Polysaccharide Ecocomposite Materials: Recyclable Synthesis and Applications

描述（由申请人提供）：该项目的目标是系统地和革命性地解决限制基于两种最丰富的生物可再生多糖，纤维素（CEL）和壳聚糖（CS）的复合材料合成和应用的缺陷。限制是：(1)目前用于溶解CEL和CS的相当昂贵且多步骤的过程涉及强酸，强碱和其他对环境有害的化学物质；(2)使用人造聚合物来增强CS基材料的机械性能；这些都是不可取的，因为它们可能会无意中改变CS的特性，使其生物相容性降低，潜在毒性降低，并降低其独特的特性。该目标将通过以下途径实现：(1)利用离子液体（IL）这一绿色溶剂的优势，开发一种新颖、简单、无污染、完全可回收的方法来溶解多糖（CEL、CS和环糊精（CDs））和角蛋白，而不使用有害的挥发性有机溶剂和/或强酸强碱；(2)仅使用天然存在的生物聚合物（包括多糖和角蛋白）作为支撑材料，在保持cs基材料的可生物降解、生物相容性和抗菌性能的同时，加强结构和扩大用途；(3)证明这些复合材料优于目前可用的cs基材料，可作为污染物的吸附剂、输送药物的载体和用于控制、清洁和治疗出血的绷带。丁基甲基咪唑氯（BMIm），一种IL，将用于溶解CEL， CS， CDs和角蛋白。然后将得到的IL溶液浇铸成薄膜，将薄膜浸泡在水中，将[BMIm]从薄膜中除去。最终获得的薄膜将只包含所有天然生物聚合物。光谱技术将用于确认合成过程的每一步，表征和确定制备的复合材料的均匀性、流变学和机械性能。随后，将进行实验，将这些新型复合材料与现有的cs基材料进行比较，以证明复合材料具有优越的性能，从而将推进以下方法：(1)去除污染物；(2)最大化止血性能和(3)给药。具体来说，复合材料去除污染物（如双酚A和氯酚）的能力将通过使用荧光或紫外可见吸收技术测量吸附过程的动力学和吸附等温线来评估。合成的CS基复合材料的血液吸收和体外抗菌活性将与三种市售绷带进行比较，即HemCon绷带（基于CS的绷带），Iodoflex垫（含碘的绷带）和Silvasorb片（含银的绷带）。还将开发抗生素药物环丙沙星与IL溶出过程中包封复合材料的方法，然后通过监测环丙沙星在水相中的荧光信号来测量其从材料中释放到水中的情况。

DESCRIPTION (provided by applicant): The goal of this project is to systematically and revolutionarily address drawbacks which limit synthesis and applications of composite materials based on the two most abundant biorenewable polysaccharides, cellulose (CEL) and chitotan (CS). The limitations are: (1) the rather costly and multistep process currently used to dissolve CEL and CS which involves strong acid, base and other environmentally harmful chemicals, and (2) the use of man-made polymers to strengthen mechanical properties of CS-based materials; these are not desirable as they may inadvertently alter CS properties, making it less biocompatible, potentially toxic and lessening the unique properties. The goal will be accomplished by (1) exploiting the advantages of ionic liquid (IL), a green solvent, to develop a novel, simple, pollution-free and totally recyclable method to dissolve polysaccharides (CEL, CS and cyclodextrins (CDs)) and keratin without using harmful, volatile organic solvents and/or strong acid and base; (2) using only naturally occurring biopolymers, including polysaccharides and keratin, as support materials to strengthen the structure and expand the utilities while keeping the biodegradable, biocompatible and anti-bacterial properties of CS-based materials intact; and (3) demonstrating that these composite materials are superior to CS-based materials currently available for use as sorbents for pollutants, vehicles to deliver drugs and bandages to control, clean and heal hemorrhages . Butyl methylimmidazolium chloride (BMIm), an IL, will be used to dissolve CEL, CS, CDs and keratin. The resulting IL solutions will then be cast into thin films, and [BMIm] will be removed from the films by soaking the films in water. The final films obtained will contain only all natural biopolymers. Spectroscopic techniques will be used to confirm each step of the synthetic process, to characterize and to determine homogeneity, rheological and mechanical properties of the composite materials prepared. Subsequently, experiments will be carried out to compare these novel composite materials with CS-based materials currently available, to demonstrate that the composite materials have superior properties and hence will advance methods for (1) removing pollutants; (2) maximizing hemostatic properties and (3) delivering drugs. Specifically, the ability of the composite materials to remove pollutants (e.g., bisphenol A and chlorophenols) will be evaluated by measuring kinetics and adsorption isotherms of the adsorption processes by using either fluorescence or UV-visible absorption techniques. Blood absorption and in vitro antimicrobial activity of synthesized CS-based composite materials will be compared to three commercially available bandages, i.e., HemCon bandage (a bandage based on CS), Iodoflex pad (a bandage with iodine) and Silvasorb sheet (bandage with silver). Methods will also be developed to encapsulate ciprofloxacin, an antibiotic drug, into composite materials during the dissolution process with IL and, subsequently, its release from the materials to water will be measured by monitoring the fluorescence signal of ciprofloxacin in the water phase. PUBLIC HEALTH RELEVANCE: The goal of this project is to systematically and revolutionarily address the drawbacks which currently limit synthesis and applications of polysaccharide composite materials, such as cellulose and chitosan. The novel ecocomposite materials obtained through this research will advance the development of innovative and/or improved methods for (1) removal of pollutants; (2) controlling, cleaning and healing hemorrhages and (3) delivering drugs. Moreover, by fabricating new biomaterials from all natural products, the novel polysaccharide ecocomposite materials will be nontoxic, biocompatible, biodegradable and can be used for external as well as internal applications without prior FDA approval, thus leading to a better environment and save lives.