Regensburg 2004 – scientific programme

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AKB: Biologische Physik

AKB 50: Poster Session "Biological Physics"

AKB 50.48: Poster

Friday, March 12, 2004, 10:30–13:00, B

Vesicle adhesion and cohesion at finite temperature — •Thomas Gruhn and Reinhard Lipowsky — MPI for Colloids and Interfaces 14424 Potsdam

Biological cells are the fundamental building blocks of living organisms. They are surrounded by a closed membrane surface that serves as an interface to the outside world. In many cases cells act very similar to vesicles, which are homogenously filled membrane shells. The bending rigidity κ of the membrane and the molecular interaction with external substances have an important influence on the cell morphology and the cell’s adhesion behavior. Rather few attention has been paid in the past to the influence of thermal fluctuations on the adhesion behavior. With the help of Monte Carlo simulations we study the behavior of a one-component vesicle adhered to a substrate at finite temperature. The adhesion behavior of vesicles was studied systematically as a function of temperature, potential depth and potential width. For high enough adhesion strength the contact area of the vesicle goes linear with T/κ. This behavior can be justified by an analytic approach. Further, a master equation has been derived which describes all our simulation results. Thus, by measuring the adhesion area one can derive the adhesion strength from κ or vice versa.