Photocatalytic properties of hybrid materials based on a multicharged polymer matrix with encored TiO<inf>2</inf>and noble metal (Pt, Pd or Au) nanoparticles

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2020. In this study, we report a synthesis of new nanocomposites, wherein TiO2is introduced into multicharged polymeric matrix and covered with noble metals (Pt, Pd or Au) for the photocatalytic application. A photocatalytic activity investigation was performed by studying the degradation of methylene blue. It revealed that all obtained nanocomposites demonstrate enhanced photocatalytic ability when compared to pure TiO2, under both UV (24 °C) and solar light (−2 °C). The morphology and catalytic properties of the composites depend on the noble metals. The kinetic speed value of photodegradation was found to increase in the following sequence: TiO2< TiO2-NPst ≈ Pd-TiO2@NPSt < Pt-TiO2@NPSt ≈ Au-TiO2@NPSt

Luminescent composite based on epoxy polymer and silica nanoparticles doped by terbium(III) complex

© 2020, Springer Nature B.V. The interaction of the NPEL-128 epoxy oligomer with silica nanoparticles doped with terbium(III) complex with p-sulfonatothiacalix[4]arene was studied for two types of nanoparticles: possessing silanol hydroxyl groups on the non-modified surface of the nanoparticles (SNs) or amino and hydroxyl groups on the amino-modified silica surface (ASNs). The possible reaction schemes of amino and hydroxyl groups on the surface of ASNs with epoxy molecules were revealed using IR spectroscopy and DSC. Based on the obtained data, a method for producing epoxy nanocomposites was developed, and their thermophysical, physicomechanical, and luminescent properties were investigated. The chemical bonding of epoxy with ASNs compared with that of SNs allows one to obtain a higher dispersion and uniform distribution of the nanoparticles in the polymer matrix, as well as to increase the glass transition temperature of the polymer. Due to the presence of terbium(III) complex in silica nanoparticles, the cured epoxyamine polymer filled by ASNs exhibits luminescent properties. [Figure not available: see fulltext.

The construction of supramolecular and hybrid Ag-AgCl nanoparticles with photodynamic therapy action on the base of tetraundecylсalix[4]resorcinarene-mPEG conjugate

The development of new nanomaterials with therapeutic potential is a modern task due to their outstanding properties and promising effectiveness. Here the usage of acylhydrazone bond-based сalix[4]resorcinarene-mPEG conjugate (C11-mPEG) in the formation of both supramolecular and hybrid nanoparticles with in vitro photodynamic therapy (PDT) activity is described. C11-mPEG is hydrolyzed with a decrease in pH of solution; the conjugate and its degradation product have the low hemolytic activity and low cytotoxicity against normal cells. The self-association of the conjugate was studied in the aqueous solutions with pH 7.4 and 5. C11-mPEG forms self-associates that serve as pH-sensitive supramolecular nanocontainers for photosensitizer Methylene Blue (MB). In the in vitro PDT experiment the stronger decrease of tumor cells (M-Hela cells) viability in the presence of encapsulated MB is observed in comparison with free MB. Also C11-mPEG acts as a stabilizing agent for Ag@AgCl nanoparticles, which were obtained with 5/1 and 2/1 Ag+/C11-mPEG molar ratio and different reducing agents (sodium borohydride and hydrazine hydrate). The stronger cytotoxicity of hybrid NPs against tumor cells in comparison with normal was shown. Further it was found that the irradiation of the hybrid nanoparticles at 630 nm leads to the sharp increase in their cytotoxicity against M-Hela cells. The high level of ROS formation in the cells in the presence of both supramolecular and hybrid NPs under in vitro PDT experiment was determined

Doxorubicin delivery by polymer nanocarrier based on N-methylglucamine resorcinarene

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. Herein we describe a simple method for the synthesis of polymer nanocarrier for the doxorubicin delivery. The nanocarrier consists of N-methyl-glucamine resorcinarenes that are covalently bound to phenylboronic acid. The nanocarrier is stable at normal pH but is hydrolysed at pH below 6. It demonstrates low cytotoxicity and haemolytic activity. Doxorubicin was successfully loaded into the nanocarriers cavity and its release occurs at pH. Flow cytometry data showed that the carrier improves the penetration of doxorubicin into M-Hela cancer cell lines. The encapsulated doxorubicin demonstrates higher cytotoxicity towards the cancer cells

Interaction of bovine serum albumin with cationic imidazolium-containing amphiphiles bearing urethane fragment: Effect of hydrophobic tail length

© 2020 Complexation ability of homologous series of amphiphiles bearing imidazolium and urethane moieties (IAC-n, n = 14, 16, 18) toward bovine serum albumin (BSA) has been investigated by various physico-chemical methods (tensiometry, fluorescence spectroscopy, spectrophotometry, dynamic and electrophoretic light scattering, circular dichroism, and transmission electron microscopy). It has been revealed, that aggregation thresholds of systems based on IAC-n could be 5–8-fold reduced by BSA addition. Fluorescent analysis allows to estimate that binding of components is favorably mediated by tryptophan amino acid residues and is driven by different forces depending on the length of amphiphile hydrophobic tail. In particular, dominate contribution of Van der Waals interactions to the complexation has been shown in the case of IAC-14 and IAC-16, while hydrophobic interactions prevailed for IAC-18. It has been demonstrated that amphiphile addition causes reversible unfolding of protein macromolecules in all cases. Spectrophotometry assay exhibits that amphiphile/BSA complexes have more significant solubilization capacity toward hydrophobic guest in comparison with individual IAC-n systems

Photocatalytic properties of supramolecular nanoassociates based on gold and platinum nanoparticles, capped by amphiphilic calix[4]resorcinarenes, towards organic dyes

© 2020 Elsevier B.V. The synthesis of colloidal platinum nanoparticles (PtNPs) (dcore≈1-40 nm) in an aqueous solution was carried out using amido(dimethyl)amino- and carboxy- calix[4]resorcinarenes with alkyl substituents on the lower rim as stabilizer. The nanoparticles were characterized by spectrophotometry, IR, TEM, DLS, PXRD and SAXS. It was shown that PtNPs and gold nanoparticles (AuNPs) obtained, stabilized by calix[4]resorcinarenes, demonstrate the photocatalytic activity in the photodegradation of methyl orange and rhodamine B toxic dyes under visible light irradiation. The rate constants of catalytic reaction (K1, min−1) and activity of nanocatalysts (K2, min−1 mol−1) were calculated. It was found that size of metal core, structure of macrocycle stabilizing the surface of metal nanoparticles, its ability to form self-associates and bind dye molecules define the rate of dye photodegradation reaction. The study of the interaction of PtNPs and AuNPs capped with amidoamine macrocycles with organic photolinkers by spectrophotometry and fluorescence showed the binding of photolinkers by macrocycles, PtNPs and AuNPs. The photocatalytic activity of obtained cooperative nanoassociates was studied. The addition of photolinkers leads to both an increase and a decrease in the reaction rate, depending on the structure of linker and macrocycle. An increase in the reaction rate occurs due to the formation of photoactive supramolecular nanoassociates and the additional photosensitizing action of the photolinker on the surface of a metal nanoparticle. Such hybrid nanocatalysts based on metal nanoparticle and calixresorcinarenes have the potential to be used in the field of effective photodegradation of toxic water pollutants

Polymer and supramolecular nanocontainers based on carboxylate derivatives of resorcinarenes for binding of substrates and design of composites for catalysis

© 2020, Springer Science+Business Media LLC. The work describes the synthesis of supramolecular and polymer nanocontainers based on carboxylate resorcinarene derivatives. A comparative analysis of their inclusive characteristics toward hydrophilic and hydrophobic substrates was carried out. The obtained containers and silver nanoparticles were used to develop composite materials, and their catalytic activity in the reduction of {tip}-nitrophenol was examined. It was shown that polymer nanocontainers are more ef cient in binding organic substrates, while the supramolecular containers are more suitable for the design of catalytically active composites. The reduction of {tip}-nitrophenol in the presence of nanocomposites based on supramolecular containers proceeds with a higher rate and does not show an induction period

Cationic liposomes mediated transdermal delivery of meloxicam and ketoprofen: Optimization of the composition, in vitro and in vivo assessment of efficiency

New liposomes modified with pyrrolidinium surfactants containing a hydroxyethyl fragment (CnPB, n = 12, 14, 16) were prepared for transdermal delivery of non-steroidal anti-inflammatory drugs. In order to obtain the optimal composition, the surfactant/lipid molar ratio (0.02/1; 0.029/1; 0.04/1) and the amphiphile hydrocarbon tail length were varied. Rhodamine B was loaded in all formulations, while meloxicam and ketoprofen in selected ones. For liposomes studied the hydrodynamic diameter was in the range of 80–130 nm, the zeta potential ranged from +35 to +50 mV, EE was 75–99%. Liposome modification leads to a prolonged release of the rhodamine B (up to 10–12 h) and faster release of non-steroidal drugs (up to 7–8 h) in vitro. The ability to cross the skin barrier using Franz cells was investigated for liposomal meloxicam and ketoprofen. The total amount of meloxicam and ketoprofen passed through the Strat-M® membranes during 51 h was 51–114 μg/cm2 and 87–105 μg/cm2 respectively. The evaluation of transdermal diffusion ex vivo showed that total amount of liposomal ketoprofen passed through the skin during 51 h was 140–162 μg/cm2. Liposomes modified with C16PB were found as the most effective inflammation reducing formulation in the carrageenan edema model of rat paw

Single excited dual band luminescent hybrid carbon dots-terbium chelate nanothermometer

The report introduces hybrid polyelectrolyte-stabilized colloids combining blue and green-emitting building blocks, which are citrate carbon dots (CDs) and [TbL]+ chelate complexes with 1,3-diketonate derivatives of calix[4]arene. The joint incorporation of green and blue-emitting blocks into the polysodium polystyrenesulfonate (PSS) aggregates is carried out through the solvent-exchange synthetic technique. The coordinative binding between Tb3+ centers and CD surface groups in initial DMF solutions both facilitates joint incorporation of [TbL]+ complexes and the CDs into the PSS-based nanobeads and affects fluorescence properties of [TbL]+ complexes and CDs, as well as their ability for temperature sensing. The variation of the synthetic conditions is represented herein as a tool for tuning the fluorescent response of the blue and green-emitting blocks upon heating and cooling. The revealed regularities enable developing either dual-band luminescent colloids for monitoring temperature changes within 25–50 °C through double color emission or transforming the colloids into ratiometric temperature sensors via simple concentration variation of [TbL]+ and CDs in the initial DMF solution. Novel hybrid carbon dots-terbium chelate PSS-based nanoplatform opens an avenue for a new generation of sensitive and customizable single excited dualband nanothermometers