Written by Matthew Young @mattbeardyoung
Even though 3D printing has already made its presence felt in the field of medicine, the biggest impacts are just starting to take shape. Very recent experiments have used living cells to construct various components of the human body, and it’s only a matter of time before these results become commercially available. Currently, 3D printers are used to produce such things as customized prostheses from titanium or cranial plates from hard plastics. Stents used to prop open collapsed windpipes in infants have even been created from the biodegradable plastic polycaprolactone. Incorporating live tissue will take things to a whole new level, and the following examples show how this advancement is now seeing success in research laboratories.
1. Embryonic Stem Cells
With their ability to transform into any other kind of cell in the human body, stem cells offer huge potential in 3D bio-printing. Until recently, stem cells were 3D printed in single layers. This would result in them exhibiting their normal tendency to migrate towards each other and form groups in an unpredictable fashion. A new approach deposits them in three-dimensional pattern of six layers. Under these conditions, the cells form these groups called embyoids by reproducing rather than altering their locations. This greatly increases their ability to differentiate into other cells later on.
2. Getting Blood Where It’s Needed
One big hurdle in the way of 3D printing organs is that once tissue reaches a thickness of 200 micrometers, oxygen can no longer permeate to its center. Equipping these manufactured organs with blood vessels solves this limitation. A new method involves 3D printing a network of filaments that are then coated with blood vessel cells. Once the cells grow and form solid structures, the filaments are extracted.
3. Skin in the Game
Although human skin can already be grown, the process is highly laborious. The French cosmetics company L’Oreal has teamed with the medical research company Organovo to employ 3D printing to automate the procedure in order to lower costs and produce a more uniform quality. Presently, L’Oreal generates an annual total of 54 square feet of the tissue divided into tens of thousands of sections less than a tenth of a square inch apiece. Along with providing skin for tissue grafts, these specimens are also used to test cosmetics and for medical research. Since skin cells average 10 microns in width and the narrowest syringe is almost ten times wider, this technique still needs further improvements. Another partnership between a French start-up, Poietis, and BASF offers a more precise method where laser pulses trigger microscopic shockwaves in an absorption material that then expels equally tiny specks of cell-containing gel. This produces tighter formations of cells at up to 100 million per millimeter and leads to nearly all of them surviving.
4. Vital Organs
Because of their extreme complexity, 3D printing organs will require further developments in computer modelling as well as in the printing mechanisms used to deposit the cells. Nevertheless, there are already success stories with miniature versions of both livers and kidney that can live anywhere between one and four months. These experimental organs can be used for testing and further research in improving organ printing techniques. More encouraging is the creation of a printed heart valve that’s slated to be tested in sheep in the near future.
5. Growing Bones and Cartilage
With non-living materials like titanium and PEKK plastic already in use with or without 3D printing as bone replacement, the next step, according to Xilloc Medical Company, is to print artificial parts with an outer layer of calcium phosphate. As the main ingredient in bone tissue, the addition of this chemical should stimulate surrounding bone to merge with it. This will reduce the chances of either rejection or infection. New technologies have harnessed the flexibility of 3D printers and their materials for use in dental settings, creating customized items that fit particular patients. Greater success has been reached with cartilage, which can already be transplanted in thin layers. 3D printers are being used to assemble cartilage into three-dimensional components like noses and ears by placing the cartilage cells in collagen.
6. Realistic Prosthetics
3D technologies can already make prosthetic limbs fit their recipient more accurately. One current strategy in 3D printing is to create limbs that look more like the originals while maintaining the same strength and agility of the existing types being used.
7. Designer Drugs
Medications are currently produced according to set formulas and in a limited range of pill sizes. 3D printing allows customized dosages to be produced for individual patients. It can also alter a medication’s formula to either include extra ingredients or remove items the person is allergic to. Similar to this, biodegradable plastics like PLA are being experimented with to create 3D-printed delivery systems that can be implanted in a patient and slowly release medication as they decompose.
One thing that becomes very obvious from these examples is that the human body is extremely complicated, so it’ll be quite some time before 3D printing can successfully tackle the big jobs of building major organs. On the other hand, some serious obstacles have already been overcome, and these brief example show that future progress will be achieved primarily through 3D printing.