Open AccessMatting Calcium Crystals by Melamine Improves Stabilization and Prevents Dissolution
Author(s) -
Eugenia Awuah Boadi,
Nikolaus J Deems,
Christopher B. Raub,
Bidhan C. Bandyopadhyay
Publication year - 2019
Publication title -
crystal growth and design
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.966
H-Index - 155
eISSN - 1528-7505
pISSN - 1528-7483
DOI - 10.1021/acs.cgd.9b01036
Subject(s) - melamine , chemistry , calcium oxalate , dissolution , oxalate , inorganic chemistry , organic chemistry
Melamine induces calcium phosphate (CaP) and calcium oxalate (CaO x ) crystal formation; however, the physicochemical mechanism is not clear. Recently, we found that melamine has a discriminatory effect on CaP, CaO x , and CaP + CaO x (Mixed) crystal dissolution. Thus, to delineate the mechanism, we examined crystal interactions through birefringence analysis and found that CaP becomes increasingly birefringent when bound to melamine, while the birefringence of CaO x decreases when it forms CaO x -melamine cocrystals. We also confirmed the feasibility of such melamine-CaP/CaO x co-crystallization at the nanomicromolar range. Interestingly, ammeline, which is a similar triazine, did not accelerate CaP/CaO x /Mixed crystal formation and growth, indicating the specificity of crystal interaction by melamine. Furthermore, melamine stabilizes the CaP/CaO x /Mixed crystals when exposed to a crystal inhibitor (etidronic acid) or dissolution agents (citrate analogues), while it induces crystal growth by increasing crystal retention, suggesting melamine's interference with conventional dissolution remedies. Morphological and elemental analysis of melamine-CaP/CaO x /Mixed co-crystals using scanning electron microscopy further revealed that melamine harbors such crystals by creating a nucleation site. Finally, we confirmed the physiological relevance of melamine exposure using artificial urine to show the induction, stabilization, and retention of mixed crystals in the presence of crystal-inhibitor/dissolution agent and thus established potential causes of recurrence of kidney stones.