The results from Guilkey's surgery show that culturing stem cells extensively before implanting them might not be the only path to take in developing new stem cell treatments. "We're thinking at this point that that might not be such a great idea—to induce them into becoming something [specific]. Maybe some of these cells need to become something else," Taylor says. To grow bone, the body also needs vascular cells, fat cells and others. So why, Taylor proposes, limit a stem cell implantation to only one kind of cultured, differentiated cell?
The procedure does highlight the vast amount of research that remains to be done. "There's so much we don't know," Taylor says. "And to pretend that we have control over everything is presumptuous." He favors using biological rather than artificial scaffolds. "I try to use as many natural cues and processes as possible," he says. "There's a lot we don't understand mechanistically," so he prefers "putting it in an environment that says, 'Become a bone.'"
Although the approach may sound overly simplistic for Guilkey and at least and two other patients who have undergone the procedure since, it appears to have been successful. "It's primitive, but it works," Taylor says. "Now the onus is on us to figure out why it works."
In the meantime, Taylor says, Guilkey, now 15, has become a lot more outgoing and has even cut his hair short for the first time in his life—rather than try to cover up his face with long locks. Taylor reports that the teen has been able to return to sports and is now dating.