All partners in BIRDIE project have collaborated and exchanged information, knowledge and technology. TissUse (TU) has transferred their HUMIMIC technology to Nantes Université (NU) who have optimized culture conditions of primary renal proximal tubule epithelial cells (hRPTEC) in HUMIMIC chips for development of improved in vitro model. The Biopen technology from FluiCell (FC) was transferred to NU and researchers were trained. The protocols of nanoparticles (virus) delivery to the cells was developed and tested. We perfomred RNAseq and spatial transcriptomic pipeline and acquired data for native renal cells/tissue biopsies (control, BKPyV and T-cell rejection). Moreover, at University of Maastricht (UM) we have optimized hiPSC differentiation to obtain metanephric mesenchyme, ureteric bud progenitors and iPSCs-derived proximal tubule-like cells for 3D bioprinting. The Biopixlar bioprinter from FC was transferred, and testing was performed. We have worked on developing new coating strategies to allow further support for cells. We transferred human induced pluripotent stem cell lines from TU to UM, and we have validated the differentiation protocol with these lines. Moreover, TU optimized the cryopreservation of organoids and tested the shipment to NU. FC redesigned the optical path of the bioprinter and developed an integrated Biopen and Biopixlar fluidic heads into the same platform. The methods for bioprinting core-shell cellularized fibers were developed, and the fiber integration into the BIRDIE chip was investigated. Due to the limited integration of bioprinted constructs observed during the final reporting periods, additional strategies were investigated and implemented. Viral infection and nephrotoxicity have been validated on chips cultured with iPSCs-derived proximal tubule-like cells. In terms of exploitable results, some of the project developments are available as new products or add-ons to the technology available before the project. The examples of exploitable results identified during the project were: a) BK virus infection diagnostics platform, b) Kidney analysis assay, c) Disposable kidney chip, d) Combined bioprinting and viral exposure assay printhead and integrated imaging module for bioprinting QC, e) Renal tubulointerstitium model. Dissemination of project results was made through participation in national and international conferences and through scientific publications. Furthermore, three workshops were organized during the project, and different stakeholders were involved.