PubMed HealthSearch

PubMed · 9818165

Forces on adhesive contacts affect cell function.

Abstract

Cellular forces acting on the adhesive contacts made with the extracellular matrix (ECM) contribute significantly to cell shape, viability, signal transduction and motility. In the past two years, research has determined how cell spreading influences cell viability as well as cytoskeletal organization. The cytoskeleton generates a level of tension against the ECM that is proportional to ECM stiffness. The strength of this tension exerted against the ECM affects the migratory speed of the cell.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C G Galbraith, M P Sheetz. 1998. Forces on adhesive contacts affect cell function.. https://doi.org/10.1016/s0955-0674(98)80030-6

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Comparative kinetics of polymerisation of three fibrin sealants and influence on timing of tissue adhesion.

The clinical performance of fibrin sealants may be influenced by physical properties such as elasticity, tensile strength, and ability to adhere to human tissue. These properties are related to the internal structure of the fibrin sealant that builds as it polymerises. Analysis of the minimum polymerisation time to achieve a functional fibrin clot is clinically important. Instant tissue-fibrin sealant adhesion is desirable to ensure that the fibrin sealant functions on contact and remains at the site of application without being washed away by blood or displaced by movement of the target tissue (e.g., the heart or lungs). The physical characteristics of fibrin sealants are related to the extent of fibrin cross-linking. Determination of the polymerisation rate allows calculation of the minimum time required to produce a functional clot. The adhesion characteristics to vital human tissue and kinetics of polymerisation between 20 and 300 seconds postapplication of Vivostat system patient-derived sealant have been analysed and compared to those obtained for two conventional fibrin sealants, Tissucol and Beriplast. Mathematical analysis of the experimental data revealed that polymerisation of Vivostat sealant followed first-order kinetics, whereas that of Beriplast and Tissucol followed second-order kinetics. This study demonstrates that Vivostat sealant polymerises faster than these other conventional fibrin sealants.

Adhesiveness

Molecular aspects of muco- and bioadhesion: tethered structures and site-specific surfaces.

Mucoadhesive controlled-release devices can improve the effectiveness of a drug by maintaining the drug concentration between the effective and toxic levels, inhibiting the dilution of the drug in the body fluids, and allowing targeting and localization of a drug at a specific site. Acrylic-based hydrogels have been used extensively as mucoadhesive systems. They are well suited for bioadhesion due to their flexibility and nonabrasive characteristics in the partially swollen state, which reduce damage-causing attrition to the tissues in contact. Crosslinked polymeric devices may be rendered adhesive to the mucosa. For example, adhesive capabilities of these hydrogels can be improved by tethering of long flexible chains to their surfaces. Tethering of long poly(ethylene glycol) (PEG) chains on poly(acrylic acid) hydrogels and their copolymers can be achieved by grafting reactions, or by copolymerization in the presence of several PEG-containing acrylates. The ensuing hydrogels exhibit mucoadhesive properties due to enhanced anchoring of the chains with the mucosa. Theoretical calculations can lead to optimization of the tethered structure. Experimental results indicate that the chain interpenetration is a strong function of the PEG molecular weight, the polymer swelling ratio and the mucosa composition.

Adhesiveness

Effect of thione primers on bonding of noble metal alloys with an adhesive resin.

OBJECTIVES: The purpose of the current study was to evaluate the effects of two metal conditioners on the bond durability of an adhesive resin joined to noble metal alloys by comparing pre- and post-thermocycling bond strengths. METHODS: Two different sizes of disk specimens (10 and 8mm in diameter by 2.5mm thickness) were prepared from silver-indium (Ag-In-Zn, Salivan), silver-palladium-copper-gold (Ag-Pd-Cu, Castwell M.C.12), metal-ceramic gold (Au-Pt-Pd, Degudent-Universal), metal-ceramic palladium (Pd-Ga-Co, PTM 88), type IV gold (type IV, Casting Gold) alloys, and pure silver (pure Ag). The specimens were air-abraded with 50-microm grain sized alumina, conditioned either with a thiouracil primer (Metaltite) or with a thione-phosphate primer (Alloy Primer), then bonded with an adhesive resin (Super-Bond Opaque). Shear bond strengths were determined both before and after repeated thermocycling (4 degrees C and 60 degrees C, 1min each, 100, 000cycles). The results were compared by analysis of variance and post-hoc multiple comparison intervals. RESULTS: The average post-thermocycling bond strengths in MPa (n=8) generated with the thiouracil primed and thione-phosphate primed groups, respectively, were: 3.4 and 5.8 for the Ag-In-Zn alloy, 40.4 and 37.7 for the Ag-Pd-Cu alloy, 26.4 and 33.5 for the Au-Pt-Pd alloy, 27.4 and 36.6 for the Pd-Ga-Co alloy, 40.2 and 40.3 for the type IV alloy, and 37.3 and 32.4 for the pure Ag. The Ag-In-Zn alloy exhibited significantly lower bond strength than the other alloys, whereas the Ag-Pd-Cu and type IV alloys exhibited the greatest magnitude of bond strength for both primers (p<0.05). CONCLUSIONS: It can be concluded that the combined use of either of the two thione primers and the adhesive resin is effective for bonding the metal/alloys examined, with the exception of the Ag-In-Zn alloy.

Adhesiveness