LAUSR

BACKGROUND The 3D printing is relevant as a manufacturing technology of functional models for forensic, pharmaceutical and bioanalytical applications such as drug delivery systems, sample preparation and point-of-care tests. OBJECTIVE Melting behavior and autofluorescence of materials are decisive for optimal printing and applicability of the product which are influenced by varying unknown additives. METHODS We have produced devices for bioanalytical applications from commercially available thermoplastic polymers using a melt-layer process. We characterized them by differential scanning calorimetry, fluorescence spectroscopy and functional assays (DNA capture assay, model for cell adhesion, bacterial adhesion and biofilm formation test). RESULTS From 14 tested material we found only deep black acrylonitrile-butadiene-styrene (ABS) and some black polylactic acid (PLA) useable for fluorescence-based assays, with low autofluorescence only in the short-wave range of 300-400 nm. PLA was suitable for standard bioanalytical purposes due to a glass transition temperature of approximately 60°C, resistance to common laboratory chemicals and easy print processing. For temperature-critical methods, such as hybridization reactions up to 90°C, ABS was better suited. CONCLUSIONS Autofluorescence was not a disadvantage per se but can also be used as a reference signal in assays. The rapid development of individual protocols for sample processing and analysis required the availability of a material with consistent quality over time. The use of commercial standard materials did not seem to fulfill this requirement.