A collaboration between two University of Pennsylvania scientists has led to the development of a novel method to regenerate cartilage. Over the past few years, Dr. Jason Burdick of the Penn Engineering department and Dr. Robert Mauck of the McKay Orthopaedic Research Laboratory have led a team of bioengineering and medical researchers in the pursuit of designing new methods to regenerate cartilage. After several years of ongoing studies, the duo has used their lab's discoveries to compile a set of regeneration techniques that have so far proved beneficial in their animal models.
Cartilage damage is a major problem for humans since we are living longer than ever before in recorded history. Furthermore, as the trend of obesity continues to climb in America, joint damage will continue to be an ever-growing problem. While there are several currently used approaches to treat cartilage damage – bone grafting, synthetic disc replacement, and even in vitro cartilage growth and transplantation – each one comes with downfalls. However, the new method developed by Penn researchers has shown great promise to be a grand advancement over current repair technologies.
Those familiar with tissue engineering are sure to know about bioengineering scaffolds. Since most tissue regeneration approaches involve regenerating tissue from a population of stem or progenitor cells, these cells need a structure to orient properly and remain in the spot of injection for patients. Currently, these scaffolds are usually composed of biologically inert synthetic materials, which are great at resisting attack from the patient's immune system and tissue degradation enzymes. However, since they are biologically inert, these synthetic scaffolds can only serve as a structure for injected cells. Tissue development also involves tightly coordinated molecular mechanisms, and current research indicates that these factors are required for stem cells to growth and differentiate into the desired tissue. Current synthetic scaffolds are unable to maintain the necessary gradient of factors needed for tissue regeneration, and non-specific injection of these factors will also not work.
To overcome these problems, the labs of Dr. Burdick and Dr. Mauck developed biologically active and interactive scaffold using hyaluronic acid, a compound found naturally in all humans. Research from Dr. Mauck's lab has demonstrated that different micro-manufacturing techniques can render different structures and porosities, each property affecting the degradation of the scaffold and integration of stem cells into the natural tissue. Additionally, the teams of researchers have been able to "tag" these scaffolds with the factors needed for proper stem cell growth and tissue regeneration. Using infrared light, scientists are able to specifically target certain areas of scaffold, allowing for a spatially-controlled release of growth factors, ultimately leading to improved tissue regeneration.
Tissue regeneration has made waves in the mainstream media over the past few years, especially with the advent of stem cell technology. While a large percentage of stem cell research has been met with great controversy over the use of embryonic stem cells, the techniques that Drs. Burdick and Mauck have develop utilize adult-dervied mesenchymal stem cells, thus enabling the duo to escape controversy. Use of adult stem cells for tissue engineering has been a fast growing field. A group of scientists using adult-derived fat stem cells for breast reconstruction were profiled in the October 2010 issue of Wired Magazine.
While the team of Penn scientists has made grand progress the past several years, use of this technology in the clinic is still a few years away. However, it is clear that this novel and advanced cartilage regeneration technique has the potential to truly revolutionize the field of tissue regeneration.
Lastly, as I myself am a current graduate student in the McKay Orthopaedic Research Laboratory, I'll be able to provide updates on this technology, so make sure you keep checking out the pnosker.com Science section for new news.
Source: Penn Current