Lab-on-chip (LOC) devices can be described as “miniature versions of their macroscale counterparts”. In other words, LOC devices are able to perform multiple biochemical processes which are usually performed in the laboratory.
Already widely used in the pharmaceutical industry, the development of LOC devices as point-of-care diagnostic devices may make this technology increasingly relevant with the recent outbreak of the Severe Acute Respiratory Syndrome coronavirus 2 (the virus responsible for COVID-19).
LOC technology is based on the field of microfluidics. Microfluidics is concerned with the manipulation of nano-litre volume liquids through microchannels and LOC devices are designed to perform chemical analysis of samples in the scale of nano-litres. LOC devices typically include microfluidic elements which perform operations such as reagent storage, fluid transport and product detection. However, rather than being performed by separate devices in a laboratory, these operations are realised by interconnected fluidic microchannel networks and other components, such as reaction chambers and detectors, which are integrated onto a single chip in the LOC device.
The first LOC was developed at Stanford University in 1979 for use in gas chromatography. On 18 September 1984, a patent (US4471647) entitled ‘Gas Chromatography System and Method’ was granted to the Board of Regents of Stanford University, and described “a gas chromatographic assembly formed on a semiconductor wafer by etching techniques”. In the intervening decades, LOC devices have been developed for use in drug development and, increasingly, in diagnostics. Their application in this field is broad; LOCs can be used for the early detection of tumours and nosocomial infections, as well as for the detection of HIV biomarkers in blood serum.
LOC devices have a number of advantages over their macroscopic counterparts. In particular, LOC devices are by definition miniaturised devices, which enhances their portability and allows for in-situ measurements. LOC devices also have low manufacturing costs, as they can be made from readily available materials such as plastic. Accordingly, LOC devices are particularly attractive for use as point-of-care diagnostic devices and, more specifically, for use in emergency circumstances for tackling the outbreak of viral diseases.
During the outbreak of SARS in 2002, the only diagnostic facility in Singapore was located in a single hospital, so that the influx of people to the facility to be tested increased the likelihood of the spread of the virus. LOC diagnostic devices remove the need of providing diagnostic facilities in a central location, which in turn can help to inhibit the spread of viral disease. For this reason, LOC diagnostic devices are already in use. For example, the Singapore-based medical device company Veredus Laboratories has developed the VereCoV detection kit, which is an LOC device capable of detecting the virus responsible for COVID-19.
There is great potential for developing LOC diagnostic devices specifically for use in developing countries. Conventional diagnostic equipment is expensive, requires skilled operators and is typically found in single-site medical centres. By contrast, the relative low cost and portability of LOC devices enables their implementation in areas with underdeveloped healthcare infrastructure. Such devices also typically output results which can be easily interpreted by operators with limited training. Proof-of-concept devices have already been developed. For example, B. J. Taylor of School of Public Health, University of Alberta, and others have developed a LOC polymerase chain reaction diagnostic device for the detection of malaria to demonstrate the potential for such devices to be used in developing countries.
The global outbreak of the virus responsible for COVID-19 has caused an increase in demand of LOC diagnostic devices and it will be interesting to see how LOC technology in the field of diagnostics develops further. It is clear that there is potential for LOC diagnostic devices to launch in both developed and developing markets. Thus, it is crucial now more than ever that developers of LOC devices ensure they have strong patent protection for their innovations.