Principles and approaches in the development of fluorescent hydrogels for cancer diagnosis

Abstract

Introduction. Early sensitive and highly specific diagnosis is crucial for successful cancer therapy. The use of fluorescent hydrogels (FHG) makes it possible to develop versatile biosensors due to the increased binding capacity of biological capture and reporter molecules, sensitive fluorescence detection, and the flexibility of combining their structural and functional elements.Aim. Analyzing the principles of designing biosensors based on FHG for the detection of cancer markers and the methodological approaches to their development, as well as summarizing and systematizing the data on the principles of detection and target signal generation used in these sensors.Results. FHG represent 3D sensing platforms, i. e., structures that combine the reporter fluorescence function with biological capture molecules, allowing the unique optical properties of fluorescent nanocrystals at the macro level to be preserved. The porous structure of hydrogels increases the active surface area of biosensors for 3D immobilization of fluorescent labels and biological capture molecules, while preserving the structure of these molecules, which ensures specific binding of the detected molecules of the sample. This ensures a higher sensitivity compared with the traditional methods of immunoenzymatic and immunochromatographic analyses. Not only the traditionally used antibodies, but also enzymes and glycoproteins, aptamers and oligonucleotides, as well as polymers obtained by molecular imprinting, can serve as biological capture molecules, which extends the range of specifically detectable analytes.Conclusion. The review presents examples of biosensors based on FHG intended for the detection of cancer markers and describes approaches to the preparation of FHG and immobilization of biological capture molecules, as well as principles of generation of the detected optical signal. The main advantages of fluorescent hydrogel biosensors over the classical tests used for quick diagnosis of cancer are shown.