title: Evaluation of poly (vinyl alcohol) based cryogel-zinc oxide nanocomposites for possible applications as wound dressing materials.
abstract: In this investigation cryogels composed of poly (vinyl alcohol) (PVA) were prepared by repeated freeze thaw method followed by in situ precipitation of zinc oxide nanoparticles within the cryogel networks. Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX) were used to characterize the nanocomposites. The morphologies of native PVA cryogels and PVA cryogel-ZnO nanocomposites were observed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) techniques. The SEM analysis suggested that cryogels show a well-defined porous morphology whereas TEM micrographs revealed the presence of nearly spherical and well separated zinc oxide nanoparticles with diameter<100nm. XRD results showed all relevant Bragg's reflections for crystal structure of zinc oxide nanoparticles. Thermo gravimetric-differential thermal analysis (TG-DTA) was conducted to evaluate thermal stability of the nanocomposites. Mechanical properties of nanocomposites were determined in terms of tensile strength and percent elongation. Biocompatible nature was ascertained by anti-haemolytic activity, bovine serum albumin (blood protein) adsorption and in vitro cytotoxicity tests. The prepared nanocomposites were also investigated for swelling and deswelling behaviours. The results revealed that both the swelling and deswelling process depend on the chemical composition of the nanocomposites, number of freeze-thaw cycles, pH and temperature of the swelling medium. The developed biocompatible PVA cryogel-ZnO nanocomposites were also tested for antibacterial activities against both Gram-negative and Gram-positive bacteria.
authors.affiliation: Bose Memorial Research Laboratory, Department of Chemistry, Government Autonomous Science College Jabalpur, India.
authors.forename: Archana
authors.initials: A
authors.lastname: Chaturvedi
authors.affiliation: Bose Memorial Research Laboratory, Department of Chemistry, Government Autonomous Science College Jabalpur, India. Electronic address: akbmrl@yahoo.co.in.
authors.forename: Anil K
authors.initials: AK
authors.lastname: Bajpai
authors.affiliation: Bose Memorial Research Laboratory, Department of Chemistry, Government Autonomous Science College Jabalpur, India.
authors.forename: Jaya
authors.initials: J
authors.lastname: Bajpai
authors.affiliation: Department of Chemistry, Guru Ghasidas University, Bilaspur, CG, India.
authors.forename: Sunil
authors.initials: S
authors.lastname: K Singh
mesh_terms: D000327:Adsorption; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D001458:Bandages; D002417:Cattle; D059985:Cryogels / Q000138:chemical synthesis / Q000737:chemistry*; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000633:toxicity; D011143:Polyvinyl Chloride / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry; D014945:Wound Healing; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D059985:Cryogels; D012710:Serum Albumin, Bovine; D011143:Polyvinyl Chloride; D015034:Zinc Oxide
keywords: Cryogel; Freeze thaw; Nanocomposite; Polyvinyl alcohol; Zinc oxide