Affiliations: Department of Clinical Chemistry and Laboratory Diagnostics, Silesian Medical Academy, Sosnowiec, Poland | Biocybernetics Lab., Institute of Heart Prostheses, Foundation of Cardiac Surgery Development and Department of Mechanical Support, Silesian Medical Academy, Zabrze, Poland
Note: [] Corresponding author: Ewa Maria Koźma, Department of Clinical Chemistry and Laboratory Diagnostics, Silesian Medical Academy, ul. Jagiellońska 4, 41‐200 Sosnowiec, Poland. Tel./fax: +48 32 292 47 95; E‐mail: chem_klin@farmant.slam.katowice.pl.
Abstract: Photooxidation is a method of tissue fixation resulting in protein crosslinking due to illumination in the presence of a dye. The aim of the study was to evaluate the impact of dyes, photooxidation time and the type of applied light on the porcine pericardial collagen crosslinking. The collagen modifications were evaluated on the basis of pericardial sensitivity to pepsin digestion. The hydrolysate components were evaluated qualitatively and quantitatively. All hydrolysates contained collagen α chains, their aggregates and degradation products. Methylene blue and methylene green‐mediated 4 h photooxidation in the presence of visible light caused similar decrease in pericardium sensitivity to pepsin. However, both fixation types generated remarkable amounts of α chain degradation products. The prolongation of photooxidation time to 8 h did not increase the pericardial sample resistance to pepsin. Moreover, these sample hydrolysates revealed an elevated α chain content. Violet light mediated photooxidation did not alter pericardial sensitivity to pepsin when compared with fixation under visible light. Nevertheless, violet light fixed tissues displayed a decrease in collagen degradation products. The application of violet light in photooxidation of porcine pericardium will probably allow to obtain enzyme resistant bioprostheses with better mechanical properties compared with those obtained after visible light mediated process.
