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.

• Klíčová slova
• Antibacterial, Light-activated, Polymethylmethacrylate, Silver nanoparticle, Triggerable release,
• 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
• Názvy látek
• antibakteriální látky MeSH
• polymethylmethakrylát MeSH
• stříbro MeSH

Photocatalytic micromotors are light-induced, chemically powered micromachines based on photocatalytic materials, activated by light illumination, and have redox reactions with environmental solutions to produce chemical gradients and bubbles that propel the micromachines through self-diffusiophoresis, self-electrophoresis, and bubble recoil. Due to the fact that excitation light relates largely to the bandgaps of selected materials, the development of photocatalytic micromotors has experienced an evolution from ultraviolet-light-activated to visible-light-activated and potentially biocompatible systems. Furthermore, due to the strong redox capacity and physical effects caused by the products or product gradients, photocatalytic micromotors have applications in environmental remediation, micropumps, reversible assembly, transportation, and biomimicry.

• Klíčová slova
• light-activated systems, photocatalytic micromotors, product gradient,
• MeSH
• biomimetické materiály MeSH
• fotochemické procesy * účinky záření   MeSH
• mikrotechnologie MeSH
• regenerace a remediace životního prostředí * trendy   MeSH
• světlo * MeSH
• ultrafialové záření * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Electrospun polymeric nanofiber materials doped with 5,10,15,20-tetraphenylporphyrin (TPP) photosensitizer were prepared from four different polymers and were characterized with microscopic methods, steady-state, and time-resolved fluorescence and absorption spectroscopy. The polymers used included polyurethane Larithane™ (PUR), polystyrene (PS), polycaprolactone (PCL), and polyamide 6 (PA6). The antibacterial activity of all nanofiber materials against E. coli was activated by visible light and it was dependent on oxygen permeability/diffusion coefficients and the diameter of the polymeric nanofibers. This activity is based on oxidation ability of singlet oxygen O₂(¹Δ(g)) that is generated upon irradiation. All tested nanofiber materials exhibited prolonged antibacterial properties, even in the dark after long-duration irradiation. The post-irradiation effect was explained by the photogeneration of H₂O₂, which provided the material with long-lasting antibacterial properties.

• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• Escherichia coli účinky léků   MeSH
• fotosenzibilizující látky chemie   MeSH
• kaprolaktam analogy a deriváty   chemie   MeSH
• nanovlákna chemie   MeSH
• oxidancia chemie   MeSH
• peroxid vodíku chemie   MeSH
• polyestery chemie   MeSH
• polymery chemie   MeSH
• polystyreny chemie   MeSH
• polyurethany chemie   MeSH
• porfyriny chemie   MeSH
• singletový kyslík chemie   MeSH
• světlo * MeSH
• testování materiálů MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 5,10,15,20-tetraphenylporphyrin MeSH Prohlížeč
• antibakteriální látky MeSH
• fotosenzibilizující látky MeSH
• kaprolaktam MeSH
• nylon 6 MeSH Prohlížeč
• oxidancia MeSH
• peroxid vodíku MeSH
• polycaprolactone MeSH Prohlížeč
• polyestery MeSH
• polymery MeSH
• polystyreny MeSH
• polyurethany MeSH
• porfyriny MeSH
• singletový kyslík MeSH

The effect of light on adenyl cyclase (E.C. 4.6.1.1) and 3':5'-cyclic-AMP-phosphodiesterase (E.C. 3.1.4.17) activity of Trichoderma viride was investigated. Adenyl cyclase proved to be a membrane-associated enzyme, requiring Mn2+ and was activated by light. In contrast, 3':5'-cyclic-AMP-phosphodiesterase showed no light-stimulated activity. The activity of 3':5'-cyclic-AMP-phosphodiesterase was present mainly in the cytosol and was stimulated by Mg2+.

• MeSH
• 1-methyl-3-isobutylxanthin farmakologie   MeSH
• adenylátcyklasy účinky léků   metabolismus   MeSH
• aktivace enzymů MeSH
• guanosintrifosfát farmakologie   MeSH
• mangan farmakologie   MeSH
• subcelulární frakce enzymologie   MeSH
• světelná stimulace MeSH
• Trichoderma enzymologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1-methyl-3-isobutylxanthin MeSH
• adenylátcyklasy MeSH
• guanosintrifosfát MeSH
• mangan MeSH

Noble metal nanoclusters protected with carboranes, a 12-vertex, nearly icosahedral boron-carbon framework system, have received immense attention due to their different physicochemical properties. We have synthesized ortho-carborane-1,2-dithiol (CBDT) and triphenylphosphine (TPP) coprotected [Ag42(CBDT)15(TPP)4]2- (shortly Ag42) using a ligand-exchange induced structural transformation reaction starting from [Ag18H16(TPP)10]2+ (shortly Ag18). The formation of Ag42 was confirmed using UV-vis absorption spectroscopy, mass spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and multinuclear magnetic resonance spectroscopy. Multiple UV-vis optical absorption features, which exhibit characteristic patterns, confirmed its molecular nature. Ag42 is the highest nuclearity silver nanocluster protected with carboranes reported so far. Although these clusters are thermally stable up to 200 °C in their solid state, light-irradiation of its solutions in dichloromethane results in its structural conversion to [Ag14(CBDT)6(TPP)6] (shortly Ag14). Single crystal X-ray diffraction of Ag14 exhibits Ag8-Ag6 core-shell structure of this nanocluster. Other spectroscopic and microscopic studies also confirm the formation of Ag14. Time-dependent mass spectrometry revealed that this light-activated intercluster conversion went through two sets of intermediate clusters. The first set of intermediates, [Ag37(CBDT)12(TPP)4]3- and [Ag35(CBDT)8(TPP)4]2- were formed after 8 h of light irradiation, and the second set comprised of [Ag30(CBDT)8(TPP)4]2-, [Ag26(CBDT)11(TPP)4]2-, and [Ag26(CBDT)7(TPP)7]2- were formed after 16 h of irradiation. After 24 h, the conversion to Ag14 was complete. Density functional theory calculations reveal that the kernel-centered excited state molecular orbitals of Ag42 are responsible for light-activated transformation. Interestingly, Ag42 showed near-infrared emission at 980 nm (1.26 eV) with a lifetime of >1.5 μs, indicating phosphorescence, while Ag14 shows red luminescence at 626 nm (1.98 eV) with a lifetime of 550 ps, indicating fluorescence. Femtosecond and nanosecond transient absorption showed the transitions between their electronic energy levels and associated carrier dynamics. Formation of the stable excited states of Ag42 is shown to be responsible for the core transformation.

• Klíčová slova
• carboranes, intercluster conversion, luminescence, near-infrared emission, silver nanoclusters, ultrafast electron dynamics,
• Publikační typ
• časopisecké články MeSH

STATEMENT OF PROBLEM: The bonding of light-activated adhesives to root canal dentin with an additional touch-polymerization activator has been insufficiently examined. PURPOSE: The purpose of this in vitro study was to investigate the effect of touch-polymerization activators and extended light-irradiation time on the microtensile bond strength (μTBS) of light-activated adhesives. MATERIAL AND METHODS: Post cavities were prepared in 50 extracted mandibular premolars and bonded using Prime&Bond Universal (PBU); PBU+Self Cure Activator (SCA); Clearfil SE Bond 2 (SEB); SEB+Clearfil DC Activator (DCA); or Clearfil Universal Bond Quick ER (UBQ). After light-irradiation for 10 or 20 seconds, the post cavities were filled with dual-activated resin core materials. Eight beams were prepared per specimen and subjected to the μTBS test. The μTBS data were analyzed by using 3-way ANOVAs with the Bonferroni correction (α=.05). RESULTS: The 3-way ANOVAs indicated that the use of touch-polymerization activators (SCA and DCA) significantly increased the μTBS of PBU and SEB in both the coronal (P=.015) and apical (P=.001) regions. The extension of light-irradiation time to 20 seconds significantly improved their μTBS in the apical region (P<.001), but not in the coronal region (P=.09). Light-irradiation for 20 seconds increased the μTBS of UBQ significantly in the coronal region (P=.014). CONCLUSIONS: Touch-polymerization activators improved the bond strength of light-activated adhesives to root canal dentin, especially when combined with an extended light-irradiation time.

• MeSH
• dentin MeSH
• dentinová adheziva * chemie   MeSH
• hmat MeSH
• kavita zubní dřeně MeSH
• pevnost v tahu MeSH
• polymerizace MeSH
• pryskyřičné cementy chemie   MeSH
• složené pryskyřice chemie   MeSH
• testování materiálů MeSH
• vazba zubní * MeSH
• zubní cementy MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dentinová adheziva * MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH
• zubní cementy MeSH

Carbon monoxide (CO) is an endogenous signaling molecule that controls a number of physiological processes. To circumvent the inherent toxicity of CO, light-activated CO-releasing molecules (photoCORMs) have emerged as an alternative for its administration. However, their wider application requires photoactivation using biologically benign visible and near-infrared (NIR) light. In this work, a strategy to access such photoCORMs by fusing two CO-releasing flavonol moieties with a NIR-absorbing cyanine dye is presented. These hybrids liberate two molecules of CO in high chemical yields upon activation with NIR light up to 820 nm and exhibit excellent uncaging cross-sections, which surpass the state-of-the-art by two orders of magnitude. Furthermore, the biocompatibility and applicability of the system in vitro and in vivo are demonstrated, and a mechanism of CO release is proposed. It is hoped that this strategy will stimulate the discovery of new classes of photoCORMs and accelerate the translation of CO-based phototherapy into practice.

• Klíčová slova
• CO release, cyanine, near-infrared light, photoCORM, photorelease,
• Publikační typ
• časopisecké články MeSH

We report on porphyrin-flavonol hybrids consisting of a porphyrin antenna and four covalently bound 3-hydroxyflavone (flavonol) groups, which act as highly efficient photoactivatable carbon monoxide (CO)-releasing molecules (photoCORMs). These bichromophoric systems enable activation of the UV-absorbing flavonol chromophore by visible light up to 650 nm and offer precise spatial and temporal control of CO administration. The physicochemical properties of the porphyrin antenna system can also be tuned by inserting a metal cation. Our computational study revealed that the process occurs via endergonic triplet-triplet energy transfer from porphyrin to flavonol and may become feasible thanks to flavonol energy stabilization upon intramolecular proton transfer. This mechanism was also indirectly supported by steady-state and transient absorption spectroscopy techniques. Additionally, the porphyrin-flavonol hybrids were found to be biologically benign. With four flavonol CO donors attached to a single porphyrin chromophore, high CO release yields, excellent uncaging cross sections, low toxicity, and CO therapeutic properties, these photoCORMs offer exceptional potential for their further development and future biological and medical applications.

• Publikační typ
• časopisecké články MeSH

The maintenance of an aseptic environment for chronic wounds is one of the most challenging tasks in the wound-healing process. Furthermore, the emergence of antibiotic-resistant bacterial strains is on the rise, rendering conventional treatments less effective. A new antibacterial material consisting of a polyurethane Tecophilic(™) nanofibre textile (NT) that was prepared by electrospinning and doped by a tetraphenylporphyrin (TPP) photosensitizer activated by visible light was tested for use in wound beds and bandages. In vitro experiments were performed to assess the antibacterial activity of the textile against three bacterial strains. Furthermore, the new textile was tested in 162 patients with chronic leg ulcers. A complete inhibition of in vitro growth of the three tested bacterial strains was observed on the surface of NTs that had been illuminated with visible light and was clinically demonstrated in 89 patients with leg ulcers. The application of the textiles resulted in a 35% decrease in wound size, as assessed via computer-aided wound tracing. Wound-related pain, which was estimated using a visual analogue scale, was reduced by 71%. The results of this trial reveal that the photoinactivation of bacteria through the photosensitized generation of short-lived, highly reactive singlet oxygen O(2) ((1) Δ(g) ) results in relatively superficial antibacterial effects in comparison with standard antiseptic treatment options. Thus, such treatment does not interfere with the normal healing process. This method therefore represents a suitable alternative to the use of topical antibiotics and antiseptics and demonstrates potentially broad applications in medicine.

• MeSH
• antibakteriální látky farmakologie   terapeutické užití   MeSH
• antiinfekční látky lokální terapeutické užití   MeSH
• bakteriální infekce farmakoterapie   patologie   patofyziologie   MeSH
• dospělí MeSH
• hojení ran účinky léků   fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• měření bolesti MeSH
• nanovlákna terapeutické užití   MeSH
• obvazy MeSH
• polyurethany MeSH
• porfyriny MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• světlo * MeSH
• techniky in vitro MeSH
• textilie MeSH
• vředy dolních končetin farmakoterapie   mikrobiologie   patofyziologie   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• antibakteriální látky MeSH
• antiinfekční látky lokální MeSH
• polyurethany MeSH
• porfyriny MeSH
• tetraphenylporphyrin MeSH Prohlížeč

Two photoactivatable dicarbonyl ruthenium(II) complexes based on an amide-functionalised bipyridine scaffold (4-position) equipped with an alkyne functionality or a green-fluorescent BODIPY (boron-dipyrromethene) dye have been prepared and used to investigate their light-induced decarbonylation. UV/Vis, FTIR and 13 C NMR spectroscopies as well as gas chromatography and multivariate curve resolution alternating least-squares analysis (MCR-ALS) were used to elucidate the mechanism of the decarbonylation process. Release of the first CO molecule occurs very quickly, while release of the second CO molecule proceeds more slowly. In vitro studies using two cell lines A431 (human squamous carcinoma) and HEK293 (human embryonic kidney cells) have been carried out in order to characterise the anti-proliferative and anti-apoptotic activities. The BODIPY-labelled compound allows for monitoring the cellular uptake, showing fast internalisation kinetics and accumulation at the endoplasmic reticulum and mitochondria.

• Klíčová slova
• anti-apoptotic activity, anti-proliferative, cellular localisation, photoCORM, ruthenium(II),
• MeSH
• 2,2'-dipyridyl chemie   MeSH
• HEK293 buňky MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• oxid uhelnatý chemie   MeSH
• prekurzory léčiv chemie   účinky záření   MeSH
• ruthenium chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 2,2'-dipyridyl MeSH
• oxid uhelnatý MeSH
• prekurzory léčiv MeSH
• ruthenium MeSH