Berlin 2024 – scientific programme

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BP: Fachverband Biologische Physik

BP 15: Poster IIb

BP 15.25: Poster

Tuesday, March 19, 2024, 18:00–20:30, Poster F

Triacylglycerides influence water content and nanomechanical properties of collagen fibrils — Martin Dehnert, •Tiberius Klose, Yang Pan, Dietrich R. T. Zahn, and Robert Magerle — Fakultät für Naturwissenschaften, TU Chemnitz

Lipids are an essential component of connective tissue, which includes tendons, ligaments and cartilage. They act as lubricants in joints and tendons, with a major component being triacylglycerides. In cases of excess adiposity and other diseases, excess cholesterol is found in tendons, where it forms granular domains (xanthoma). However, the presence and effect of lipids in natural (healthy) collagen fibrils is poorly understood. Here, we show that collagen fibrils extracted from chicken calcaneal (Achilles) tendon contain triacylglycerides that influence the nanomechanical properties and water uptake of the fibrils. After extracting the lipids with organic solvents, we measure an increased swelling behavior and an increased indentation modulus in collagen fibrils using atomic force microscopy. With Raman spectroscopy, we identify triacylglycerides as the major lipid component. Our results demonstrate that triglycerides are an essential component of the natural collagen fibril structure, where they act as plasticizers and mediate the fibril's water content and mechanical properties. This methodology could be used to investigate the influence of lipids on the biomechanical properties of connective tissues during development, ageing, and diseases. In particular, the effect of nutrition, which has a major influence on lipid balance, could be studied.

Keywords: Collagen; Lipids; Biomechanics; Atomic force microscopy; Raman spectroscopy