Engineering Approaches for the Detection and Control of Orthopaedic Biofilm Infections
Garth D. Ehrlich, PhD,1,2 Paul Stoodley, Ph.D,1 Sandeep Kathju, M.D., Ph.D,1 Yongjun Zhao, Ph.D,3 Bruce R. McLeod, Ph.D,4 Naomi Balaban, Ph.D,5 Fen Ze Hu, Ph.D,1 Nicholas G. Sotereanos, M.D.,1,6 J. William Costerton, Ph.D,4,7 Philip S. Stewart, Ph.D,4 J. Christopher Post, M.D., Ph.D,1 and Qiao Lin, Ph.D.3
1 From the Center for Genomic Sciences, Allegheny Singer Research Institute, Pittsburgh, PA; the
2 Department of Microbiology and Immunology, Drexel University College of Medicine, Allegheny Campus, Pittsburgh, PA; the
3 Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA; the
4 Center for Biofilm Engineering Montana State University, Bozeman, MT; the
5 Department of Biomedical Sciences, Tufts University School of Veterinary Medicine, North Grafton, MA; the
6 Department of Orthopedic Surgery, Allegheny General Hospital, Pittsburgh, PA; and the
7 Center for Biofilms, University of Southern California, Los Angeles, CA
Artificial joints are subject to chronic infections associated with bacterial biofilms, which only can be eradicated by the traumatic removal of the implant followed by sustained intravenous antibiotic therapy. We have adopted an engineering approach to develop electrical–current-based approaches to bacterial eradication and microelectromechanical systems that could be embedded within the implanted joint to detect the presence of bacteria and to provide in situ treatment of the infection before a biofilm can form. In the former case we will examine the combined bactericidal effects of direct and indirect electrical fields in combination with antibiotic therapy. In the latter case, bacterial detection will occur by developing a microelectromechanical–systems-based biosensor that can “eavesdrop” on bacterial quorum–sensing-based communication systems. Treatment will be effected by the release of a cocktail of pharmaceutical reagents contained within integral reservoirs associated with the implant, including a molecular jamming signal that competitively binds to the bacteria’s quorum sensing receptors (which will “blind” the bacteria, preventing the production of toxins) and multiple high dose antibiotics to eradicate the planktonic bacteria. This approach is designed to take advantage of the relatively high susceptibility to antibiotics that planktonic bacteria display compared with biofilm envirovars. Here we report the development of a generic microelectromechanical systems biosensor that measures changes in internal viscosity in a base fluid triggered by a change in the external environment.
Source: Clin Orthop Relat Res. 2005 August; (437): 59–66.