| 1. |
- Galkina, Olga, et al.
(författare)
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Antibacterial and photochemical properties of cellulose nanofiber-titania nanocomposites loaded with two different types of antibiotic medicines
- 2015
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Ingår i: Journal of materials chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-750X .- 2050-7518. ; 3:35, s. 7125-7134
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposite dermal drug delivery systems based on cellulose nanofibers with grafted titania nanoparticles loaded by two antibiotic medicines from different classes, i.e. tetracycline (TC) and phosphomycin (Phos), were successfully produced by a "green chemistry'' approach in aqueous media. The influence of a different surface binding mechanism between the drug molecule and modified cellulose nanofibers on the release of the drug and, as a result, on antimicrobial properties against common pathogens Gram-positive, Staphylococcus aureus and Gram-negative Escherichia coli was investigated. The disk diffusion method and broth culture tests using varying concentrations of drugs loaded to nanocomposites were carried out to investigate the antibacterial effects. The influence of UV irradiation on the stability of the obtained nanocomposites and their antibacterial properties after irradiation were also investigated, showing enhanced stability especially for the TC loaded materials. These findings suggest that the obtained nanocomposites are promising materials for the development of potentially useful antimicrobial patches.
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| 2. |
- Galkina, Olga, et al.
(författare)
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Cellulose nanofiber-titania nanocomposites as potential drug delivery systems for dermal applications
- 2015
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Ingår i: Journal of Materials Chemistry B. - : Royal Society of Chemistry (RSC). - 2050-750X. ; 3, s. 1688-1698
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Tidskriftsartikel (refereegranskat)abstract
- In this work, new efficient drug delivery systems based on cellulose nanofiber-titania nanocomposites grafted with three different types of model drugs such as diclofenac sodium, penicillamine-D and phosphomycin were successfully synthesized and displayed distinctly different controlled long-term release profiles. Three different methods of medicine introduction were used to show that various interactions between TiO2 and drug molecules could be used to control the kinetics of long-term drug release. All synthesis reactions were carried out in aqueous media. The morphology, chemical structure and properties of the obtained materials were characterized by SEM, TEM and AFM microscopy, nanoparticle tracking analysis, X-ray diffraction, and TGA analysis. According to FT-IR and UV-Vis spectroscopy data, the titania binds to cellulose nanofibers via formation of ester bonds and to drug molecules via formation of surface complexes. The drug release kinetics was studied in vitro for diclofenac sodium and penicillamine-D spectrophotometrically and for phosphomycin using a radio-labeling analysis with P-33-marked ATP as a model phosphate-anchored biomolecule. The results demonstrated that the obtained nanocomposites could potentially be applied in transdermal drug delivery for anesthetics, analgesics and antibiotics.
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| 3. |
- Galkina, Olga
(författare)
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Functional hybrid bionanomaterials based on titanium dioxide and cellulose, possessing antibacterial and drug delivery properties
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present work focuses on development and investigation of new functional hybrid nanomaterials based on titania nanoparticles and cellulose, possessing an important set of practical properties. The study includes two parts: first, nanocrystalline TiO₂ hydrosols produced by low-temperature sol-gel synthesis were successfully applied for cotton fabric modification. Comprehensive characterization of the cotton/TiO₂ composite was undertaken using such techniques as SEM-EDX analysis, FT-IR spectroscopy, X-ray diffraction, low-temperature nitrogen adsorption/desorption, Nanoparticle Tracking analysis, X-ray diffraction, and TGA. The interaction of TiO₂ nanoparticles with the functional groups of cotton fibers was achieved with the help of a cross-linking agent (1,2,3,4 –butanetetracarboxylic acid) through the formation of transverse ester bonds. The obtained TiO₂/composite demonstrated high bacteriostatic effect against gram-negative Escherichia coli bacteria after exposure to UV-irradiation for 10 minutes, and reduced bacteria survival by 70%. In the second part of the thesis, the nanocomposites with potential for dermal drug delivery application were developed. They were produced using titania nanosol chemically grafted onto cellulose nanofibers as active ingredient for enhanced uptake and controlled release of model drug loads. Four different medicines, Diclofenac sodium, Penicillamine-D, Phosphomycin and Tetracycline were chosen as model drugs for the synthesis and further investigation of resulting drug release systems. Two different methods of medicine introduction were used to show that various interactions between TiO₂ and drug molecule could be used to control the kinetics of long-term drug release. The viability on the action of the released drug was examined for common and most widely tested pathogen micro-organisms: Staphylococcus aureus and Escherichia coli. The photocatalytic test showed that cellulose nanofibers–titania nanocomposites possessed high photocatalytic properties and could potentially be utilized in photovoltaic devices and photocatalysis. The influence of UV irradiation on the stability of the obtained nanocomposites loaded with drugs and their antibacterial properties was also investigated.
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| 4. |
- Galkina, Olga, et al.
(författare)
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The sol-gel synthesis of cotton/TiO2 composites and their antibacterial properties
- 2014
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Ingår i: Surface and Coatings Technology. - : Elsevier BV. - 0257-8972. ; 253, s. 171-179
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Tidskriftsartikel (refereegranskat)abstract
- Present work is devoted to investigation of structure and functional properties of hybrid nanomaterials based on the TiO2-modified cellulose fibers of cotton. The titania hydrosol was successfully prepared using the titanium tetraisopropoxide as precursor and the nitric acid as peptizing agent via the low-temperature sol-gel synthesis in aqueous medium and applied to cotton fabric. For cross-linking of titania nanoparticles to cotton the 1,2,3,4-butanetetracarboxylic acid (BTCA) was used as a spacer. The morphology and composition of the surface pure and TiO2 modified cotton fibers were investigated by the scanning electron microscopy (SEM). The cotton/TiO2 composite was characterized by the dielectric permittivity. For the estimation of total titania concentration, all samples were calcined at 650 degrees C The antimicrobial activity of the treated TiO2 cotton fibers was investigated against Escherichia coli as a model Gram-negative bacteria after exposure to UV-irradiation for 10 min. (C) 2014 Elsevier B.V. All rights reserved.
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| 5. |
- Proletov, Ian, et al.
(författare)
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Primary and secondary glomerulonephritides 1.
- 2014
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Ingår i: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. - : Oxford University Press (OUP). - 1460-2385. ; 29 Suppl 3:May, s. 186-200
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Tidskriftsartikel (refereegranskat)
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