During the Howell Foundation luncheon in May, the audience was taken once again to the world of futuristic medicine with the presentation “Advanced Tissue Therapies: Progress in Tissue Engineering and Regenerative Medicine, presented by Dr. Benjamin Shepherd, Senior Director of Therapeutics at Organovo Inc.
Dr. Shepherd talked about examples of tissue engineering for both drug discovery and therapeutic tissue development. His presentation focused on current research areas where bioscience and technology have been very successful. He elaborated on the areas of challenge in tissue regeneration: 1) current efforts in organ reconstruction based on previous research in vascular grafts (the blood vessel space), and 2) efforts focused on “additive manufacturing”, also known as 3-dimensional printing. Of significant importance are the future applications of his own research in both areas.
As individuals live longer, the need to address the surmounting gaps between tissue donors and recipients becomes a point of research focus for many organizations. Today there are hundreds more recipients on waiting lists than there are donors, making the need for regenerating tissues and organs an obvious one.
|Dr. Benjamin Shepherd|
The idea of tissue regeneration started by joining engineering principles with biology; in other words, taking a biopsy, isolating and expanding those cells. His laboratory can grow and expand most type of cells under inherent conditions. Enter the engineering part: creating a tubular, three dimensional component (or scaffold) to grow the cells onto, or establishing a cell production process that can be used time and time again.
Turns out there are several organizations nationwide interested in bringing new bio-engineering techniques to fruition. Dr. Shepherd presented several companies’ research efforts that are currently focused on enhancing technology-based science into applicable patient treatments by either continued scientific research, or by bio-fabrication hubs, where the “manufacturing” of future organ tissue will be developed. Dr. Shepherd is, of course, involved.
Although the novel idea sounds great in principle, there are currently a number of challenges. Among them, vascularization; that is, establishing blood flow through the new tissue. Blood vessels from a donor will be rejected by the recipient. Technology that has been developed collaboratively for over 20 years offers encouraging results. One approach is to build a “manufactured”, non-biological, vasculature. A second approach would be the removal of cellular components of blood vessels from the donor that lead to rejection. By a process of “de-cellularization” of the tissue meant for transplantation, the potential for donor rejection is minimized.
As explained by Shepherd, the process:
- Started with a tissue sample from a biopsy, regardless of a familial relationship to the patient,
- Grew and matured blood vessels in the lab
- Wiped all the cells away and held on to the structural elements of the blood vessels which serve as scaffolding for blood vessels comprised of the recipient’s cells, keeping the structural part and putting the patient’s cells in.
“We’ve gotten rid of the [transplant] rejection response that would be associated with taking cells from one patient and putting it into another because we’ve gotten rid of all the cells. This means that doctors are left with a perfectly ’native-like’, human-derived blood vessel substitute that, when treated with blood thinners, doesn’t clot. This now presents an opportunity for off-the-shelf blood vessel development on which doctors can capitalize to further their own research.”
This is just one example of how technology applied to medicine is becoming the cornerstone of treatment for researchers and physicians. Did you know doctors can now visualize the actual anatomy of an organ by bio-printing it before facing a complicated surgery? Prosthetics is another area where bio-printing is heavily supported and effectively used in patients with congenital defects or injuries of war, for example. Dr. Shepherd’s current research includes taking that technology and utilizing bio-printing principles for the development of tissue – explained in lay terms, instead of ink on a printer, cells are injected from the printer to create three-dimensional tissues — that eventually can be either used for transplant surgery, treatment for damaged/diseased tissue or for testing of new therapeutic drugs.
The possibilities are endless and quite encouraging! Dr. Sheppard’s research indicates that the applications for this bio-technology will be extremely beneficial for illnesses where organs are damaged or inflamed. Past and current efforts include research work on bladder re-construction, synthetic skin substitutes for non-healing wounds such as diabetic foot ulcers or burns, fatty liver disease and cardio-thoracic/heart disease afflictions, to name a few.
The biggest challenge for his lab is to homogenize the process of cell sourcing. “What we are focusing on is building better systems that are useful for others and, in the process of building those systems, understanding how to do a good job. When we understand how one makes the good tissue, and how one should handle that tissue, from that starting point, we have a better chance of successfully developing a therapeutic tissue”.
How exciting for our audience to see the actual building of a bladder by 3-D bio-printing and populating that bladder with living cells! The future of medical therapeutics beckons. Thank you, Dr. Shephard!
About the Doris A. Howell Foundation:
For the past 23 years, The Doris A. Howell Foundation for Women’s Health Research has been dedicated to keeping to women we love healthy by making a long-term, positive impact on women’s health. To date, it is the premier organization advancing women’s health.
The organization does so by funding scholarships to students researching issues affecting women’s health; providing a forum for medical experts, scientists, doctors, and researchers to convey timely information on topics relevant to women’s health, and by funding research initiatives that improve the health of under-served women and increase awareness and advocacy in the community; bringing women’s health research to a full cycle. ###
Summary & Design prepared by Carolyn Northrup and revised by Carole Banka, PHD with information provided by the key note speakers. Shutterstock image licensed to Carolyn Northrup