Microfluidic biosensors and devices for brain tumor diagnosis and monitoring.

Glioblastoma (GBM), a WHO grade IV astrocytoma, is the most common and aggressive primary brain cancer in adults and represents approximately half of all malignant brain tumors across different age groups. Modern treatment approaches, including surgical removal, combined radiochemotherapy, and follow-up chemotherapy, have yet to significantly improve patient prognosis. Patients typically survive only 15 months, with most experiencing quick tumor recurrence and less than 7% surviving beyond five years. Early GBM detection faces significant obstacles due to the vague initial symptoms and constraints of existing diagnostic tools, such as magnetic resonance imaging and invasive tissue sampling. These limitations often result in late-stage diagnosis, reducing treatment effectiveness. While liquid biopsy has emerged as a less invasive alternative allowing repeated sampling and ongoing monitoring, the low concentration of biomarkers in blood presents a significant challenge. Microfluidic technologies offer a revolutionary approach to GBM diagnosis. These biosensors enable precise microscale fluid handling and significantly increase the detection, concentration, and real-time analysis of circulating GBM biomarkers, including exosomes, nucleic acids, and proteins. This technology reduces sample volume requirements and allows quick, sequential disease monitoring, making early detection and personalized patient care more achievable. This review examines cutting-edge developments in microfluidic biosensor technology for brain tumor diagnosis, with a particular focus on GBM. By combining molecular analysis, miniaturized engineering, and liquid biopsy techniques, microfluidic biosensors have become crucial in neuro-oncology diagnostics. This review evaluates current capabilities, addresses technical challenges, and explores future possibilities for implementing microfluidic platforms in clinical settings to improve early intervention and treatment outcomes for patients with malignant brain tumors.