title: Physicochemical and biological characteristics of the nanostructured polysaccharide-iron hydrogel produced by microorganism Klebsiella oxytoca.
abstract: There is an increasing interest in the nanostructured polysaccharide-iron hydrogel produced by Klebsiella oxytoca. Critical physicochemical and biological characteristics of these nanostructures should be revealed for biomedical applications. Accordingly, an iron reducing strain K. oxytoca, which synthesizes biogenic polysaccharide-iron hydrogel nanoparticles, known as Fe (III)-exopolysaccharide (Fe-EPS) was isolated from a mineral spring. For microbiological identification purpose 16S rRNA sequence analysis and different morphological, physiological, and biochemical characteristics of the isolate were studied. Critical physicochemical and biological characteristics of the produced Fe-EPS were evaluated using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray crystallography (XRD), vibrating sample magnetometer (VSM). In addition, for the first time, Fe-EPS which synthesized by K. oxytoca was evaluated by dynamic light scattering (DLS), thermo gravimetric analysis (TGA), and cytotoxicity assay. TEM micrographs showed that the biogenic Fe-EPS is composed of ultra-small (about 1.8 nm) iron oxide nanoparticles (IONs) which are trapped in a polysaccharide matrix. The matrix was about 17% (w/w) of Fe-EPS total weight and provided a large negative charge of -71 mV. Interestingly, Fe-EPS showed a growth promotion effect on hepatocarcinoma cell line (Hep-G2) and 36% increase in the percentage of viability was observed by 24 h exposure to 500 μg ml-1Fe-EPS.
authors.affiliation: Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.|Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Kianpour
authors.affiliation: Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.|Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran.|Department of Medical Biotechnology, School of Medicine, Fasa University of Medical Sciences, Fasa, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Ebrahiminezhad
authors.affiliation: Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.|Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Milad
authors.initials: M
authors.lastname: Mohkam
authors.affiliation: Center for Nanotechnology in Drug Delivery and Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Shiraz University of Medical Science, Shiraz, Iran.
authors.forename: Ali Mohammad
authors.initials: AM
authors.lastname: Tamaddon
authors.affiliation: Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Dehshahri
authors.affiliation: Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Heidari
authors.affiliation: Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.|Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Younes
authors.initials: Y
authors.lastname: Ghasemi
mesh_terms: D015373:Bacterial Typing Techniques; D055598:Chemical Phenomena; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry* / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D041121:Klebsiella oxytoca / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D011134:Polysaccharides / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D011134:Polysaccharides; D012336:RNA, Ribosomal, 16S; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007501:Iron
keywords: Biosynthesis; Exopolysaccharide; Ferric citrate; Iron oxide nanoparticles; Klebsiella oxytoca