated a sustained release of VEGF and IBU, which significantly enhanced cell adhesion, proliferation, migration and angiogenesis in Human umbilical vein endothelial cells (HUVEC), as well as promoted adhesion and proliferation in rat Schwann cells (RSC96). This proangiogenic hydrogel-filled nerve conduit thus emerged as a potent candidate for advancing peripheral nerve regeneration.

An imprint-based approach to replicate nano- to microscale roughness on gelatin hydrogel scaffolds: surface characterization and effect on endothelialization

Biologization of biomaterials with endothelial cells (ECs) is an important step in vascular tissue engineering, aiming at improving hemocompatibility and diminishing the thrombo-inflammatory response of implants. Since subcellular topography in the scale of nano to micrometers can influence cellular adhesion, proliferation, and differentiation, we here investigate the effect of surface roughness on the endothelialization of gelatin hydrogel scaffolds. Considering the micron and sub-micron features of the different native tissues underlying the endothelium in the body, we carried out a biomimetic approach to replicate the surface roughness of tissues and analyzed how this impacted the adhesion and proliferation of human umbilical endothelial cells (HUVECs). Using an imprinting technique, nano and micro-roughness ranging from Sa= 402 nm to Sa= 8 μm were replicated on the surface of gelatin hydrogels. Fluorescent imaging of HUVECs on consecutive days after seeding revealed that microscale topographies negatively affect cell spreading and proliferation. By contrast, nanoscale roughnesses of Sa= 402 and Sa= 538 nm promoted endothelialization as evidenced by the formation of confluent cell monolayers with prominent VE-cadherin surface expression. Collectively, we present an affordable and flexible imprinting method to replicate surface characteristics of tissues on hydrogels and demonstrate how nanoscale roughness positively supports their endothelialization.

Electrospun membranes of diselenide-containing poly(ester urethane)urea for in situ catalytic generation of nitric oxide

Nitric oxide (NO) plays an important role as a signalling molecule in the biological system. Organoselenium-coated or grafted biomaterials have the potential to achieve controlled NO release as they can catalyse decomposition of endogenous S-nitrosothiols to NO. However, such biomaterials are often challenged by the loss of the catalytic sites, which can affect the stability in tissue repair applications. In this work, we prepare a diselenide-containing poly(ester urethane)urea (SePEUU) polymer with Se–Se in the backbone, which is further electrospun into fibrous membranes by blending with poly(ester urethane)urea (PEUU) without diselenide bonds. The presence of catalytic sites in the main chain demonstrates stable and long-lasting NO catalytic activity, while the porous structure of the fibrous membranes ensures uniform distribution of the catalytic sites and better contact with the donor-containing solution. PEUU/SePEUU50 in 50/50 mass ratio has a physiologically adapted rate of NO release, with a sustained generation of NO after exposure to PBS at 37 °C for 30 d. PEUU/SePEUU50 has a low hemolysis and protein adsorption, with mechanical properties in the wet state matching those of natural vascular tissues. It can promote the adhesion and proliferation of human umbilical vein endothelial cells in vitro and control the proliferation of vascular smooth muscle cells in the presence of NO generation. This study exhibits the electrospun fibrous membranes have potential for utilizing as hemocompatible biomaterials for regeneration of blood-contacting tissues.

3D Foaming Printing Biomimetic Hierarchically Macro-Micronanoporous Hydrogels for Enhancing Cell Growth and Proliferation.

Hydrogel, recognized as a promising biomaterial for tissue engineering, possesses notable characteristics, including high water uptake, an interconnected porous structure, and excellent permeability. However, the intricate task of fabricating a hierarchically macro-micronanoporous structure, essential for providing adequate space for nutrient diffusion and cell growth within hydrogels, remains a formidable challenge. In response to these challenges, this study introduces a sustainable and straightforward three-dimensional (3D) foaming printing strategy to produce hierarchically macro-micronanoporous hydrogels (HPHs) without the utilization of porogens and post-etching process. This method entails the controlled generation of air bubbles within the hydrogels through the application of optimal mechanical stirring rates. Subsequent ultraviolet (UV) cross-linking serves to effectively stabilize the macropores within the HPHs. The resulting hierarchically macro-micronanoporous structures demonstrate a substantial improvement in the viability, adhesion, and proliferation of human umbilical vein endothelial cells (HUVECs) when incubated with the hydrogels. These findings present a significant advancement in the fabrication of hierarchically macro-micronanoporous hydrogels, with potential applications in the fields of tissue engineering and organoid development.

PH-responsive, self-sculptured Mg/PLGA composite microfibers for accelerated revascularization and soft tissue regeneration

Biodegradable Mg/polymer composite fibers offer a promising therapeutic option for tissue injury because of bioactive Mg2+ and biomimetic microstructure. However, current studies are limited to the contribution of Mg2+ and the single microstructure. In this study, we designed Mg/poly (lactic-co-glycolic acid) (Mg/PLGA) composite microfibers that significantly enhanced angiogenesis and tissue regeneration synergistically by Mg2+ and self-sculptured microstructure, due to spontaneous in situ microphase separation in response to the weakly alkaline microenvironment. Our composite microfiber patch exhibited superior performance in the adhesion, spreading, and angiogenesis functions of human umbilical vein endothelial cells (HUVECs) due to the joint contribution of the hierarchically porous microstructure and Mg2+. Genomics and proteomics analyses revealed that the Mg/PLGA composite microfibers activated the cell focal adhesion and angiogenesis-related signaling pathways. Furthermore, the repair of typical soft tissue defects, including refractory urethral wounds and easily healed skin wounds, validated that our Mg/PLGA composite microfiber patch could provide favorable surface topography and ions microenvironment for tissue infiltration and accelerated revascularization. It could cause rapid urethral tissue regeneration and recovery of rabbit urethral function within 6 weeks and accelerate rat skin wound closure within 16 days. This work provides new insight into soft tissue regeneration through the bioactive alkaline substance/block copolymer composites interactions.

Polymer-Based Electrospun Vascular Grafts: A Study of Constructs and Endothelial Interactions

This study investigates tissue-engineered vascular grafts using electrospun polycaprolactone (PCL) and poly(l-lactide-co-caprolactone) (PLCL) polymers. The goal is to assess human umbilical endothelial cell (HUVEC) adhesion and proliferation on the fabricated grafts. Electrospinning produces nanofibrous scaffolds mimicking the ECM, fostering a suitable environment for cellular growth. Tubular surfaces from PCL and PLCL with randomly distributed fibers are cultured with HUVECs. The scaffolds underwent MTS analysis to assess cell viability, along with PECAM1 and PCDH12 gene expression analysis to observe cell-scaffold interactions. In the MTS analysis, on the 14th day, the PCL samples exhibit a 20% higher proliferation value than the control group, while the PLCL samples show an 8% increase. However, upon examining gene expression analyses, it is evident that the PLCL samples demonstrated a higher fold-change in both PECAM1 and PCDH12 gene expressions on days 3, 7, and 14 compared to the PCL samples. The outcomes demonstrate the potential of the developed electrospun vascular grafts for cardiovascular tissue engineering.

Strengthened Decellularized Porcine Valves via Polyvinyl Alcohol as a Template Improving Processability.

The heart valve is crucial for the human body, which directly affects the efficiency of blood transport and the normal functioning of all organs. Generally, decellularization is one method of tissue-engineered heart valve (TEHV), which can deteriorate the mechanical properties and eliminate allograft immunogenicity. In this study, removable polyvinyl alcohol (PVA) is used to encapsulate decellularized porcine heart valves (DHVs) as a dynamic template to improve the processability of DHVs, such as suturing. Mechanical tests show that the strength and elastic modulus of DHVs treated with different concentrations of PVA significantly improve. Without the PVA layer, the valve would shift during suture puncture and not achieve the desired suture result. The in vitro results indicate that decellularized valves treated with PVA can sustain the adhesion and growth of human umbilical vein endothelial cells (HUVECs). All results above show that the DHVs treated with water-soluble PVA have good mechanical properties and cytocompatibility to ensure post-treatment. On this basis, the improved processability of DHV treated with PVA enables a new paradigm for the manufacturing of scaffolds, making it easy to apply.

Enhancing mechanical property, osteogenesis and angiogenesis of 3D-plotted β-tricalcium phosphate bioceramic scaffolds incorporated with magnesium silicate: In Vitro and In Vivo study

The balance between porosity and compressive strength, as well as the pro-osteogenic and pro-angiogenesis effects of β-tricalcium phosphate (β-TCP) are not satisfactory in the clinical application even though it has good biocompatibility, osseointegration and osteoconductivity. Herein, different contents (10, 20 and 30 wt%) of magnesium silicate (Mg2SiO4, MS) and β-TCP composite bioceramic scaffolds (MS/β-TCP) were fabricated by three-dimensional fiber deposition (3DF) technology. The physicochemical, in vitro osteogenic and angiogenic properties, the early (6 weeks) cranium defect repair effects in rats and the underlying molecular mechanism on accelerating osteogenic differentiation of MS/β-TCP were systematically investigated. The results showed that MS compounding not only promoted the sintering of β-TCP and significantly enhanced the compressive strength, but also greatly improved its osteogenic and angiogenic performances, such as the viability, adhesion, and proliferation of mouse bone marrow mesenchymal stem cells (mBMSCs) and human umbilical vein endothelial cells (HUVECs), ALP activity and the expression of adhesion-related, osteogenesis-related and angiogenesis-related genes. The in vivo experiments presented that 10MS/β-TCP had more new bone formation and better angiogenesis compared to β-TCP and Blank. Analysis of the transcriptome sequencing results confirmed that the Wnt signaling pathway was involved in the regulation of osteogenic differentiation in mBMSCs by the MS/β-TCP composite bioceramic scaffold. The MS/β-TCP holds great potential in bone repair and regeneration.

Facile exfoliation of natural silk nanofibrils for homogeneous reinforced composites

AbstractRegenerated silk fibroin (SF) as a biomaterial has attracted increasing attention due to its outstanding biocompatibility and processibility. However, it faces great challenges in practical application because of the deterioration of the intrinsic mechanical properties of natural silk during the regeneration process. Natural silk nanofibrils (SNFs) has a typical hierarchical structure and maintains excellent mechanical properties of natural silk. Based on principle of homogeneous reinforced composites, herein, the SNFs were isolated as a reinforcing material and regenerated SF as matrix material to fabricate high‐performance SF nanocomposites. The SNFs with diameters ranging from 100 to 600 nm were prepared with yields of 87%. They not only maintained the crystallinity of natural silk, but also remained high stability in acid and alkaline solutions. Thanks to homogenous reinforcement of the SNFs, the tensile stress of the reinforced film was up to 2.2 MPa, the strain was 129%, and the water absorption was 50% in wet state. In vitro, the reinforced films supported adhesion and proliferation of human umbilical vein endothelial cells, which has potential in the application of biomedical dressings.Highlights Natural silk nanofibrils (SNFs) were exfoliated using a facile approach. The SNFs reinforced the silk nanocomposites significantly. The silk nanocomposites showed remarkable cytocompatibility. Homogeneous reinforcement is useful strategy to fabricate nanocomposites.

Celastrol inhibits angiogenesis and the biological processes of MDA-MB-231 cells via the DEGS1/S1P signaling pathway.

Celastrol (Cel) shows potent antitumor activity in various experimental models. This study examined the relationship between Cel's antivascular and antitumor effects and sphingolipids. CCK-8 assay, transwell assay, Matrigel, PCR-array/RT-PCR/western blotting/immunohistochemistry assay, ELISA and HE staining were used to detect cell proliferation, migration and invasion, adhesion and angiogenesis, mRNA and protein expression, S1P production and tumor morphology. The results showed that Cel could inhibit proliferation, migration or invasion, adhesion and angiogenesis of human umbilical vein endothelial cells (HUVECs) and MDA-MB-231 cells by downregulating the expression of degenerative spermatocyte homolog 1 (DEGS1). Transfection experiments showed that downregulation of DEGS1 inhibited the above processes and sphingosine-1-phosphate (S1P) production of HUVECs and MDA-MB-231 cells, while upregulation of DEGS1 had the opposite effects. Coculture experiments showed that HUVECs could promote proliferation, migration and invasion of MDA-MB-231 cells through S1P/sphingosine-1-phosphate receptor (S1PR) signaling pathway, while Cel inhibited these processes in MDA-MB-231 cells induced by HUVECs. Animal experiments showed that Cel could inhibit tumor growth in nude mice. Western blotting, immunohistochemistry and ELISA assay showed that Cel downregulated the expression of DEGS1, CD146, S1PR1-3 and S1P production. These data confirm that DEGS1/S1P signaling pathway may be related to the antivascular and antitumor effects of cel.

The silk fibroin nanofibrous membrane loaded with polyhexamethyl biguanide for promoting infected wound healing

The design of wound dressings with both antibacterial activity and physicochemical properties to promote infected wound healing is still an urgent need for clinical application. Silk fibroin (SF) exhibited good mechanical properties, anti-ultraviolet, whitening, and moisturizing activities, which had been widely used in the biomedical field. However, SF-based dressings tend to adhere to bacteria and cause additional infections due to lack of antibacterial activity. Therefore, the present study employed electrospinning technology to produce a silk fibroin nanofibrous membrane (SFM) loaded with polyhexamethyl biguanide (PHMB), an effective antibacterial agent, thereby obtaining the PHMB-loaded silk fibroin nanofibrous membrane (SF/PBM). SF/PBM exhibited excellent physicochemical properties, hemostatic activity, antibacterial activity, and biocompatibility. Furthermore, Actin/DAPI staining results revealed that SF/PBM promoted the adhesion and proliferation of human umbilical vein endothelial cells (HUVECs). The healing effect verified that SF/PBM could facilitate the infected wound healing speed via accelerating hemostasis, suppressing bacterial infection, and promoting re-epithelialization and collagen deposition. Taken together, these results demonstrate that this novel antibacterial dressing is promising for clinical use in the treatment of infected wounds.

Chitosan-salvianolic acid B coating on the surface of nickel-titanium alloy inhibits proliferation of smooth muscle cells and promote endothelialization.

Introduction: Intracranial stents are of paramount importance in managing cerebrovascular disorders. Nevertheless, the currently employed drug-eluting stents, although effective in decreasing in-stent restenosis, might impede the re-endothelialization process within blood vessels, potentially leading to prolonged thrombosis development and restenosis over time. Methods: This study aims to construct a multifunctional bioactive coating to enhance the biocompatibility of the stents. Salvianolic acid B (SALB), a bioactive compound extracted from Salvia miltiorrhiza, exhibits potential for improving cardiovascular health. We utilized dopamine as the base and adhered chitosan-coated SALB microspheres onto nickel-titanium alloy flat plates, resulting in a multifunctional drug coating. Results: By encapsulating SALB within chitosan, the release period of SALB was effectively prolonged, as evidenced by the in vitro drug release curve showing sustained release over 28days. The interaction between the drug coating and blood was examined through experiments on water contact angle, clotting time, and protein adsorption. Cellular experiments showed that the drug coating stimulates the proliferation, adhesion, and migration of human umbilical vein endothelial cells. Discussion: These findings indicate its potential to promote re-endothelialization. In addition, the bioactive coating effectively suppressed smooth muscle cells proliferation, adhesion, and migration, potentially reducing the occurrence of neointimal hyperplasia and restenosis. These findings emphasize the exceptional biocompatibility of the newly developed bioactive coating and demonstrate its potential clinical application as an innovative strategy to improve stent therapy efficacy. Thus, this coating holds great promise for the treatment of cerebrovascular disease.

Dual peptide functionalization of Zn alloys to enhance endothelialization for cardiovascular applications

A new generation of fully bioresorbable metallic Zn-based alloys could be used for stenting applications; however, the initial surface degradation delays stent re-endothelialization. Thus, this work proposes a dual strategy to control the corrosion and accelerate the endothelialization of ZnMg and ZnAg biodegradable alloys. First, a stable polycaprolactone (PCL) coating is obtained and followed by its functionalization with either linear RGD (Arg-Gly-Asp) or REDV (Arg-Glu-Asp-Val) peptides or a dual peptide-based platform combining both sequences (RGD-REDV). Scratching tests showed neither delamination nor detachment of the polymeric coating. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) measurements confirmed the corrosion resistance after PCL coating by revealing lower current density and higher absolute impedance values. X-ray photoelectron spectroscopy (XPS) and fluorescent microscopy confirmed the correct peptide immobilization onto PCL coated Zn alloys. The functionalized samples exhibited enhanced human umbilical vein endothelial cells (HUVEC) adhesion. The higher number of adhered cells to the functionalized surfaces with the RGD-REDV platform demonstrates the synergistic effect of combining both RGD and REDV sequences. Higher corrosion resistance together with enhanced endothelialization indicates that the dual functionalization of Zn alloys with PCL and peptide-based RGD-REDV platform holds great potential to overcome the clinical limitations of current biodegradable metal stents.

Dienogest does not augment the gene expression of adhesion molecules, MCP-1, and monocyte adherence in human endothelial cells

Objective Medroxyprogesterone acetate (MPA) may increase the risk of atherosclerosis during hormone replacement therapy (HRT); therefore, the effect of progestogens other than MPA on atherosclerotic lesions requires evaluation. Adhesion of monocytes to vascular endothelial cells is an important early step in atherosclerosis progression. MCP-1 is a key chemokine that promotes monocyte migration and adhesion to vascular endothelial cells. In this study, we investigated the effects of dienogest (DNG), an alternative progestogen, on monocyte adhesion and cytokine expression in human umbilical vein endothelial cells (HUVECs). Study Design HUVECs were treated with DNG, natural progesterone, or MPA, followed by interleukin (IL)-1β stimulation. The mRNA expression of adhesion molecules (E-selectin and ICAM-1) and cytokines (MCP-1 and IL-6) was examined using real-time PCR. A flow chamber system was used to examine the effect of DNG on the adhesion of U937 monocytic cells to monolayer HUVECs. Results Unlike MPA, DNG did not alter the mRNA expression of E-selectin, ICAM-1, MCP-1, and IL-6 in HUVECs. Moreover, it did not increase the number of monocytes adhering to HUVECs in the flow chamber system. However, MPA treatment significantly enhanced monocyte adhesion to HUVECs (p < 0.05). Conclusions DNG had no effect on the mRNA expression of adhesion molecules and cytokines in HUVECs, as well as the monocyte adhesion to HUVECs, suggesting that DNG can be explored as an alternative to MPA for HRT.

Surface Functionalization of Electrospun Scaffolds by QK-AG73 Peptide for Enhanced Interaction with Vascular Endothelial Cells.

Rapid endothelialization still remains challenging for blood-contacting biomaterials, especially for long-term, functional, small-diameter vascular grafts. The vascular endothelial growth factor (VEGF)-mimicking QK peptide holds great promise in promoting vascular endothelial cellular activities such as adhesion, spreading, proliferation, and migration. Syndecans are transmembrane proteoglycans that are highly expressed on cell surfaces, including vascular endothelial cells, which can act as docking receptors to provide binding sites for a variety of cellular growth and signaling molecules. Herein, a novel peptide QK-AG73 that coupled the QK domain with the syndecan binding peptide AG73 was proposed, aiming to synergistically enhance the interaction with vascular endothelial cells. In addition, mechanically matched bioactive scaffolds based on poly(l-lactide-co-ε-caprolactone) were successfully prepared by surface functionalization of the covalently combined QK-AG73 peptide. The result showed that the adhesion of human umbilical vein endothelial cells (HUVECs) was increased by approximately 2-fold on QK-AG73-modified surface compared with those modified with a single QK or AG73 peptide. Moreover, surface functionalization of electrospun scaffolds by this QK-AG73 peptide was more efficient in specifically promoting the proliferation of HUVECs and allowing them to grow with an elongated cobblestone-like cell morphology. It was hypothesized that both VEGF receptors and transmembrane syndecan receptors were involved in cellular regulation by the QK-AG73 peptide, which resulted in synergistic improvement of the interactions with vascular endothelial cells and provided a promising strategy to promote endothelialization of small-diameter vascular grafts.

Ethylene glycol-based thermoresponsive block copolymer brushes with cell-affinity peptides for thermally controlled interaction with target cells

Tissue engineering has recently attracted attention as a potential remedy for intractable diseases. To be effective, such treatments require cell separation methods that do not modify cellular surfaces. In this study, we developed cell separation materials using ethylene glycol-based thermoresponsive block copolymer brushes and cell-affinity peptides. A poly(2-hydroxyethyl methacrylate-co-propargyl acrylate) (P(HEMA-co-PgA)) brush was grafted onto a glass substrate through atom transfer radical polymerization (ATRP). Subsequently, poly(2-(2-methoxyethoxy)ethyl methacrylate) (PMEO2MA), P(MEO2MA-co-HEMA-co-poly(ethylene glycol) methacrylate [PEGMA]), or P(MEO2MA-co-PEGMA) was grafted onto the P(HEMA-co-PgA) brush-coated substrates through a second ATRP. A Gly-Gly-Gly-Arg-Glu-Asp-Val (GGGREDV) peptide was conjugated to the copolymer brush via a click reaction. The prepared copolymer brushes exhibited thermoresponsive properties. The block copolymer brushes having the P(MEO2MA-co-HEMA-co-PEGMA) and P(MEO2MA-co-PEGMA) segment exhibited effective human umbilical vein endothelial cells (HUVECs) adhesion and normal human dermal fibroblasts (NHDFs) repulsion at 37 °C. By reducing temperature to 20 °C, adherent HUVECs were successfully recovered from the copolymer brushes. Using these copolymer brushes, HUVECs were separated from contaminant NHDFs and smooth muscle cells with these simple changes in temperature. The development of thermoresponsive ethylene glycol-based copolymer brushes with affinity peptides could be a useful cell separation material for tissue engineering applications.