Finding out whether
you have been infected with dengue may soon be as easy as spitting into a rapid
test kit. The Institute of Bioengineering and Nanotechnology (IBN) of ASTAR has
developed a paper-based disposable device that will allow dengue-specific
antibodies to be detected easily from saliva within 20 minutes. This device is
currently undergoing further development for commercialization.
Director Professor Jackie Y. Ying shared, "Our rapid diagnostic kit can detect
a key dengue antibody from saliva that is present in early-stage secondary
infection. The ability to differentiate between primary and secondary dengue
infections makes it a valuable early diagnosis tool that would help to ensure
timely treatment and proper care of patients."
secondary infection, who have previously been infected with other serotypes of
dengue virus, stand a higher risk of developing dengue hemorrhagic fever or
dengue shock syndrome.
Singapore's National Environment Agency, dengue fever and its more severe form,
dengue hemorrhagic fever, are the most common mosquito-borne viral diseases in
the world. This disease poses a serious health threat, and is a leading cause
of illness and death in tropical and subtropical climates. There are four known
serotypes of the dengue virus, but no vaccine or medicine has been developed to
treat the illness. The incubation period before symptoms develop generally
ranges from 4 to 10 days after infection. Therefore, early diagnosis would
enable the patient to receive prompt medical attention and avoid further
infection is diagnosed in the laboratory by testing the patient's blood sample
for the presence of dengue antigens or antibodies. IBN's device, on the other
hand, is capable of detecting IgG, a dengue-specific antibody found at the
onset of secondary infections, directly from saliva in one step.
samples, saliva can be collected easily and painlessly for rapid point-of-care
diagnostics. However, unlike other body fluids, it cannot be applied directly
to commercially available test kits as it would cause the sensor nanoparticles
to stick haphazardly to the test strip. In addition, conventional paper-based
tests are not designed to handle the larger sample volume of saliva required.
As described in the
journal Lab on a Chip
, the IBN researchers used an innovative stacking
flow design to overcome key challenges faced by existing lateral flow designs,
such as those used in pregnancy test kits.
In IBN's device,
different flow paths are created for samples and reagents through a multiple
stacked system. This allows the saliva sample to flow separately through a
fiber glass matrix, which removes the substances that would interfere with the
nanoparticle-based sensing system before it mixes with the sensor
nanoparticles. IBN's device configuration also helps to regulate the flow in
the test strip, generating uniform test lines for more accurate results.
By simplifying the
diagnostic procedure, the researchers hope to make the device as easy to use as
over-the-counter pregnancy or fertility test kits. IBN's oral test kit may be
adapted to detect other infectious diseases. The IBN researchers are also
investigating the use of other common fluid samples, such as blood, urine and
serum for rapid, high-sensitivity test kits.
The Institute is
currently collaborating with ARKRAY Inc., a pioneer in the field of automated
analysis systems, to commercialize its paper-based diagnostic technology. In
2013, ARKRAY opened its first Asian research center outside Japan in IBN with
an investment of S$9.1 million over five years. The research center is focused
on developing novel detection kits for infectious diseases based on IBN's
innovative diagnostic platforms.
Murakami, General Manager of the R&D Division of ARKRAY Inc., said: "We
have developed an excellent working relationship with IBN over the past two
years, and our research activities have progressed rapidly. Together, we will
continue to focus on the successful commercialization of new technologies for
the diagnosis of tropical infectious diseases."
IBN has been focused
on research in medical technologies since 2003, and has created unique devices
and assays for the rapid and accurate diagnosis of diseases. The institute has
an active portfolio of 500 patents/patent applications, of which 86 have been
licensed. It has spun off seven companies in the medical technology sector and
its innovations have attracted major interest from the industry.