Scientists at NSU Are Developing Prototypes of Microfluidic Chips for Cancer Detection and Household Allergies

The development of microfluidic devices for detecting biomarkers in human blood for cancer screening and assessing the risk of developing allergic diseases is carried out by researchers microfluidic technology laboratories Institute of Medicine and Medical Technologies of Novosibirsk State University (IMMT NSU), which will subsequently be located on the squares new NSU campus, being constructed within the framework of the national project “Youth and Children.” The development of express chips for oncology and allergy diagnostics is being carried out with the support of the “Priority-2030” programs, as well as an industrial partner — the company “Medico-Biological Union” (MBU). Cooperation with a leading company in the real sector of the economy allows scientists to develop their own test systems without relying on foreign counterparts, which contributes to Russia’s technological sovereignty in medical diagnostics and the achievement of the goals of the national project “Youth and Children”.

Microfluidics — is a technology that studies the behavior of liquids and gases in microscopic channels and structures. It provides the ability to control small volumes of liquid, ensuring high sensitivity and efficiency in various applications. Microfluidics using fluorescent, optical, and electrochemical detectors is widely applied in various fields, including analytical chemistry, biomedicine, and biotechnology. It is used for analyzing biological samples, detecting biomarkers, diagnosing diseases, and monitoring body reactions.

Microfluidic device (microfluidic chip) — is a compact laboratory device that controls microscopic volumes of liquids (from several microliters to picoliters), flowing through a system of thin channels measuring tens or hundreds of micrometers. The chips themselves are made from polymer materials, glass, silicon, ceramics, or metals. The device consists of a network of microchannels that are cut, etched, or molded into the substrate material (glass, silicon, or polymer). A device is considered microfluidic if at least one channel dimension is in the micrometer range, while it uses or controls small volumes of liquid, allowing for minimal reagent consumption. Very low fluid flow rates in such devices improve mass transfer efficiency and enhance analysis sensitivity.

Currently, the laboratory’s researchers are engaged in three key developments. They are creating a microfluidic platform for the quantitative analysis of prostate-specific antigen (PSA), tumor markers (CA-125 and HE4) for ovarian cancer, and for the semi-quantitative determination of immunoglobulin E specific to household allergens. The first prototypes of analytical chips for the quantitative detection of PSA for prostate cancer screening have already been created. At present, the laboratory is developing methods for combined analysis of tumor markers to verify gynecological neoplasms at early stages.

— The relevance of this work is due to the fact that the modern cancer screening program, which is part of one of the directions of preventive health check-ups, does not cover all types of cancer and consists of a large number of separate tests carried out in large diagnostic centers or specialized laboratories. Another drawback of this approach is the high cost of blood tests for tumor markers. Therefore, microfluidic devices are considered the most promising solution for cancer screening problems, as they have several advantages, such as the ability to perform multiple types of analysis on one device, using small amounts of reagents, and rapid test execution. It is assumed that the devices we develop will be easy to use and capable of delivering results within 20-30 minutes while the patient is still at the doctor’s appointment., — said the head of the microfluidics technology laboratory at IMMT NSU Ksenia Minyaylo.

An express chip for allergy diagnostics is also under development, which will become an important element of a portable system for assessing the risk of developing allergic diseases. In just 15–20 minutes, using a single drop of blood, the test detects allergies to cats, dogs, or house dust mites. Timely identification of triggers allows the patient to immediately avoid contact with the allergen, adjust their lifestyle, and promptly initiate targeted therapy.

— It is important to understand that our microfluidic devices will not become alternative methods for cancer diagnosis or allergen detection. Our goal is not to replace the doctor, but to provide them with a tool for “initial routing” of patients, — clarified Ksenia Minyailo.

The device works as follows: a drop of the patient’s blood enters the sample introduction area, where plasma is separated and moves through a microchannel to the conjugation zone. If the target protein is present in the blood, it binds to a labeled antibody, and then the flow in the microchannel carries it to the detection zone, which begins to glow, allowing for quick signal reading and obtaining results. Currently, scientists are optimizing the reagent base and the method for immobilizing antibodies and antigens on the polymer to achieve high sensitivity. Initially, the focus is on accurately determining one biomarker on the chip; the next step will be transitioning to a multiplex platform that allows for parallel analysis of several biomarkers. They are also producing labeled antibodies with which it is possible to qualitatively or quantitatively determine the target biomolecules in the blood. The possibility of full automation is also being considered—from reading the signal using a smartphone or special reader to displaying results on a computer or in a dedicated app, which will make the device easier and more efficient to use.

In parallel, work is underway to optimize the technology for creating prototypes of microfluidic devices from thermoplastic polymers using the laser ablation method. This work is carried out by graduate biology students. Novosibirsk State University’s Advanced Engineering School (AES) and molecular biology Veronika Sachkova and Marina Kuznetsova under scientific supervision.

When it comes to materials and manufacturing technology, the polymer PDMS (polydimethylsiloxane) is popular due to its optical transparency, flexibility, and biocompatibility, which is why it is often used for making microbiosensors. However, for large-scale production of disposable microfluidic platforms, thermoplastics are increasingly used—such as polymethyl methacrylate (PMMA), polycarbonate (PC), and polystyrene (PS). One of the most common printing methods is soft lithography, which is employed for rapid prototyping of PDMS chips. The process involves creating a master mold (most often using photolithography) and pouring in liquid PDMS, which after curing is peeled off the mold. The production of microchannels from polymers is carried out either by replication methods such as injection molding, thermoforming with molding, micro-milling, or by photodefined methods such as lithography and laser cutting. Among these manufacturing processes, material ablation using a CO2 laser is an inexpensive and fast method that provides high precision, neatness, and flexibility.The use of the polymer laser ablation process allows very rapid cutting of microchannels with a minimum hydraulic diameter of 80 µm. An important aspect is the correct selection of laser cutting modes, which affect the shape and surface roughness of the channels. When adjusting the flow rate of the tested liquid, not only the diameter and length of the channel are taken into account, but also the hydrophilicity/hydrophobicity of the microchannel surfaces for subsequent work with biomolecules.

In the future, it is planned to transfer the developed immunochemical scheme to a ready-made prototype of a microfluidic device specially designed for the detection of specific biomarkers. The task has also been set to develop a semi-quantitative method for assessing the severity of allergies with signal gradation into low/medium/high. In addition, the laboratory scientists intend to create a prototype suitable for home use, possessing features such as integrated sample preparation, ease of operation, and visual or semi-quantitative assessment without complex equipment. Looking ahead — the creation of a multiplex oncology chip that can operate not only in laboratory conditions but also directly in the doctor’s office.

— The process of creating microfluidic chips and devices involves the use of specialized and expensive materials such as glass, silicon, high-purity polymers, and the use of complex technologies. During manufacturing, reagent losses may occur due to adsorption on the surface of the channels or improper device design, which can lead to inaccurate analysis results or reduced reaction efficiency. Finally, controlling the fluid flow can be challenging due to the small size of the channels and limitations in managing pressure and flow rate, which may require the use of complex pumps and valves or additional manipulations to achieve the desired conditions. Despite these drawbacks, microfluidics continues to develop actively, and many of these limitations can be addressed and overcome with new scientific and technological solutions. Microfluidic technology allows the control of very small volumes of liquid, including significantly less than a drop of blood, and offers a number of other advantages.The microfluidic platforms being developed drastically accelerate and reduce the cost of analyzing key biomarkers, as their use eliminates the need for laboratory infrastructure, — explained Ksenia Minyaylo.

Analogues for all three developments already exist — some are already on the market, while others are still in the development stage. The only test approved by the FDA (Food and Drug Administration, the US Food and Drug Administration, a federal agency under the US Department of Health) in 2019 is a quantitative express test (Point-of-Care test) for determining total PSA, developed by OPKO Health (formerly Claros Diagnostics). The OPKO system, marketed as the Claros® 1 analyzer with the Sangia™ Total PSA test, provides full implementation of the “sample-to-result” principle thanks to a sealed microfluidic cartridge into which a capillary blood sample is introduced, and the quantitative result is delivered in about 10 minutes. The OPKO system also demonstrates multiplexing capability, potentially including determination of free PSA levels and other biomarkers.However, in the current implementation, the system operates in single-plex mode to determine total PSA, emphasizing that when ensuring the commercial viability of the device, priority is often given to clear clinical indications rather than the maximum level of multiplexing. Another drawback is the high cost of the sealed microfluidic cartridge and the reader device, which is about 2500 US dollars.

Multiplex laboratory systems (ImmunoCAP ISAC, ALEX, domestic allergy chip ProAllergy) dominate global and Russian allergodiagnostic practice, and new platforms are also being actively developed, including as part of the RNF project “AllergochipRF” (Sechenov University, grant No. 23-75-30016). These systems have high sensitivity and the ability to analyze up to 300 allergens, but they are designed for use in laboratories by qualified personnel on complex analytical equipment and do not provide for self-use by patients. Thus, there remains a need for an affordable and portable device for regular monitoring of immunoglobulin E levels, which are responsible for the development of allergic disease. The development of such a device, aimed at home use, is a relevant task, the solution of which will improve the quality of life for patients with allergies and reduce the burden on the healthcare system.

In the Russian Federation, the closest analogue in terms of diagnostic task is the “Allergochip RF” project, implemented at the First MSMU named after I.M. Sechenov. Another domestic solution is the ProAllergy system, developed by specialists of the Moscow Institute of Physics and Technology and the Skolkovo medical cluster. This platform belongs to the class of allergen microchips and is intended for multiplex determination of specific IgE to a wide range of allergenic components. The development represents a domestic molecular allergodiagnostic platform based on allergen micromatrix technology. The essence of the analysis is that allergens immobilized on the surface of a solid carrier interact with the patient’s specific IgE present in the blood serum sample. Subsequent registration of the signal from the labeled complex allows simultaneous determination of sensitization (the organism’s acquisition of increased sensitivity to any substance or irritant) to a large number of allergens and the formation of an individual allergic sensitivity profile.

— We rely on a solid methodological and experimental foundation. Two key results from the past two years are master’s theses dedicated to the determination of IgE and protein markers of prostate cancer. Based on their outcomes, we have developed reproducible protocols: we consistently synthesize antibody conjugates with optical and fluorescent labels for both targets. A separate part of our work involves laser engraving of microchannels in polymer on the LaserPro Mercury III complex. Here, we have not only worked out the modes but also established the dependence of channel geometry on printing parameters. We have formed the architecture of our chips, which includes zones for sample introduction, conjugation, and detection, as well as a capillary, passive liquid flow. For antibody immobilization, we implemented two approaches that provide high coverage density. Based on these solutions, model test systems (IHA) were created. Their functionality was tested on real plasma samples and the results were verified using ELISA. — Ksenia Minyaylo said.

The development by scientists at the microfluidics technology laboratory will be easier to use, cheaper to produce, and more accessible for both doctors and patients.