Díaz-Soler Felipe, Rodriguez-Navarro Carlos, Ruiz-Agudo Encarnación, Neira-Carrillo Andrónico
Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur Universidad de Chile, Santa Rosa 11315, La Pintana, Santiago 8820808, Chile.
Department of Biological and Animal Science, University of Chile, Santa Rosa 11735, La Pintana, Santiago 8820808, Chile.
Nanomaterials (Basel). 2021 Jan 18;11(1):235. doi: 10.3390/nano11010235.
In this work, calcium oxalate (CaOx) precursors were stabilized by poly(acrylic acid) (PAA) as an additive under in vitro crystallization assays involving the formation of pre-nucleation clusters of CaOx via a non-classical crystallization (NCC) pathway. The in vitro crystallization of CaOx was carried out in the presence of 10, 50 and 100 mg/L PAA by using automatic calcium potentiometric titration experiments at a constant pH of 6.7 at 20 °C. The results confirmed the successful stabilization of amorphous calcium oxalate II and III (ACOII and ACO III) nanoparticles formed after PNC in the presence of PAA and suggest the participation and stabilization of polymer-induced liquid-precursor (PILP) in the presence of PAA. We demonstrated that PAA stabilizes CaOx precursors with size in the range of 20-400 nm. PAA additive plays a key role in the in vitro crystallization of CaOx stabilizing multi-ion complexes in the pre-nucleation stage, thereby delaying the nucleation of ACO nanoparticles. Indeed, PAA additive favors the formation of more hydrated and soluble phase of ACO nanoparticles that are bound by electrostatic interactions to carboxylic acid groups of PAA during the post-nucleation stage. These findings may help to a better understanding of the pathological mineralization resulting in urolithiasis in mammals.
在这项工作中，在体外结晶试验中，通过添加聚丙烯酸（PAA）来稳定草酸钙（CaOx）前体，该试验涉及通过非经典结晶（NCC）途径形成CaOx的预成核簇。通过在20℃、pH值恒定为6.7的条件下进行自动钙电位滴定实验，在10、50和100mg/L PAA存在的情况下进行CaOx的体外结晶。结果证实，在PAA存在下，预成核后形成的无定形草酸钙II和III（ACOII和ACO III）纳米颗粒成功得到稳定，这表明在PAA存在下聚合物诱导的液体前体（PILP）参与并得到了稳定。我们证明PAA能稳定尺寸在20 - 400nm范围内的CaOx前体。PAA添加剂在CaOx的体外结晶中起着关键作用，在预成核阶段稳定多离子复合物，从而延迟ACO纳米颗粒的成核。实际上，在成核后阶段，PAA添加剂有利于形成更多水合且可溶的ACO纳米颗粒相，这些颗粒通过静电相互作用与PAA的羧酸基团结合。这些发现可能有助于更好地理解导致哺乳动物尿路结石的病理性矿化。
