Blood vessel decellularization – challenges and perspectives.

Tissue Engineering and Cell Cultures laboratory, Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of MoldovaIntroduction. Cardiovascular disease is a general term for conditions affecting the heart and circulation. It is the number one cause of death globally. It is predicted that the annual incidence of cardiovascular disease - related mortalities will rise to 23,3 million globally by 2030. Developed disorders are often associated with the narrowing or blockage of the luminal diameter leading to inhibited blood flow through the affected vessels and tissue damage due to inadequate nutrient supply. The treatment options depend on the type of condition the person has and may range from dietary and lifestyle modification to pharmaceutical therapies and endovascular or surgical interventions. Despite advantages and increased popularity of endovascular surgery, the preferred treatment for the long term revascularization is surgery utilizing vascular grafts. Currently available conduits for vascular grafting do not satisfy completely surgeons’ requirements due to poor clinical efficacy, especially in small diameter vessels applications (< 6 mm). Therefore, tissueengineered materials are the only alternative solution through the generation of biologically based functional vessels. Aim of the study. To provide an overview of decellularization techniques employed current to produce a clinically viable tissue-engineered vascular grafts; to highlight both benefits and drawbacks of each strategy. Materials and methods. Articles containing the keywords: Cardiovascular disease; Tissueengineered vascular grafts (TEVG); Vessel decellularization; Decellularization reagents; Mechanical properties of vessel substitutes were selected from the PubMed and Springer Link databases. Results. The use of biological scaffolds composed by extracellular matrix (ECM) as a strategy for tissue or organ replacement has increased. One technique that has shown good results in several tissue engineering applications, including blood vessels, is the use of decellularized scaffolds. Decellularization is the complete removal of all cellular and nuclear matters from a tissue while preserving ECM, and can be done by using detergents, enzymatic digestion, or mechanical stimulation. Decelullarization process induces the loos of the major histocompatibility complex while avoiding any adverse immunological reactions by the host. It allows the use of decellularized biological tissue not only as autografts but also as allografts and xenografts. Conclusions. It is confirmed that the decellularization process is suitable for the generation of acellular scaffolds for vascular tissue engineering applications. However, the best technique that allows the preservation physicochemical properties similar to fresh vessels is yet to be determined. Researches and clinical trials should be continued in this field