Lab Grown Lung Video

The following excerpt from a NOVA program on tissue engineering shows a lab grown lung breathing on its own.

How to Make Your Own Jellyfish

Jellyfish, one of the strangest organisms known to man. They can be found in every ocean in large quantities, and they are one of the oldest organisms in existence, surviving for nearly 500 million years! Yet, something this old is not the slightest bit wise, as it doesn't even have a brain.

However, the bioengineers at Caltech and Harvard chose to artificially create a jellyfish. You may think why do we need more of something that is already so plentiful, and potentially dangerous. Well, the bioengineers explain that jellyfish have a simple structure to them. Jellyfish are pretty much just "a pulsating bell, a tassel of trailing tentacles and a single digestive opening through which it both eats and excretes." The bell of the jellyfish contains its vitals, and by understanding how it works, the bioengineers began their attempt at creating an artificial jellyfish.

A polymer jellyfish

A schematic of the bell was created, detailing the tissue used. Using the schematic, the bioengineers began constructing the jellyfish. First, they cut a thin polymer membrane, a material similar to jellyfish tissue, into the shape of a jellyfish. Then, they placed rat heart cells and protein into the polymer. The rat hearts served as the vitals, while the protein served as a guide for the rat hearts to grow correctly. Once this was finished, they submerged their invention into a tank and sent a current through it. Amazingly, the invention came to life and had movements similar to a real jellyfish.

This successful experiment can lead to many new discoveries in the future. Despite the simplicity of a jellyfish, this is a great starting point for future construction of more complicated organisms, and eventually to the possibility of being able to operate on humans. In the meantime, the bioengineers at Caltech and Harvard will continue to improve their jellyfish, hoping to give it the ability to move without a current and capture its own food.

http://www.time.com/time/health/article/0,8599,2120119,00.html

The following video sums up the creation of the jellyfish:

Mass Production of Tissue- Engineered Meat a Possibility

The CEO of the company "Modern Meadow" has announced that his company has and will continue to work on the process of 3-D bioprinting leather. The company believes that the leather will be mass-produced by 2017 and manufactured meat may follow in several years. Modern Meadow's main focus will be on leather for the time being.

While meat may be a more helpful and useful use of their funding, skin is a much simpler material to imitate. Additionally, leather will be a much less controversial material to the public. The company has found that only 40% of the population would be willing to try this manufactured meat, while very few would have a problem using this mass-produced leather. In fact, this process should go over very well with the public, as the scientists will not need to kill any animals.

The scientists have already come up with the process and just need to find a way to increase the scale of production. In other words, they face engineering, not scientific obstacles. The five step process includes taking punch biopsies of donor animals. While these animals need to be dead, the researchers are using animals that were already going to be killed for meat or skin. The researchers then make necessary modifications to these cells.

By using a bio reactor or growth apparatus, the cells multiply from millions to billions in number. They are then centrifuged to eliminate the growth medium of the cells and to lump them together into clumps of cells.

These aggregates are fused together using a process known as bioassembly. There are still several possible processes and Modern Meadow is still trying to find the best approach.



The complex process of manufacturing leather


The scientists then put these fused cells into a bioreactor and given time to mature. They create an environment which allows "nature to take over" the growing process of these cells. This increases the growth of the collagen cells

Several weeks later, the food supply is cut off. The skin tissues turn into hide. The leather goes through a short tanning process that minimalizes the use of toxic chemicals.

The future of this field is very promising. The researchers are confident of the science involved in this process. They just face engineering problems that they will overcome in the next few years. If the growth is successful on a large scale, thousands of lives of animals would be saved. If meat can be produced in several years, millions of animals’ lives would be saved. Tissue-engineering may be the answer to prevent different types of food shortages around the world.

 

Source:

http://www.scientificamerican.com/article.cfm?id=tissue-engineered-leather-could-be-mass-produced-by-2017

UCLA Discovers Migrating Cells' Tendency to Turn Right

The diagonal pattern formed

It has often been said that observation is the key to success in science. A group of researchers at UCLA brought this concept to a whole new level by keeping a close watch on cells as part of a study. Not only did they find patterns in the migration of the cells but they also were able to spot a certain right and left symmetry.

In particular, the UCLA research team created a culture surface of cells and used various protein substrates that were either cell-repellant and cell-adhesive. The floor of the lab surface consisted of stripes of tile and carpet, which created the overall surface change that cells face in a body. Microtechnology was used to observe the cells.

The difference in the surfaces used brought about a completely unexpected discovery: that cells were able to reorganize themselves based on the surfaces they encountered. However, in addition to simply cross the different types of surfaces, the cells also formed a pattern. These migrating cells turned twenty degrees to the right in parallel rows, which created an overall diagonal pattern.

It was not expected that the cells would form this type of pattern, let alone, a pattern at all. The study had been conducted to observe the process of vascular cells forming structures in cultures. Instead, the researchers had observed a left-right assymetry caused by the surfaces.

In the future, this fact can be utilized to have control over the migration of cells and the shapes formed by these cell cultures. Substrate interfaces can be used to develop cells in different ways. This study adds to knowledge of tissue architecture. In particular, this reserach can allow a person's own stem cells to be used for the development of organs. Becuase there are a limited number of organ donations, this research can help to solve this issue.

New Hydrogel for Tissue Engineering

One of the most important considerations to make in tissue engineering is the kind of material you use, because it has to be both capable of sustaining the constant stress placed on it by the body and still be biocompatible. This can make it very difficult to replace or grow new tissues with synthetic materials because oftentimes something that is strong enough might have too high toxicity levels, and something that's proven to be perfectly safe might simply be inadequate for the job.

Hydrogels can be very stretchy.

 

An example of such a material that has been troublesome in the past are hydrogels. As the name suggests, these are composed mostly of liquid yet behave as a solid because of their structure. The liquid molecules are dispersed throughout a solid and are cross-linked in such a way that makes them have a jelly-like consistency.

Because they are both water-based and biocompatible, hydrogels make ideal candidates for tissue engineering applications such as cartilage replacements or usage in spinal disks. However, the problem lies in their weakness. Current hydrogels have been very brittle and thus unsuitable, so many researchers have been attempting to create a hydrogel that would be stretchy and strong enough to suffice.

At last, Harvard researchers have had a break-through. The hydrogel they created is made of two common polymers, polyacrylamide and alginate, combined in an 8:1 ratio, and although the two polymers aren't very impressive on their own, their combination is tough, self-healing, and can be stretched to 21 times its original length without breaking.

The alginate chains bond weakly with one another and trap calcium ions, and when the hydrogel is stretched, the bonds but not the chains break, thus releasing the calcium ions and allowing the gel to expand. However, the stretchiness is increased when the alginate is combined with polyacrylamide because of the grid-like, cross-linking phenomenon that occurs.

The polyacrylamide chains bond very tightly with the alginate chains, so the breaking of bonds diffuses across a wide area rather than being concentrated in one place and risking a crack or tear. The self-healing comes in because the alginate chains are able to re-form the ionic bonds between them, essentially renewing the hydrogel.