Kuliasha Cary A, Rodriguez Douglas, Lovett Archana, Gower Laurie B
Department of Materials Science and Engineering, University of Florida, Gainesville, FL, USA.
CrystEngComm. 2020 Feb 28;22(8):1448-1458. doi: 10.1039/c9ce01587f. Epub 2020 Feb 5.
A significant portion of the population suffers from idipoathic calcium oxalate (CaOx) kidney stones, and current clinical treatments of stones have limited lasting success with a high rate of patients suffering from reoccurring stones. Understanding the role of physiologically relevant urinary species on the formation, aggregation, and growth of CaOx crystals can allow for better understanding of this complex biomineralization process and lead to more effective clinical treatments. Our prior work has focused on developing a two-stage model system, where the first stage emulates the formation of Randall's plaque, and the second stage examines the influence of the plaque on overgrowth of CaOx into a stone. Herein, we report on the development of an easy-to-use flow-cell platform that utilizes basement membrane extract (BME) as a biologically relevant crystallization substrate to study the influence of urinary 'inhibitors' on the formation and growth of CaOx on BME under flow conditions. Magnesium, citrate, and osteopontin were studied because of their known ability to inhibit CaOx formation, but their influence also led to interesting modifications to the terminal crystal habit. Magnesium had little to no effect on the CaOx crystallization, but both citrate and osteopontin resulted in significant changes to the crystallization kinetics and the terminal crystal habits. Triply inhibited artificial urine solutions resulted in CaOx monohydrate formations that resembled physiological stones, and the platform allowed for morphogenesis to be dynamically monitored. The BME was also used in a two-stage model system to first grow CaP that mimicked Randall's plaques, whereby the impact of the CaP crystallizing surface on CaOx formation could be studied. It was found that the CaP surface did not result in any significant changes in CaOx crystal formation or growth indicating that the urinary inhibitors and the basement membrane substrate were the dominant factors in modulating CaOx crystallization. It was also found that the basement membrane surface promoted the attachment and/or nucleation and growth of both CaOx and CaP crystals compared to bare glass surfaces, thereby enabling easy study of the urinary inhibitors. The work presented here has elucidated the terminal growth habit of different COM structures and has provided an easy to use platform that can be widely adopted by the kidney stone and other crystallization communities.
相当一部分人群患有特发性草酸钙（CaOx）肾结石，目前结石的临床治疗取得的持久成功有限，有很高比例的患者会复发结石。了解生理相关尿液成分在CaOx晶体形成、聚集和生长中的作用，有助于更好地理解这一复杂的生物矿化过程，并带来更有效的临床治疗方法。我们之前的工作重点是开发一个两阶段模型系统，其中第一阶段模拟兰德尔斑的形成，第二阶段研究斑块对CaOx过度生长形成结石的影响。在此，我们报告一种易于使用的流动池平台的开发，该平台利用基底膜提取物（BME）作为生物相关的结晶基质，以研究尿液“抑制剂”在流动条件下对BME上CaOx形成和生长的影响。研究了镁、柠檬酸盐和骨桥蛋白，因为它们已知具有抑制CaOx形成的能力，但它们的影响也导致了最终晶体习性的有趣改变。镁对CaOx结晶几乎没有影响，但柠檬酸盐和骨桥蛋白都导致结晶动力学和最终晶体习性发生显著变化。三重抑制的人工尿液溶液导致形成类似于生理结石的一水合CaOx，并且该平台允许动态监测形态发生。BME还用于两阶段模型系统中，首先生长模拟兰德尔斑的磷酸钙（CaP），从而可以研究CaP结晶表面对CaOx形成的影响。发现CaP表面在CaOx晶体形成或生长方面没有导致任何显著变化，这表明尿液抑制剂和基底膜基质是调节CaOx结晶的主要因素。还发现与裸露的玻璃表面相比，基底膜表面促进了CaOx和CaP晶体的附着和/或成核与生长，从而便于研究尿液抑制剂。这里展示的工作阐明了不同草酸钙一水合物（COM）结构的最终生长习性，并提供了一个易于使用的平台，该平台可被肾结石及其他结晶领域广泛采用。
