One of the most exciting fields in modern medicine is restorative medicine, which involves replacing tissues or even entire organs that have been injured by disease, maldevelopment, or trauma. Rather than treating the symptoms of a problem, restorative medicine seeks to address the issue itself.
Technologies from a variety of different fields have been used to create the techniques found in restorative medicine, from the creation of artificial organs to cellular-level therapies. The goals of these therapies can be different depending on the circumstances. Sometimes, researchers seek to enhance the body’s natural ability to heal. Other times, the goal is to replace the function of an organ completely. With its unique multidisciplinary approach, restorative medicine could have unlimited applications in the future.
When researching how to boost the body’s ability to heal or restore the function of lost tissues and organs, there are many paths to consider. With individuals from a large number of disciplines contributing to this research, it is important to have clearly defined paths of inquiry. Currently, the field of regenerative medicine focuses on three primary subfields. These subfields are:
1. Artificial organs and medical devices
Organ failure is a common and complex issue. The current strategy for addressing organ failure is to transplant an organ from a donor into the person needing one. However, this strategy comes with several challenges. For example, there are long waiting lists of people with failing organs awaiting a donor, and many pass away before they receive a new organ. Even beyond that, the recipient will need to take powerful immunosuppressive drugs for as long as the organ is in place. This leaves the person vulnerable to disease and infection.
This subfield first asks the question of how medical devices can be used to prolong the life of a failing organ. A great example of this is the ventricular assist device, which helps a failing heart to beat sufficiently. Historically, these devices were used to prolong the life of a heart until another solution was available. Now, a ventricular assist device can be implanted as a permanent support system so that the recipient does not ever need to undergo a heart transplant at all.
Many devices are being developed to support and replace organs. Of course, the ultimate goal of this subfield is to provide artificial organs that can replace a failed one. The use of artificial organs could address the shortage of transplantable organs as well as the need for immunosuppressives, depending on how the organ is created.
2. Tissue engineering and biomaterials
Sometimes, a person does not require an entire organ but rather a piece of it. Perhaps they need a graft of tissue due to a burn. Historically, biomaterials have played an important role in addressing some medical processes, such as materials that act like skin or meshes that help reinforce the weakened walls of major blood vessels. Over time, the line between biomaterial and engineered tissues has begun to blur, namely because the materials are designed to regenerate tissues in the exact size and shape needed. This allows for the perfect, personalized repair.
Tissue engineering involves implanting scaffold material in the site where new tissue is desired. The scaffold then attracts cells that begin to build the new tissues in the shape of the implanted material. If subjected to certain conditions, this engineering tissue can develop blood vessels and become a fully functional part of the body. While this subfield is still in its infancy, already millions of patients have been treated using a tissue engineering device. So far, the most success has been seen with soft tissue regeneration. However, the ability to grow soft tissue speaks to the ability to do much more in the years and decades to come.
3. Cellular therapies
Cellular therapies largely refer to the use of human stem cells in aiding the natural repair systems of our bodies. Our bodies already use stem cells as part of this repair mechanism. A stem cell is essentially an undifferentiated cell capable of becoming many different types depending on the circumstances. Studies have demonstrated that harvested stem cells can facilitate the reconstruction of tissues when introduced at the site of damage. The right circumstances have to exist for the reconstruction process to happen. Often, it is determining the ideal conditions that holds the key to success.
Stem cells exist throughout the body. Scientists have harvested them from bone marrow, dental pulp, skeletal muscle, and more benign sources like blood and fat. The blood in the umbilical cord at birth is rich in stem cells. Soon, this blood may be collected and stored for use in regenerative medicine down the line. Researchers are still figuring out the best way to harvest, refine, and deliver stem cells to damaged or diseased tissue to get the best result.