Biomedical Engineering Reference
In-Depth Information
tests or collection kits direct to practicing dentists, who in many instances see patients on a more rou-
tine basis than a general practice physician. In such circumstances, the dentist is well placed to iden-
tify the disease risk early on. Tests targeted for the dentist office that are in the development or
available already include tests for dental caries, HPV, periodontal disease, and gingivitis.
The area of drug abuse is rapidly growing, but linked with this is an increase in the abuse of
prescription drugs, particularly painkillers and antidepressants. With this comes a need to detect
drug concentrations accurately and in real time. Saliva offers the best matrix in most cases to do
this, and a number of companies with detection kits (ELISA tests) are evaluating options to use
saliva as a specimen of choice to expand their product portfolios. As another example, the
“designer” drug known as Spice (or K2) has led to several deaths in the United States and has been
banned in many states. This and other such drugs will be logical targets for saliva test developers.
Lateral flow immunochromatography is a technique used to provide rapid diagnostic test results
for multiple diseases using bodily fluids. Progress in manufacturing and development technology in
the 1990s has been rapid, and this has resulted in the development of a whole series of rapid, point-
of-care devices that initially were based upon the use of urine (the currently accepted mainstay for
drug testing today) or blood specimens. In the area of drug testing, there has been a lot of work
done to validate a number of multi-drug screening panels based on oral sampling. Up until now,
most tests are qualitative in nature, i.e. provide a yes or no indication of drug presence. The oppor-
tunity to provide immediate results at the point-of-care using noninvasive samples is an attractive
proposition; however, oral-based rapid tests for drugs of abuse have certain drawbacks that have
limited the broader utilization of these devices to date. Potential problems include poor recovery of
analytes (particularly marijuana (THC) from collection media), insufficient saliva delivery to the
test strips, strip failure, and lack of sensitivity. Despite this, the “convenience factor” of oral testing
has led to a proliferation of companies developing such tests and subsequent adoption of these tests
in drug screening projects, criminal justice, employee screening, random testing, and other
instances where immediate results can be beneficial. Further inroads into the market will be made
once the above issues have been resolved.
Acknowledgments
The authors would like to acknowledge the financial support from the Queensland Government Smart Futures
Fellowship Programme (QGSFF), the University of Queensland New Staff Research Funds (UQNSRSF
601252), and the University of Queensland Foundation Research Excellence Award Scheme. In addition, we
would like to express our sincere gratitude to Professor William B. Coman and Dr. Scott Coman for providing
us with the illustrations. In addition, we thank Mr. Jared Foo and Ms Ling Li Long for their technical
assistance.
References
[1] D. Marmud, Saliva as a diagnostic fluid second now to blood? BMJ 305 (1992) 25.
[2] S. Hu, D.T. Wong, M. Arellano, P. Boontheing, J. Wang, H. Zhou, et al., Salivary Protein Biomarkers for
Human Oral Cancer, Clin Cancer Research 14 (19) (2008) 6246
6252.
