Milkova Viktoria
Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Gels. 2023 Jun 16;9(6):493. doi: 10.3390/gels9060493.
Alginates are a family of natural polysaccharides with promising potential in biomedical applications and tissue regeneration. The design of versatile alginate-based structures or hydrogels and their stability and functionality depend on the polymer's physicochemical characteristics. The main features of alginate chains that determine their bioactive properties are the molar ratio of mannuronic and glucuronic residues (M/G ratio) and their distribution along the polymer chain (MM-, GG-, and MG blocks). The present study is focused on investigating the influence of the physicochemical characteristics of alginate (sodium salt) on the electrical properties and stability of the dispersion of polymer-coated colloidal particles. Ultrapure and well-characterized biomedical-grade alginate samples were used in the investigation. The dynamics of counterion charge near the vicinity of adsorbed polyion is studied via electrokinetic spectroscopy. The results show that the experimental values of the frequency of relaxation of the electro-optical effect are higher compared to the theoretical ones. Therefore, it was supposed that polarization of the condensed Na counterions occurs at specific distances according to the molecular structure (G-, M-, or MG-blocks). In the presence of Ca, the electro-optical behavior of the particles with adsorbed alginate molecules almost does not depend on the polymer characteristics but was affected by the presence of divalent ions in the polymer layer.
藻酸盐是一类天然多糖，在生物医学应用和组织再生方面具有广阔的潜力。多功能藻酸盐基结构或水凝胶的设计及其稳定性和功能性取决于聚合物的物理化学特性。决定藻酸盐链生物活性的主要特征是甘露糖醛酸和葡萄糖醛酸残基的摩尔比（M/G比）及其沿聚合物链的分布（MM-、GG-和MG嵌段）。本研究聚焦于考察藻酸盐（钠盐）的物理化学特性对聚合物包覆胶体颗粒分散体的电学性质和稳定性的影响。研究中使用了超纯且表征良好的生物医学级藻酸盐样品。通过电动光谱研究了吸附聚离子附近抗衡离子电荷的动力学。结果表明，与理论值相比，电光效应弛豫频率的实验值更高。因此，推测根据分子结构（G-、M-或MG嵌段），凝聚的Na抗衡离子在特定距离处发生极化。在有Ca存在的情况下，吸附了藻酸盐分子的颗粒的电光行为几乎不依赖于聚合物特性，而是受聚合物层中二价离子存在的影响。
