Conventional surgical treatments for cardiovascular disease rely on autografts, which require invasive surgery. Synthetic vascular grafts made from polymer materials are also available, but these are prone to infection and blood clotting, especially in smaller diameter vessels. A new technique is needed, and this is where tissue engineering fits in, enabling new blood vessels to be grown in the lab and then used for implantation.
Dr. Sam Pashneh-Tala from the University of Sheffield is now using high-precision desktop stereolithography (SLA) 3D printing to produce tissue-engineered blood vessels with a variety of geometries. His unique methods will allow for patient-specific vascular graft designs to be produced, so patients and doctors will have more surgical options. The technology also provides a unique testing platform for new vascular medical devices for those suffering from cardiovascular disease.
Dr Pashneh-Tala uses scaffold-based tissue engineering to produce his blood vessels. Cells are grown over a scaffold that is in the shape of the required vessel. The scaffold guides and supports the growth of the cells and is produced from a material developed by Dr Pashneh-Tala. 3D printing is used to produce moulds which are used to manufacture the scaffold in the required vascular geometries.
“Previously I would have paid between £270-£300 to outsource a polycarbonate chamber,” explained Dr Pashneh-Tala. “With my Formlabs printer, I am able to print the design in my lab using Dental SG, a biocompatible and autoclavable material, for £30-£40. The chamber is then easily sterilised and ready to be used straight away.”
To manufacture the mould, Dr Pashneh-Tala designed the blood vessel mould with Solidworks CAD software, and then 3D prints the desired shape with his Formlabs SLA printer. Following a process, the researcher is then left with a porous scaffold with microscopic holes that cells are able to grow in. Over time the structure will dissolve, leaving just the cells in the desired shape which can be implanted to treat cardiovascular disease.
