January 11, 2006
Unlikely team--engineer, dentist, and veterinarian--build bone tissue
by Lynn Nystrom
Oral and pharyngeal cancers rank among the most prevalent worldwide, although they account for only about three percent of all cancers in the United States. Unfortunately, most oral cancers are detected at advanced stages when combinations of surgery and radiation are required, and the most recent studies show the five-year survival rate of 53 percent has not changed in the past 30 years.
If two Virginia Tech researchers, collaborating with the American Dental Association (ADA), are able to successfully construct a tissue engineered composite material for oral reconstructions, these dismal statistics might yield a better outcome.
The repair of the diseased tissue in these cancers often requires reconstruction of the bone, and Brian Love, professor of materials science and engineering in the College of Engineering at Virginia Tech and principal investigator on a National Institutes for Health (NIH) grant, believes "substantially better clinical outcomes for all oral constructions could result if a more viable scaffold material were used that was capable of faster and higher quality bone formation."
Love and the team are looking at amorphous calcium phosphates (ACPs) as inorganic host materials in the rebuilding of tissue. ACPs, in the presence of cells that make bone (called osteoblasts), are believed to "more readily" provide the host material for new bone formation in tissue engineering than other choices, Love explains.
"By constructing tissue engineered composites containing ACPs, living osteoblasts, and donor materials," Love believes the result could be faster and higher quality bone formation.
The Paffenbarger Research Center of the ADA is supplying the ACP for the current studies. Aaron Goldstein of Virginia Tech's Chemical Engineering Department is a co-principal investigator, and Drago Skrtic of the ADA Paffenbarger Research Center and Peter Shires of Virginia/Maryland Regional College of Veterinary Medicine are collaborating with Love and Goldstein. Both are also affiliated with the Virginia Tech Wake Forest School of Biomedical Engineering and Science.
In earlier studies, Love recently completed a research leave at the Dental Polymers Group of the National Institute for Standards and Technology (NIST) working on photopolymers used in dentistry. Goldstein has performed post-doctoral work at the Rice University's Tissue Engineering Laboratories and has six years of cell culture and tissue engineering experience with bone marrow stromal osteoprogenitor cells here at Virginia Tech. Skrtic has studied ACP precipitation, purification, and incorporation into remineralizing resins for the past 12 years. Shires' primary research interests are bone defects, osteoarthritis, and surgical repair. He has the facilities to evaluate host tissue responses to the tissue-engineered materials.
As the interdisciplinary research team better understands how bone-making cells respond to ACP, their next challenge will be to assess these re-growth characteristics in vivo.