Published by P.M. Fornasari April 28, 2016 17:48
The 3D printing lab at Mayo Clinic’s Rochester campus, now called “the anatomical modeling lab” has been in operation nearly a decade. The use of 3D printing for surgical practice at Mayo has grown to the point that every department has utilized it. The decision was made early to put the 3D printing lab inside the hospital and not a free-standing unit in a biomedical engineering building. That enabled surgeons and physicians to use 3D printing within their normal course of work.
Broad adoption on the scale of the 3D printing lab at Rochester’s Mayo clinic is stymied until a reimbursement code [for health care providers] is created, and the printers get faster, the materials get cheaper, the software gets easier to use. Currently, only the Rochester campus, Beth Israel and Walter Reed have such an extensive 3D printing facility
UCB Researchers Help Bioprinting Tissue Become Safer and More Affordable
BY P.M. Fornasari
APRIL 16, 2016.
Just a few years ago bioprinting tissues would be an outrageous idea, but now, it’s becoming more and more of a reality. Last year, one Wake Forest professor, Dr. James Yoo, said with confidence that these bioprinted tissues can be implanted into human patients within a 10 year timeframe. Now, researchers from the University of British Columbia have just announced the development of a new chemical compound that stands to make bioprinting tissues safer and more affordable.
The chemical compound is a new type of biological ink used in the 3D printing of tissue, which is able to function without the use of UV light systems, using a much safer and more conventional light source instead. In fact, the bioink could create biological tissue using an everyday light projector.
“UV light is known to be cancer-causing and can damage a cell’s DNA, which is not ideal when trying to create tissue for medical purposes,” said Keekyong Kim, the head researcher and assistant professor of Engineering at UBC. “By developing our own bio-ink, we can create bone, cartilage and tissue without the risk that we will make the cells sick in the development process.”
The 3D printing process works by combining processed cells with the newly developed bioink, which creates a hydrogel when exposed to light. Kim and his team used SLA printing in order to build the biomaterial in a layer by layer fashion, creating a scaffolding system to allow bone and tissue regeneration. For Kim, the biggest factor of the research was photo-initiating chemical compound that allowed the bioink to react to the much safer and affordable light projector, similar to the light source used for 3D printing with plastics.
“With our photo-initiator, we were able to use a more conventional light source, which hadn’t really been tried in 3D bio-printing before,” said Kim. “The result is we are able to make medical tissue in a way that is not only safer, it’s cheaper.”
In this paper, we present a low-cost stereolithography-based bioprinting system that uses visible light crosslinkable bioinks. This low-cost stereolithography system was built around a commercial projector with a simple water filter to prevent harmful infrared radiation from the projector. The visible light crosslinking was achieved by using a mixture of polyethylene glycol diacrylate (PEGDA) and gelatin methacrylate (GelMA) hydrogel with eosin Y based photoinitiator. Three different concentrations of hydrogel mixtures (10% PEG, 5% PEG + 5% GelMA, and 2.5% PEG + 7.5% GelMA, all w/v) were studied with the presented systems. The mechanical properties and microstructure of the developed bioink were measured and discussed in detail. Several cell-free hydrogel patterns were generated to demonstrate the resolution of the solution. Experimental results with NIH 3T3 fibroblast cells show that this system can produce a highly vertical 3D structure with 50 μm resolution and 85% cell viability for at least five days. The developed system provides a low-cost visible light stereolithography solution and has the potential to be widely used in tissue engineering and bioengineering for microscale cell patterning.
Carbon3D: The shape of things to come
Kirk Phelps wants to change how things get made. He holds up a floppy yellow circle of plastic, a sealing gasket for a generic automotive engine, and explains how this gasket is limiting human creativity.
“If you want to make a new kind of engine, you don’t get to design the engine from the ground up. You actually go to your gasket supplier and ask what standard gaskets are available and you design the engine around it. This is backward,” says Phelps, a 33-year-old product designer who helped develop the multitouch on the iPhone.
That frustration led him to take the job as head of product development at Carbon3D, one of the hottest startups to come along in the emerging 3D printing industry. The promise of 3D printing is the ability to produce a solid part on the spot based on any digital 3D file, freeing engineers to build their dream engine. While some of the highest-end machines can precisely print small-batch items such as hearing aids and artificial joints, the vast majority of 3D printers in use today are slow and capable of making only trinkets and small prototypes. The early hype around 3D printing peaked a couple of years ago, and now shares of the two big publicly traded printer manufacturers, Stratasys and 3D Systems, are 80 percent off their highs.
Carbon3D is reinjecting excitement into the field. Its CEO and cofounder, Joseph DeSimone, a 51-year-old entrepreneur and former chemistry professor from the University of North Carolina at Chapel Hill, came up with a new way to print objects in 3D so quickly and precisely that Sequoia Capital partner Jim Goetz (the sole backer of WhatsApp) led a $11-million Series A round and lured him to Redwood City, California from his tenured chair in Chapel Hill. The company has since raised more than $140 million, including a $100-million round in August led by Google Ventures. Its valuation is already estimated to be above $1 billion without releasing anything more than a product for early customer trials. “The industry is dominated by mechanical engineers who print two-dimensional objects up layer by layer,” DeSimone says. “Let’s not do this layer by layer—let’s grow these parts.”
Most 3D printers use a technique known as fused deposition modelling, which is basically a hot-glue gun controlled by a robot arm that zig-zags back and forth depositing layers of plastic to make a solid object. A Carbon3D machine pulls a solid object from a small tub of liquid plastic—akin to the way the killer robot in Terminator 2 lifted itself out of liquid-metal puddles. It’s a variation of a decades-old technique called stereolithography, or the use of light to solidify liquid plastic. DeSimone’s contribution as a chemist was to replace the bottom of the tub with a pane of glass that, like a contact lens, is porous to air. The air creates a cushion under the resin that is one-thousandth of an inch thick, so the liquid never sticks to the glass. A laser firing from beneath the glass solidifies the bottom layer of plastic in a precise pattern dictated by the object’s 3D file. A robotic arm slowly pulls the object out of the pool, and more resin flows under to be heated.
Carbon3D says it can produce objects of higher resolutions at speeds 25 to 100 times faster than traditional stereolithographic printers and several other techniques. Because the action of the machine is so smooth, it allows manufacturers access to a wider variety of performance materials such as stretchy elastomers and high-temperature-resistant resin. Carbon3D aims to develop its own resins for making objects ready for commercial sale. “We’re focussed on applications where the 3D-printed part is the functional part, where it could go into a car. Existing 3D printers don’t do that,” says Phelps. “And if it works as a final part would, why not just ship the 3D-printed part? If it’s just as good, why worry about injection moulding?”
A dozen companies, including Ford Motor and Hollywood special effects studio Legacy Effects, are testing Carbon3D machines, each of which will cost north of $10,000. Legacy, which worked on the Iron Man and Avengers movies, uses it to print prosthetics and props. The studio cut the time it took to print one crucial job from 16 hours to two hours.
“If I have speed, detail and material choice, that are high-grade engineering materials, that’s a winner,” says Jason Lopes, a lead systems engineer at Legacy Effects. “The throughput is absolutely amazing.” Ford liked it so much that its former CEO Alan Mulally joined Carbon3D’s board. Ellen Lee, Ford’s team leader of additive manufacturing research in Dearborn, Michigan, is now assessing the idea of using a Carbon3D machine in its rapid-prototyping unit. While Ford is still clearly years away from printing critical car parts, Lee has joked about printing gear shifters to fit the owner’s hand. “A lot more potential remains untapped in 3D printing,” Lee says. “It’s really going to change the way we manufacture in America. We want to understand how to best use it.”
Industry expert Terry Wohlers of Wohlers Associates says that while Carbon3D’s speed is a big deal for manufacturing, he’s uncertain of the quality of the end product. Over time, light can degrade the photopolymers used in stereolithography, making them less reliable than the thermoplastics used by more common fused deposition-modelling printers. Carbon3D says that its polymers use UV-blockers and pigments to protect them from light.
Carbon3D machines are priced well above the mass market, but that shouldn’t be an issue for large businesses if it works as advertised. “Ford spends hundreds of thousands of dollars on individual pieces of manufacturing equipment,” says Wohlers.
Carbon3D’s talk about disrupting injection moulding (a widely used manufacturing process) is a bit far-fetched, but its machines are bringing excitement back to 3D printing. “Ten years ago, a lot of firms started building 3D printing manufacturing plans,” DeSimone says, “and it was really exciting. Then they shelved plans, because the technology didn’t have enough horsepower to take them there. Now they’re starting to dust off those plans.”