Effect of Functionalized Multiwalled CNTs on the Selective Formation of Calcium Oxalate Crystals by Electrocrystallization

Abstract

The electrocrystallization (EC) of calcium oxalate (CaOx) crystals in the presence of multiwalled carbon nanotubes (MWCNTs) functionalized with itaconic acid (IA) and the monoester derivatives monomethylitaconate or mono-octadecylitaconate, which were used as new IA-ester templates supported on indium tin oxide glass substrate as working electrode, was performed by applying a 9 mA current at 37 and 60 °C for 5 min. Under the above EC reaction conditions, a broad variety of CaOx morphologies and crystal forms was found. The morphology control and coexistence of CaOx monohydrate (COM) and CaOx dihydrate was achieved through in vitro EC according to X-ray diffraction spectra. We found that all the functionalized MWCNTs were more efficient inhibitors of CaOx crystallization than the typical citrate model, where MWCNT-IA was the most effective stabilizing template of COM crystals, because carboxylic acid groups of IA moieties in MWCNT-IA would be better Ca 2+ ions binding sites than IA ester groups.

Elucidating the role of hyaluronic acid in the structure and morphology of calcium oxalate crystals

“…The COD form is often present in the urine of healthy subjects while COM calculi are more prevalent in the urine of recurrent stone formers compared with urine from healthy subjects [14,15]. Thus, recent reports focused on how natural and synthetic additives, for example, amino acids [16][17][18][19], polymers [20,21], lipids [22], proteins [23,24], peptides [25,26], metal ions [27][28][29], and carboxylic acids [30,31], affect the formation of the different forms of CaOx and how they can be leveraged to prevent or treat kidney stones. Various additives show specific binding with different surfaces of the CaOx crystals and can inhibit their growth via various mechanisms [32].…”

Effect of L-alanyl-glycine dipeptide on calcium oxalate crystallization in artificial urine

“…Crystal growth modifiers are small amounts of additives that can be used to either promote or inhibit crystallization/transformation processes. Several types of additives, such as amino acids [21][22][23][24][25][26][27][28], proteins [29,30], carboxylic acids [31][32][33] and polymers [34][35][36] have been shown to affect CaOx crystallization. In addition, studies have shown that peptides containing aspartic acidglutamic acid, glutamic acid-glutamic acid, alanine-aspartic acid amino acids have a profound effect on the CaOx crystals and could promote the formation of COD and COT crystals and stabilize these metastable phases over very long periods of time [37][38][39][40][41][42].…”