bio printing biology oral presentation ppt

The Future of Regenerative Medicine

IntroToday I am going to briefly go over what bio-printing is and a few of the many ways researchers are making progress in this area of bioengineering.

Leading in For decades the goal of tissue engineers has been to advance beyond simple two-dimensional cell cultures to creating three-dimensional organs (Invetech).

In 2013, bioengineers at Cornell publicized their artificial ear created using 3-D printing and injectable molds (Cornell).

Also in 2013, scientists at Heriot-Watt University in Edinburgh developed the worlds first 3d printer that prints embryonic stem cells and in 2014, Harvards bioengineering researchers published a revolutionary 3D bio-printing method for creating tissues and their essential nourishing blood vessels at the same time.

All the RageThere are teams of scientists all over the world working on 3D bio-printing projects from printing 3D heart valves and muscles for drug testing and for use as medical models to bio-printing liver tissues in hopes of printing complete tissues for implantation.

GizMag.com

3D Printed Ear and Heart ValveCornellPrinceton

A Little BizarreYes. It is. What is 3D bio-printing?

The idea of regenerative medicine is to repair, replace and/or regenerate damaged cells, tissues or organs. Bio-printing produces three-dimensional biological objects or parts that are highly precise in shape and mechanical complexity. Using a computer-assisted design (CAD) and/or computer-assisted manufacturing (CAM) blueprints, the bio-printer deposits ultra-thin layers of living cells upon each other, following a precise geometric pattern that matches the [tissue]dimensions, building the part vertically as the layers accumulate. Over a period of time, the final tissue construct is completed (ASME). The tissues may continue to grow and develop depending on what is being printed and what physiological environment it is put in after the initial printing.

Same as Prosthetics?Nope. Prosthetics are non-living. Although prosthetic valve replacement is the standard procedure for adults, these prosthetic devices are inadequate for younger adults and growing children. Tissue engineering has the potential to address these limitations of nonliving prosthetics (as well as human donor supply shortages) by providing living tissues that can grow, remodel, and integrate with the patient (ASME).

Biomaterials have been adapted for 3-D bio-printing, including co-polymer hydrogels. Alginate, for example, is a naturally occurring anionic polymer with many attractive features for biomedical applications, including low cost, excellent biocompatibility, low toxicity, and a variety of cross-linking capabilities (ASME).

Why are we doing this?We can save lives! Well, yes, there is the possibility of growing new organs for sick patients awaiting transplants. And these transplants would be less likely to be rejected as they would be essentially grown from the patients own cells. While these advantages alone are amazing to think about, the other real win that is associated with tissue engineers being able to 3D print human tissues, is that they can study cell behavior, such as cancer cell resistance to therapy, and test new drugs or combinations of drugs to treat many diseases (Science Daily) including neurodegenerative and autoimmune disorders.

The Challenge?The problems have revolved around being able to create complex enough structures that do not die from within. Printing thick layers of cells, in which the inner cells survive, has proven to be difficult. Harvard researchers have developed a method that opens up new possibilities in the quest to 3D print complete human organs.

What is their NEW Method?Their method creates intricately patterned, three-dimensional tissue constructs with multiple types of cells and tiny blood vesselsTo print 3D tissue constructs with a predefined pattern, the researchers needed functional inks with useful biological properties, so they developed several bio-inkstissue-friendly inks containing key ingredients of living tissues (Harvard).

Bio-inks?One ink contained extracellular matrix, the biological material that knits cells into tissues. A second ink contained both extracellular matrix and living cells.

To create blood vessels, they developed a third ink with an unusual property: it melts as it cools, rather than as it warms. This allowed the scientists to first print an interconnected network of filaments, then melt them by chilling the material and suction the liquid out to create a network of hollow tubes, or vessels (Harvard).

What does that look like?

So, who is making these printers? Can I buy one?Organovo is one of the big bio-tech names in the field. Right now, Organovo is leading the game with an article released earlier this month stating that they have been able to create blood vessels that are up to 5 centimeters long and can be kept alive outside the body for about 40 days and can be used to test drugs (Miami-CBS).

You can buy anything with enough money.

Organovos TedMed Talk

Final NoteBillions of dollars are spent every year on medical research. Very few drugs actually make it to market. Most fail before making the leap from pre-clinical animal trials to actual human testing. If you think about it, we are always hearing about successes in mice and rats, but we hear little about successful human trials. I encourage everyone to watch the TedMed Talk that Organovo presented in 2011.

This is just some of the exciting news in the area of bio-printing. There is new research coming out regularly, and institutions of higher learning are developing entire programs devoted to the creation of bio-printed materials to be used in future drug testing, medical research and tissue and bone replacement.

SourcesRetrieved April 2014Invetech World's First Bio-PrinterLive Science 3D Printed Embryonic Stem CellsMiami CBS 3D Printer Could Make Human Body PartsASME Bioengineering Valve TissueCornell Bioengineers 3D Print EarScience Daily 3D Bio-PrintingOrganovo TedMed Talk 2011