Raman spectroscopy as a tool for quality and sterility analysis for tissue engineering applications like cartilage transplants.

At present, the production of tissue engineered cartilage requires the concurrent production of two identical transplants. One transplant is used for destructive quality control and the second one is implanted into the patient. A non-invasive characterization of such tissue engineering samples would be a promising tool to achieve a production process of just one transplant that is both implanted and tested. Raman spectroscopy is a method that satisfies this requirement by analyzing cells without lysis, fixation or the use of any chemicals. This pure optical technique is based on inelastic scattering of laser photons by molecular vibrations of biopolymers. Characteristic peaks in Raman spectra of cells could be assigned to typical biochemical molecules present in biological samples. For the analysis of chondrocytes present in cartilage transplants, the determination of the cell vitality as well as the discrimination of another cell type have been studied by Raman spectroscopy. Another bottleneck in such biological processes under GMP conditions is sterility control, as most of the commonly used methods require long cultivation times. Raman spectroscopy provides a good alternative to conventional methods in terms of time saving. In this study, the potential of Raman spectroscopy as a quality and sterility control tool for tissue engineering applications was studied by analyzing and comparing the spectra of cell and bacteria cultures.