Bioprinting for Regenerative Medicine

credits: wscs.com

– following up on my previous post (more than six years ago!) –

Anthony Atala is a pediatric surgeon, urologist and directs the Wake Forest Institute for Regenerative Medicine (WFIRM) in North Carolina. Together with 400 colleagues and in a work that spans more than three decades, he has successfully implanted in human patients a variety of tissues regenerated from the patient’s own cells. Dr. Atala talked to 3DPrint.com about ways to translate the science of regenerative medicine into clinical therapy and the importance of adopting new technologies, as well as some of the challenges.

“Back in the 90’s we created by hand, even without using the printer, bladders, skin, cartilage, urethra, muscle and vaginal organs, and later implanted them successfully in patients. The printer automated what we were already doing and scaled it up making some of the processes easier. Still, the technology has its own challenges. With hand made constructs you have more control as you are creating the tissue, but with the printed structure everything has to be built in before it is created, so that you have to have the whole plan and information ready to go once you push that ‘start’ button”.

The WFIRM is working to grow tissues and organs and develop healing cell therapies for more than 40 different areas of the body, from kidney and trachea to cartilage and skin. Dr. Atala and his team of scientists have been first in the world to implant lab-grown tissues and organs into patients. Starting in 1990 with most of their research and implanting the first structures at the end of that decade, using a 3D printer to build a synthetic scaffold of a human bladder, which they then coated with cells taken from their patients. New research at WFIRM shows innovative wound healing through the use of a bedside 3D skin printer.

“Today, we continue to develop replacement tissues and organs, and are also working to speed up the availability of these treatments to patients. The ultimate goal is to create tissues for patients. Part of that is taking a very small piece of the patients tissue from the organ that we are trying to reconstruct, like muscle or blood vessels, only to expand the cells outside of the body and then use them to create the organ or structure along with a scaffold or a hydrogel which is the glue that holds the cells together. We have been doing this for quite some time with patients and 16 years ago we realized that we needed to scale up the technology and automate it to work with thousands of patients at a time, so we started thinking about 3D printers, and began using the typical desktop inkjet printer which was modified in-house to print cells into a 3D shape”.

The living cells were placed in the wells of the ink cartridge and the printer was programmed to print them in a certain order. The printer is now part of the permanent collection of the National Museum of Health and Medicine. According to Dr. Atala, all the printers at the WFIRM continue to be built in-house specifically to create tissues, so that they are highly specialized and able to create cells without damaging the tissue as it gets printed. Inside the institute, more than 400 scientists in the fields of biomedical and chemical engineering, cell and molecular biology, biochemistry, pharmacology, physiology, materials science, nanotechnology, genomics, proteomics, surgery and medicine work to try to develop some of the most advanced functional organs for their patients. At WFRIM they are focusing on personalized medicine, whereby the scientists use the sample tissue from the patient they are treating, grow it and implant it back to avoid rejection. Dr. Atala claims that “these technologies get tested extensively before they are implanted into a patient”, and that “it could take years or even decades of research and investigation before going from the experimental phase to the actual trial in humans. Our goal for the coming decade is to keep implanting tissues in patients, however, the most important thing for us is that we temper peoples expectations because these tissues come out very slowly and they come out one at a time, so we don’t give false hopes and provide the technology to patients who really need them. Working with over 40 different tissues and organs, means that about 10 applications of this technologies are already in patients. The research we have done helps us categorize tissues under order of complexity, so we know that flat structures (like skin) are the least complex; tubular structures (such as blood vessels) have the second level of complexity, and hollow non-tubular organs, including the bladder or stomach, have the third level of complexity because the architecture of the cells are manifold. Finally, the most complex organs are solid ones, like the heart, the liver and kidneys, which require more cells per centimeter”.

Repairing and Replacing Body Parts: What’s Next

A friend of mine sent me the link to this webpage. It’s an interesting article that I simply copy and paste here! Enjoy!

🙂

Advances in medical technology have helped us live longer. Now, researchers are exploring ways to repair, refurbish, or replace human organs that have been damaged by chronic disease, traumatic injury, heart attack, stroke, or just plain aging.

“Medicine is saving people who previously we weren’t able to save,” says Dr. Doris A. Taylor, director of regenerative medicine research at the Texas Heart Institute in Houston. Even so, demand for donor organs exceeds the number available. “Each year thousands of people die while waiting for an organ,” Taylor says. That gap in supply and demand is one factor that has led researchers to ever more innovative treatments; at times these treatments can sound like science fiction come to life. Here’s a look at what repaired and replacement parts are available to patients now, which treatments are undergoing clinical trials, and what medical scientists are working to achieve in the future.

Eyesight

Here’s a new take on magnifying glasses: Surgeons can now implant a tiny telescope within the eye, to help restore some of the vision lost to end-stage age-related macular degeneration (AMD), a disease that affects 1.8 million Americans and is the leading cause of legal blindness for adults age 60 years and older. The device—which the Food and Drug Administration approved in 2010 and which is becoming more widely available to medical institutions across the country—is implanted via an hour-long outpatient procedure under local anesthesia. It requires about a month of working with an occupational therapist to get used to, says Dr. Mark Mannis, director of the Eye Center at the University of California Davis Health System. “The reason is that this is not a simple restoration of vision,” he says. “It really requires the patient to see in another way, much in the same way that a patient who loses a lower limb and then gets a prosthesis needs to learn how to walk in a new way.” In this case, the patient learns to use one eye—the one with the implant—for detailed vision and the other for peripheral vision.

Regenerative Medicine

As director of the Wake Forest Institute for Regenerative Medicine in Winston-Salem, North Carolina, Dr. Anthony Atala is researching treatments to repair or restore—or “regenerate”—damaged or failing tissues and organs by using the patient’s own cells and healing abilities. That can mean “boosting” healing by injecting stem cells, or by implanting tissues or organs that have been artificially bio-engineered in the lab starting with stem cells usually harvested from the patient, a strategy that minimizes the risk of the tissues or organs being rejected. “We’re working on about 30 different tissues and organs,” Atala says. Already a number of implants have been tried successfully in humans, including knee cartilage, skin, blood vessels, urethras, windpipes (trachea), and bladders. Clinical trials are underway to treat urinary incontinence by implanting cells to help boost functionality of the urinary valve and thus keep patients dry. Says Atala: “The future is focused on making sure that these technologies can get to as many patients and as many conditions as possible.”

“Printing” Body Parts

At Atala’s lab and other regenerative medicine research centers, 3-D printing is another experimental strategy being used to build bio-artificial body parts and organs. “We’ve printed ear lobes and nose parts and miniature kidneys and skin,” he says. “You are laying [down] the cells one layer at a time, and placing the cells right where you need them,” by customizing the different layers to form the necessary shape, he says. “If you think of your printer and your ink cartridge, instead of using ink you’re using cells and a gel.” Wake Forest is also investigating the possibility of “printing” skin cells directly onto burn wounds.

Stem Cells for Stroke Recovery

Neurologist Dr. Lawrence Wechsler of the University of Pittsburgh’s Schools of the Health Sciences is in the early stages of exploring whether stem cells, injected directly into the brain, can aid stroke victims in their recovery. The first step—now being tested in a clinical trial—is establishing that it’s safe just to try the technique. If that goes well, Wechsler says, “then we can design a study that will more reasonably look at the issue of efficacy and clinical benefit.” Such therapies wouldn’t “unparalyze” patients, he warns. But small improvements in function could yield big improvements in quality of life. “If you can begin to use your hand to grip something and do some small tasks,” Wechsler says, “or gain enough strength in your leg to help you move from being in a wheelchair to walking in some way, that change is a huge benefit.”

Growing an Artificial Heart

Perhaps the ultimate goal of regenerative medicine researchers is creating and transplanting a functioning bio-artificial heart. Is it feasible? Building complex solid organs like the heart, liver, lungs, and pancreas is challenging, and a major issue will be “where do you get those hundreds of billions of cells to do this,” says Taylor of the Texas Heart Institute. But she adds, “we’re making huge strides,” and predicts that a transplant of one kind of bio-artificial solid complex organ will be possible within five years. “And if I have anything to say about it,” Taylor says, “I will be there when it happens.”

For more, see “On Beyond 100“