April 05, 2013

from RT Website

Spanish version

Droplet network that self-folded

into hollow ball c.400 microns across

(credit: Oxford University / G Villar)
 

Researches have built a new type of 3D printer that creates tissue-like material that could revolutionize medicine.

The artificial material produces the properties of living tissues and could potentially replace them in the future. The new material developed by scientists at Oxford University consists of water, coated and protected by lipid molecules.

The tens of thousands of 3D connected caviar-like droplets were named 'droplet networks'.

“We add chemicals and bio chemicals. This changes the water. After all we humans are made of networks of water droplets” Professor Hagan Bayley of Oxford University's Department of Chemistry commented, as cited by the Daily Mail.

The 'droplet networks' could one day replace damaged living tissue or deliver drugs to specific locations, the researchers said in a study released Friday in Science magazine.

"We aren't trying to make materials that faithfully resemble tissues but rather structures that can carry out the functions of tissues," said Professor Bayley in a news briefing on the Oxford university website.

Droplet network c.500 microns across

with electrically conductive pathway

between electrodes mimicking nerve

(credit: Oxford University / G Villar)
 

"The droplets can be printed with protein pores to form pathways through the network that mimic nerves and are able to transmit electrical signals from one side of a network to the other," he added.

Eventually this material could replace the use of stem cells, a completely synthetic material, has no genome and does not replicate. The creation of 'droplet networks' avoids many problems such as harvesting living tissue.

The Oxford scientists said that there was no printer to build these aqueous droplets as so far they have developed 3D printers that can only create solid objects. So they found a way out by building one in their laboratory.

The unique 3D printer was built by Gabriel Villar, a student and the lead author of the paper.

"Conventional 3D printers aren't up to the job of creating these droplet networks, so we custom built one in our Oxford lab to do it," said Professor Bayley.

Printed droplet networks c.500 microns across

(Credit: Oxford University / A Graham)
 

Each droplet is 50 microns in diameter, about 0.05 millimeters, but it is five times larger than a living cell.

Professor Hagan Bayley said that given more time and funding they will be able to develop smaller networks.

"At the moment we've created networks of up to 35,000 droplets but the size of network we can make is really only limited by time and money. For our experiments we used two different types of droplet, but there's no reason why you couldn't use 50 or more different kinds."

At present the material remains stable for weeks.

This synthetic material can be designed to take on different shapes after it was printed. This resembles muscle movement. The researchers have demonstrated the through the creation of a flowerlike droplet network that from the initial flat shape curls into a sphere.
 

The movement is triggered by a process called osmosis.

The droplets on the bottom of the network are filled with a high concentrated solution, and the ones on the top are filled with a low concentration. After the droplets are printed the solvent molecules on top flow into the droplets on the bottom through a partially permeable membrane.

When that happens the droplets on top shrink and the droplets on the bottom blow up causing the whole structure to curl.
 

3D printing gives vast opportunities such as to create objects as complex as human organs.

There are certain advantages of using artificial tissue in comparison with living tissue, says Cameron Ferris a research associate from the ARC Centre of Excellence for Electromaterials Science at the University of Wollongong, ABC Science reports.

He is part of a team that develops 3D printers to potentially create replacement organs using living cells.

"It's incredibly expensive to harvest stem cells [for 3D printing of living tissue], and the food you have to feed them, to grow and expand them so that you have enough stem cells to print takes some time” he said, according to ABC science.

Hear, hear!...

Scientists Create Human-Like Ears

...with 3D Printing
February 21, 2013

from RT Website

Spanish version

Larry Bonassar,

Cornell Associate Professor of Mechanical Engineering.

(AFP Photo / Lyndsay France)
 

The latest innovation in 3D printing - artificial ears - feel, look and behave identically to human ones. The new product developed in the US could provide patients who are missing all or just part of their ear with a chance at reconstructive surgery.

Cornell biomedical engineers and Weill Cornell Medical College physicians published their study online in the PLOS ONE journal on Wednesday.

They show how they developed an ear over the course of three months by inserting living cells into an injection mold and then growing cartilage in the shape of its mold.

"This is such a win-win for both medicine and basic science, demonstrating what we can achieve when we work together," co-lead author Lawrence Bonassar, associate professor of biomedical engineering at Cornell, told AP.

According to the study, the first implant could be tried in around three years.

A 3-D printer.

(AFP Photo / Lyndsey France)
 

Researchers began the project by creating a digitized 3D image of a human ear, which was used to build an ear-shaped mold using a 3D printer.

Then they injected a gel made of living cow ear cells and collagen (a substance used to make gelatin) into the mold and the ear was done.

The production part took less than two days: only half a day to build the mold, a day to print it, 30 minutes to insert the gel, then wait 15 minutes and everything was ready to go.
 

Digitization process for human ears.

(Image from plosone.org)
 

Scientists tested the artificial ears by implanting them on the backs of rats and it took one to three months for the ears to grow. Rodents are often used by scientists to test the growing of artificial ears.

"We trim the ear and then let it culture for several days in nourishing cell culture media before it is implanted," Bonassar told AP.

The need for the product is there. Thousands of children who are born with ear deformities and those who have lost an ear during their life could benefit from the new technology.

The most common deformity is microtia, when the external ear does not fully develop. In US one to four children per 10,000 are born with it, according to the study.

People born with microtia usually have an inner part of the ear fully functional, but they still have impaired hearing because they are missing part of their external ear.
 

Mold design based on ear anatomy.

(Image from plosone.org) )
 

"A bioengineered ear replacement like this would also help individuals who have lost part or all of their external ear in an accident or from cancer," co-lead author Jason Spector told Live Science.

Researchers identified the best time for implantation for the kids to be at around the age of five or six, when the ears are at 80 per cent of their adult size.

The study says that a chance of rejection during implant procedure could be potentially decreased by using human cells from the same patient when constructing the bioengineered ear.

Before this point, technology only allowed to build replacement ears with a foam-like consistency or by using a patient's harvest rib, the latter is a painful process and ears still often looked unnatural and did not properly work.
 

Schematic representation of length and width measurements.

(Image from plosone.org)

A Tissue-Like Printed Material

April 2013

from 2n2n Website

Spanish version
 

British researchers said in a report published in the journal "Science", they use a special 3D printer to print out material similar to the biological tissue, this outcome expected future applications in the medical field.

This report is published jointly by Professor Hagan Bayley of the University of Oxford and colleagues.

According to reports, they take advantage of the the 3D printer hierarchical profuse droplets of lipid film wrapped, these droplets form a mesh structure, constitute a special new material.

The researchers say, to print out the material texture with brain and adipose tissue similar folding action can make a similar muscle-like activities, with work like neurons as the communication network structure can be used to repair or enhance the failure of the organ. Synthetic materials, it also avoids the problems caused by some the way manufacturing living tissue with stem cells.

The researchers also said that conventional 3D printers can not print this new material, experiment, they used a special 3D printer, this printer ejected droplet diameter of approximately 50 microns, 5 living cells so but I believe will be able to reduce the size of the droplets.

In recent years, 3D printing technology rapid development, from engineering to aerospace, from education to health care, application more widely.

In February of this year, Cornell University researchers had reported that,

"They use cells from ears of cattle on 3Dprinters to print out the artificial ear."

 

 

A Tissue-Like Printed Material
by Gabriel Villar, Alexander D. Graham, Hagan Bayley

Science 5 April 2013:
Vol. 340 no. 6128 pp. 48-52
DOI: 10.1126/science.1229495

Living cells communicate and cooperate to produce the emergent properties of tissues.

 

Synthetic mimics of cells, such as liposomes, are typically incapable of cooperation and therefore cannot readily display sophisticated collective behavior. We printed tens of thousands of picoliter aqueous droplets that become joined by single lipid bilayers to form a cohesive material with cooperating compartments.

 

Three-dimensional structures can be built with heterologous droplets in software-defined arrangements.

 

The droplet networks can be functionalized with membrane proteins; for example, to allow rapid electrical communication along a specific path. The networks can also be programmed by osmolarity gradients to fold into otherwise unattainable designed structures.

 

Printed droplet networks might be interfaced with tissues, used as tissue engineering substrates, or developed as mimics of living tissue.

 

Read the full report: "A Tissue-Like Printed Material".