scholarly journals Sustained Release of VEGF to Promote Angiogenesis and Osteointegration of Three-Dimensional Printed Biomimetic Titanium Alloy Implants

2021 ◽  
Vol 9 ◽  
Author(s):  
Youbin Li ◽  
Yuzhe Liu ◽  
Haotian Bai ◽  
Ronghang Li ◽  
Jing Shang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Growth Factor ◽  
Composite Scaffold ◽  
Umbilical Vein ◽  
Tumor Resection ◽  
Bone Defects ◽  
Porous Titanium ◽  
Bone Integration

Tumor resection and treatment of trauma-related regional large bone defects have major challenges in the field of orthopedics. Scaffolds that treat bone defects are the focus of bone tissue engineering. 3D printing porous titanium alloy scaffolds, prepared via electron beam melting technology, possess customized structure and strength. The addition of a growth factor coating to the scaffold introduces a specific form of biological activation. Vascular endothelial growth factor (VEGF) is key to angiogenesis and osteogenesis in vivo. We designed a porous titanium alloy scaffold/thermosensitive collagen hydrogel system, equipped with VEGF, to promote local osseointegration and angiogenesis. We also verified the VEGF release via thermosensitive collagen and proliferation and induction of the human umbilical vein endothelial cells (HUVECs) via the composite system in vitro. In vivo, using microscopic computed tomography (Micro-CT), histology, and immunohistochemistry analysis, we confirmed that the composite scaffold aids in angiogenesis-mediated bone regeneration, and promotes significantly more bone integration. We also discovered that the composite scaffold has excellent biocompatibility, provides bioactive VEGF for angiogenesis and osteointegration, and provides an important theoretical basis for the restoration of local blood supply and strengthening of bone integration.

scholarly journals Pharmacologic Characterization of a Kinetic In Vitro Human Co-Culture Angiogenesis Model Using Clinically Relevant Compounds

2013 ◽  
Vol 18 (10) ◽  
pp. 1234-1245 ◽  
Author(s):  
Ashley Wolfe ◽  
Belinda O’Clair ◽  
Vincent E. Groppi ◽  
Dyke P. McEwen
Keyword(s):  
Growth Factor ◽  
Umbilical Vein ◽  
Dermal Fibroblasts ◽  
Tube Length ◽  
Endothelial Cell Proliferation ◽  
Discovery Research ◽  
Drug Discovery Research ◽  
Angiogenesis Model

Angiogenesis, the formation of new vessels from preexisting vessels, involves multiple cell types acting in concert to cause endothelial cell proliferation, migration, and differentiation into microvascular arrays. Under pathologic conditions, microenvironment changes result in altered blood vessel production. Historically, in vitro angiogenesis assays study individual aspects of the process and tend to be variable, difficult to quantify, and limited in clinical relevance. Here, we describe a kinetic, quantitative, co-culture angiogenesis model and demonstrate its relevance to in vivo pharmacology. Similar to in vivo angiogenesis, a co-culture of human umbilical vein endothelial cells with normal human dermal fibroblasts remains sensitive to multiple cytokines, resulting in a concentration-dependent stimulation of tube formation over time. Treatment with axitinib, a selective vascular endothelial growth factor (VEGF) antagonist, inhibited VEGF-mediated tube length and branch point formation and was selective for inhibiting VEGF over basic fibroblast growth factor (bFGF), similar to previous studies. Conversely, an FGFR-1 selective compound, PD-161570, was more potent at inhibiting bFGF-mediated angiogenesis. These results demonstrate the cytokine dynamics, selective pharmacology, and translational application of this model system. Finally, combining quantitative angiogenic biology with kinetic, live-content imaging highlights the importance of using validated in vitro models in drug discovery research.

I-309 binds to and activates endothelial cell functions and acts as an angiogenic molecule in vivo

Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4039-4045
Author(s):  
Giovanni Bernardini ◽  
Gaia Spinetti ◽  
Domenico Ribatti ◽  
Grazia Camarda ◽  
Lucia Morbidelli ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Rnase Protection Assay ◽  
Chorioallantoic Membrane ◽  
Rnase Protection ◽  
Cc Chemokine ◽  
Cell Functions

Several chemokines have been shown to act as angiogenic molecules or to modulate the activity of growth factors such as fibroblast growth factor 2 (FGF-2) and vascular endothelial growth factor (VEGF). The detection of the CC chemokine receptor (CCR) 8 message in human umbilical vein endothelial cells (HUVECs) by reverse transcription– polymerase chain reaction (RT-PCR) and RNase protection assay (RPA), prompted us to investigate the potential role exerted by the CC chemokine I-309, a known ligand of such receptor, in both in vitro and in vivo angiogenesis assays. We show here that I-309 binds to endothelial cells, stimulates chemotaxis and invasion of these cells, and enhances HUVEC differentiation into capillary-like structures in an in vitro Matrigel assay. Furthermore, I-309 is an inducer of angiogenesis in vivo in both the rabbit cornea and the chick chorioallantoic membrane assay (CAM).

Abstract P639: Sildenafil Treatment Improves Placental Levels of Placental Growth Factor in the Dahl Salt-Sensitive Pregnant Rat Model of Superimposed Preeclampsia

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Ana C Palei ◽  
Jennifer M Sasser ◽  
Joey P Granger
Keyword(s):  
Growth Factor ◽  
Umbilical Vein ◽  
Resistance Index ◽  
Placental Growth Factor ◽  
Trophoblast Invasion ◽  
Maternal Circulation ◽  
Pregnant Rats ◽  
Pregnant Rat

Although the etiology of preeclampsia (PE) remains unclear, evidence indicates that impaired trophoblast invasion followed by placental ischemia promotes the release of placental anti-angiogenic factors into the maternal circulation. These factors then elicit maternal endothelial dysfunction and hypertension by blocking the action of molecules such as the placental growth factor (PlGF). Inhibition of phosphodiesterase (PDE)-5 with sildenafil or other has been proposed as a potential therapy for PE; however, the mechanisms whereby PDE-5 inhibitors reduce blood pressure (BP) and improve uteroplacental perfusion during pregnancy are not clear. While previous studies have shown that PDE-5 inhibition induces PlGF production from human umbilical vein endothelial cells; it is unknown whether PDE-5 inhibitors also increase PlGF from placenta. Thus, the aim of this study was to evaluate whether sildenafil enhance placental secretion/production of PlGF in vitro and in vivo. In our in vitro protocol, we incubated placental villous explants from Sprague Dawley (SD) pregnant rats (n=4, 2-3 placentas per rat) at gestational day (GD)19 with different doses of sildenafil for 48h at 37°C under normoxia (8% O 2 ). PlGF-2 was measured in media of cultured explants by ELISA. We observed that sildenafil had no effect on PlGF-2 secretion from rat placental villi (vehicle: 562.7±46.6, 10nM: 559.3±39.5, 100nM: 556.4±35.9, 10uM: 546.2±37.5, and 100uM: 558.7±48.2pg/mg; P>0.05). In our in vivo protocol, we treated Dahl Salt-Sensitive (DS) pregnant rats (n=6-8 per group), which we had previously characterized as a model of superimposed PE, with sildenafil (50mg/kg per day, via food) from GD10 to 20. PlGF-2 was measured in placental homogenates by ELISA. While untreated DS dams exhibited an increase in BP and uterine artery resistance index (UARI) from baseline to late pregnancy, sildenafil-treated DS dams exhibited a significant decrease in BP and UARI. In addition, we found that placental levels of PlGF-2 were elevated in sildenafil-treated DS dams compared with untreated counterparts (1019±107.3 and 646.8±125.1pg/mg; P=0.0407). In conclusion, our findings suggest that the BP and UARI reduction in response to sildenafil may involve the indirect production of PlGF.

Abstract 12659: Hepatoma-Derived Growth Factor Related Protein-3 as a Novel Endothelial Ligand

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Michelle LeBlanc ◽  
Weiwen Wang ◽  
Feiye Guo ◽  
Chen Shen ◽  
Rui Chen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Growth Effect ◽  
Human Aorta ◽  
Related Protein ◽  
And Migration ◽  
Endothelial Ligands

Background: Endothelial ligands extrinsically regulate a broad spectrum of vascular functions with therapeutic potentials, but are traditionally identified on a case-by-case basis with technical challenges. We recently developed open reading frame phage display (OPD) for unbiased identification of phagocytosis ligands. In this study, we identified hepatoma-derived growth factor related protein-3 (HRP-3) as a putative endothelial ligand by OPD. We hypothesized that HRP-3 is a novel endothelial growth factor, capable of promoting endothelial cell (EC) growth and migration. Methods and Results: We performed 3 rounds of in vivo phage binding selection in mice with an OPD library, screened enriched phage clones by next generation DNA sequencing, and identified HRP-3 as one of the putative endothelial ligands. To confirm the finding, clonal phages displaying HRP-3, VEGF and GFP were generated and analyzed for their binding to human umbilical vein endothelial cells (HUVECs). The results show that HRP-3-Phage and VEGF-Phage had significantly higher binding to HUVECs than GFP-Phage. Functional analysis showed that purified recombinant HRP-3 significantly increased the proliferation of HUVECs at 24 and 48 h, whereas VEGF induced significant growth only at 48 h. Consistent with these findings, HRP-3 significantly stimulated cell proliferation by MTT assay. In vitro wound-healing assay indicated that both HRP-3 (500 ng/ml) and VEGF (50 ng/ml) significantly promoted the migration of HUVECs into the denuded area. To dissect the downstream signaling pathway, we demonstrated that HRP-3 significantly induced ERK1/2 phosphorylation in HUVECs after 10 min treatment. Similar effects of HRP-3 and VEGF on EC growth, migration, and ERK activation were also verified using human aorta endothelial cells. Conclusions: Our findings demonstrate that HRP-3 is a novel ligand, capable of promoting proliferation and migration of ECs. The pro-growth effect of HRP-3 is at least partially mediated through ERK pathway activation. These results in turn support the broad applicability of OPD for the systematic discovery of endothelial ligands.

I-309 binds to and activates endothelial cell functions and acts as an angiogenic molecule in vivo

Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4039-4045 ◽  
Author(s):  
Giovanni Bernardini ◽  
Gaia Spinetti ◽  
Domenico Ribatti ◽  
Grazia Camarda ◽  
Lucia Morbidelli ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Rnase Protection Assay ◽  
Chorioallantoic Membrane ◽  
Rnase Protection ◽  
Cc Chemokine ◽  
Cell Functions

Abstract Several chemokines have been shown to act as angiogenic molecules or to modulate the activity of growth factors such as fibroblast growth factor 2 (FGF-2) and vascular endothelial growth factor (VEGF). The detection of the CC chemokine receptor (CCR) 8 message in human umbilical vein endothelial cells (HUVECs) by reverse transcription– polymerase chain reaction (RT-PCR) and RNase protection assay (RPA), prompted us to investigate the potential role exerted by the CC chemokine I-309, a known ligand of such receptor, in both in vitro and in vivo angiogenesis assays. We show here that I-309 binds to endothelial cells, stimulates chemotaxis and invasion of these cells, and enhances HUVEC differentiation into capillary-like structures in an in vitro Matrigel assay. Furthermore, I-309 is an inducer of angiogenesis in vivo in both the rabbit cornea and the chick chorioallantoic membrane assay (CAM).

Aggretin, a snake venom–derived endothelial integrin α2β1 agonist, induces angiogenesis via expression of vascular endothelial growth factor

Blood ◽  
2004 ◽  
Vol 103 (6) ◽  
pp. 2105-2113 ◽  
Author(s):  
Ching-Hu Chung ◽  
Wen-Bin Wu ◽  
Tur-Fu Huang
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
Vascular Endothelial ◽  
Angiogenic Effect ◽  
Endothelial Growth Factor

Abstract Aggretin, a collagen-like α2β1 agonist purified from Calloselasma rhodostoma venom, was shown to increase human umbilical vein endothelial cell (HUVEC) proliferation and HUVEC migration toward immobilized aggretin was also increased. These effects were blocked by A2-IIE10, an antibody raised against integrin α2. Aggretin bound to HUVECs in a dose-dependent and saturable manner, which was specifically inhibited by A2-IIE10, as examined by flow cytometry. Aggretin elicited significant angiogenic effects in both in vivo and in vitro angiogenesis assays, and incubation of HUVECs with aggretin activated phosphatidylinositol 3-kinase (PI3K), Akt, and extracellular-regulated kinase 1/2 (ERK1/2); these effects were blocked by A2-IIE10 or vascular endothelial growth factor (VEGF) monoclonal antibody (mAb). The angiogenic effect induced by aggretin may be via the production of VEGF because the VEGF level was elevated and VEGF mAb pretreatment inhibited Akt/ERK1/2 activation as well as the in vivo angiogenesis induced by aggretin. The VEGF production induced by aggretin can be blocked by A2-IIE10 mAb pretreatment. In conclusion, aggretin induces endothelial cell proliferation, migration, and angiogenesis by interacting with integrin α2β1, leading to activation of PI3K, Akt, and ERK1/2 pathways, and the increased expression of VEGF may be responsible for its angiogenic activity.

scholarly journals In vitro and in vivo evaluations of mechanical properties, biocompatibility and osteogenic ability of sintered porous titanium alloy implant

RSC Advances ◽  
2018 ◽  
Vol 8 (64) ◽  
pp. 36512-36520 ◽  
Author(s):  
Ji Li ◽  
Zhongli Li ◽  
Ruiling Li ◽  
Yueyi Shi ◽  
Haoran Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Bone Ingrowth ◽  
Porous Titanium ◽  
Porous Ti ◽  
Good Biocompatibility

The sintered porous Ti6Al4V with 75% porosity has optimal mechanical properties, good biocompatibility and osteogenic ability for more bone ingrowth.

scholarly journals MSC-derived small extracellular vesicles overexpressing miR-20a promoted the osteointegration of porous titanium alloy by enhancing osteogenesis via targeting BAMBI

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Liu ◽  
Jinghuan Huang ◽  
Feng Chen ◽  
Dong Xie ◽  
Longqing Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Extracellular Vesicles ◽  
Porous Titanium ◽  
Fluorescent Labeling ◽  
In Vivo Studies ◽  
Osteoporotic Bone ◽  
Alizarin Red ◽  
Alkaline Phosphatase Staining

Abstract Background Patients with osteoporosis have a high risk of implant loosening due to poor osteointegration, possibly leading to implant failure, implant revision, and refracture. RNA interference therapy is an emerging epigenetic treatment, and we found that miR-20a could enhance osteogenesis. Moreover, small extracellular vesicles (sEVs) derived from bone marrow mesenchymal stem cells (hBM-MSCs) were utilized as nanoscale carriers for the protection and transportation of miR-20a (sEV-20a). In this study, we intended to determine whether sEVs overexpressing miR-20a could exert a superior effect on osteoporotic bone defects and the underlying mechanism. Methods For evaluating the effect of sEV-20a on osteogenesis, in vitro and in vivo studies were performed. In vitro, we first showed that miR-20a was upregulated in the osteogenic process and overexpressed sEVs with miR-20a by the transfection method. Then, the proliferation, migration, and osteogenic differentiation abilities of hBM-MSCs treated with sEV-20a were detected by CCK-8 assays, alkaline phosphatase staining and alizarin red staining, qRT-PCR, and western blot. In vivo, we established an osteoporotic bone defect model and evaluated the effect of sEV-20a on bone formation by micro-CT, sequential fluorescent labeling, and histological analysis. To further explore the mechanism, we applied a bioinformatics method to identify the potential target of miR-20a. Results In vitro, sEV-20a was successfully established and proved to promote the migration and osteogenesis of hBM-MSCs. In vivo, sEV-20a promoted osteointegration in an osteoporotic rat model. To further elucidate the related mechanism, we proved that miR-20a could enhance osteogenesis by targeting BAMBI. Conclusions Collectively, the in vitro and in vivo results confirmed that MSC-derived sEV-20a therapy effectively promoted osteoporotic porous titanium alloy osteointegration via pro-osteogenic effects by targeting BAMBI.

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