Tecnologico de Monterrey, School of Engineering and Sciences, Atizapan de Zaragoza, Estado de Mexico 52926, Mexico.
Tecnologico de Monterrey, School of Engineering and Sciences, Atizapan de Zaragoza, Estado de Mexico 52926, Mexico.
Eur J Pharm Biopharm. 2021 Feb;159:123-136. doi: 10.1016/j.ejpb.2020.12.013. Epub 2020 Dec 31.
This review discusses the physicochemical and mechanical properties of porcine gastrointestinal mucus from a rheological point of view. Considering mucus as a viscoelastic gel that functions as a biological barrier by limiting particles passage, lubricating the gastrointestinal tract, and protecting the stomach from gastric acids. The viscoelastic and protective properties of mucus are mainly produced by its mucin network, which is stabilized through electrostatic, hydrophobic and hydrogen bonding interactions. Otherwise, mucus rheology is determined by its polyanionic nature at physiological pH. At neutral pH, mucus presents a viscous behavior produced by chains crosslinking. While, at acidic pH, mucus exhibits an elastic behavior related with the extended conformation that produces mucus gelation at the stomach. Additionally, rheology studies the degree of adhesion between a polymer-mucus mixture through rheological synergism, and how it varies at different pH conditions. Finally, mucoadhesion phenomenon is exemplified with chitosan (cationic) and poly (lactic-co-glycolic) acid (anionic) polymers.
本文从流变学的角度讨论了猪胃肠粘液的物理化学和机械性能。考虑到粘液作为一种粘弹性凝胶，通过限制颗粒通过、润滑胃肠道和保护胃免受胃酸的作用来发挥生物屏障的功能。粘液的粘弹性和保护性能主要是由其粘蛋白网络产生的，该网络通过静电、疏水和氢键相互作用得到稳定。此外，粘液流变学由其在生理 pH 值下的聚阴离子性质决定。在中性 pH 值下，粘液呈现出由链交联产生的粘性行为。而在酸性 pH 值下，粘液表现出与伸展构象有关的弹性行为，在胃中产生粘液胶凝作用。此外，流变学通过流变协同作用研究了聚合物-粘液混合物之间的粘附程度，以及在不同 pH 值条件下的变化。最后，以壳聚糖（阳离子）和聚（乳酸-共-羟基乙酸）（阴离子）聚合物为例说明了粘液粘附现象。
