Recognizing different tissues in human fetal femur cartilage by label-free Raman microspectroscopy

Abstract

Abstract. Traditionally, the composition of bone and cartilage is determined by standard histological methods. We used Raman microscopy, which provides a molecular "fingerprint" of the investigated sample, to detect differences between the zones in human fetal femur cartilage without the need for additional staining or labeling. Raman area scans were made from the (pre)articular cartilage, resting, proliferative, and hypertrophic zones of growth plate and endochondral bone within human fetal femora. Multivariate data analysis was performed on Raman spectral datasets to construct cluster images with corresponding cluster averages. Cluster analysis resulted in detection of individual chondrocyte spectra that could be separated from cartilage extracellular matrix (ECM) spectra and was verified by comparing cluster images with intensity-based Raman images for the deoxyribonucleic acid/ ribonucleic acid (DNA/RNA) band. Specific dendrograms were created using Ward's clustering method, and principal component analysis (PCA) was performed with the separated and averaged Raman spectra of cells and ECM of all measured zones. Overall (dis)similarities between measured zones were effectively visualized on the dendrograms and main spectral differences were revealed by PCA allowing for label-free detection of individual cartilaginous zones and for label-free evaluation of proper cartilaginous matrix formation for future tissue engineering and clinical purposes.

Ions-modified nanoparticles affect functional remineralization and energy dissipation through the resin-dentin interface

“…These indexes concerned with the maximum relative degree of mineralization (Karan et al, 2009;Kunstar et al, 2012;Schwartz et al, 2012).…”

Ex vivo detection and characterization of remineralized carious dentin, by nanoindentation and single point Raman spectroscopy, after amalgam restoration

“…6. Peak at 954 cm -1 , representative of PO 4 3-v 1 symmetric vibration, is a marker for calcification of the ECM [23] . 7.…”

“…3. Collagen (proline/hydroxyproline/C-C skeletal of collagen backbone), is indicated by bands at 937 cm -1 [23] . 4.…”

“…6. Lipids and proteins (CH 2 and amide I) are identified with peaks at 1448 and 1656 cm -1 [23] . 7.…”

“…Scanning probe microscopes and, in particular, the atomic force microscope have facilitated the imaging and analysis of biological surfaces with little or no sample preparations [4] . Raman spectroscopy is an analytical technique able to measure the molecular composition by providing a spectrum that contains information regarding all the chemical bonds present within the sample [23] for investigating molecular species. MicroRaman mapping technique has been a powerful method to directly analyze the dentin interface and the mineral content, and distribution, after placing the restorative and the application of mechanical [14] and thermal stimuli.…”