Electrospun nanofiber mats as a platform for the development of microfluidic devices for rare cells capture with diagnostic purposes

Early detection and effective treatment significantly impact survival rates in disease management. Micromanipulation is a dependable method for manually isolating rare cells from biological fluids for molecular or cytogenetic analysis. While effective, this approach is costly and time-consuming due to the need for skilled personnel and specialized equipment1. This study aims to enhance the efficiency and affordability of diagnosis in hospital settings by developing a device for semi-automated selection of rare cells from biological samples. The device utilizes electrospun nanofiber mats, that offer high surface area to be functionalized with antibodies to selectively capture target cells based on surface antigens, in the optics of being used as a substrate for a microfluidic device (Fig. 1). The advantages of microfluidic systems include the micro-scale features that match that of many biological systems and laminar flow, which enables precision delivery of fluids, in combination with high surface-to-volume ratio that favours mass exchange2. Nanofiber mats were fabricated from Nylon 6.6 and Polyacrylic Acid (PAA) polymers solution. The first phase of the work was devoted to the determination of the operating parameters for electrospinning to optimize the morphology of the mats, their mechanical resistance and handling characteristics. Bioconjugation methods employing EDC/NHS chemistry were developed to impart cell-capture capabilities to the mats. Fluorescently labeled antibodies enabled assessment of conjugation success via fluorimetry and spectrofluorimetry. Cell capture tests were conducted using mesenchymal stem cells (MSC), as a model, on antibody-decorated mats. Optical and confocal microscopy were used to evaluate capture efficacy. Subsequent release strategies were also studied. Capture of model cells resulted successful holding the potential of the implementation of this nanotechnology for the development of microfluidic devices with diagnostic purposes.