[Script Info]
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Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:06.74,0:00:12.05,Default,,0000,0000,0000,,There are currently hundreds of thousands \Nof people on transplant lists,
Dialogue: 0,0:00:12.05,0:00:16.40,Default,,0000,0000,0000,,waiting for critical organs like kidneys, \Nhearts, and livers
Dialogue: 0,0:00:16.40,0:00:18.45,Default,,0000,0000,0000,,that could save their lives.
Dialogue: 0,0:00:18.45,0:00:19.61,Default,,0000,0000,0000,,Unfortunately,
Dialogue: 0,0:00:19.61,0:00:24.62,Default,,0000,0000,0000,,there aren’t nearly enough donor organs \Navailable to fill that demand.
Dialogue: 0,0:00:24.62,0:00:26.58,Default,,0000,0000,0000,,What if instead of waiting,
Dialogue: 0,0:00:26.58,0:00:31.12,Default,,0000,0000,0000,,we could create brand-new, customized \Norgans from scratch?
Dialogue: 0,0:00:31.12,0:00:33.78,Default,,0000,0000,0000,,That’s the idea behind bioprinting,
Dialogue: 0,0:00:33.78,0:00:38.06,Default,,0000,0000,0000,,a branch of regenerative medicine \Ncurrently under development.
Dialogue: 0,0:00:38.06,0:00:41.27,Default,,0000,0000,0000,,We’re not able to print complex \Norgans just yet,
Dialogue: 0,0:00:41.27,0:00:44.56,Default,,0000,0000,0000,,but simpler tissues including blood\Nvessels and tubes
Dialogue: 0,0:00:44.56,0:00:47.50,Default,,0000,0000,0000,,responsible for nutrient \Nand waste exchange
Dialogue: 0,0:00:47.50,0:00:49.68,Default,,0000,0000,0000,,are already in our grasp.
Dialogue: 0,0:00:49.68,0:00:53.74,Default,,0000,0000,0000,,Bioprinting is a biological \Ncousin of 3-D printing,
Dialogue: 0,0:00:53.74,0:00:57.48,Default,,0000,0000,0000,,a technique that deposits layers of \Nmaterial on top of each other
Dialogue: 0,0:00:57.48,0:01:01.99,Default,,0000,0000,0000,,to construct a three-dimensional object \None slice at a time.
Dialogue: 0,0:01:01.99,0:01:05.19,Default,,0000,0000,0000,,Instead of starting with metal, plastic, \Nor ceramic,
Dialogue: 0,0:01:05.19,0:01:09.75,Default,,0000,0000,0000,,a 3-D printer for organs and \Ntissues uses bioink:
Dialogue: 0,0:01:09.75,0:01:13.62,Default,,0000,0000,0000,,a printable material that \Ncontains living cells.
Dialogue: 0,0:01:13.62,0:01:18.89,Default,,0000,0000,0000,,The bulk of many bioinks are water-rich \Nmolecules called hydrogels.
Dialogue: 0,0:01:18.89,0:01:21.84,Default,,0000,0000,0000,,Mixed into those are \Nmillions of living cells
Dialogue: 0,0:01:21.84,0:01:26.68,Default,,0000,0000,0000,,as well as various chemicals that \Nencourage cells to communicate and grow.
Dialogue: 0,0:01:26.68,0:01:29.85,Default,,0000,0000,0000,,Some bioinks include a \Nsingle type of cell,
Dialogue: 0,0:01:29.85,0:01:35.37,Default,,0000,0000,0000,,while others combine several different \Nkinds to produce more complex structures.
Dialogue: 0,0:01:35.37,0:01:37.74,Default,,0000,0000,0000,,Let’s say you want to print a meniscus,
Dialogue: 0,0:01:37.74,0:01:39.91,Default,,0000,0000,0000,,which is a piece of cartilage in the knee
Dialogue: 0,0:01:39.91,0:01:44.04,Default,,0000,0000,0000,,that keeps the shinbone and thighbone \Nfrom grinding against each other.
Dialogue: 0,0:01:44.04,0:01:46.82,Default,,0000,0000,0000,,It’s made up of cells called chondrocytes,
Dialogue: 0,0:01:46.82,0:01:50.52,Default,,0000,0000,0000,,and you’ll need a healthy supply of \Nthem for your bioink.
Dialogue: 0,0:01:50.52,0:01:55.32,Default,,0000,0000,0000,,These cells can come from donors whose\Ncell lines are replicated in a lab.
Dialogue: 0,0:01:55.32,0:01:58.34,Default,,0000,0000,0000,,Or they might originate from a \Npatient’s own tissue
Dialogue: 0,0:01:58.34,0:02:03.49,Default,,0000,0000,0000,,to create a personalized meniscus less\Nlikely to be rejected by their body.
Dialogue: 0,0:02:03.49,0:02:05.42,Default,,0000,0000,0000,,There are several printing techniques,
Dialogue: 0,0:02:05.42,0:02:09.48,Default,,0000,0000,0000,,and the most popular is extrusion-based \Nbioprinting.
Dialogue: 0,0:02:09.48,0:02:13.10,Default,,0000,0000,0000,,In this, bioink gets loaded into a \Nprinting chamber
Dialogue: 0,0:02:13.10,0:02:17.43,Default,,0000,0000,0000,,and pushed through a round nozzle \Nattached to a printhead.
Dialogue: 0,0:02:17.43,0:02:23.53,Default,,0000,0000,0000,,It emerges from a nozzle that’s rarely \Nwider than 400 microns in diameter,
Dialogue: 0,0:02:23.53,0:02:26.12,Default,,0000,0000,0000,,and can produce a continuous filament
Dialogue: 0,0:02:26.12,0:02:29.17,Default,,0000,0000,0000,,roughly the thickness \Nof a human fingernail.
Dialogue: 0,0:02:29.17,0:02:33.43,Default,,0000,0000,0000,,A computerized image or file guides the \Nplacement of the strands,
Dialogue: 0,0:02:33.43,0:02:36.85,Default,,0000,0000,0000,,either onto a flat surface or into a \Nliquid bath
Dialogue: 0,0:02:36.85,0:02:40.74,Default,,0000,0000,0000,,that’ll help hold the structure in place \Nuntil it stabilizes.
Dialogue: 0,0:02:40.74,0:02:45.13,Default,,0000,0000,0000,,These printers are fast, producing the \Nmeniscus in about half an hour,
Dialogue: 0,0:02:45.13,0:02:47.84,Default,,0000,0000,0000,,one thin strand at a time.
Dialogue: 0,0:02:47.84,0:02:51.53,Default,,0000,0000,0000,,After printing, some bioinks \Nwill stiffen immediately;
Dialogue: 0,0:02:51.53,0:02:55.72,Default,,0000,0000,0000,,others need UV light or an additional \Nchemical or physical process
Dialogue: 0,0:02:55.72,0:02:57.59,Default,,0000,0000,0000,,to stabilize the structure.
Dialogue: 0,0:02:57.59,0:02:59.97,Default,,0000,0000,0000,,If the printing process is successful,
Dialogue: 0,0:02:59.97,0:03:01.76,Default,,0000,0000,0000,,the cells in the synthetic tissue
Dialogue: 0,0:03:01.76,0:03:05.50,Default,,0000,0000,0000,,will begin to behave the same way\Ncells do in real tissue:
Dialogue: 0,0:03:05.50,0:03:09.70,Default,,0000,0000,0000,,signaling to each other, exchanging \Nnutrients, and multiplying.
Dialogue: 0,0:03:09.70,0:03:13.91,Default,,0000,0000,0000,,We can already print relatively simple \Nstructures like this meniscus.
Dialogue: 0,0:03:13.91,0:03:17.56,Default,,0000,0000,0000,,Bioprinted bladders have also been \Nsuccessfully implanted,
Dialogue: 0,0:03:17.56,0:03:23.09,Default,,0000,0000,0000,,and printed tissue has promoted facial \Nnerve regeneration in rats.
Dialogue: 0,0:03:23.09,0:03:26.94,Default,,0000,0000,0000,,Researchers have created lung tissue,\Nskin, and cartilage,
Dialogue: 0,0:03:26.94,0:03:33.67,Default,,0000,0000,0000,,as well as miniature, semi-functional \Nversions of kidneys, livers, and hearts.
Dialogue: 0,0:03:33.67,0:03:37.02,Default,,0000,0000,0000,,However, replicating the complex \Nbiochemical environment
Dialogue: 0,0:03:37.02,0:03:39.95,Default,,0000,0000,0000,,of a major organ \Nis a steep challenge.
Dialogue: 0,0:03:39.95,0:03:42.98,Default,,0000,0000,0000,,Extrusion-based bioprinting may destroy
Dialogue: 0,0:03:42.98,0:03:47.75,Default,,0000,0000,0000,,a significant percentage of cells in the \Nink if the nozzle is too small,
Dialogue: 0,0:03:47.75,0:03:50.89,Default,,0000,0000,0000,,or if the printing pressure is too high.
Dialogue: 0,0:03:50.89,0:03:52.86,Default,,0000,0000,0000,,One of the most formidable challenges
Dialogue: 0,0:03:52.86,0:03:58.70,Default,,0000,0000,0000,,is how to supply oxygen and nutrients \Nto all the cells in a full-size organ.
Dialogue: 0,0:03:58.70,0:04:01.39,Default,,0000,0000,0000,,That’s why the greatest successes so far
Dialogue: 0,0:04:01.39,0:04:04.42,Default,,0000,0000,0000,,have been with structures \Nthat are flat or hollow—
Dialogue: 0,0:04:04.42,0:04:06.92,Default,,0000,0000,0000,,and why researchers are busy \Ndeveloping ways
Dialogue: 0,0:04:06.92,0:04:11.32,Default,,0000,0000,0000,,to incorporate blood vessels \Ninto bioprinted tissue.
Dialogue: 0,0:04:11.32,0:04:13.78,Default,,0000,0000,0000,,There’s tremendous potential to use \Nbioprinting
Dialogue: 0,0:04:13.78,0:04:16.18,Default,,0000,0000,0000,,to save lives and advance our \Nunderstanding
Dialogue: 0,0:04:16.18,0:04:19.21,Default,,0000,0000,0000,,of how our organs function \Nin the first place.
Dialogue: 0,0:04:19.21,0:04:23.36,Default,,0000,0000,0000,,And the technology opens up a dizzying \Narray of possibilities,
Dialogue: 0,0:04:23.36,0:04:27.26,Default,,0000,0000,0000,,such as printing tissues with \Nembedded electronics.
Dialogue: 0,0:04:27.26,0:04:31.56,Default,,0000,0000,0000,,Could we one day engineer organs that \Nexceed current human capability,
Dialogue: 0,0:04:31.56,0:04:35.92,Default,,0000,0000,0000,,or give ourselves features like \Nunburnable skin?
Dialogue: 0,0:04:35.92,0:04:42.24,Default,,0000,0000,0000,,How long might we extend human life \Nby printing and replacing our organs?
Dialogue: 0,0:04:42.24,0:04:44.75,Default,,0000,0000,0000,,And exactly who—and what—
Dialogue: 0,0:04:44.75,0:04:49.05,Default,,0000,0000,0000,,will have access to this technology \Nand its incredible output?