Photosensitive resin gets a new coat for 3D printing hearts
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.
The process of making a biological scaffold (HUVECs short for human umbilical vein endothelial “stem” cells) Image via: RSC Advances
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.
Image for comparison to the below. The surface of a 3D printed resin scaffold at 1000x zoom. Via: RSC Advances
Image for comparison to the above. The surface resin coated in WPU at 1000x zoom. Via: RSC Advances
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
3D printing or Additive manufacturing is a process of making a three-dimensional solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes. 3D printing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes).
A 3D printer is a limited type of industrial robot that is capable of carrying out an additive process under computer control.
While 3D printing technology has been around since the 1980s, it was not until the early 2010s that the printers became widely available commercially. The first working 3D printer was created in 1984 by Chuck Hull of 3D Systems Corp. Since the start of the 21st century there has been a large growth in the sales of these machines, and their price has dropped substantially. According to Wohlers Associates, a consultancy, the market for 3D printers and services was worth $2.2 billion worldwide in 2012, up 29% from 2011.[
The 3D printing technology is used for both prototyping and distributed manufacturing with applications in architecture, construction (AEC), industrial design, automotive, aerospace, military, engineering, civil engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, education, geographic information systems, food, and many other fields. One study has found that open source 3D printing could become a mass market item because domestic 3D printers can offset their capital costs by enabling consumers to avoid costs associated with purchasing common household objects.
3D Printable Models
3D printable models may be created with a computer aided design package or via 3D scanner. The manual modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as sculpting. 3D scanning is a process of analyzing and collecting data of real object; its shape and appearance and builds digital, three dimensional models.