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The vascular network has a complex architecture such as branches, curvatures, and bifurcations which is even more complicated in view of individual patients' defect anatomy requiring custom‐specifically designed vascular implants. In this work, 3D printing is used to overcome these challenges and a new shorter impregnation method was developed to incorporate S‐nitroso‐N‐acetyl‐d‐penicillamine (SNAP) as a nitric oxide (NO) donor to printed grafts. The 3D‐printed small‐diameter vascular grafts (SDVGs) were impregnated with SNAP solution during SNAP synthesis (S1) or with SNAP dissolved in methanol (S2). The advantage of the newly developed S1 impregnation method is the elimination of the synthesis step by direct impregnation inside the S1 solution. Scanning electron microscopy imaging reveals the successful crystal formation in both methods. The results demonstrate that both S1‐ and S2‐impregnated grafts, after covering with polycaprolactone topcoat, can release NO in a controlled manner and in the physiological range (0.5–4.0 × 10−10 mol cm−2 min−1) over a 15 days period. The created grafts with a NO‐releasing surface have also shown bactericidal effect while the healing properties of the implant were improved by promoting migration and proliferation of endothelial cells (ECs). These results suggest that incorporation of 3D printing technology with the newly developed S1 impregnation of SNAP can optimize and shorten the manufacturing process of the next generation of patient‐based antibacterial SDVGs with a higher attraction for ECs. [ABSTRACT FROM AUTHOR]

Current vascular grafts have a high incidence of failure, especially in the grafts less than 6 mm in diameter, due to thrombus formation. Nitric oxide (NO) is released by endothelium and has some beneficial influences such as an antithrombotic effect. We hypothesized that applying different shear stress regiments and low temperature or aspirin would result in an increase in the amount of NO release from human umbilical vein endothelial cells (HUVECs) and decrease in platelet aggregation in the same manner as expected in vivo. HUVECs were cultured into the intraluminal surface of silicone tubes. HUVECs were subjected for 60 min to different parameters of shear stress, temperature, aspirin, and platelets or a combination in a perfusion bioreactor by monitoring NO secretion. We found that shear stress leads to an elevation of NO production in HUVECS, independent of the shear stress magnitude (0.9 or 1.8 dyne/cm2). The magnitude of this response increased with a decrease in temperature. Our results also show that by addition of platelets in combination with aspirin to media circulation, no thrombus formation occurred during the test time. Presence of aspirin resulted in marked increase in NO levels. In conclusion, shear stresses, temperature lowering, and aspirin increase the amount of NO release from HUVECs. Also no thrombus formation was detected in our experimental setting. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1231-1237, 2015. [ABSTRACT FROM AUTHOR]

Biomaterials rapid prototyping (RP), recently known as additive manufacturing (AM), has appeared as a revolutionary technology, promising to transform research into medical therapeutics. RP is a layer by layer manufacturing process which directly translates computer data such as Computer Aided Design (CAD), Computer Tomography (CT), and Magnetic Resonance Imaging (MRI) into three‐dimensional (3D) objects. RP technologies play a significant role in biomedical industry such as anatomical models for surgery training/planning, rehabilitation, dentistry, customized implants, drug delivery devices, tissue engineering, and organ printing. The integration of biomaterials and rapid prototyping technologies is an exciting route in developing biomaterial implants for the past decade. This review describes and classifies the RP systems into three categories of liquid‐based, solid‐based, and powder‐based according to the initial form of their feed materials. Then, discusses possible benefits, drawbacks, and applications of each process in the field of biomaterials science and engineering. Additive manufacturing has recently appeared as a revolutionary technology in biomedical engineering. It plays a critical role in biomedical industry such as anatomical models for surgery training/planning, rehabilitation, dentistry, customized implants, drug delivery devices, tissue engineering, and organ printing. This comprehensive review summarizes all the possible categories of liquid‐based, solid‐based, and powder‐based systems for additive manufacturing of biomaterials. [ABSTRACT FROM AUTHOR]