Nanopatterned Hydrogel Probes for Rapid Detection of Staphylococcus aureus
- PDF / 224,235 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 15 Downloads / 211 Views
0954-H05-03
Nanopatterned Hydrogel Probes for Rapid Detection of Staphylococcus Aureus Ishtiaq Saaem1, Barry Kreiswirth2, and Matthew Libera1 1 Dept of Chemical, Biomedical and Materials Engineering, Stevens Inst. of Technology, Hoboken, NJ, 07030 2 Hospital Infections Program, Public Health Research Institute, Newark, NJ, 07103 ABSTRACT We studied the use of nanopatterned hydrogels as a possible foundation for medical devices for the detection of Staphylococcus aureus. Nanopatterned hydrogels, approximately 200 nm in diameter, were created by locally crosslinking dry amine-terminated poly(ethylene glycol) [PEG] (6000 Da) thin films using a focused electron beam. These gels then had a dry height of 50 nm and a swell ratio of about five. They were patterned into arrays with approximately 500 nm inter-gel spacing. These arrayed gels were functionalized with Immunoglobulin G [IgG], a biomolecule that binds protein A. We are interested in seeing whether these arrayed gels can be used for bacterial capture and subsequent detection. We show, using an assay that binds IgG to protein A expressing Staphylococcus aureus [S. aureus], that nanopatterned hydrogels can indeed be used as probes for detection. We further show that the specificity of our assay by using a knock-out variant of S. aureus that doesn’t express protein A as a negative control.
INTRODUCTION Staphylococcus aureus is a major public health threat and is also the leading nosocomially acquired pathogen in the United States [1]. This gram-positive species is armed with an incredible range of virulence determinants that produce a diverse spectrum of disease states, including the common boil, food poisoning, toxic shock syndrome, osteomyelitis, necrotizing pneumonia, and endocarditis [2]. If left undiagnosed for even a short period of time, a simple infection can turn into any of the aforementioned life threatening diseases. The rapid determination that a particular infection is due to S. aureus is important in order to quickly begin the administration of the most effective type of antibiotic. Conventional identification methods are time-consuming and traditional cell-plating or bottle-incubation techniques can take as long as 2-3 days to reach a definitive identification [3]. In this context, we believe that nanopatterned hydrogels can be developed as a probe for detecting S. aureus in a binary manner within two hours. We have previously described a method to create chemically functional nanoscale PEG hydrogels patterned on solid substrates [4-6]. This method exploits the ability of an electronoptical system to deliver ionizing radiation to a solid with very high spatial resolution. As part of an effort to develop a rapid S. aureus detection method, we have been exploring how to functionalize surfaces to preferentially enhance S. aureus binding at specific surface locations.
EXPERIMENTAL DETAILS Thin films (~100 nm) of PEG-NH2 (6000 Da) were prepared on glass slides as in [5]. The PEG arrays were arranged to yield 100 µm diameter spots with an inter-gel spaci
Data Loading...
