Polyelectrolyte Microcapsule Based Assay for Monitoring Biotechnological Processes In Vitro and In Vivo

The development of non-invasive techniques for monitoring diverse biotechnological processes under production conditions is a challenging and fascinating task. It requires a novel tool that specifically detects final or intermediate products of biotechnological processes, e.g. antibodies or carbohydrates in cell cultures, or moreover any impurities, such as lipopolysaccharides, while eliminating the risk of contamination. The proposed assay should be universally adaptable to many analytes at technologically relevant concentrations and should provide real-time monitoring, high sensitivity, specificity, and robustness under production conditions.Polyelectrolyte (PE) microcapsules produced by Layer-by-Layer (LbL) assembly can serve as a perfect platform for multiple sensing, because their surface chemistry can be broadly adapted to detect various biomarkers. The measurement principle is based on the induced proximity (clustering) of two different populations of PE-microcapsules carrying detectors for specific recognition sites of an analyte. Due to the relatively large surface area and large number of binding sites, the analyte can be detected over a wide range of concentrations. As a future prospective, the methods developed on the basis of this measurement principle will provide the opportunity to determine the analytes that cannot yet be detected (e.g. intracellular proteins, nucleic acids or metabolites) with high temporal and spatial resolution.