Comparative Research On Nanocrystals And Crystallites In Urines Of Healthy Persons And Stone Patients

The composition, morphology and size distribution of crystallites and nanoparticles inurines of healthy people and stone patients were comparatively investigated by X-ray diffraction(XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy(TEM), scanning electron microscopy (SEM) and laser light scattering apparatus. Therelationship between these differentiations and the formation of urinary stones was discussed.The composition, morphology and size distribution of urinary crystallites and nanoparticlesin urines of healthy people and stone patients were different. Most of the particles in urines ofhealthy persons were crystalline material. The main composition of urinary crystallites in healthypersons were calcium oxalate, tricalcium phosphate and uric acid. However, the maincomposition of urinary crystallites in lithogenic patients were magnesium ammonium phosphate,calcium oxalate, uric acid and tricalcium phosphate. The morphology of urinary crystallites inhealthy urines was rounded with a narrow size distribution from 1.5μm to 40μm. The size ofmost particles was between 2μm to 20μm, and the average size was 10μm. And thenanoparticles ranged from 100 nm to 500 nm. In contrast, the particles in lithogenic urines hadsharply angled edges and tips with a broad size distribution from 5μm to 70μm. And moreaggregated crystals existed. The amount of particles with the size large than 20μm was morethan that in healthy urines. And the nanoparticles distributed from several tens to 1000 nm. Thatresulted in the increase of the particles aggregation, thus the probability of stone formationincreases. The small-size particles in urines of healthy persons were primary. With the depositedtime prolong, the size of these particles had no great change, the number was decreased a little,and the aggregation was little. However, with the deposited time prolong, the number of particlesin lithogenic urines decreased dramatically, the size was increased, and the aggregation wasmanifold.The degree of dilution, centrifugation and filter could influence the test results when thesize and size distribution of nanoparticles in urines were tested by laser light scattering apparatus.The results showed that the stability of urine was well when the urine diluted degree was 20%, atthe same time with centrifugation and a cellulose acetate filter (1.2μm). But the stability of the health urines was better than the stability of lithogenic urines at the same conditions. The figureof size distribution indicated that the distribution of the nanoparticles in healthy urines wasuniform and the size of nanoparticles ranged from 100 nm to 500 nm. In contrast, in lithogenicurines, the aggregation was more and the size distribution of nanoparticles was ununiform fromseveral tens to1000 nm.These differentiations mentioned above were explained by the physical and chemicaldifferentiations of urinary inhibitors. And the concentration and activity of urinary inhibitors inhealthy urines were higher than that in lithogenic urines. The inhibitors in healthy urine havestronger ability to inhibit the growth and aggregation of urinary nanoparticles than that inlithogenic urines. The results in this paper suggested that diminishing the size, surface area andaggregation differentiation of nanocrystals in urine by physical and chemical methods may beone of the ways to prevent urinary stone formation.