DFG Collaborative Research Centre 1444
This Collaborative Research Centre aims to unravel the basic mechanisms that differentiate between success and failure in regeneration of musculoskeletal tissue using bone healing as a role model.
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The role and the development of internal tissue tension in normal versus compromised healing bone
Mechanical stress in biological tissues is used as a communicative signal that prompts cells to discriminate and explore the geometric and mechanical properties of their environment. Internal stress in bones significantly increases the resistance of the material to mechanical overload. However, stress is also generated by modulating osmotic gradients, locally controlling the molecular composition of the extracellular matrix and regulating pH and salt concentration. We are using X-ray diffraction, in situ collagen visualisation and NanoCT strategies to unravel the principles of pre-stress restoration in bone healing to improve the macroscopic understanding of mechanical stress and strain within the fracture zone. In parallel, we aim to deepen the understanding of how internal stress is generated in bone tissue. To do this, we are investigating the hypothesis that cells coordinate and use large polymer molecules (collagen, glycosaminoglycans, etc.) to induce and express internal stress conditions in the extracellular matrix surrounding them.
In-situ measurement of residual internal stress due to radiation damage
Energy Supply & Consumption | Force Transmission & Sensing
Radioactive radiation destroys the collagen mineral bond. This also changes the residual stress. However, we can also use this radiation damage directly to determine it and compare it in different bone types.
Residual internal stress in normal healing bones
Energy Supply & Consumption | Force Transmission & Sensing
Taking bone healing as an example, we measure the internal stress in bone tissue by measuring the lattice spacing with the help of mineral particles using synchrotron radiation diffraction, which act as stress sensors. It turns out that the values are strongly site-dependent and thus also depend on the age and condition of the bone tissue.
Residual internal stress in impaired healing bone
Energy Supply & Consumption | Force Transmission & Sensing
Bones from older mice exhibit lower internal stresses, resulting in greater fragility of the mineralized tissue. At the same time, the increased immune experience of the mice leads to a delay in healing, allowing more stages of bone healing to be studied.
In collaboration with subproject P01
Mineralisation in the early stage of bone healing
Energy Supply & Consumption | Force Transmission & Sensing
The methods used in this project are based on the measurement of mineralized tissue. Here we investigate how mineral particles and collagen staggering behave in the early stages of bone healing. In the future, these results can then also be compared to those of various influences.
In collaboration with subproject P01
Polarisation microscopy
Energy Supply & Consumption | Force Transmission & Sensing
With the help of polarization microscopy, not only the alignment of collagen fibers but also the internal stress due to delay can be shown. This is because drying bone samples reduces the compressive stress on the mineral, which affects the optical retardation of the bones and can be measured by us.
In collaboration with subproject P09
Publications
- Authors:Zhang, W.; Bertinetti, L.; Yavuzsoy, E. C.; Gao, C.; Schneck, E.; Fratzl, P.
Journal:Adv Healthc Mater Year:2023; Volume:12Issue:(9)
Title:Submicron-Sized In Situ Osmotic Pressure Sensors for In Vitro Applications in Biology - Authors:Sauer, K.; Zizak, I.; Forien, J. B.; Rack, A.; Scoppola, E.; Zaslansky, P.
Journal:Nat commun Year:2022; Volume:13Issue:(1):Pages:7829.
Title:Primary radiation damage in bone evolves via collagen destruction by photoelectrons and secondary emission self-absorption
