scholarly journals Nanostructured interfacial self-assembled peptide–polymer membranes for enhanced mineralization and cell adhesion

Nanoscale ◽  
2017 ◽  
Vol 9 (36) ◽  
pp. 13670-13682 ◽  
Author(s):  
Sofia Ribeiro ◽  
Elham Radvar ◽  
Yejiao Shi ◽  
João Borges ◽  
Rogério P. Pirraco ◽  
...  

Multiscale structured membranes with selective molecular functionalities for controlled mineralization and cell attachment.

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1703
Author(s):  
Małgorzata Mrugacz ◽  
Anna Bryl ◽  
Mariusz Falkowski ◽  
Katarzyna Zorena

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.


1975 ◽  
Vol 18 (1) ◽  
pp. 123-132
Author(s):  
V.O. Sing ◽  
S. Bartnicki-Garcia

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.


2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Claudia Kleinhans ◽  
Gabriele Vacun ◽  
Roman Surmenev ◽  
Maria Surmeneva ◽  
Petra Juliane Kluger

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.


2013 ◽  
Vol 2 (10) ◽  
pp. 1377-1387 ◽  
Author(s):  
Zheng Li ◽  
Alexander Köwitsch ◽  
Guoying Zhou ◽  
Thomas Groth ◽  
Bodo Fuhrmann ◽  
...  

1996 ◽  
Vol 134 (1) ◽  
pp. 227-240 ◽  
Author(s):  
J W Ramos ◽  
D W DeSimone

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.


1998 ◽  
Vol 544 ◽  
Author(s):  
D. B. Haddow ◽  
R. M. France ◽  
R. D. Short ◽  
S. Macneil ◽  
R. A. Dawson

AbstractHuman keratinocytes have been cultured on plasma co-polymers (PCPs), self assembled monolayers (SAMs), tissue culture poly(styrene) (TCPS) and collagen I. The degree of keratinocyte attachment was measured over 24 hours and cell proliferation and growth monitored over 7 days using optical microscopy and DNA concentrations. Cell attachment and proliferation and growth on the PCP surfaces were compared with 2 self assembled monolayer (SAM) systems. PCP surfaces containing carboxylic acid functionalities promoted keratinocyte attachment, with optimum attachment levels seen on surfaces containing less than 5% acid groups. The level of attachment on these surfaces was comparable to that seen on collagen I, a preferred substratum for the culturing of keratinocytes. After several days in culture the cells were well attached and proliferative. Keratinocytes attached well to acidterminated SAMs but attached poorly to methyl-terminated SAMs.


1998 ◽  
Vol 111 (8) ◽  
pp. 1127-1135 ◽  
Author(s):  
A.J. Messent ◽  
D.S. Tuckwell ◽  
V. Knauper ◽  
M.J. Humphries ◽  
G. Murphy ◽  
...  

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.


Nanoscale ◽  
2019 ◽  
Vol 11 (24) ◽  
pp. 11596-11604 ◽  
Author(s):  
Arzu Çolak ◽  
Bin Li ◽  
Johanna Blass ◽  
Kaloian Koynov ◽  
Aranzazu del Campo ◽  
...  

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


2006 ◽  
Vol 95 (05) ◽  
pp. 873-880 ◽  
Author(s):  
Steven Barthel ◽  
Mats Johansson ◽  
Douglas Annis ◽  
Deane Mosher

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.


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