Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019 Florence, Italy; CSGI Consortium, via della Lastruccia 3, Sesto Fiorentino, 50019 Florence, Italy.
Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019 Florence, Italy.
J Colloid Interface Sci. 2018 Dec 1;531:681-692. doi: 10.1016/j.jcis.2018.07.102. Epub 2018 Jul 24.
Amorphous Magnesium-Calcium Phosphate (AMCP) particles in the distal small intestine have been shown to have a fundamental role in mammals' immune-surveillance mechanisms. Their formation in the gut lumen and their stability against crystallization are expected to depend upon physiological conditions such as pH and [Mg]. Knowing the influence of these parameters on AMCP stability would allow to predict the presence and the activity of the particles in physiological or pathological conditions.
We performed the synthesis of AMCP particles at physiological temperature, in phosphate buffer at variable pH from ∼7.0 to 7.4. The stability of the particles was then tested by dispersing them in different conditions of [Mg], pH and concentration, so to mimic different biological conditions. The particles were characterized in terms of morphology, crystallinity, chemical composition and porosity.
The characterization showed that we managed to prepare AMCPs with features matching those of the endogenous particles. Both the lifetime of the amorphous phase and the nature of the formed crystalline material were found to depend upon [Mg], pH and concentration. This article paves the way for the comprehension of possible dysfunctions of the gut immune-surveillance mechanisms due to imbalances of these physico-chemical parameters.
在哺乳动物的免疫监视机制中，已经证明在远端小肠中的无定形镁钙磷酸盐 (AMCP) 颗粒具有基本作用。它们在肠道腔中的形成及其对结晶的稳定性预计取决于生理条件，如 pH 值和 [Mg]。了解这些参数对 AMCP 稳定性的影响可以预测颗粒在生理或病理条件下的存在和活性。
我们在生理温度下、在从约 7.0 到 7.4 的可变 pH 值的磷酸盐缓冲液中进行了 AMCP 颗粒的合成。然后通过在不同的 [Mg]、pH 值和浓度条件下分散颗粒来测试它们的稳定性，以模拟不同的生物条件。通过形态、结晶度、化学组成和孔隙率对颗粒进行了表征。
该表征表明，我们成功地制备了具有与内源性颗粒相匹配特征的 AMCPs。无定形相的寿命和形成的结晶材料的性质都被发现取决于 [Mg]、pH 值和浓度。本文为理解由于这些理化参数失衡而导致的肠道免疫监视机制可能出现的功能障碍铺平了道路。
