Morphological and biomechanical modifications in blood vessels decellularization: 341.01 Tissue engineering and cell cultures: Summary of PhD thesis in medical sciences

Abstract

Structure of the thesis. The thesis includes annotations in Romanian, Russian and English, list of abbreviations, 48 figures, 6 tables, introduction, 4 chapters with general conclusions, practical recommendations, and study limitations. The paper is followed by the list of bibliographic references with 287 sources, author’s disclaimer, and author's CV. The principal results of the study were published in 20 scientific papers. Keywords: Cardiovascular diseases, peripheral arterial disease, bypass surgery, vascular graft, tissue engineering, tissue engineered vascular graft, decellularization, detergent, enzymatic treatment, sonication. The aim of study. To develop new methods for decellularization of large- and small-diameter blood vessels. Objectives of the study. (1) To evaluate the efficiency of sonication-assisted methods for decellularization of arterial vessels; (2) To test the effect of acoustic amplitude on the vascular matrix; (3) To evaluate the effectiveness of chemical (SDS, SDC, Triton X-100, hypotonic solution) and enzymatic (DNase-I) treatment in vascular tissue decellularization; (4) To evaluate whether the decellularization protocol efficiency is depending on the vessel diameter; (5) To check the informativeness of qualitative methods (H&E and DAPI) for confirmation of the decellularization process; (6) To do morphological, biochemical, and biomechanical characterization of treated blood vessels; (7) To assess the biocompatibility of acellular scaffold by performing in vitro contact test; (8) To determine the efficiency of perfusion decellularization for uniform cells’ elimination from long segments of blood vessels. Scientific originality and novelty. Conducting the experimental study with comparison and multilateral characterization of decellularization efficiency of different decellularization approaches in term of cells’ elimination and matrix strength preservation contributed to the completion of some gaps in the current scientific literature. The scientific problem solved in the thesis consists in identifying the factors associated with efficient cells’ removal and establishing a novel procedure for blood vessels decellularization and optimal characterization of acellular scaffold’s structure, a fact that will allow the modification of the experimental paradigm through the scientifically reasoned selection of the optimal experimental conditions. Theoretical significance and applicative value. Decellularization efficiency of different chemicals was specified; in addition, the indispensability of the enzymatic treatment in combination with strong detergents for accelular vascular scaffolds production was demonstrated. The data obtained during the research scientifically argue for the modification of the current research strategy through the preferential use of carotid artery vs aorta as testing model for development of small-diameter tissue-engineered vascular grafts. The failed attempt to use the ultrasound for vascular tissue DC defines the necessity to perform additional studies regarding the mechanism of ultrasound-induced cellular destruction. The practical impact of the present study consists in implementation of a novel technique of blood vessels decellularization in the Laboratory of Tissue Engineering and Cell Culture, Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of Moldova.