Printing vascular grafts with graphene oxide bioink
Three-dimensional bioprinting (3DBP) is an exciting and innovative technology that allows the creation of intricate tissue structures using special materials called bioinks. These bioinks are designed to help cells grow and develop. However, one of the biggest challenges in this field is improving the strength and durability of bioinks, especially when it comes to creating vascular tissues, like blood vessels. Scientists have created a novel bioink made from graphene oxide (GO) and collagen, demonstrating improved mechanical and viscoelastic properties. The bioink showed in vitro biocompatibility, with no signs of cytotoxicity.
Artificial vascular networks could be an important treatment asset for a number of cardiovascular diseases. Experimental tissue engineering of vascular networks has started as early as 1980, although to this day practical application remains a challenge, due to difficulties in precise fabrication and interaction of cells with the surrounding matrix. Vascular grafts must be biocompatible, but also mechanically flexible, in order to maintain integrity under blood flow. Tissue transplantation is a method of choice in many cases, however that method is plagued by variable quality and limited availability of tissue.
Tissue-engineered vascular grafts through electrospinning or 3D printing have recently been considered as possible alternative solutions, with a possibility to engineer graft diameter and shape. Although 3D printing and 3D bioprinting of vascular grafts are promising methods, the search for optimal materials continues.
The novel bioink, highlighted in a study published in ACS Applied Bio Materials, is shown to improve printing resolution and to have better mechanical performance compared to other bioinks. The material also supports cellular development and biocompatibility, making it a promising starting point for well-defined 3D bioprinted vascular grafts.
The ink was produced by making formulations that contain GO, as well as control formulations without the GO. The inks were chemically characterized by Fourier transform infrared spectroscopy (FTIR), after which structures were printed using a bioprinter, with a resolution of 0.6 mm. Printed scaffolds were analysed with scanning electron microscopy (SEM) and were subsequently thoroughly mechanically characterized. Finally, the interaction of the printed structures with living cells was studied in a comprehensive effort to evaluate biocompatibility and cellular activity. Cell survival was observed after 7 days, and a tubular construct was printed to emulate walls of a vascular graft. The results indicate potential for use of the novel bioink material for advanced tissue engineering applications.
