Humphreys Owen, Pickering Mark, O'Cearbhaill Eoin D, Flanagan Thomas C
School of Medicine, University College Dublin, Dublin, Ireland; UCD Centre for Biomedical Engineering, University College Dublin, Dublin, Ireland.
UCD Centre for Biomedical Engineering, University College Dublin, Dublin, Ireland.
J Mech Behav Biomed Mater. 2020 Aug;108:103792. doi: 10.1016/j.jmbbm.2020.103792. Epub 2020 Apr 18.
The standard method of evaluating the lubricity of intermittent urinary catheters with coefficient of friction (CoF) testing is not physiologically relevant, while there is also a dearth of published research on catheter-associated urethral micro-trauma. We developed a novel human urethral epithelial cell-seeded model of the urethra to replace the rubber counter-surface used in standard CoF testing. This cell-seeded model, in conjunction with a novel testing device, allows an investigation of catheter-associated epithelial micro-trauma in vitro for the first time. The CoF of four brands of commercially-available hydrophilic-coated intermittent catheters was measured using both the rubber and urethral model counter-surfaces. Post-catheterisation of the urethral model, the damage to the epithelial layer was analysed using standard cell imaging. The rubber counter-surface was shown to over-estimate the CoF of gel-coated catheters compared to our urethral model due to stick-slip behaviour caused by polymer-on-polymer interaction of the catheter base material on the rubber counter-surface. We identified no deleterious effect due to the presence or design of catheter eyelets to either the CoF measurements or the degree of epithelium damage in our model. Furthermore, the epithelial damage did not correlate with the measured CoF of the low friction catheters, suggesting a more nuanced pathogenesis of urethral irritation and casting doubt on the translatability of a solely mechanical assessment of lubricity of urinary catheters to a clinical effect.
用摩擦系数（CoF）测试来评估间歇性导尿管润滑性的标准方法与生理情况不相关，同时关于导尿管相关尿道微创伤的已发表研究也很匮乏。我们开发了一种新型的接种人尿道上皮细胞的尿道模型，以取代标准CoF测试中使用的橡胶对磨面。这种接种细胞的模型与一种新型测试装置相结合，首次能够在体外研究导尿管相关的上皮微创伤。使用橡胶和尿道模型对磨面测量了四个品牌市售亲水涂层间歇性导尿管的CoF。在尿道模型插管后，使用标准细胞成像分析上皮层的损伤情况。结果显示，与我们的尿道模型相比，橡胶对磨面高估了凝胶涂层导尿管的CoF，这是由于导尿管基材与橡胶对磨面之间的聚合物-聚合物相互作用导致的粘滑行为。在我们的模型中，我们没有发现导尿管小孔的存在或设计对CoF测量或上皮损伤程度有有害影响。此外，上皮损伤与低摩擦导尿管的测量CoF不相关，这表明尿道刺激的发病机制更为微妙，也让人怀疑仅通过机械方式评估导尿管润滑性能否转化为临床效果。
