Harvard bioengineers say they have taken a big step toward using 3-D printers to make living tissue. They’ve made a machine with multiple printer heads that each extrudes a different biological building block to make complex tissue and blood vessels.
Their work represents a significant advance toward producing living medical models upon which drugs could be tested for safety and effectiveness.
It also advances the ball in the direction of an even bigger goal. Such a machine and the techniques being refined by researchers offer a glimpse of the early steps in a sci-fi healthcare scenario: One day surgeons might feed detailed CT scans of human body parts into a 3-D printer, manipulate them with design software, and produce healthy replacements for diseased or injured tissues or organs.
Read more below and click the gifs for explanations.
How it’s made: Bioengineers take a 3-D scan of a child’s ear, design a seven-part mold in the SolidWorks CAD program, and print the pieces. The mold is injected with a high-density gel made from 250 million bovine cartilage cells and collagen from rat tails (the latter serves as a scaffold). After 15 minutes, the ear is removed and incubated in cell culture for several days. In three months, the cartilage will have propagated enough to replace the collagen.
Benefit: At least one child in 12,500 is born with microtia, a condition characterized by hearing loss due to an underdeveloped or malformed outer ear. Unlike synthetic implants, ears grown from human cells are more likely to be successfully incorporated into the body.
UC Berkeley bioengineers have built a heart-on-a-chip. The inch-long silicone device effectively models human heart tissue — a major step in the development of a fast, accurate method for testing for drug toxicity.
“Ultimately, these chips could replace the use of animals to screen drugs for safety and efficacy,” said Healy.
The study authors noted a high failure rate associated with the use of nonhuman animal models to predict human reactions to new drugs. Much of this is due to fundamental differences in biology between species, the researchers explained. For instance, the ion channels through which
heart cells conduct electrical currents can vary in both number and type
between humans and other animals.
“Many cardiovascular drugs target those channels, so these
differences often result in inefficient and costly experiments that do
not provide accurate answers about the toxicity of a drug in humans,”
said Healy. “It takes about $5 billion on average to develop a drug, and
60 percent of that figure comes from upfront costs in the research and
development phase. Using a well-designed model of a human organ could
significantly cut the cost and time of bringing a new drug to market.”
For a wearable biomedical device to be comfortable and practical, it should provide a seamless ‘second skin’ for the patient. To do so the device must move with the body, emulating the elasticity of skin. This has sparked a lot of interest in thin, film-like materials, and has led to a new breed of biocompatible electronics with controllable flexibility. Such materials are highly elastic, and consist of a spiral network interweaved through a gel-like substance – as pictured. The spiral symmetry allows the material to be stretched evenly in all directions – mimicking the stretching properties of skin – although subtle changes to the structure can tweak the elasticity, adapting it for different patches of skin, and even different organs. These composite materials are a step forward in tissue engineering and could be used to create both wearable and fully implanted biomedical devices in the future.
Of course you do. Well now bioengineers have developed a skin made in part with spider silk that is capable of stopping a speeding bullet. Spider silk may not seem that strong, but in a strength to weight comparison a weave of it out distances Kevlar 4 fold. I once heard that an inch thick rope of the stuff could stop a jet plane at full throttle. For videos of the tests you can click here. The first test shows a bullet moving only at half speed, while the second test shows it moving at full speed under which conditions the skin is compromised. To be fair though, it’s a step in the right direction and I look forward to being the super villain hero I’ve always wanted to be.
Droplets containing two liquids with different properties can be made into fluid machines. Engineers in the lab of Stanford University’s Manu Prakash (creator of the 50-cent paper microscope) found that mixtures of simple ingredients like water and propylene glycol-based food coloring could propel themselves in intricate patterns and move other droplets around a standard glass slide.
“We demonstrate experimentally and analytically that these droplets are stabilized by evaporation-induced surface tension gradients and that they move in response to the vapour emitted by neighbouring droplets,” the authors write in a paper published yesterday in the journal Nature. “Our fundamental understanding of this robust system enabled us to construct a wide variety of autonomous fluidic machines out of everyday materials.”
The work trying to understand the dynamics of these different fluids began with an unexpected observation by coauthor and bioengineering graduate student Nate Cira in 2009. While completing an unrelated experiment as an undergraduate, Cira noticed that drops of food coloring began to move of their own accord on a glass slide. See video below.
A flexible, absorbable tube helps a baby boy breathe, and heralds a future of body parts printed on command.
Kaiba Gionfriddo was six weeks old when he suddenly stopped breathing and turned blue at a restaurant. Kaiba’s parents quickly rushed him to the hospital where they learned that his left bronchial tube had collapsed because of a previously undetected birth defect. During the next few weeks the life-threatening attacks recurred, increasing in number until they became everyday events. Physicians and researchers, however, used some of the most sophisticated bioengineering techniques available to 3-D print a synthetic tube to hold the baby’s airway open. Kaiba had the surgery in January 2012 and hasn’t suffered an airway collapse since.
This is one way of growing replacement body parts from scratch. This involves implanting a biorubber ear seeded with living cells into a specially engineered lab rat. The rat’s body nurtures the ear until it has the proper vascular structures suited to a living, moving body.
The left column shows the stepwise increase in cell-culture volume, starting with a vial from the working cell bank (note that a new working cell bank is made from a vial from the master cell bank). Exponentially growing cells from each step serve, after growing to a certain cell density, as the inoculum of the next culture vessel, which is an order of magnitude larger. The final bioreactor starts only partially filled and is fed with sterile medium at such a rate that the cells grow further under optimal conditions.
When the bioreactor is full and the desired cell density is reached, the protein-crosslinking enzyme transglutaminase and binding protein are added to induce the formation of easily settling aggregates of cells, which quickly settle when stirring is stopped (bottom right). The harvested cells are pressed and the cake is extruded into retailer- and/or consumer-size portions of minced meat (right column).
Say good-bye to root canals and fillings! The Gizmodo article (excerpt below) has the story….
The current study builds on years of anecdotal reports about low-power laser stimulating skin or hair growth. (Yes, at the same time high-power lasers do the opposite.) Something about laser light stimulates certain biological pathways in cells. Scientists have now figured what that something is when it comes to dentin. A blast of laser induces reactive oxygen species, which are chemically active molecules that then activate a growth factor to stimulate dentin growth.
Although studies have regenerated parts of a tooth from stem cells in a petri dish before, the laser procedure can happen right in the mouth. This study’s authors got it to work in tiny rodent teeth, and now they’re continuing onto human clinical trials in hope it could someday replace some current dental procedures. I don’t know if the thought of even low-power lasers makes the dentist less terrifying, but I’d take it over a root canal. [Science Translational Medicine]
When University of California, Berkeley, bioengineers say they are
holding their hearts in the palms of their hands, they are not talking
about emotional vulnerability.
Instead, the research team led by bioengineering professor Kevin Healy is presenting a network of pulsating cardiac muscle cells housed in an inch-long silicone device that effectively models human heart tissue,
and they have demonstrated the viability of this system as a
drug-screening tool by testing it with cardiovascular medications.
This organ-on-a-chip, reported in a study to be published Monday, March 9, in the journal Scientific Reports,
represents a major step forward in the development of accurate, faster
methods of testing for drug toxicity. The project is funded through the
Tissue Chip for Drug Screening Initiative, an interagency collaboration
launched by the National Institutes of Health to develop 3-D human tissue chips that model the structure and function of human organs.
"Ultimately, these chips could replace the use of animals to screen drugs for safety and efficacy," said Healy.
UC Berkeley researchers have created a ‘heart-on-a-chip’ that effectively uses human cardiac
muscle cells derived from adult stem cells to model how a human heart
reacts to cardiovascular medications. The system could one day replace
animal models to screen for the safety and efficacy of new drugs.
Credit: Photo by Anurag Mathur/Healy Lab
Cardiovascular scientists have announced they’ll be able to 3D print a whole human heart - “the easiest” organ to bioprint - from a patients’ own cells within a decade. The ambitious US team is already building custom 3D printers for the job.
Scientists grow teeth from human urine because why the hell not
A new study shows that stem cells extracted from urine can be turned into rudimentary tooth-like structures. Oh, and the researchers did so by growing the teeth inside the kidneys of mice.
To make the teeth, Duanqing Pei, who works at the Chinese Academy of Sciences in Guangzhou, mixed the stem cells with the connective tissue cells of mice. This concoction was grown for two days prior to being implanted under the outer layer of a mouse’s kidney. Once there, the cells were coaxed into becoming dental epithelial tissue, and eventually enamel.
Drug developers such as pharmaceutical companies spend large amounts of time and money testing on animals and cell cultures, which often produce inaccurate predictions for human side effects. But in the hopes of creating a cheaper, more efficient and more accurate method, researchers are currently developing microchips configured to mimic the structure and biochemical behaviour of human organs. At the Wyss Institute for Biologically Inspired Engineering, researchers recently created a ‘lung-on-a-chip,’ made of crystal-clear flexible polymer and roughly the size of a memory stick. A thin, porous membrane is sandwiched by lung cells that simulate air flow and capillary cells that simulate blood flow, with vacuum channels on either side to stretch the tissue and simulate breathing. The chip was used to test cancer chemotherapy drug IL-2, which has a toxic side effect called pulmonary edema that fills the lungs with fluid and blood clots. The results gave a new insight into the condition, showing that the physical act of breathing made the fluid leakage worse, which may not have been obvious in other kinds of testing. These bio-inspired ‘organs’ hold enormous potential to replace traditional drug testing, bringing therapy to patients faster and at a lower cost, and the chips could even be personalised to predict a specific individual’s drug response. Ultimately, the goal is to create chips that mimic more complex systems—and perhaps even whole humans.
Cloning a woolly mammoth? Might not be as crazy as you think.
Geneticist Hendrik Poinar is working on bringing the woolly mammoth back from the dead.In a talk at TEDxDeExtinction, he explains how scientists are extracting DNA from the remains of woolly mammoths preserved in permafrost.
From his talk:
If you had asked me ten years ago whether or not we would ever be able to sequence the genome of extinct animals, I would have told you, “It’s unlikely.” If you had asked whether or not we would actually be able to revive an extinct species, I would have said, “Pipe dream.”
But I’m actually standing here today, amazingly, to tell you thatnot only is the sequencing of extinct genomes a possibility, actually a modern-day reality, but the revival of an extinct species is actually within reach…
Interactive Bionic Man, featuring 14 novel biotechnologies
The National Institute of Biomedical Imaging and Bioengineering has launched the “NIBIB Bionic Man,” an interactive Web tool that showcases cutting-edge research in biotechnology. The bionic man features 14 technologies currently being developed by NIBIB-supported researchers. Examples include a powered prosthetic leg that helps users achieve a more natural gait, a wireless brain-computer interface that lets people who are paralyzed control computer devices or robotic limbs using only their thoughts, and a micro-patch that delivers vaccines painlessly and doesn’t need refrigeration. (via Interactive Bionic Man, featuring 14 novel biotechnologies | KurzweilAI)
Breakthrough Could Lead to ‘Artificial Skin’ That Senses Touch, Humidity and Temperature
July 8, 2013 — Using tiny gold particles and a kind of resin, a team of scientists at the Technion-Israel Institute of Technology has discovered how to make a new kind of flexible sensor that one day could be integrated into electronic skin, or e-skin. If scientists learn how to attach e-skin to prosthetic limbs, people with amputations might once again be able to feel changes in their environments.