Institute of Biomineralization and Lithiasis Research and the Department of Chemistry, Jinan University, Guangzhou 510632, China.
IEEE Trans Nanobioscience. 2010 Jun;9(2):156-63. doi: 10.1109/TNB.2010.2045510. Epub 2010 Apr 26.
The first step in urinary stone formation is the nucleation of urinary mineral from supersaturated urine. The formed nuclei then grow or/and aggregate to a pathological size. Thus, the nanocrystallites in urine may be related to the formation of urinary stones.
Nanocrystallites with a size of less than 1000 nm in the urine samples of 85 healthy persons and 65 lithogenic patients were comparatively investigated using laser scattering spectroscopy, TEM, and X-ray diffraction.
Most of the nanocrystallites in healthy urine samples were spheroidal, less aggregated, well-dispersed, and with a narrow particle size distribution from about 20 to 350 nm. In contrast, most of the particles in lithogenic urines had sharply angled edges and tips, were aggregated, and had a broad particle size distribution from 1.1 to 1000 nm. More calcium oxalate dihydrate (COD) nanocrystallites were found in healthy urine; however, more calcium oxalate monohydrate (COM) nanocrystallites were found in lithogenic urine.
The morphology, particle size, aggregation, and crystal phase of nanocrystallites in the urine of lithogenic patients are pronouncedly different from those of healthy persons. The results suggest, in ascending order of importance, that making nanocrystallites rounded, diminishing their size differentiation, and decreasing their aggregation in urine by physical and chemical methods maybe the means to prevent urinary stone formation. The most crucial among the four differences is the crystal phase differential of calcium oxalate (CaOxa). That is, the formation of COD nanocrystallites in urine can be considered as being relatively more favorable in preventing stone formation than the formation of COM nanocrystallites, which are in accord with those found for larger crystallites.
尿石形成的第一步是尿液中过饱和矿物质的成核。形成的核然后生长或/和聚集到病理大小。因此，尿液中的纳米晶可能与尿石的形成有关。
使用激光散射光谱法、TEM 和 X 射线衍射法比较研究了 85 名健康人和 65 名结石形成患者尿液样本中小于 1000nm 的纳米晶。
健康尿液样本中的大多数纳米晶呈球形，聚集较少，分散良好，粒径分布从约 20nm 至 350nm 较窄。相比之下，大多数结石尿液中的颗粒具有尖锐的棱角和尖端，聚集在一起，粒径分布从 1.1nm 至 1000nm 较宽。健康尿液中发现更多的草酸钙二水合物（COD）纳米晶，但结石尿液中发现更多的草酸钙一水合物（COM）纳米晶。
结石患者尿液中纳米晶的形态、粒径、聚集和晶体相明显不同于健康人。结果表明，通过物理和化学方法使纳米晶呈圆形、减小粒径差异并减少尿液中的聚集，可能是预防尿石形成的手段。这四个差异中最重要的是草酸钙（CaOxa）的晶体相差异。也就是说，尿液中 COD 纳米晶的形成可以被认为比 COM 纳米晶的形成更有利于预防结石形成，这与较大晶体的发现一致。
