Preparation And Study On The Antibacterial Properties Of Curcumin-loaded Polyvinyl Butyral Membrane

Recently,antibacterial materials are widely interested in different fields,more and more antibacterial natural active ingredients were introduced into the natural or synthetic polymers to fabricate multifunctional materials.Turmeric(Curcuma longa)has been used as the spice and traditional natural herbal medicine from ancient times to the present.Curcumin(Cur)is one kind of polyphenolic phytoconstituent found in the rhizomes of turmeric featuring with antibacterial,anti-inflammatory,anti-cancer and antioxidant activities.The pleiotropic activities of curcumin originate from its complex molecular structure and chemical property,as well as its ability to respond to multiple signaling molecules.Curcumin can directly interact with numerous signal molecules through the multiple interaction forces.Until now,curcumin is one part of the daily diet in Asian countries without causing any toxic events.Clinical trials have indicated Cur is safe even when humans are imposed a high doses(12 g/day).Polyvinyl butyral(PVB)is a synthetic polymer with excellent film-forming and mechanical properties.Meanwhile,it also can be used in food packaging and medical industries on the advantage of its good biocompatibility and adhesion to a variety of substrates.In this paper,Cur was incorporated into PVB matrix by using ethanol as solvent,the multifunctional PVB-Cur composite film was successfully prepared through the solvent evaporation.Based on the pharmacological activity of curcumin and unique properties from PVB polymer,the PVB-Cur composite film effectively makes up for the limitation of single materials.Fourier infrared(FTIR)spectroscopy confirmed the intermolecular forces(such as hydrogen bonds)between PVB polymer and Cur molecules.X-ray diffraction Shear viscosity and Scanning electron microscopy(SEM)characterization analysis demonstrated the excellent uniform dispersion and excellent biocompatibility of PVB and Cur composite system.The water contact angle of the composite film was less than 80°,indicating its hydrophilicity.Thermogravimetric analysis exhibited that the thermal stability of the composite was effectively improved;Ultraviolet-visible light(UV-vis)characterization exhibited the excellent ultraviolet shielding properties of composite materials;Tensile testing results demonstrated that the introduction of Cur did not damage the mechanical properties of PVB film materials.In addition,the antibacterial activity and in vitro cytocompatibility of PVB-Cur composite film was further explored and evaluated.Based on the antibacterial studies of film,it was found that the composite film exhibited the obvious antibacterial activity against Gram-negative bacteria(Escherichia coli,E.coli,ATCC 25922)and Gram-positive bacteria(Staphylococcus aureus,S.aureus,ATCC 25923).Moreover,it exhibited a higher antibacterial activity against Staphylococcus aureus,which was related to the cell wall structure and composition of the two bacteria.In vitro cell of mouse fibroblasts experiments demonstrated that the composite film did not exhibit obvious cytotoxicity after 72 hours of co-culture.