Towards bioreactor development with physiological motion control and its applications

- Physiological movements with knee joints and movement segments were established in bioreactors.
- Remodelling in form of an increasing stiffness due to mechanical stimulation was proven for cartilage replacement material.
- A constitutive material model, taking mechanobiological interaction into account, was proposed.
- An experimental validation method for remodelling phenomena by means of bioreactors was introduced.

In biomedical applications bioreactors are used, which are able to apply mechanical loadings under cultivation conditions on biological tissues. However, complex mechanobiological evolutions, such as the dependency between mechanical properties and cell activity, depend strongly on the applied loading conditions. This requires correct physiological movements and loadings in bioreactors. The aim of the present study is to develop bioreactors, in which native and artificial biological tissues can be cultivated under physiological conditions in knee joints and spinal motion segments. However, in such complex systems, where motions with different degrees of freedom are applied to whole body parts, it is necessary to investigate elements of joints and spinal parts separately. Consequently, two further bioreactors for investigating tendons and cartilage specimens are proposed additionally. The study is complemented by experimental and numerical examples with emphasis on medical and engineering applications, such as biomechanical properties of cartilage replacement materials, injured tendons, and intervertebral discs.