We admit that 3-D-printing out feet for wee ducks is cool (and perhaps more useful than a Lego prosthetic), but medical science, as always, is barreling ahead. The marriage between medicine and technology has produced yet another miracle solution: 3-D-printing bone scaffolds and layering them with 3-D-printed stem cells (the first printing of which was announced last February). After three months—poof, the scaffold degrades, leaving a new stem cell-grown bone to replace defects.
Of course, it’s not as easy as picking up a desktop 3-D printer and going to town: the printed bone scaffolding needs to be precisely created using a 3-D bioprinter that spits out a polymer of polylactic acid (for strength) and gelatinous alginate (for cushioning). Critical to that creation is the delicate installation of printed-out blood vessels, a precision that requires manipulation at the cellular level, said Kevin Shakeshaff, Professor of Pharmacy at the University of Nottingham in England.
"The first advantage is you get something in the exact shape of the defect you're trying to replace," Shakeshaff said. "More subtly, you have the ability to organize where the cells go within the scaffold," he said, adding that it leads to better blood vessel formation and ultimately better bone formation.
To accomplish such microscopic dexterity, researchers at the University of Nottingham who are pioneering the technology have crafted optical "laser tweezers"—a pair of lasers that, when crossed, create an attractive force to move cells. The printed scaffolding replicates the bone defect and then the researchers continually shift the blood vessels with the superprecise tweezers, guiding the development of a proper bone. But the tweezers are as much a tool as a research opportunity: Shakeshaff said that their microscopic precision will allow them to play with many other types of cells, which could lead to development of scaffolding and stem cell repair of more complex tissues for the liver or heart, which typical stem cells aren’t suitable to build. To find appropriate stem cells for those, one must go to embryonic stem cells.
Shakeshaff and his peers from the University of Nottingham are exhibiting the 3-D-bioprinting tech at London’s Royal Science Society’s Summer Science Exhibition, running July 2 through Sunday. Attendees can play with the laser tweezers, craft veins, and print scaffolds for skulls and bones themselves. Shakeshaff says the bioprinting technology could be deployed within five years and clinically applied in a decade’s time.
[Image: Flickr user Starpause Kid]