Dresden 2014 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 19: Poster Session 1 (joint session with BP)
CPP 19.14: Poster
Tuesday, April 1, 2014, 09:30–13:00, P1
Mapping nanomechanical properties of hydrated type-I collagen fibrils with MUSIC mode AFM — Julia Hann1, •Diana Voigt1, Eike-Christian Spitzner1, Anke Bernstein2, and Robert Magerle1 — 1Chemische Physik, Fakultät für Naturwissenschaften, Technische Universität Chemnitz, D-09107 Chemnitz, Germany — 2Muskuloskelettales Forschungslabor, Department Orthopädie und Traumatologie, Universitätsklinikum Freiburg, Freiburg i. Br., Germany
Type-I collagen forms fibrils with water embedded between the tropocollagen molecules. The amount and distribution of structural, free, and adsorbed water has a large impact on the fibril's mechanical properties. We study native type-I collagen fibrils using multi-setpoint intermittent contact (MUSIC) mode atomic force microscopy (AFM) in air and in phosphate buffered saline (PBS) solution with different salt concentrations. MUSIC mode AFM is based on point-wise recording amplitude and phase of an oscillating AFM cantilever as the tip-sample distance is reduced. In this way, the unperturbed surface, the tip indentation as well as a quantitative and depth-resolved information about the tip-sample interaction is obtained. Our measurements aim at a better understanding of the tip-sample interaction in liquids as well as the structural and nanomechanical properties of native collagen fibrils under physiological conditions. We find that the fibril's shape and its nanomechanical properties in PBS solution differ distinctly from the fibril's properties in air and we discuss the physical origin of these differences.