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J-F Stoltz

Publications and source records attributed to J-F Stoltz.

4 recordsLinked to original sources
PubMed2003

Modeling of the detachment of a molecule from a surface: illustration of the "Bell-Evans effect".

This article deals with the modeling of the detachment of a molecule initially adsorbed on a surface and submitted to an external force whose strength increases with time. By means of an atomic force microscope (AFM), it is possible to measure the force when the molecule separates from the substrate. However, it is known that this force depends to a large extend on the rate at which the pulling force is applied ("Bell-Evans effect"). Two models are described to illustrate this behavior. First, a random walk approach is suggested to reveal the fundamental principle of the escape over a time-dependent energy barrier. Second, a multi bead-and-spring model is proposed to mimic the AFM experiment and numerical simulations, based on Brownian dynamics, are performed.

Binding Sites↗
PubMed2002

From biomechanics to mechanobiology.

Biomechanics can be defined as the application of mechanical concepts to the living world, and various fields of research have been developed such as the mechanics of movement, ergonomics, the mechanical properties of cells and tissues, and the relationship between physiology and applied forces. In this paper, the authors give, through several examples, an outline of these approaches and their potential biomedical applications, as in tissue remodelling, cell and tissue engineering and the development of biotissues.

Biomechanical Phenomena↗
PubMedDate not supplied

Cell interactions with polyelectrolyte multilayer films.

The short-term interactions of chondrosarcoma cells with polyelectrolyte multilayer films built up by the alternate adsorption of poly(L-lysine) (PLL) and poly(L-glutamic acid) (PGA) was studied in the presence and in the absence of serum. The films and their interaction with serum proteins were first characterized by means of optical waveguide lightmode spectroscopy, quartz crystal microbalance, and zeta potential measurements. In a serum-containing medium, the detachment forces measured by the micropipet technique were about eight times smaller on PGA-ending than on PLL-ending films. For these latter ones, the adhesion force decreased when the film thickness increased. In a serum-free medium, the differences between the negative- and positive-ending films were enhanced: adhesion forces on PLL-ending films were 40-100% higher, whereas no cellular adherence was found on PGA-terminating films. PGA-ending films were found to prevent the adsorption of serum proteins, whereas important protein adsorption was always observed on PLL-ending films. These results show how cell interactions with polyelectrolyte films can be tuned by the type of the outermost layer, the presence of proteins, and the number of layers in the film.

Blood Proteins↗