Development of a highly sensitive spectral camera for cartilage monitoring using fluorescence spectroscopy

Abstract. The Ulm University Medical Center and the Ulm University of Applied Sciences are developing a bioreactor to grow facial cartilage using the methods of tissue engineering. To ensure a sufficient quality of the cartilage prior to implantation, the cartilage growth has to be monitored continuously. Current cartilage analysis methods are destructive so that analysed cartilage sample is no longer suitable for implantation. Alternatively, it seems feasible to analyse cartilage during the cultivation process and before implantation using fluorescence spectroscopy after UV light excitation. This approach is non-invasive and allows an evaluation of the cartilage in terms of composition and quality. Cultured cartilage implants can reach sizes of several square centimetres and therefore it is necessary to examine it over its entire area. For recording fluorescence spectra of different spots of the cartilage sample, a highly sensitive spectral camera is being developed in two steps. The first step is a one-dimensional spectral camera that is able to record fluorescence spectra along a sample line. The second step enables the detection of spectra over the required two-dimensional sample area. This approach is based on computed tomography imaging spectrometry (CTIS) and allows non-invasive distinguishing of the most important cartilage compounds collagen I and collagen II.