Artificial blood vessels: A challenging and crucial implant for cardiovascular diseases

Blood vessels are one of the vital tissues in the body which are responsible for carrying oxygen and nutrients to other tissues and removing toxic and waste metabolites from them. Some issues like inflammation, metabolite diseases, and altering in cell proliferation, will cause damages to blood vessels like thrombosis, stenosis, and etc. Furthermore, according to the importance of tissue engineering and regenerative medicine in last decades, enhancing the blood grafts and artificial blood vessels are becoming more significant. Also, in step with the growing rate of using 3D bioprinters, embedding blood vessels in the organs which are printed is necessary. Natural blood vessels consist of three main parts: endothelium, medial layer, and adventitia. So, a suitable blood vessel should be similar to these parts. Investigating and working on blood vessels has been prevalent since 1960s when scientists utilized plastics, porous metals, and fiberglass in producing blood vessels. 1980s and 1990s were the zenith of searching on this object. Transplantation of autologous blood vessels or doing saphenous surgeries are other solutions for patients who need vessel s grafts. Nowadays, some other materials, hydrogels, and polymers are used, which are: Collagen, Polytetraflouroethylene (Dacron), Fibrin, Polyurethane (PU), Agarose filaments, Poly D-lactic-co-glycolic (PLGA), Nylon filaments, Hydroxybutyrate, Polycaprolactone (PCL), Polyethylene glycol dicrylate (PEGDA), Gelatin, Chitosan, Bacterial nano-cellulose (BNC), Polyethylene terephthalate (PET), Pethytetraflouroethylene (ePTFE), Methyl methacrylate (MMA), Alginate, and Siloxane.Scaffold is one of the main parts of vascular grafts which sometimes is decellularized with the purpose of decreasing immune response. This scaffolds attract vascular cells after they have been plated in the body. CD31 and CD34 are two biomarkers which show the proliferation of vascular and endothelial cells on artificial blood vessels. As the result, such vessels must have some special properties like: being personalized, not evoking immune response, growing in pediatric patients, avoiding blood rupturing, reducing thrombosis, stenosis, atherosclerosis, and ischemia, having good patency and suitable diffusion, being free of toxicity, and having high absorbance to other tissues

Keywords:

Artificial blood vessels , Vascular grafts , Tissue engineering , Polymer-based scaffolds