Relaxation Behaviour of Ionically and Enzymatically Microbial Transglutaminase (mTG)-Crosslinked Alginate-di-aldehyde and Gelatin (ADA-GEL) Hydrogels for Cartilage RegenerationTuesday (18.06.2019) 20:04 - 20:05
Hydrogels have a wide range of possible applications in medical technology, for example in contact lenses, wound-healing dressings, drug delivery devices and in tissue regeneration. In particular, biomaterials for tissue regeneration require challenging engineering and control over material properties. The characteristics of hydrogels material properties -make them excellent candidates for tissue engineering approaches.For this reason, a detailed understanding and characterization of hydrogel properties are required. A comprehensive characterization of the viscoelastic behaviour of hydrogels can result in a better understanding of cell-material interactions, while chondrocyte cell response and cartilage matrix formation are key requirements for successful cartilage regeneration therapies. This work in particular deals with the mechanical properties of hydrogels for cartilage repair. Therefore, three different scaffold materials, ADA-GEL (alginate-di-aldehyde and gelatine), alginate-gelatine and commercially available Chondrofillerliquid (Amedrix GmbH) were investigated to evalutate the hydrogels stiffness and viscoelastic relaxation behaviour. Cylindrical specimens were prepared and tested in a relaxation test setup. The mechanical tests were performed in a 37°C environment to simulate physiological conditions. All scaffolds underwent an uniaxial and unconfined compression of 15%. The analysed materials showed different Young's moduli, ranging from 35 to 80 kPa. The relaxation time τ1/2 when the stress is relaxed to half of its initial value was measured. τ1/2 ranged from 7 to more than 2400 seconds. The results indicate that the different chemical compositions of the materials can significantly alter the detailed mechanical behaviour and stress relaxation, while the latter has been found to play a crucial role in cartilage tissue engineering.