Development and study on mechanical properties of small diameter artificial blood vessel by using electrospinning and 3d printing

The small diameter artificial blood vessel is synthesized with a diameter less than or equal to 6 millimetres. This technique has been used in coronary artery bypass grafting to treat coronary artery disease. Currently, the problem of coronary artery disease is still common, in addition to aortic aneurysm caused by the incompatibility of mechanical properties between the artificial blood vessel and the local blood vessel in the patient’s body. This research aims to solve the aforementioned problems using electrospinning and 3D printing technologies, as many types of materials are supported, all parameters are easy to change, and the cost is low. In this report, we describe a design for a small diameter polylactic acid (PLA) vascular graft fabricated by electrospinning with solutions of PLA in AC/DMF (1:1) 10, 12 and 15% w/v at 4 mm. The electrospun PLA nanofibers are tested for their morphology, contact angle, and seam strength. As the results, the fibres are still no same direction alignment due to insufficient rotation speed. The filament holding force is in the range of 1.90-2.71 N and the contact angles are greater than 90° because the samples are not wettable and have hydrophobic property. Further on, we will investigate other required properties, such as cell culture and other mechanical properties. Furthermore, we will compare the results with 3D printed artificial blood vessels with small diameter.

The novel hybrid polycarbonate polyurethane / polyester three-layered large-diameter artificial blood vessel

Background The most common materials of artificial blood vessels are polyethylene terephthalate and polytetrafluoroethylene. But polycarbonate polyurethane (PCU) is an ideal material for vascular prostheses because of their excellent characteristics. As far as we know, our artificial blood vessel is the first type of hybrid PCU/polyester three-layered large-diameter artificial blood vessel in the world. Objective The purpose of this preclinical animal experiment is to evaluate the hemocompatibility, histocompatibility, effectiveness, and safety of the three-layered large-diameter artificial blood vessel in sheep. Methods The artificial blood vessels took place of the initial segments of the sheep’s thoracic aorta by end-to-end anastomosis. Results All of the 14 sheep are male, their average body weight (BW) was 30.57 ± 3.95 kg. All 14 artificial blood vessels successfully replaced the thoracic aortas. 5 sheep did not survive to the end of the experiment, while the remaining 9 sheep did. After the surgery, the blood biochemical and blood routine indicators fluctuate slightly within the normal range. The angiography showed that the implanted artificial blood vessels were unobstructed without obvious stenosis or expansion. 24 weeks after surgery, the lumen surfaces of the artificial blood vessels were covered by endothelia in different degrees, and the average endothelialization rate was 69.44% (range: 20% to 100%). Conclusions This artificial blood vessel is the first to use PCU in large-diameter artificial vascular grafts. It has excellent blood compatibility, wonderful biocompatibility, high endothelialization rate, and 100% patency.