Two Fridays ago, Ira Flatow did a story on the Human Microbiome project:
FLATOW: Thank you. I mean, how many, how many microorganisms inhabit our body?And last Friday, he did one about 3D printing, which included this exchange on printing body parts:
HUTTENHOWER: The rule of thumb is that each of us carries around about 10 times as many microbial cells as human cells and that they have about 100 times as many genes as we do. So not only are we outnumbered, we're outgunned. They're able to perform a lot of biological functionality that we don't get to do, necessarily, in our own genome.
FLATOW: So is this really the first census of figuring out who they are and what they do?
HUTTENHOWER: This has been the largest and deepest survey of this many healthy individuals over this many different body sites. It's been interesting since each of these body sites, these areas, represent really a different ecosystem. They're very different. So profiling what the normal variation, even in health, there's a tremendous number of differences between people and seeing how those map out, what the boundaries of that healthy variation are from person to person at each of these different body sites is really important for the project to lay out.
FLATOW: Hod Lipson, you're already printing stuff, body parts.For achinhibitor and for dpolicar, as well as everyone else interested in this topic.
LIPSON: Yeah, we've printed meniscus, cartilage of the knee.
FLATOW: Right, and you say you make tissue already?
LIPSON: Yeah, so we've been quite a while working on this area which we call bio-printing, together with Larry Bonassar and Jonathan Butcher at Cornell, where we actually print with live cells. It's not printing a scaffold on which you put cells but actually taking the cells, putting them in a hydrogel ink and actually printing the final constructs out of live cells.
And the benefit is that you can merge multiple cells into the same print in order to make a heterogeneous tissue.
FLATOW: And what tissues have you made?
LIPSON: So so far, we've made cartilage, meniscus of the knee, and Larry and Jonathan are working on printing spinal disks and heart valves. And so bones and bone tissue and cartilage are kind of the lowest-hanging fruit, so to speak, because they are very amorphous, and they're very simple structures, but little vascularity. And that's where the state of the art is.
But I think as the technology progresses, we'll be able to make more sophisticated implants.
FLATOW: Maybe kidneys, livers, things like that?
LIPSON: The trend is going for moving - is again moving from parts, so to speak, from simple tissue, to making complex, more complex organs, kidneys certainly have been reported to have been done, liver and you know, it will take a while before we can do more complex things.