Polysaccharide Ecocomposite Materials: Recyclable Synthesis and Applications

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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.