Cell Catcher: a new method to extract and preserve live renal cells from urine.

Patient-specific urine-derived cells are valuable tools for biomedical research and personalised medicine since collection is non-invasive and easily repeated, unlike biopsies. The full potential of urine-derived cells remains untapped, however, due to the short shelf life of samples and necessity for prompt centrifugation. This study aims to address this limitation by evaluating a novel filtration-based Cell Catcher device and comparing its efficiency to centrifugation. We obtained urine from 18 tubulopathy patients and using paired analysis demonstrated that the Cell Catcher device significantly improves the success rate of isolating viable renal cells, and the cell yield. The findings were confirmed in a second independent study, using 44 samples obtained from healthy controls or patients with Bardet-Biedl syndrome or tubulopathies, where colonies were established in 90% of the Cell Catcher-processed samples. Cultured cells displayed a variety of morphologies and expressed markers of podocyte and proximal tubule cells. Collectively, we describe an improved, point-of-care methodology to obtain live patient cells from urine using a filtration technique, with potential personalised medicine applications in nephrology, regenerative medicine, and urological cancers. ### Competing Interest Statement KN and DAL hold shares in Encelo Laboratories Ltd. ### Funding Statement This work was supported by Encelo Laboratories Ltd, a Kidney Research UK Innovation Grant (Paed\_IN\_005_20190926 to DAL, PB and JN) and the NIHR Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee of Royal Free Hospital, St Thomas Hospital and Great Ormond Street Hospital, London gave ethical approval for this work (references: 05/Q0508/6, 08/H0713/82). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript.