The knowledge of the temperature distribution in protein solder and cartilage - bone - tissue is crucial for the laser induced fixation of cartilage grafts in order to set the laser parameters. Hence, in this contribution a simulation model is provided, which calculates the temperature distribution in the aforesaid layer model. The results are compared to experimental data and evaluated.

The biomechanical properties are crucial indicators for the functional characterization of cartilaginous tissue. In this contribution native articular cartilage and three-dimensional scaffold-free cartilage constructs (SFCCs) are characterized by hyperelastic material models (Yeoh, Ogden and Demiray). SFCCs were developed for the therapy of damaged articular cartilage. The normalized error (NE) of fit and experiment is in the range of 0.04 and 0.13. The material model Yeoh with two parameters yields the best fit. The stress-like parameter c 20 is 0.489 MPa for native cartilage, 0.120 MPa and 0.041 MPa for SFCCs produced from mesenchymal stem cells and chondrocytes, respectively. The significance of the fits and the derived parameters are presented and evaluated.

A new technology for fixation of articular cartilage grafts was developed based on laser induced coagulation of a dye doped protein, i.e. bovine serum albumin (BSA) enhanced by indocyanine green (ICG) (0.025% ICG and 60 % BSA). To assess the occurrence of thermally induced damages, histological examination of laser exposed areas of cartilage tissue was performed using live/dead and haematoxylin eosin (HE) staining. Lowest thermally induced injuries were observed microscopically after exposition of cartilage tissue with or without dye doped protein using power density of 5.09 W/cm(2) for 120 s. Increase in power density and/ or duration of laser exposition caused a raise in tissue injuries.