Research Experiences for Undergraduates

The focus of work by Georgia Tech/Emory Center for the Engineering of Living Tissues (GTEC) faculty member, Dr. Andrés García, is the design of “bioinspired” synthetic scaffolds and implant coatings to facilitate bone tissue engineering and the bioloigical integration between living bone tissue and the surface of an artificial implant (termed “osseointegration”). Hundreds of thousands of bone grafting procedures and total hip replacements are performed in the United States each year. Bone grafting is the transplantation of healthy bone from the patient or a bone donor to the defect site, whereas total hip replacement makes use of synthetic material implants that completely take the place of native bone. Although these strategies have shown success, the list of associated problems and complications is extensive. Improving osseointegration in implants will help to circumvent the limitations of current treatments for large bone defects.

García’s research group has developed and employed a collagen-mimicking peptide, GFOGER, designed to elicit a specific bone-building cellular response and promote bone tissue ingrowth into synthetic scaffolds. Initial work with GFOGER surface coatings has demonstrated (see figure) significant increases in osseointegration into titanium implants in rat tibial defects, compared to both uncoated titanium implants (Ti in the figure) and implants coated with full-length collagen I (COL in the figure). Moreover, García’s group has investigated the ability of GFOGER-coated polymer scaffolds to promote osteogenesis in non-healing segmental defects in rat femurs. These GFOGER-engineered scaffolds significantly increased bone volume within the defects, compared to uncoated scaffolds, further demonstrating the robust potential of GFOGER in modulating bone response to
biomaterials.

This strategy offers significant advantages over current bone tissue engineering and osseointegration technologies because GFOGER elicits a reduced immune response and has a lower risk of disease transmission compared to other biologic strategies, such as the implantation of full-length proteins (i.e., collagen) or cells. Furthermore, this strategy allows improved stability and ease of fabrication compared to protein or cell-based strategies. Finally, GFOGER specifically targets cellular pathways that are involved in bone tissue development, so it allows precise control over the response of host cells to orthopaedic implants. Developing a cell-free strategy for bone tissue engineering and osseointegration reduces the rejection problems and increases the rate of bone growth, compared to cell-based treatments, thus demonstrating that there are ways to improve upon the current procedures for the treatment of large bone defects.

Primary Strategic Outcome Goal:
Engineering Research Centers

In terms of intellectual merit, why is this outcome notable and/or important?
The design of “bioinspired” synthetic scaffolds and implant coatings to facilitate bone tissue engineering and better integration between living bone tissue and the surface of an artificial implant is a major advance over current treatments.


In terms of  broader impacts , why is this outcome notable and/or important?
Merit Review Broader Impacts Criterion: Representative Activities, July 2007
Because this research was conducted at an Engineering Research Center, the results are fully integrated into both undergraduate and graduate education. In addition, improved procedures for performing hip replacements and bone grafts will have obvious benefits for a great many people worldwide, especially with an aging U.S. population.


Does this highlight represent transformative or potentially transformative research?  If so, please explain why. For more information, see  Report to Congress: Transformative Research at the National Science Foundation, April 16, 2008
No

Does this highlight represent Broadening Participation?  If so, please explain why.
For more information, see  Broadening Participation at the National Science Foundation: A Framework for Action
Yes
Every Engineering Research Center involves the participation of several institutions across the U.S., as well as a diverse faculty and student body.


Are there existing or potential societal benefits of this research? It is important for NSF to be able to provide examples of NSF-supported research that have societal benefits, including benefits to the U.S. economy.
For more information, see  Excerpt from Merit Review Broader Impacts Criterion: Representative Activities, July 2007
Yes
Improved procedures for performing hip replacements and bone grafts will have obvious benefits for a great many people worldwide, especially with an
aging U.S. population.

ENG/EEC 2009