Abstract：
The administration of Mg ions is advantageous in pathological scenarios such as pre-enclampsia and forms of neuroinflammation (e.g. stroke or injury); yet, few systems exist for their sustained delivery. Here, we present the (static light scattering and diffusing-wave spectroscopy) characterization of magnesium alginate (MgAlg) as a potentially injectable vehicle ifor the delivery of Mg. Differently from other divalent cations, Mg does not readily induce gelation: it acts within MgAlg coils, making them more rigid and less prone to entangle. As a result, below a threshold concentration (notionally below 0.5 % wt.) MgAlg are inherently less viscous than those of sodium alginate (NaAlg), which is a major advantage for injectables; at higher concentrations, however, (stable, Mg-based) aggregation starts occurring. Importantly, Mg can then be released e.g. in artificial cerebrospinal fluid, via a slow (hours) process of ion exchange. Finally, we here show that MgAlg protects rat neural stem cells from the consequence of an oxidative insult (100 μM H2O2), an effect that we can only ascribe to the sustained liberation of Mg ions, since it was not shown by NaAlg, MgSO4 or the NaAlg/MgSO4 combination. Our results therefore indicate that MgAlg is a promising vehicle for Mg delivery under pathological (inflammatory) conditions.
摘要：
镁离子的施用在病理情况下是有利的，例如子痫前期和神经炎症（例如中风或损伤）的形式；然而，很少有系统存在他们的持续交付。这里,我们介绍了海藻酸镁（MgAlg）作为用于递送Mg的潜在可注射载体的（静态光散射和扩散波光谱）表征。与其他二价阳离子不同，Mg不容易诱导凝胶化：它在MgAlg线圈内发挥作用，使它们更僵硬，不易纠缠。因此,低于阈值浓度(理论上低于0.5%wt。）MgAlg本质上比海藻酸钠（NaAlg）的粘性低，这是注射剂的主要优势；在较高的浓度下，然而,(稳定,基于Mg的)聚集开始发生。重要的是,然后可以释放Mg，例如在人工脑脊液中，通过缓慢（小时）的离子交换过程。最后,我们在这里显示，MgAlg保护大鼠神经干细胞免受氧化损伤（100μMH2O2）的后果，我们只能归因于镁离子的持续释放，因为NaAlg没有显示,MgSO4或NaAlg/MgSO4组合。因此,我们的结果表明,MgAlg是在病理(炎性)条件下用于Mg递送的有前景的载体。
