{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T05:11:22Z","timestamp":1778735482999,"version":"3.51.4"},"reference-count":21,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T00:00:00Z","timestamp":1778716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Urol."],"abstract":"<jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>\n                      To develop and characterize standardized\n                      <jats:italic>in vitro<\/jats:italic>\n                      artificial urine (AU) models for three major stone-forming environments\u2014calcium oxalate (CaOx), uric acid (UA), and infection-related struvite\u2014and to identify assay operating conditions that maximize stent-associated surface deposition while limiting excessive bulk precipitation.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats:p>Homemade AU models were formulated from a physiologic base composition and modified to create disease-specific lithogenic conditions. The CaOx model used sodium oxalate fixed at 80 mg\/L with stepwise calcium chloride escalation to 600%. The UA model was tested at uric acid concentrations of 500\u20131000 mg\/L under acidic pH. The bacterial infection model was tested as two independent live-bacterial arms preset at bulk pH 6.5 or 9.0 before immersion to capture urease-driven alkalinization and surface colonization, and a non-bacterial ammonia-alkalinized control was also evaluated. Stents of three commercial types were immersed for 48\u00a0h under CDC biofilm-reactor conditions, and surface deposition was quantified as weight change per unit length (mg\/mm).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>In the CaOx model, surface-associated weight gain increased with calcium concentration up to 200% (0.98 g\/L) but declined at higher levels owing to competing bulk precipitation. The UA model produced minimal deposition, with maximal weight gain at 600 mg\/L. In the bacterial infection assay, weight gain was numerically highest in the arm preset at bulk pH 6.5 before immersion and remained substantial in the arm preset at pH 9.0, whereas the non-bacterial alkalinization model resulted in negligible deposits.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>\n                      These stone type\u2013specific AU models provide defined, lab-preparable lithogenic screening conditions. Within this 48-h reactor assay, CaCl\n                      <jats:sub>2<\/jats:sub>\n                      200% + oxalate 80 mg\/L, uric acid 600 mg\/L, and the bacterial infection model initiated at preset bulk pH 6.5 yielded the highest observed stent-associated deposition. The platform may serve as an accelerated screening tool for evaluating stent materials, coatings, and anti-encrustation strategies.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fruro.2026.1806726","type":"journal-article","created":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T04:30:49Z","timestamp":1778733049000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Optimal artificial urine formulations for in vitro urolithiasis models"],"prefix":"10.3389","volume":"6","author":[{"given":"Deok Hyun","family":"Han","sequence":"first","affiliation":[{"name":"Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine","place":["Seoul, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jae Hoon","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Urology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine","place":["Anyang, Republic of Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,14]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"85","DOI":"10.1177\/1756287210370699","article-title":"Ureteral stents: new ideas, new designs","volume":"2","author":"Al-Aown","year":"2010","journal-title":"Ther Adv Urol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1097\/mou.0000000000000275","article-title":"Advances in ureteral stent development","volume":"26","author":"Chew","year":"2016","journal-title":"Curr Opin Urol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/s0022-5347(17)38146-6","article-title":"Polyurethane internal ureteral stents in treatment of stone patients: morbidity related to indwelling times","volume":"146","author":"el-Faqih","year":"1991","journal-title":"J Urol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1016\/j.urology.2015.05.015","article-title":"Chemical and mineralogical analysis of ureteral stent encrustation and associated risk factors","volume":"86","author":"Sighinolfi","year":"2015","journal-title":"Urology"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/s0140-6736(06)68071-9","article-title":"Kidney stones: pathophysiology and medical management","volume":"367","author":"Moe","year":"2006","journal-title":"Lancet (Lond Engl)"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.4111\/icu.20240410","article-title":"Comparison of encrustation between silicon-covered and polytetrafluoroethylene-covered metallic stent, in vitro experimental study","volume":"66","author":"Han","year":"2025","journal-title":"Invest Clin Urol"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.7150\/ijms.61720","article-title":"Optimization of artificial urine formula for in vitro cellular study compared with native urine","volume":"18","author":"Sueksakit","year":"2021","journal-title":"Int J Med Sci"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.18388\/abp.2014_882","article-title":"Various intensity of Proteus mirabilis-induced crystallization resulting from the changes in the mineral composition of urine","volume":"62","author":"Torzewska","year":"2015","journal-title":"Acta Biochim Pol"},{"key":"B9","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/s00240-020-01217-3","article-title":"Urine and stone analysis for the investigation of the renal stone former: a consensus conference","volume":"49","author":"Williams","year":"2021","journal-title":"Urolithiasis"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1007\/s002400050115","article-title":"Calcium oxalate crystallization kinetics at different concentrations of human and artificial urine, with a constant calcium to oxalate ratio","volume":"27","author":"Kavanagh","year":"1999","journal-title":"Urol Res"},{"key":"B11","doi-asserted-by":"publisher","first-page":"14332","DOI":"10.1038\/s41598-022-18357-8","article-title":"Consumption of soft drinks rich in phosphoric acid versus struvite crystallization from artificial urine","volume":"12","author":"Skubisz","year":"2022","journal-title":"Sci Rep"},{"key":"B12","article-title":"Urease. The primary cause of infection-induced urinary stones","volume":"13","author":"Griffith","year":"1976","journal-title":"Invest Urol"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1021\/acsomega.3c01800","article-title":"Comparison of ureteral stent biomaterials: encrustation profile in lithogenic artificial urine models","volume":"8","author":"Wu","year":"2023","journal-title":"ACS Omega"},{"key":"B14","doi-asserted-by":"publisher","first-page":"12001","DOI":"10.1038\/s41598-024-62766-w","article-title":"Establishment of an artificial urine model in vitro and rat or pig model in vivo to evaluate urinary crystal adherence","volume":"14","author":"Hayashi","year":"2024","journal-title":"Sci Rep"},{"key":"B15","article-title":"Crystallization of calcium oxalate from synthetic urine","volume":"15","author":"Doremus","year":"1978","journal-title":"Invest Urol"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1042\/cs19990257","article-title":"Calcium oxalate crystallization kinetics studied by oxalate-induced turbidity in fresh human urine and artificial urine","volume":"98","author":"Kavanagh","year":"2000","journal-title":"Clin Sci (Lond Engl: 1979)"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0111184","article-title":"Theobromine inhibits uric acid crystallization. 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