Chitosan nanofiber
Chitosan nanofiber
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DOI：
10.1021/bm0604395
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发表时间：
2006-11-13
影响因子：
6.2
通讯作者：
Yamamoto, Hiroyuki
中科院分区：
文献类型：
--
作者：
Ohkawa, Kousaku;Minato, Ken-Ichi;Yamamoto, Hiroyuki
纳米纤维技术形成了最近材料研究的重要对象。一个优雅的方法来生产纤维是现在众所周知的“静电纺丝”，1，2，它允许制造一个精细和密集的网状结构的给定的聚合物纤维直接从其溶液中的电场的存在。1静电纺丝的历史，它的重新发现和普及，以及与静电纺丝现象相关的理论方面已经被描述，特别是由一个开创性的研究小组，3-6和几篇综述文章可用于当前的趋势在静电纺丝技术。1，7，8在电纺非织造织物的可能的工业期望中，在这里，纳米纤维的两个特定应用被认为是对天然多糖非常有效的;一个是使用纳米纤维网络空间作为新型分离材料，9另一个是作为组织培养的生物医学支架材料。7.生物医学方法已被描述为生物材料和培养细胞的多种组合。细胞形态和细胞培养特性之间的关系尚未系统地阐明。只有成功的方面的细胞生长特性的重点，沿着与纳米织物制备一个指定的生物相容性聚合物。在分离技术方面，静电纺非织造布的直径和机械强度是影响其材料性能的关键因素。最近，已经报道了用于生物分子的亲和分离的纤维素膜。10.天然多糖是生物医学和分离技术中有前途的一类聚合物材料。从天然多糖中稳定生产纳米纤维材料可以被认为是一种突破性技术，可以激发基于目前纳米材料研究的新前沿。壳聚糖是一种天然的阳离子多糖，由于其固态结构和溶解状态下的链构象等物理化学性质，仍然是一种令人感兴趣的聚合物。11在壳聚糖的分子结构中，羟基和氨基在β（1，4）-连接的D-葡萄糖胺重复单元中规则地排列在赤道位置。12羟基通过在固态下形成相对刚性的微晶（形式I和II）而起作用。13在溶液状态下，壳聚糖分子之间的氢键驱动微纤维的形成，这取决于浓度。14.壳聚糖的这些特性将启发成功地电纺这种材料的方法，并将进一步形成基础聚合物化学和先进纳米材料科学之间的相互作用。最近，静电纺丝现象的解释已经从流变学方面更先进，和特定的聚合物分子在预纺溶液中的链构型与后纺纤维形态有关。Long等人开发了聚（对苯二甲酸乙二醇酯-共-间苯二甲酸乙二醇酯）的经验方程，纤维直径D（μm））0.18（C/Ce）2.6，允许根据标准化浓度C/Ce预测电纺纤维直径，其中Ce是缠结浓度。15后来，他们发现，在特定的溶液状态下，聚合物侧链之间的氢键使纤维比方程预测的更厚。16他们还报道了一种纤维素的分子间缔合状态的影响，导致生产更厚的静电纺丝纤维，并加入中性盐。
Nanofiber technology forms an important object for recent material research studies. An elegant method for nanofiber production is now well-known as “electrospinning”, 1, 2 which allows fabricating a fine and dense meshwork of given polymer fibers directly from its solution in the presence of an electric field. 1 The history of electrospinning, its rediscovery and popularization, and theoretical aspects associated with the electrospinning phenomenon have been described, especially by a pioneering research group, 3-6 and several review articles are available for current trends in nanofiber technologies. 1, 7, 8 Among the possible industrial expectations of the electrospun nonwoven fabrics, here, two of the particular applications of nanofibers are considered highly potent for natural polysaccharides; one is to use the nanofiber network space as a novel separation material, 9 and the other is as biomedical scaffolding materials for tissue cultures. 7 The biomedical approaches have been described for the numerous combinations of the nanofiber materials and the culturing cells. The relationships between the nanofiber morphologies and the cell culturing properties have not yet been systematically clarified. Only the successful aspects of the cell growth properties are focused, along with the nanofabric preparation of a specified biocompatible polymer. As for the separation technology, the diameters and the mechanical strength of the electrospun nonwoven fabrics are critical factors for their material properties. Recently, a cellulose nanofiber membrane for affinity separation of the biological molecules has been reported. 10 Natural polysaccharides were of the promising classes of polymeric materials for both the biomedical and separation technologies. The stable production of nanofibrous materials from natural polysaccharides can be recognized as a breakthrough technique for inspiring a new frontier based on the present nanofiber material research. Chitosan, a natural cationic polysaccharide, is still an interesting polymer based on its physicochemical properties, including its solid-state structure and the chain conformations in the dissolved state. 11 In the molecular structure of chitosan, the hydroxyl and amino groups were regularly arranged at the equatorial positions in the β (1, 4)-linked D-glucosamine repeating units. 12 The hydroxyl groups contribute by forming relatively rigid crystallites (forms I and II) in the solid state. 13 In the solution state, hydrogen bonding between chitosan molecules drives the formation of microfibrils, depending on the concentrations. 14 These characteristics of chitosan will inspire the methodology for successful electrospinning of this material and will further form an interplay between basic polymer chemistry and advanced nanomaterial science. Recently, interpretations of the epectrospinning phenomena have been more advanced from the rheological aspects, and the chain configurations of given specific polymer molecules in the prespun solutions are being related to the postspun fiber morphology. Long et al. have developed an empirical equation for poly (ethylene terephthalate-co-ethylene isophthatate), fiber diameter D (μm)) 0.18 (C/Ce) 2.6, allowing a prediction of the electrospun fiber diameters, based on the normalized concentration, C/Ce, where Ce is the entanglement concentration. 15 Later, they found that hydrogen bonding between polymer side chains in a specific solution state rendered the fibers thicker than those predicted from the equation. 16 They also reported the effect of the intermolecular association state of a polyelectrolyte leads to production of a thicker electrospun fiber, and the addition of neutral salt …