Microfluidic devices are an innovative technology that overcomes the limitations of traditional two-dimensional experiments by culturing cells in a three-dimensional environment to mimic in vivo conditions. This technology provides more accurate results in anticancer drug efficacy testing and diagnostics, and has the potential to transform cancer research and treatment.

Microfluidic Device

Cancer remains one of the leading causes of death in South Korea, with 82,688 people dying from cancer in 2021. The cancer mortality rate has been increasing year by year, and the importance of cancer diagnosis and treatment is growing. Despite improving survival rates for cancer patients, the development of effective anticancer drugs remains a major challenge. Traditional anti-cancer drug research has mainly involved culturing cancer cells on two-dimensional glass to test drug efficacy. However, these experimental methods differ significantly from the in vivo environment, making it difficult to accurately predict the actual effects of drugs.
An innovative technology to solve this problem is the microfluidic device. Microfluidic devices are a type of ‘lab on a chip’ – literally, a lab on a tiny chip. They are small, about 3 cm across and 3 cm deep, and use micro- and nanotechnology to house a variety of experimental devices. A micrometre (μm) is one millionth of a metre, and a nanometre (nm) is a unit 1000 times smaller. Considering that a human hair is about 100 μm thick, you can get an idea of how small microfluidic devices are. These devices are widely used in cellular experiments, especially for culturing cancer cells and testing the efficacy of anticancer drugs.

Structure and principle

The structure of a microfluidic device consists of channels and passages for cell experiments. They are mainly made of a transparent, soft, rubber-like material called polydimethylsiloxane (PDMS), which is made by stamping patterns and drilling holes in the rubber. This fabrication method is called soft lithography, and is similar to using a plaster mould to print a shape. The resulting devices have the advantage of allowing cells to be cultured in a three-dimensional environment. Unlike traditional experiments in two-dimensional glass, by mimicking three-dimensional structures, experiments can be performed in conditions that mimic the in vivo environment.
For example, cancer cells grow in the body by drawing on the surrounding blood vessels for nutrients, and microfluidic devices can be used to experimentally recreate this environment. By moving fluid through the channels, you can create conditions that mimic real-world fluid flow in the body and more accurately observe how cancer cells react.

Expanding applications

Microfluidic devices have applications beyond cancer research. For example, in diagnostic technology, they can perform a variety of tests with very small amounts of blood, enabling fast and accurate diagnosis. They also play an important role in drug development and toxicity testing. In particular, they are used to test the efficacy of new drug candidates and offer the possibility of replacing traditional animal testing. This technology allows drugs to be tested in conditions that more closely mimic the human cellular environment, which has the advantage of overcoming the limitations of animal testing and saving money and time.

Next-generation research trends

Microfluidic device research is currently expanding in several ways. For one thing, researchers are working on how to design the structure of the devices more precisely so that fluids can flow smoothly and the thin, μm- and nanometre-thin passageways are more robust. There are also efforts to simplify how the devices are made and how they are used so that they are easier for non-experts to use. As a next-generation diagnostic device, it is likely to become popular for diagnosing cancer or measuring the number of red and white blood cells in a small amount of blood.
Another important challenge is to improve the adhesion of the PDMS and glass, which is currently a drawback. Once the PDMS and glass are bonded, it is difficult to separate them again, making it difficult to extract the cells cultured inside the device and observe them under a microscope. To solve this problem, attempts are being made to improve the bonding method or develop reusable devices.

Looking to the future

Microfluidic devices are currently being developed at the intersection of biotechnology and other fields of science and engineering. In particular, precision machining techniques from mechanical engineering are being incorporated to improve the performance of the devices and provide better data precision. This has greatly improved the accuracy of cell experiments and made it possible to implement various biomimetic environments. This has the potential to revolutionise not only drug discovery, but also disease diagnosis, personalised medicine, and more.
Microfluidic technology is also contributing to the development of new levels of research and diagnostic tools through its convergence with electronics and nanotechnology. For example, nanotechnology is being used to fabricate smaller channels, and electronics is being used to increase the speed and accuracy of data processing. These technologies are expected to be applied to portable diagnostic devices and real-time monitoring systems, changing the paradigm of healthcare in the future.
Furthermore, they can play an important role in healthcare and disease prevention for an aging society. Early diagnostic technologies using microfluidic devices can make a significant contribution to the early detection and treatment of chronic diseases and cancer, which are increasingly prevalent in the elderly population. Accurate diagnosis can be made from small amounts of body fluids, reducing healthcare costs and making diagnostic tools accessible to more patients.
As a result, microfluidic devices are expected to be a major growth driver for the bio industry, and this rapidly evolving technology in a variety of fields is poised to become a key component of cancer research, drug discovery, personalised medicine, and the next generation of healthcare systems.