Effect of layer-by-layer confinement of polypeptides and polysaccharides onto thermoresponsive microgels: A comparative study
Effect of layer-by-layer confinement of polypeptides and polysaccharides onto thermoresponsive microgels: A comparative study
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DOI：
10.1016/j.jcis.2010.03.042
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发表时间：
2010-07-01
影响因子：
9.9
通讯作者：
Wong, John E.
中科院分区：
文献类型：
--
作者：
Diez-Pascual, Ana M.;Wong, John E.
采用动态光散射（DLS）和电泳技术研究了聚L赖氨酸（PLL）/聚L谷氨酸（PGA）和壳聚糖（CHIT）/硫酸葡聚糖（DEX）多层膜对柔软多孔温敏性聚（N-异丙基丙烯酰胺-co-甲基丙烯酸）（P（NiPAM-co-MAA））微凝胶的约束作用。DLS证明了流体动力学半径的“奇-偶”效应，取决于最外层中的微球的类型，并且涂覆的微凝胶保留了其天然的温敏特性。发现用多肽包被的微凝胶的溶胀和去溶胀过程之间存在强烈的滞后，而用多糖包被的微凝胶几乎是可逆的。电泳迁移率的结果表明电荷反转后，每层沉积，其幅度随层数的增加而减少。用多糖包被的微凝胶表现出更高的迁移率值。稳定性研究揭示了在几周内聚合物链的空间和时间重组。随着时间的增加，多肽封端的微凝胶的流体动力学半径减小，而多糖封端的微凝胶的流体动力学半径增加到几乎未涂覆的微凝胶的原始尺寸。这两个系统都表现出双层厚度与沉积步骤的数量呈指数增长，更明显的多肽包被的微凝胶。我们的研究结果表明，这些生物聚合物到微凝胶，这可能有潜在的应用存储和释放的生物分子的逐层组装的可行性。(C)2010年爱思唯尔公司All rights reserved.
The confinement of polyelectrolyte multilayers of poly-L-lysine (PLL)/poly-L-glutamic acid (PGA) and chitosan (CHIT)/dextran sulfate (DEX) onto soft and porous thermoresponsive poly(N-isopropylacrylamide-co-methacrylic acid) (P(NiPAM-co-MAA)) microgel was studied by dynamic light scattering (DLS) and electrophoretic measurements. DLS demonstrates an "odd-even" effect in the hydrodynamic radius depending on the type of polyelectrolyte in the outermost layer and that coated microgels retain their native thermoresponsive property. Strong hysteresis is found between the swelling and deswelling processes of microgels coated with polypeptides, whilst for those coated with polysaccharides are nearly reversible. Electrophoretic mobility results indicate charge reversal after each layer deposition, which magnitude decreases with increasing number of layers. Microgels coated with polysaccharides exhibit higher mobility values. Stability studies reveal spatial and temporal reorganization of the polymer chains over several weeks. Upon increasing time, the hydrodynamic radius of polypeptide-terminated microgels decreases, whereas that of polysaccharide-terminated increases to almost the original size of the uncoated microgel. Both systems exhibit an exponential growth of the bilayer thickness with the number of deposition steps, more pronounced for microgels coated with polypeptides. Our results demonstrate the feasibility of the layer-by-layer assembly of these biopolymers onto microgels, which could have potential application for storage and release of biomolecules. (C) 2010 Elsevier Inc. All rights reserved.