The main constituents of kidney stones are inorganic crystals such as calcium oxalate (CaOxa). At present kidney stones can be diagnosed only after formation, which brings great suffering to patients. The formation of kidney stones related closely to the properties of urinary nanocrystallites. If kidney stone can be detected prior to its formation, it might be effectively prevented. In this paper, an review is given about the differences of urinary nanocrystallites between the patients of kidney stone and healthy controls, as well as the relationship with the formation of kidney stones. These differences comprise size and distribution, agglomeration, morphology, chemical composition, Zeta potential and stability of the microcrystals. The changes in these properties in CaOxa stone patients before and after taking potassium citrate are discussed. It is concluded that agglomeration of urinary nanocrystallites is a key factor leading to rapid growth of the crystallites and formation of urinary stones. Through the regulation of physical and chemical properties of nanocrystallites, the formation and recurrence of kidney stones are possibly inhibited.

Contents
1 Introduction
2 Differences of urine crystallites of kidney stone patients and controls
2.1 Size
2.2 Aggregation
2.3 Morphology
2.4 Chemical composition
2.5 Zeta potential
2.6 Stability
3 Agglomeration of urinary nanocrystallites promotes stone formation
4 Properties changes in urinary nanocrystallites in calcium oxalate stone patients before and after potassium citrate administration
5 Conclusions and outlook