Researchers at the University of Pennsylvania in Philadelphia have pioneered a technology that may pave the way to printing life-saving tissue and even organs. Using a RepRep printer, an open-source 3D printer with a custom-designed extruder and controlling software, scientists were able to create a network of blood vessels from a simple sugar-based mixture.
Vascular systems are used through the body in order to transport nutrients and facilitate the removal of waste and without them, cells die quickly. The ability to create these systems outside of the body is a huge leap forward in the bioengineering and medical world. Sugar proved to be the perfect building material as it is rigid, dissolves in water without damaging any cells and is compatible with 3D printers.
Bioengineers have been developing and assembling single layers of cells that have direct access to oxygen and nutrients, by layer-by-layer fabrication - a process called 'bioprinting'. However, this method did not solve the problems of vasculature as the structural seams left by this creation method could not withstand the pressure of fluid pumping being passed through and could push the seams apart. Scientists also faced the problem that many cells, such as liver cells cannot survive the rigors of 3D printing.
In order to solve this problem, Penn researchers turned this process inside out and focussed on developing a free-standing 3D filament network in the shape of a vascular system that was placed inside a mould. This was then covered in a mixture of sucrose and glucose, with dextran for reinforcement. Once the tunnels were formed the new vasculatures were covered in a thin layer of degradable polymer, derived from corn that allowed the sugar to dissolve without damaging the cells or harming the growing vasculature.
Christopher Chen, the Skirkanich Professor of Innovation in the Department of Bioengineering at Penn, said: "This new platform technology, from the cell's perspective, makes tissue formation a gentle and quick journey because cells are only exposed to a few minutes of manual pipetting and a single step of being poured into the moulds before getting nourished by our vascular network."
This process is quick and inexpensive and Penn researchers are hoping to build their own specialist 3D printers in order to continue their groundbreaking research.