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Preparation of antibacterial electrospun scaffold for skin cells culture.
Bajsić, E.G. ; Veceric, M. ; Zdraveva, E. ; Mijović, B. ; Grgurić, T.H. ; Ujčić, Massimo ; Trcin, M.T. ; Slivac, I.
In this work the function and application of titanium dioxide as a filler in a composite system polycaprolactone/titanium dioxide (PCL/TiO2) was examined. Titanium dioxide was applied by ultrasonic bath on already electrospun PCL fibrous scaffold treated and non-treated with NaOH. A procedure of surface modification of the electrospun PCL fibrous scaffold was made to enhance the interaction of the surface with the TiO2 particles. The surface modification was performed using NaOH for the formation of carboxyl groups on the fibers' surfaces. The water contact angle was measured by goniometer to prove the change from hydrophobic to hydrophilic polymer surface. SEM was used to study the morphology structure of the electrospun PCL fibrous scaffold before and after NaOH treatment and introduction of TiO2. The content of TiO2 on the electrospun PCL fibrous scaffold was determined by TGA. After NaOH treatment the surface of the electrospun PCL fibrous scaffolds changed from hydrophobic to hydrophilic. SEM micrographs show that with the sonification of 30 min homogeneous TiO2 particles distribution was obtained, while after sonification of 60 min, the TiO2 particles tend to agglomerate. The modification of the scaffold surface with NaOH enhances the adhesion of the TiO2 filler. TG analysis show that longer treatment of the electrospun PCL fibrous scaffolds in the ultrasonic bath gives lower thermal stability. The time of 30 minutes in the ultrasonic bath is optimal to provide sufficient amount of the TiO2 particles on the electrospun PCL fibrous scaffold.
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Biomarkers of Oxidative Stress and Inflammation in Researches Exposed to Nanoparticles by Inhalation During the Handling of Nanocomposites.
Pelclová, D. ; Ždímal, Vladimír ; Schwarz, Jaroslav ; Komarc, M. ; Vlčková, Š. ; Fenclová, Z. ; Lischková, L. ; Dvořáčková, Š. ; Rössnerová, Andrea ; Rössner ml., Pavel
At present, little is known about the health effects in the workers processing nanocomposites. In our study, 20 researchers (41.8 +/- 11.4 y/o), handling nanocomposites for 17.8 +/- 10.0 years were examined pre-shift and post-shift, together with 21 controls (42.7 +/- 11.5 y/o). Biomarkers of oxidative stress derived from lipids, nucleic acids, proteins and markers of inflammation were analyzed in the exhaled breath condensate (EBC). Aerosol exposure was monitored during three nanoparticle generation operations: smelting, welding and nanocomposite machining. Mass concentrations during these operations ranged from 0.120 to 1.840 mg/m(3), and median particle number concentrations from 4.8x10(4) to 5.4x10(5) particles/cm(3). Nanoparticles accounted for 40 to 95 % of particles, with Fe and Mn prevailing. Significant elevations were already seen in most oxidative stress markers and in several inflammation markers in the pre-shift samples relative to the controls. Significant associations were found between working in nanocomposite synthesis and the majority of EBC biomarkers. Chronic bronchitis was more frequent in researchers. A minor, but significant post-shift decrease of lung function parameters was found. We conclude that workers in nanocomposite synthesis may be at risk of developing airway disorders with time. From all the markers analyzed in EBC, the following markers were most robust and could be recommended for preventive examinations: 8-hydroxy-2-deoxyguanosine (8-OHdG) and 5-hydroxymethyl uracil (5-OHMeU) from nucleic acids, o-tyrosine (o-Tyr) and 3-nitrotyrosine (3-NOTyr) from proteins, and malondialdehyde and aldehydes C6-C13 from lipids. Among the markers of inflammation, tumor necrosis factor (TNF) and leukotriene B4 appeared to be the most useful.
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