Osteogenic Cell Attachment to Degradable Polymers

1991 ◽  
Vol 252 ◽  
Author(s):  
Kevin E. Healy ◽  
Davis Tsai ◽  
Jung E. Kim
Keyword(s):  
Cell Adhesion ◽  
Synthetic Peptide ◽  
Glycolic Acid ◽  
Cell Attachment ◽  
Polymer Surface ◽  
Degradable Polymers ◽  
Osteogenic Cell ◽  
Treatment Groups ◽  
Osteogenic Cells ◽  
Degradable Polyesters

ABSTRACTModifications were made to increase osteogenic cell adhesion to homo and copolymers of lactic and glycolic acid. A synthetic peptide containing the cell attachment signal Arginine-Glycine-Aspartate (RGD) was loaded into the polymers or adsorbed to the polymers' surfaces. Cell attachment was assayed after 24 hours incubation with an osteogenic cell line (ROS 17/2.8). Statistically significant differences in cell adhesion occurred between the polymers with the adsorbed peptides and the other treatment groups. Significant differences were not observed for the peptide loaded polymers and controls. These data indicate that precoating the polymer surface with a RGD-containing peptide prior to exposure to osteogenic cells increased cell attachment. For the current materials tested, the surface modification is preferred to increase osteogenic cell adhesion to degradable polyesters.

scholarly journals Integrins: An Important Link between Angiogenesis, Inflammation and Eye Diseases

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1703
Author(s):  
Małgorzata Mrugacz ◽  
Anna Bryl ◽  
Mariusz Falkowski ◽  
Katarzyna Zorena
Keyword(s):  
Cell Adhesion ◽  
Tissue Repair ◽  
Normal Development ◽  
Cell Attachment ◽  
Biological Activities ◽  
Integrin Receptors ◽  
Cytokine Activation ◽  
Eye Disorders ◽  
Membrane Bound ◽  
Cell To Cell Adhesion

Integrins belong to a group of cell adhesion molecules (CAMs) which is a large group of membrane-bound proteins. They are responsible for cell attachment to the extracellular matrix (ECM) and signal transduction from the ECM to the cells. Integrins take part in many other biological activities, such as extravasation, cell-to-cell adhesion, migration, cytokine activation and release, and act as receptors for some viruses, including severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). They play a pivotal role in cell proliferation, migration, apoptosis, tissue repair and are involved in the processes that are crucial to infection, inflammation and angiogenesis. Integrins have an important part in normal development and tissue homeostasis, and also in the development of pathological processes in the eye. This review presents the available evidence from human and animal research into integrin structure, classification, function and their role in inflammation, infection and angiogenesis in ocular diseases. Integrin receptors and ligands are clinically interesting and may be promising as new therapeutic targets in the treatment of some eye disorders.

Adhesion of Phytophthora palmivora zoospores: electron microscopy of cell attachment and cyst wall fibril formation

1975 ◽  
Vol 18 (1) ◽  
pp. 123-132
Author(s):  
V.O. Sing ◽  
S. Bartnicki-Garcia
Keyword(s):  
Electron Microscopy ◽  
Cell Adhesion ◽  
Cyst Wall ◽  
Cell Attachment ◽  
Sodium Dodecyl ◽  
Film Surface ◽  
Phytophthora Palmivora ◽  
Thin Sections ◽  
Electron Dense Deposit ◽  
Dense Deposit

Zoospores of Phytophthora palmivora adhered to a plastic film surface were examined by electron microscopy. Three stages of adhesion were compared: (1) non-adhesive, unencysted zoospores, (2) adhered incipient cysts, and (3) adhered mature cysts. Thin sections of incipient cysts revealed cells attached to the film surface through the partially discharged contents of the so-called peripheral vesicles; this seems to be the first step in cell adhesion. In mature cysts, the adhesive appeared to have been compacted into an electron-dense deposit binding the cyst wall to the plastic surface. The adhesion zone was also examined in face view after lysing attached incipient cysts with sodium dodecyl sulphate. Cyst wall microfibrils were seen together with an amorphous substance (presumably the adhesive material). The microfibrils were in various stages of formation. Seemingly, adhesion and microfibril formation take place concurrently. The possibility was considered that the material contained in the peripheral vesicles serves in both cell adhesion and microfibril elaboration.

scholarly journals Testing the in vitro performance of hydroxyapatite coated magnesium (AZ91D) and titanium concerning cell adhesion and osteogenic differentiation

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Claudia Kleinhans ◽  
Gabriele Vacun ◽  
Roman Surmenev ◽  
Maria Surmeneva ◽  
Petra Juliane Kluger
Keyword(s):  
Cell Adhesion ◽  
Osteogenic Differentiation ◽  
Cell Attachment ◽  
Human Mesenchymal Stem Cell ◽  
Adhesion Properties ◽  
Sputtering Deposition ◽  
Initial Cell ◽  
Tissue Culture Polystyrene ◽  
Diffraction Patterns

AbstractIn the current study the in vitro outcome of a degradable magnesium alloy (AZ91D) and standard titanium modified by nanostructured-hydroxyapatite (n-HA) coatings concerning cell adhesion and osteogenic differentiation was investigated by direct cell culture. The n-HA modification was prepared via radio-frequency magnetron sputtering deposition and proven by field emission scanning electron microscopy and X-ray powder diffraction patterns revealing a homogenous surface coating. Human mesenchymal stem cell (hMSCs) adhesion was examined after one and 14 days displaying an enhanced initial cell adhesion on the n-HA modified samples. The osteogenic lineage commitment of the cells was determined by alkaline phosphatase (ALP) quantification. On day one n-HA coated AZ91D exhibited a comparable ALP expression to standard tissue culture polystyrene samples. However, after 14 days solely little DNA and ALP amounts were measurable on n-HA coated AZ91D due to the lack of adherent cells. Titanium displayed excellent cell adhesion properties and ALP was detectable after 14 days. An increased pH of the culture was measured for AZ91D as well as for n-HA coated AZ91D. We conclude that n-HA modification improves initial cell attachment on AZ91D within the first 24 h. However, the effect does not persist for 14 days in in vitro conditions.

Comparative Study of Ceramics Structure for Culturing Human Mesenchymal Stromal Cells

2007 ◽  
Vol 361-363 ◽  
pp. 1067-1070 ◽  
Author(s):  
Asako Matsushima ◽  
Noriko Kotobuki ◽  
Mika Tadokoro ◽  
Hajime Ohgushi
Keyword(s):  
Bone Tissue ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Cell Attachment ◽  
Osteoblastic Differentiation ◽  
Human Mscs ◽  
Osteogenic Cells ◽  
Human Mesenchymal Stromal Cells ◽  
Viable Cells ◽  
Different Types

Hydroxyapatite (HA) ceramics together with various kinds of osteogenic cells have been used in bone tissue engineering. It is well known that the ceramics structure and composition affect cell proliferation / differentiation. In this study, three different types of HA ceramics were used to investigate initial cell attachment followed by osteoblastic differentiation of human mesenchymal stromal cells (MSCs). The results indicated that micro-pore affected the cell attachment and porosity (pore diameter and inter-pore connection) was the key to allow spacious distribution of the viable cells in the ceramics. This study also confirmed that surface pore areas of HA ceramics support the differentiation of human MSCs and thus the ceramics have the capability to regenerate damaged bone tissue.

scholarly journals Xenopus embryonic cell adhesion to fibronectin: position-specific activation of RGD/synergy site-dependent migratory behavior at gastrulation.

1996 ◽  
Vol 134 (1) ◽  
pp. 227-240 ◽  
Author(s):  
J W Ramos ◽  
D W DeSimone
Keyword(s):  
Cell Adhesion ◽  
Matrix Protein ◽  
Marginal Zone ◽  
Cell Attachment ◽  
Extracellular Matrix Protein ◽  
Mesoderm Induction ◽  
Type Iii ◽  
Basic Body ◽  
And Migration

During Xenopus laevis gastrulation, the basic body plan of the embryo is generated by movement of the marginal zone cells of the blastula into the blastocoel cavity. This morphogenetic process involves cell adhesion to the extracellular matrix protein fibronectin (FN). Regions of FN required for the attachment and migration of involuting marginal zone (IMZ) cells were analyzed in vitro using FN fusion protein substrates. IMZ cell attachment to FN is mediated by the Arg-Gly-Asp (RGD) sequence located in the type III-10 repeat and by the Pro-Pro-Arg-Arg-Ala-Arg (PPRRAR) sequence in the type III-13 repeat of the Hep II domain. IMZ cells spread and migrate persistently on fusion proteins containing both the RGD and synergy site sequence Pro-Pro-Ser-Arg-Asn (PPSRN) located in the type III-9 repeat. Cell recognition of the synergy site is positionally regulated in the early embryo. During gastrulation, IMZ cells will spread and migrate on FN whereas presumptive pre-involuting mesoderm, vegetal pole endoderm, and animal cap ectoderm will not. However, animal cap ectoderm cells acquire the ability to spread and migrate on the RGD/synergy region when treated with the mesoderm inducing factor activin-A. These data suggest that mesoderm induction activates the position-specific recognition of the synergy site of FN in vivo. Moreover, we demonstrate the functional importance of this site using a monoclonal antibody that blocks synergy region-dependent cell spreading and migration on FN. Normal IMZ movement is perturbed when this antibody is injected into the blastocoel cavity indicating that IMZ cell interaction with the synergy region is required for normal gastrulation.

Effects of collagenase-cleavage of type I collagen on alpha2beta1 integrin-mediated cell adhesion

1998 ◽  
Vol 111 (8) ◽  
pp. 1127-1135 ◽  
Author(s):  
A.J. Messent ◽  
D.S. Tuckwell ◽  
V. Knauper ◽  
M.J. Humphries ◽  
G. Murphy ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Type I Collagen ◽  
Cell Attachment ◽  
Heat Denaturation ◽  
Type I ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
Triple Helices ◽  
Collagen Fragment ◽  
Cell Matrix Interactions

In this paper we show that collagenase-3 cleavage of type I collagen has a marked effect on alpha2beta1 integrin-mediated interactions with the collagen fragments generated. Isolated alpha2beta1 integrin and alpha2 integrin A-domain were found to bind to both native collagen and native 3/4 fragment and, to a lesser degree, native 1/4 fragment. Whole integrin and integrin A-domain binding were lost after heat denaturation of the collagen fragments. At physiological temperature, cell adhesion to triple-helical 3/4 fragment via alpha2beta1 integrin was still possible; however, no alpha2beta1 integrin-mediated adhesion to the 1/4 fragment was observed. Unwinding of the collagen fragment triple helices by heating to physiological temperatures prior to adsorption to plastic tissue culture plates resulted in total abrogation of HT1080 cell attachment to either fragment. These results provide significant evidence in support of a role for matrix-metalloproteinase cleavage of the extracellular matrix in modifying cell-matrix interactions.

The mechanics of single cross-links which mediate cell attachment at a hydrogel surface

Nanoscale ◽  
2019 ◽  
Vol 11 (24) ◽  
pp. 11596-11604 ◽  
Author(s):  
Arzu Çolak ◽  
Bin Li ◽  
Johanna Blass ◽  
Kaloian Koynov ◽  
Aranzazu del Campo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Adhesion ◽  
Cell Attachment ◽  
Force Spectroscopy ◽  
Single Cross ◽  
Mediate Cell Adhesion ◽  
Cross Links ◽  
Hydrogel Surface ◽  
Mediate Cell

The mechanical properties of single cross-links which mediate cell adhesion are explored by force spectroscopy.

Cleavage of human 7-domain VCAM-1 (CD106) by thrombin

2006 ◽  
Vol 95 (05) ◽  
pp. 873-880 ◽  
Author(s):  
Steven Barthel ◽  
Mats Johansson ◽  
Douglas Annis ◽  
Deane Mosher
Keyword(s):  
Cell Adhesion ◽  
Blood Cell ◽  
White Blood Cell ◽  
Cell Attachment ◽  
Chinese Hamster ◽  
Full Length ◽  
Type I ◽  
Thrombin Cleavage ◽  
Alternatively Spliced ◽  
Splice Forms

SummaryVascular cell adhesion molecule 1 (VCAM-1,CD106) is expressed as a type I transmembrane integrin counter-receptor on activated endothelium and mediates white blood cell attachment. The alternatively spliced 7-domain (7d) form of VCAM-1 contains a potential thrombin cleavage site. Thrombin proteolysis of 7d-VCAM-1 may help regulate adhesive activity of VCAM-1. We determined whether 7d-VCAM-1 is proteolyzed and rendered inactive by thrombin. Recombinant extracellular domain of 7d-VCAM-1 was cleaved by thrombin to generate 33- and 44-kDa products. Cleavage was in the sequence PGPR/IAAQIG near the N-terminal border of the alternatively spliced fourth immunoglobulin (Ig)-like module. There was no cleavage of 6d-VCAM-1 lacking the fourth module. Expression of full-length 7d-VCAM-1 presented on Chinese hamster ovary (CHO) monolayers, as detected by flow cytometry with an antibody directed to Ig-like modules 1–3, was reduced by thrombin treatment whereas there was no reduction in the expression of fulllength 6d-VCAM-1. Adhesion of blood eosinophils to full-length 7d-VCAM-1 was reduced after treatment of CHO cells with thrombin, whereas adhesion to full-length 6d-VCAM-1 was not affected. We conclude that cleavage of 7d-VCAM-1 by thrombin is a potential mechanism for differential regulation of VCAM-1 splice forms in white blood cell adhesion and trafficking.

scholarly journals CD13 tethers the IQGAP1-ARF6-EFA6 complex to the plasma membrane to promote ARF6 activation, β1 integrin recycling, and cell migration

2019 ◽  
Vol 12 (579) ◽  
pp. eaav5938 ◽  
Author(s):  
Mallika Ghosh ◽  
Robin Lo ◽  
Ivan Ivic ◽  
Brian Aguilera ◽  
Veneta Qendro ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Migration ◽  
Cell Adhesion ◽  
Cell Attachment ◽  
Leading Edge ◽  
Small Gtpase ◽  
Β1 Integrin ◽  
Recycling Endosomes ◽  
Cellular Processes ◽  
Early Endosomes

Cell attachment to the extracellular matrix (ECM) requires a balance between integrin internalization and recycling to the surface that is mediated by numerous proteins, emphasizing the complexity of these processes. Upon ligand binding in various cells, the β1 integrin is internalized, traffics to early endosomes, and is returned to the plasma membrane through recycling endosomes. This trafficking process depends on the cyclical activation and inactivation of small guanosine triphosphatases (GTPases) by their specific guanine exchange factors (GEFs) and their GTPase-activating proteins (GAPs). In this study, we found that the cell surface antigen CD13, a multifunctional transmembrane molecule that regulates cell-cell adhesion and receptor-mediated endocytosis, also promoted cell migration and colocalized with β1 integrin at sites of cell adhesion and at the leading edge. A lack of CD13 resulted in aberrant trafficking of internalized β1 integrin to late endosomes and its ultimate degradation. Our data indicate that CD13 promoted ARF6 GTPase activity by positioning the ARF6-GEF EFA6 at the cell membrane. In migrating cells, a complex containing phosphorylated CD13, IQGAP1, GTP-bound (active) ARF6, and EFA6 at the leading edge promoted the ARF6 GTPase cycling and cell migration. Together, our findings uncover a role for CD13 in the fundamental cellular processes of receptor recycling, regulation of small GTPase activities, cell-ECM interactions, and cell migration.

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