Tag: 3D printing

This Toner Might Be More Expensive: 3-D Printing Artificial Organs

For most people in the United States who need an organ transplant, they will need to wait an average of three to five years on a list before they can get a lifesaving surgery. On average, 20 people die daily waiting on this list. There is a possibility of being able to bypass the wait time by manufacturing the required organs with 3D printing. This manufacturing technique was first used in the medical field for prosthetics and surgery practice models, with a goal to create fully functioning organs for those in need. Instead of using plastic or printer ink, the 3D printer uses cells to create biological constructions. 

A biological 3D printer making a small model of a human heart
Biological 3D Printing Market Update Photo

Traditional methods of artificial tissue and organ creation involve the use of stem cells, which are cells that do not have a designated purpose yet, to create a scaffold or frame for the organ. If cells for a desired organ are placed on the appropriate scaffold, they could multiply and grow into an artificial organ over time. If 3D printing is implemented using the same scaffold procedure, cells could be placed more precisely; the cell diameter can be better controlled, and the speed of the process can be controlled digitally. All of these aspects allow for better replication of the complex networks and structures found within biological tissues. A major advantage of the 3D printed organs are the customizations and variability that can be implemented with the method. Implants can be made to different sizes to suit each unique individual. If the original cells used for 3D printer material are from the intended recipient, the compatibility of the implant or artificial organ is nearly guaranteed. The risk of organ rejection is always present in the time following a transplant operation. 

A man who received 3D printed skull implants following deformation from a bicycle crash.
Xilloc Medical Before and After Photo

The 3D printing process is near perfect for certain medical uses, such as prosthetics, and dental implants, but more work needs to be done with the printing of tissues and organs. Small simple organs with thin walls can be done but printing larger organs such as hearts and kidneys requires integration of the vascular network, which cannot be done at this time. As printers become more precise and able to use a higher variety of cells, the creation of these vascular networks becomes more and more plausible. 

Scientists are currently investigating a new way to print these complex organs by combining organic material with mechanical chips. These chips are able to replicate certain biological stimuli, including fluid flow and chemical gradients, in order to achieve some degree of organ function within a much simpler biological structure. Using these chips will allow for better mass production of a variety of tissues and organs. This particular technology is being used to create tissues that will be used for testing pharmaceutical drugs. There is an opportunity for these tissues to be expanded to use in the human body, but the majority of companies using this technology are still in the startup phase. 

            While the use of 3D printing to create complex artificial organs is not completely viable today, the technology is improving rapidly. Within a few years, the waiting times and problems with organ transplants could be a thing of the past.  

Can we 3D print our own skin?

Can you imagine a world where amputees receive replacement limbs which are able to detect temperature and pressure like an actual limb? How about a world where when you get a cut, you can 3D print some of your own skin to patch the wound?

To the average citizen, this might seem like something out of a science fiction movie. To researchers at the Graz University of Technology, the Wake Forest School of Medicine, and the Universidad Carlos III de Madrid, this is a reality that they are helping bring ever closer. Both of these scenarios are discussed in a recent article by Mark Crawford, who investigated the recent breakthroughs in 3D printing human skin and creating sense-sensitive artificial skin.

photograph of an arm reaching into the sky to feel the rain in the palm of their hand
photo by Alex Wong on Unsplash

At the Graz University of Technology, researchers are working on creating an artificial skin that can sense temperature, humidity, and pressure. Currently, artificial skins can measure one sense at best, but with the use of the nanoscale sensors that these researchers are developing, sensing all three at once could be possible. This is achieved through the materials that the nanosensors are created out of: a smart polymer core and a piezoelectric shell. The smart polymer core can detect humidity and temperature through expansion, and the piezoelectric shell detects pressure through an electric signal that is created when pressure is applied. With this technology, prosthetics could be made which could allow the wearer to retain some of their lost senses.

At the Wake Forest School of Medicine, researchers have created a handheld 3D printer which produces human skin. This device could be used to replace skin grafts, as it can apply layers of skin directly onto the wound. Through the use of bioink, this handheld printer can create different types of skin cells. After scanning the wound to see what layers of tissue have been disrupted, it can print the appropriate skin needed to correct the injury.

Photograph of the 3D skin printer created at the Universidad Carlos III de Madrid, which is still in its prototype phase.
modified from Crawford, ASME January 2019

At the Universidad Carlos III de Madrid, researchers are also 3D printing human skin using bioink. They are creating both allogenic and autologous skin to create the optimal skin, which is a combination of the patient’s own cells and cells created from a stock. Although they have managed to print functioning skin in its natural layered state, it is tricky to create the cells in such a way that they do not deteriorate.

It is also tricky to correctly deposit the product. To illustrate, more research needs to be done on the mechanical properties of artificial skin before it could be used on humans. The artificial skin must be able to stretch and react to tension in a similar manner to the real skin it will be connected to. Additionally, researchers must figure out how to safely send the signals the artificial skin is detecting to the brain.

Overall, both advancing artificial skins and 3D printing human skins could largely impact humanity. Even though we have yet to use these skins on people, they are already being used in industries, such as L’Oreal, to limit testing on humans and animals. Already, these skins are being used on robots, as seen in this video, to help prepare the skin for human transplant:



Interested in seeing more? Check out some more articles on the advancement of artificial skin from Caltech and Time.

3-D Print a New Leg for Your 4-Legged Friend

3-D printing is a quite exciting technology that has come to light in recent years. The process involves a nozzle much like in a regular inkjet printer that layers material upon material to build up a 3D structure. The printer receives this data from a computer designed file that maps out where the printer should add material. Combine this with filler material that serves to hold everything in its final upright position, and the final product is born, after setting and clearing off the filler. This process has been used to make many different things, from simple objects like phone cases and luggage tags to complex scaffolds used to hold cells for tissue engineering, or as in this post, specific implants for dogs and other animals. The usual types of orthopedic implants that have somewhat of a cookie cutter size distribution for humans do not always fit in dogs or other animals. So, 3-D printing has been employed to create implants used to repair and replace bones in veterinary situations.

Examples of computer-modeled custom implants
Examples of computer-modeled custom implants on dog legs

The most prominent veterinary application for 3-D printed implants is dogs. This is due to their slight differences in body type, even within breeds, that can make finding a pre-sized and pre-made implant difficult to find. One such example of this is a dachshund, named Patches, that received a custom made skull implant after other implants were found to be ineffective or dangerous to her long term health. Patches had a brain tumor, one that grew to a very large size and began encroaching on her eyes. The tumor was successfully removed, but the process involved the removal of large portions of her skull, leaving her brain unprotected. If a preexisting implant were tried, the way it would fit would leave her head vulnerable to an impact, making the implant quite pointless. A 3-D printed implant was made, and old Patches made a full recovery.

The process involves taking a CT scan of the area in question and gaining an understanding as to the layout of the area. This allows designers to make a 3-D model of the implant using a computer, and that model can be printed out using a 3-D printer. In the case of implants, titanium is usually used due to its biocompatibility and great mechanical strength. The implants can be used for surgery and repair, or an array of other applications, even studying the cranial activities of primates. In any case, these exciting new developments in 3-D printing are leading to advancements in the medical and biological fields. So, the next time you fire up you 3-D printer to make a cool-looking hood ornament, know that the same technology is at work, saving lives and giving scientists new knowledge about animals they previously had no good way of studying.