论文标题
互穿生物表面活性剂 - 聚合物正交水凝胶：生物表面活性剂相控制水凝胶的力学
Interpenetrated biosurfactant-biopolymer orthogonal hydrogels: the biosurfactant's phase controls the hydrogel's mechanics
论文作者
论文摘要
控制水凝胶的粘弹性是许多应用的挑战。低分子量凝胶剂（LMWG）如胆汁盐和糖脂，以及壳聚糖和藻酸盐等生物聚合物，是开发完全生物生物基的混合水凝胶的良好候选物，结合了这两个组件的优势。生物聚合物会增强力学，而LMWG添加了功能。在这项工作中，混合水凝胶由生物聚合物（明胶，壳聚糖，藻酸盐）和微生物糖脂生物抑制剂（称为生物表面活性剂）组成。除了它们的生物相容性和自然来源外，生物学还可以呈现变色位的行为，因为pH和离子在强稀释的条件下控制中性周围的水中的相图（<5 wt％）。在这项工作中使用的糖脂表现得像表面活性剂（胶束相）在高pH值或低pH值下的磷脂（囊泡相）。此外，在钙存在的中性到卵生pH下，它的行为就像凝胶剂（纤维相）。这些相对于生物聚合物的弹性特性的影响通过振荡性流变学探索，而杂种结构则通过小角度X射线散射研究。胶束和囊泡相降低了水凝胶的弹性特性，而纤维相具有相反的作用，它通过形成互穿渗透的生物聚合物-LMWG网络来增强水凝胶的强度。
Controlling the viscoelastic properties of hydrogels is a challenge for many applications. Low molecular weight gelators (LMWG) like bile salts and glycolipids, and biopolymers like chitosan and alginate, are good candidates for developing fully biobased hybrid hydrogels that combine the advantages of both components. Biopolymers lead to enhanced mechanics while LMWG add functionality. In this work, hybrid hydrogels are composed of biopolymers (gelatin, chitosan, alginate) and microbial glycolipid bioamphiphiles, known as biosurfactants. Besides their biocompatibility and natural origin, bioamphiphiles can present chameleonic behavior, as pH and ions control their phase diagram in water around neutrality under strongly diluted conditions (< 5 wt%). The glycolipid used in this work behaves like a surfactant (micellar phase) at high pH or like a phospholipid (vesicle phase) at low pH. Moreover, at neutral-to-alkaline pH in the presence of calcium, it behaves like a gelator (fiber phase). The impact of each of these phases on the elastic properties of biopolymers is explored by means of oscillatory rheology, while the hybrid structure is studied by small angle X-ray scattering. The micellar and vesicular phase reduce the elastic properties of the hydrogels, while the fiber phase has the opposite effect, it enhances the hydrogel's strength by forming an interpenetrated biopolymer-LMWG network.
