Scientists from the Regenerative Medicine Research Center and Sichuan Languang 3D Bio-printing Institute, both in China, have developed a coating for photosensitive resin that might yet see SLA printers 3D printing hearts.
Above gif shows an anatomical heart being printed using vat polymerisation on a form1+ 3D printer. Clip taken from 3D print of a heart video by Bob Jones on Youtube.
Due to the precision of vat photopolymersiation, and the order it forms an object, research is being conducted into the use of photosensitive resin for application within the body. So far, resin has not been found to be biocompatible. Living cells don’t stick well to the surface of resin, and using UV light to cure the liquid is hazardous to living tissue due to the potential of raw material within the finished structure of an object. Indeed, UV light can be used to sterilise objects in some laboratories.
Polyurethane, on the other hand, is considered a safe material. It is the same polymer being used in organ-on-a-chip technology, as in the recent heart on a chip from Harvard University and the Wyss Institute. This recent study, published in the RSC Advances journal for chemical sciences, uses waterborne polyurethane (WPU) to coat the photosensitive resin parts. Researchers found that this coating gave the resin a smoother surface, no toxicity, and even saw stem cells attaching to the surface. The umbilicial vein endothelial cells cultured on the surface of the WPU coated resin are the type of cells that typically form lining of blood vessels, in-between the circulating blood and the vein’s wall. This, combined with the added precision of computer aided design for 3D printing, is what gives the research its potential for printing parts of the heart.
This research is not dissimilar to a a project that looks at a new 3D printing material for fractures composed of bioglass and a component found in cement. To make that solution work, researchers had to add a curing process to the material. Both projects are taking the best of two different elements and combining them to create one more effect biomedical solution .
Such key developments in the research surrounding 3D printed hearts gives credit to the radical thought that one day hospitals will be printing organs suitable for transplant. It’s not so much science fiction as it is an accurate premonition.
Featured image is a still from the new CBS tech drama ‘Pure Genius’ that sees a heart 3D printed in its Pilot episode. Image via: CBS