Physical and Antibacterial Properties of Iodine Containing Pullulan/Poly(vinylpyrrolidone) /Poly(vinylalcohol) Polymer Films

Iodine releasing polymer films were prepared by blending the polysaccharide pullulan (PUL) with poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) while glutaraldehyde (GA) was used as a cross linker and glycerine (GL) as a plasticizer. Cross linking was done at 25°C and 60°C and homogeneity was improved by heating. Physical, chemical and thermal properties of the films were assessed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and by differential scanning calorimetry (DSC). In addition, the swelling behavior was followed in aqueous solution. Polymer films were loaded with 0.10%, 1.0% and 10% (w/v) iodine solutions, a wide spectrum antibacterial agent. The quantities of iodide I- and triiodide I3- loaded and released were measured by UV-VIS spectroscopy. Release kinetics was followed for 168 hr using the film treated with 10% (w/v) iodine solution. Antibacterial activity of iodine species released was tested against two types of bacterial strains Escherichia coli IFO3972 as gram negative and Staphylococcus aureus ATCC25923 as gram positive bacteria. Inhibition zone measurements proved antibacterial activity. The results obtained in this thesis work show that iodine containing PUL/PVP/PVA blend films are potential candidates for controlled release iodine systems for antibacterial applications under suitable conditions. Keywords: Pullulan, Antibacterial Agent, Iodine Release System, Poly(vinyl alcohol), Poly(vinyl pyrrolidone)