Nanoparticles and nanofibers
Dotaz
Zobrazit nápovědu
The purpose of this review was to present basic forms of fibrous nanoparticles and the methods of their preparation. Particularly nanofibers in the form of threads, such as flat-surface structures or 3D wadding, were discussed. The most common methods for their preparation are electrospinning, melt-blowing, drawing, template synthesis and phase separation. Out of them, only the first two mentioned might be referred to as applicable in technology. Special attention was paid to the introduction of biocompatible and biodegradable nanofibers. These properties are understood as essential regarding the frequently discussed toxicological aspects of wide use of various nanostructures. There are few materials which are assumed to fulfil requirements for biocompatibility and biodegradability. The nanofibers produced from natural biopolymers, such as collagen, gelatin and cellulose, are compared with nanofibers of synthetic origin such as poly(glycolic acid) and poly(?-caprolactone).
The creation of an antibacterial material with triggerable properties enables us to avoid the overuse or misuse of antibacterial substances and, thus, prevent the emergence of resistant bacterial strains. As a potential light-activated antibacterial material, polymethylmethacrylate (PMMA) nanofibers doped with silver nanoparticles (AgNPs) and meso-tetraphenylporphyrin (TPP) were prepared by electrospinning. TPP was chosen as an effectively reactive oxygen species (ROS) producer. Antibacterial tests on Staphylococcus epidermidis (S. epidermidis) and Enterococcus faecalis (E. faecalis) showed the excellent light-triggerable antibacterial activity of the doped materials. Upon light irradiation at the wavelength corresponding to the TPP absorption peak (405nm), antibacterial activity dramatically increased, mostly due to the release of AgNPs from the polymer matrix. Furthermore, under prolonged light irradiation, the AgNPs/TPP/PMMA nanofibers, displayed enhanced longevity and photothermal stability. Thus, our results suggest that the proposed material is a promising option for the photodynamic inactivation of bacteria.
- MeSH
- antibakteriální látky chemie MeSH
- Enterococcus faecalis růst a vývoj MeSH
- kovové nanočástice chemie ultrastruktura MeSH
- nanovlákna chemie ultrastruktura MeSH
- polymethylmethakrylát chemie MeSH
- Staphylococcus epidermidis růst a vývoj MeSH
- stříbro chemie MeSH
- Publikační typ
- časopisecké články MeSH
In this study, we have developed a combined approach to accelerate the proliferation of mesenchymal stem cells (MSCs) in vitro, using a new nanofibrous scaffold made by needleless electrospinning from a mixture of poly-ε-caprolactone and magnetic particles. The biological characteristics of porcine MSCs were investigated while cultured in vitro on composite scaffold enriched with magnetic nanoparticles. Our data indicate that due to the synergic effect of the poly-ε-caprolactone nanofibers and magnetic particles, cellular adhesion and proliferation of MSCs is enhanced and osteogenic differentiation is supported. The cellular and physical attributes make this new scaffold very promising for the acceleration of efficient MSC proliferation and regeneration of hard tissues.
- MeSH
- biokompatibilní materiály chemie farmakologie MeSH
- buněčná adheze účinky léků MeSH
- buněčná diferenciace účinky léků MeSH
- kapronáty chemie farmakologie MeSH
- laktony chemie farmakologie MeSH
- magnetické nanočástice chemie MeSH
- mezenchymální kmenové buňky cytologie účinky léků MeSH
- nanovlákna chemie MeSH
- polyestery farmakologie MeSH
- prasata MeSH
- proliferace buněk účinky léků MeSH
- tkáňové inženýrství MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Titania nanofibers were fabricated using the industrial Nanospider(TM) technology. The preparative protocol was optimized by screening various precursor materials to get pure anatase nanofibers. Composite films were prepared by mixing a commercial paste of nanocrystalline anatase particles with the electrospun nanofibers, which were shortened by milling. The composite films were sensitized by Ru-bipyridine dye (coded C106) and the solar conversion efficiency was tested in a dye-sensitized solar cell filled with iodide-based electrolyte solution (coded Z960). The solar conversion efficiency of a solar cell with the optimized composite electrode (η = 7.53% at AM 1.5 irradiation) outperforms that of a solar cell with pure nanoparticle film (η = 5.44%). Still larger improvement was found for lower light intensities. At 10% sun illumination, the best composite electrode showed η = 7.04%, referenced to that of pure nanoparticle film (η = 4.69%). There are non-monotonic relations between the film's surface area, dye sorption capacity and solar performance of nanofiber-containing composite films, but the beneficial effect of the nanofiber morphology for enhancement of the solar efficiency has been demonstrated.
- MeSH
- 2,2'-dipyridyl analogy a deriváty chemie MeSH
- barvicí látky chemie MeSH
- elektrody MeSH
- elektrolyty chemie MeSH
- nanočástice chemie MeSH
- nanovlákna chemie ultrastruktura MeSH
- organokovové sloučeniny chemie MeSH
- polymery chemie MeSH
- sluneční energie * MeSH
- titan chemie MeSH
- zdroje elektrické energie * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Various types of nanofibers are increasingly used in tissue engineering, mainly for their ability to mimic the architecture of tissue at the nanoscale. We evaluated the adhesion, growth, viability, and differentiation of human osteoblast-like MG 63 cells on polylactide (PLA) nanofibers prepared by needle-less electrospinning and loaded with 5 or 15 wt % of hydroxyapatite (HA) nanoparticles. On day 7 after seeding, the cell number was the highest on samples with 15 wt % of HA. This result was confirmed by the XTT test, especially after dynamic cultivation, when the number of metabolically active cells on these samples was even higher than on control polystyrene. Staining with a live/dead kit showed that the viability of cells on all nanofibrous scaffolds was very high and comparable to that on control polystyrene dishes. An enzyme-linked immunosorbent assay revealed that the concentration of osteocalcin was also higher in cells on samples with 15 wt % of HA. There was no immune activation of cells (measured by production of TNF-alpha), associated with the incorporation of HA. Moreover, the addition of HA suppressed the creep behavior of the scaffolds in their dry state. Thus, nanofibrous PLA scaffolds have potential for bone tissue engineering, particularly those with 15 wt % of HA.
- MeSH
- buněčná adheze MeSH
- buněčná diferenciace * MeSH
- buněčné linie MeSH
- hydroxyapatit chemie MeSH
- kostní náhrady MeSH
- lidé MeSH
- nanovlákna chemie MeSH
- osteoblasty cytologie metabolismus MeSH
- osteokalcin biosyntéza MeSH
- polyestery chemie MeSH
- tkáňové inženýrství metody MeSH
- viabilita buněk MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Novel nanofibers mats were fabricated by electrospinning of polyvinyl alcohol/hyaluronan (PVA/HA) solutions in the presence of silver nanoparticles (AgNPs). The AgNPs were synthesized by in-situ chemical reduction of silver ions (Ag+) using HA as a reducing and stabilizing agent. Narrow size distribution and spherical shape of AgNPs were achieved by optimizing the initial silver nitrate concentration (0.01 to 1 M) and reaction time (10-60 min). HA-AgNPs nanocomposite and PVA/HA-AgNPs nanofibrous mats were fabricated by electrospinning technique from aqueous solution containing a different mass ratio of PVA and HA-AgNPs and characterized by UV/Vis spectroscopy, SEM, TEM, DLS, XRD, TGA, and ATR-FTIR. Mechanical and rheological properties were also investigated and discussed. The novel nanofibrous mats show great potential in skin regeneration and drug carrier applications.
- MeSH
- dusičnan stříbrný chemie MeSH
- elektrochemie MeSH
- ionty MeSH
- kovové nanočástice chemie MeSH
- kyselina hyaluronová chemie MeSH
- nanokompozity chemie MeSH
- nanovlákna MeSH
- nosiče léků MeSH
- obvazy MeSH
- polyvinylalkohol chemie MeSH
- povrchové vlastnosti MeSH
- reologie MeSH
- rozpouštědla MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- stříbro chemie MeSH
- technologie zelené chemie * MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
In the present work, nanofibre membranes composed of polyvinyl alcohol (PVA) and a natural gum karaya (GK) hydrocolloid were prepared using electrospinning. The electrospun membranes of PVA/GK were cross-linked with heat treatment and later methane plasma was used to obtain a hydrophobic membrane. The morphology, characterization and adsorption ability of P-NFM was assessed using scanning electron microscopy, UV-vis spectroscopy, ATR-FTIR techniques, water contact angle and ICP-MS analytical methods. The membrane was employed for the extraction of nanoparticles (Ag, Au, Pt, CuO and Fe3O4) from water. The nanoparticle extraction kinetic and adsorption isotherm perform the pseudo-second-order model and Langmuir isotherm model, respectively. The adsorption capacities of the membrane for the removal of NPs from water diverge in the order Pt>Au>Ag>CuO>Fe3O4. The high adsorption efficiency for the removal of NPs from water was compared with an untreated membrane. Physisorption, functional group interactions, complexation reactions between metal/metal oxide nanoparticles with various functional groups present in NFM and modified surface properties such as the balance of hydrophilicity/hydrophobicity, surface free energy, and the high surface area of the plasma treated membrane were possible mechanisms of NPs adsorption onto NFM. The regeneration and reusability were tested in five consecutive adsorption/desorption cycles.
- MeSH
- adsorpce MeSH
- guma karaya chemie MeSH
- kinetika MeSH
- kovové nanočástice * MeSH
- látky znečišťující vodu izolace a purifikace MeSH
- membrány umělé MeSH
- mikroskopie elektronová rastrovací MeSH
- nanovlákna chemie ultrastruktura MeSH
- polyvinylalkohol chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- termodynamika MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
A novel sorbent for solid phase extraction (SPE) based on hybrid nanofibrous polycaprolactone containing graphene nanoparticles has been prepared. The preparation of hybrid polymer nanofibers with a very high 1:1 polymer/graphene ratio was achieved for the first time using alternating current electrospinning. The final appearance of these nanofibers was a thick porous layer that was cut into the shape of easy-to-handle extraction discs. Based on the preliminary study in which the graphene content varied, 30% graphene-doped nanofibers (w/w) exhibited the highest recoveries and enabled a significant increase in the retention of analytes, 2-25 times in comparison to PCL. The incorporation of graphene resulted in a higher surface area of 12 g/m2 compared to 2 g/m2 determined for the native polycaprolactone (PCL) nanofibers. This unique material was applied for a simple stirred disc sorptive extraction and preconcentration of trace levels of emerging organic environmental contaminants, bisphenols A, AF, AP, C, S, Z, 3-chlorophenol, and pesticides fenoxycarb, deltamethrin, and kadethrin from surface waters prior to HPLC-DAD determination. This was accomplished by stirring the unsupported nanofiber disc in a large-volume sample with RSD of five extractions of 3-15%. Recoveries yielded 87-120%, except 52% for bisphenol S due to its high polarity. Optimization of the extraction procedure included conditioning, sample volume, extraction time, and elution solvent. Our novel desorption procedure carried out in a vial used for the direct injection into the HPLC system significantly reduced sample handling and minimized potential human error.
- Publikační typ
- časopisecké články MeSH
Aqueous dispersions of sulfonated polystyrene nanoparticles (average diameter: 30 ± 14 nm) with encapsulated 5,10,15,20-tetraphenylporphyrin (TPP) are promising candidates for antibacterial treatments due to the photogeneration of cytotoxic singlet oxygen species O2(1Δg) under physiological conditions using visible light. The antibacterial effect on gram-negative Escherichia coli was significantly enhanced after the addition of nontoxic potassium iodide (0.001-0.01 M) because photogenerated O2(1Δg) oxidized iodide to I2/I3-, which is another antibacterial species. The improved antibacterial properties were predicted using luminescence measurements of O2(1Δg), transient absorption of TPP triplets and singlet oxygen-sensitized delayed fluorescence (SODF). In contrast to a solution of free photosensitizers, the aqueous dispersion of photoactive nanoparticles did not exhibit any quenching of the excited states after the addition of iodide or any tendency toward aggregation and/or I3--induced photo-aggregation. We also observed a decrease in the lifetime of O2(1Δg) and a significant increase in SODF intensity at higher temperatures, due to the increased oxygen diffusion coefficient in nanoparticles and aqueous surroundings. This effect corresponds with the significantly stronger antibacterial effect of nanoparticles at physiological temperature (37 °C) in comparison with that at room temperature (25 °C).
- MeSH
- antibakteriální látky farmakologie MeSH
- časové faktory MeSH
- Escherichia coli účinky léků MeSH
- fotosenzibilizující látky farmakologie MeSH
- jodidy farmakologie MeSH
- kinetika MeSH
- luminiscence MeSH
- mikrobiální testy citlivosti MeSH
- nanočástice chemie ultrastruktura MeSH
- nanovlákna chemie ultrastruktura MeSH
- teplota * MeSH
- Publikační typ
- časopisecké články MeSH
