Raman and surface-enhanced Raman scattering in the study of human rotator cuff tissues after shock wave treatment

Abstract

Important improvements of diseases of the rotator cuff supraspinatus tendons are seen after shock wave (SW) treatment. Neo-angiogenesis stimulation and hypercellularization result from short periods of treatment. The present work is an attempt to provide a first approach to these bioprocesses, most likely associated with structural aspects resulting from biochemical changes brought about by the SW. Immunohistochemical data indicate that collagen areas in the tissues are influenced the most by the SW. Presence of additional collagens I and III by the SW treatment is inferred from an observed increase of the tissue’s tinctorial properties. The tools selected for our studies are Ramanspectroscopy and the ultrasensitive surface-enhanced Raman scattering (SERS). Here we extract information from 1016 SERS spectra of 52 biopsies of human tendon tissues on Ag nanoparticles before and after the SW treatment. The spectral information is analyzed on the basis of Raman and SERS data of collagen types I and III and their most abundant amino acid components. SERS spectra of tissues reveal the presence of characteristic modes related mainly to amino acids. It has been found that the main differences between both tissue samples could be correlated with the structural conformational aspects of collagen.