Characterizing the nanomechanical properties of microcomedones after treatment with sodium salicylate ex vivo using atomic force microscopy.

OBJECTIVE: The treatment of acne presents a major clinical and dermatological challenge. Investigating the nanomechanical properties of the microcomedone precursor lesions using atomic force microscopy (AFM) may prove beneficial in understanding their softening, dissolution and prevention. Although the exact biochemical mechanism of NaSal on microcomedones is not fully understood at present, it appears to exhibit a significant exfoliation effect on the skin via corneodesmosome dissolution. METHODS: Therefore, to support this exploration, sodium salicylate (NaSal), a common ingredient employed in skin care products, is applied ex vivo to microcomedones,collected by nose strip adhesive tape, and their nanomechanical properties are assessed using AFM. Although the exact biochemical mechanism of NaSal on microcomedones is not fully understood at present, it appears to exhibit a significant exfoliation effect on the skin via corneodesmosome dissolution. RESULTS: Herein, our findings demonstrate that when microcomedones are treated with 2% NaSal, samples appeared significantly more compliant ('softer') ((1.3 ± 0.62) MPa) when compared to their pre-treated measurements ((7.2 ± 3.6) MPa; p = 0.038). Furthermore, elastic modulus maps showed that after 2% NaSal treatment, areas in the microcomedone appeared softer and swollen in some, but not in all areas, further proving the valuable impact of 2% NaSal solution in altering the biomechanical properties and morphologies in microcomedones. CONCLUSION: Our results are the first of their kind to provide qualitative and quantitative mechanobiological evidence that 2% NaSal decreases the elastic modulus of microcomedones. Therefore, this study provides evidence that NaSal can be beneficial as an active ingredient in topical treatments aimed at targeting microcomedones.

OBJECTIF: Le traitement de l'acné présente un défi clinique et dermatologique majeur. L'étude des propriétés nanomécaniques des lésions précurseurs en tant que microcomédons à l'aide de la microscopie à force atomique (AFM) peut s'avérer bénéfique pour comprendre leur ramollissement, leur dissolution et leur prévention. MÉTHODES: Par conséquent, pour soutenir cette exploration, le salicylate de sodium (NaSal), un ingrédient couramment utilisé dans les produits de soins de la peau, est appliqué ex vivo aux microcomédons et leurs propriétés nanomécaniques sont évaluées à l'aide de l'AFM. Bien que le mécanisme biochimique exact du NaSal sur les microcomédons ne soit pas entièrement compris à l'heure actuelle, il semble présenter un effet exfoliant significatif sur la peau via la dissolution des cornéodesmosomes. RÉSULTATS: Ici, nos résultats démontrent que lorsque les microcomédons sont traités avec 2% de NaSal, les échantillons semblaient significativement plus conformes ("plus doux") ((1.3 ± 0.62) MPa) par rapport à leurs mesures pré-traitées ((7.2 ± 3.6) MPa ; P = 0,03826). De plus, les cartes du module d'élasticité ont montré qu'après un traitement à 2 % de NaSal, les zones du microcomédon semblaient plus molles et gonflées dans certaines zones, mais pas dans toutes, prouvant ainsi l'impact précieux d'une solution de NaSal à 2 % dans la modification des propriétés biomécaniques et de la morphologie des microcomédons. CONCLUSION: Nos résultats sont les premiers du genre à fournir des preuves mécanobiologiques qualitatives et quantitatives que 2% de NaSal diminue le module d'élasticité des microcomédons. Par conséquent, cette étude fournit des preuves que NaSal peut être bénéfique en tant qu'ingrédient actif dans les traitements topiques visant à cibler les microcomédons.

Revealing 3D structure of gluten in wheat dough by optical clearing imaging.

Gluten, which makes up 85% of endosperm wheat protein, is considered a crucial quality determinant of wheat-based food products. During wheat dough manufacture, the molecular packing of gluten causes formation of large structures that exceed the millimetre scale. However, due to lack of imaging techniques for complex systems composed of giant macromolecules, the entire gluten structure remains unknown. Here, we develop an optical clearing reagent (termed SoROCS) that makes wheat-based products transparent. Combined with two-photon microscopy, we image the three-dimensional (3D) structure of gluten at the size in the millimetre scale and at submicron resolution. Further, we demonstrate how the 3D structure of gluten dramatically changes from a honeycomb-shaped network to sparse large clumps in wheat noodles, depending on the salt added during dough making, thereby reducing stress when compressing the noodle. Moreover, we show that SoROCS can be used for noodle imaging using confocal laser scanning microscopy.

Wireless, battery-free and wearable device for electrically controlled drug delivery: sodium salicylate released from bilayer polypyrrole by near-field communication on smartphone.

Compared with traditional drug delivery methods, transdermal drug delivery has many advantages in avoiding the side effects in gastrointestinal tract, reducing the fluctuations in drug concentration, and improving patients' compliance. Among them, electrically controlled drug delivery is a promising solution. This work presents a wireless, battery-free and wearable device with electrically controlled drug delivery capability. The electronic component of the device is a flexible circuit board with a temperature sensor and a near-field communication module. With the help of smartphone, the device could wirelessly obtain energy and implement data transmission. The drug delivery component is a paper-based electrode modified with polypyrrole, in which non-steroidal anti-inflammatory drug sodium salicylate was encapsulated. The applied potential for electrically controlled drug delivery was more negative than -0.6 V. The drug release dose and release rates could be controlled by applying potentials with different amplitudes and durations through this device. It provided a minimalized wearable transdermal drug delivery platform for monitoring diseases such as gout. This wearable device shows promising potential in develop closed-loop drug delivery and monitoring systems for the treatment of various diseases.

Encapsulation of graphene quantum dot-crosslinked chitosan by carboxymethylcellulose hydrogel beads as a pH-responsive bio-nanocomposite for the oral delivery agent.

Oral delivery most commonly used due to the non-invasive nature and the fact that avoids patient pain and discomfort in compression with the intravenous administration. Herein, the obtained graphene quantum dots (GQDs) from citric acid were employed as a cross-linker for chitosan (CS). Sodium salicylate (SS) as a model drug was loaded in the prepared graphene quantum dots-crosslinked chitosan hybrid bio-nanocomposite beads (CS-GQD). SS-loaded CS-GQD (CS-GQD/SS) was protected with pH-sensitive biopolymeric carboxymethylcellulose (CMC) hydrogel beads. The CMC encapsulated CS-GQD/SS bio-nanocomposite hydrogel beads (CS-GQD/SS@CMC) were characterized using FT-IR, PL and SEM analysis. For determination of surficial charge of the carrier, pH point of zero charges (pHpzc) was measured. In-vitro drug delivery tests were carried out in simulating the gastrointestinal tract conditions for proving the efficiency of the prepared beads as a controlled oral drug delivery. The synergistic effects of CMC and CS enhanced the stability of drug dosing for a long time with controlling the drug releases in the gastrointestinal tract conditions. The MTT test confirmed that the bio-nanocomposite beads have low toxicity against human colon adenocarcinoma HT29 cells. The obtained results showed that the prepared novel CS-GQD/SS@CMC could potentially be used as a safe carrier for oral drug delivery.

Gelatinized-core liposomes: Toward a more robust carrier for hydrophilic molecules.

The use of liposomes as a delivery system for hydrophobic and hydrophilic drugs is well recognized. However, they possess several limitations that remained unresolved, including stability problems, low entrapment of the hydrophilic drugs, and the subsequent rapid release. This study introduces a novel approach to incorporate gelatin in the liposomal core to overcome these limitations. A rheological study was conducted to select suitable masses of the gelatin used in the liposomal formulations. Moreover, a full-factorial experimental design was utilized to compare the newly produced gel-core liposomes to the conventional liposomes with respect to the amount of a model hydrophilic molecule loading. An advanced machine learning method, namely, artificial neural networks was utilized to capture the effects of gelatin and cholesterol incorporation in the liposomes on the entrapment efficiency. The results revealed the successful preparation of the novel vesicles and their superiority over the conventional liposomes in drug loading, sustaining the drug release and stability which pose the newly introduced liposomal system as a successful delivery carrier for hydrophilic molecules and drugs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3086-3092, 2017.

Preparation of a stable aqueous suspension of reduced graphene oxide by a green method for applications in biomaterials.

A green approach for the preparation of a stable reduced graphene oxide (RGO) suspension from graphene oxide (GO) has been developed. This method uses l-serine (l-Ser) as the reductant and yellow dextrin (YD) as the stabilizing agent. X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction and thermogravimetric analyses showed that l-Ser can efficiently reduce GO at a comparatively low temperature, and that the YD adsorbed onto the RGO facilitating the formation of a stable RGO aqueous suspension. Since l-Ser and YD are natural environmentally friendly materials, this approach provides a green method to produce stable RGO from GO on a large scale. Sodium salicylate (SS) which has an aromatic structure was loaded onto the RGO through π-π interactions and a maximum loading capacity of 44.6mg/g was obtained. The release of the loaded SS can be controlled by adjusting the solution pH, and a 74.8% release was reached after 70h at pH 7.4. The release profile of SS could be further controlled by incorporating it into RGO Dispersed carboxylated chitosan films.

MgAl- Layered Double Hydroxide Nanoparticles for controlled release of Salicylate.

Layered double hydroxides (LDHs), have been known for many decades as catalyst and ceramic precursors, traps for anionic pollutants, and additives for polymers. Recently, their successful synthesis on the nanometer scale opened up a whole new field for their application in nanomedicine. Here we report the efficacy of Mg1-xAlx (NO3)x (OH)2 LDH nanoparticles as a carrier and for controlled release of one of the non-steroidal anti-inflammatory drugs (NSAID), sodium salicylate. Mg1-xAlx (NO3)x (OH)2.nH2O nanoparticles were synthesized using co-precipitation method from an aqueous solution of Mg(NO3)2.6H2O and Al(NO3)3.9H2O. Salicylate was intercalated in the interlayer space of Mg-Al LDH after suspending nanoparticles in 0.0025(M) HNO3 and 0.75 (M) NaNO3 solution and using anion exchange method under N2 atmosphere. The shift in the basal planes like (003) and (006) to lower 2θ value in the XRD plot of intercalated sample confirmed the increase in basal spacing in LDH because of intercalation of salicylate into the interlayer space of LDH. FTIR spectroscopy of SA-LDH nano hybrid revealed a red shift in the frequency band of carboxylate group in salicylate indicating an electrostatic interaction between cationic LDH sheet and anionic drug. Differential thermal analysis of LDH-SA nanohybrid indicated higher thermal stability of salicylate in the intercalated form into LDH as compared to its free state. DLS studies showed a particle size distribution between 30-60 nm for pristine LDH whereas salicylate intercalated LDH exhibited a particle size distribution between 40-80nm which is ideal for its efficacy as a superior carrier for drugs and biomolecules. The cumulative release kinetic of salicylate from MgAl-LDH-SA hybrids in phosphate buffer saline (PBS) at pH7.4 showed a sustained release of salicylate up to 72h that closely resembled first order release kinetics through a combination of drug diffusion and dissolution of LDH under physiological conditions. Also the cytotoxicity tests performed revealed the less toxic nature of the nanohybrid as compared to the bare SA drug.

Salicylic acid analogues as chemical exchange saturation transfer MRI contrast agents for the assessment of brain perfusion territory and blood-brain barrier opening after intra-arterial infusion.

The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Predicted, focal opening of the BBB through intra-arterial infusion of hyperosmolar mannitol is feasible, but there is a need to facilitate imaging techniques (e.g. MRI) to guide interventional procedures and assess the outcomes. Here, we show that salicylic acid analogues (SAA) can depict the brain territory supplied by the catheter and detect the BBB opening, through chemical exchange saturation transfer (CEST) MRI. Hyperosmolar SAA solutions themselves are also capable of opening the BBB, and, when multiple SAA agents were co-injected, their locoregional perfusion could be differentiated.

Silver deposition on polypyrrole films electrosynthesised onto Nitinol alloy. Corrosion protection and antibacterial activity.

The electrosynthesis of polypyrrole films onto Nitinol from sodium salicylate solutions of different concentrations is reported. The morphology and corrosion protection properties of the resulting coatings were examined and they both depend on the sodium salicylate concentration. The immobilisation of silver species in PPy films constituted by hollow rectangular microtubes was studied as a function of the polymer oxidation degree. The highest amount of silver was deposited when the coated electrode was prepolarised at -1.00V (SCE) before silver deposition, suggesting an increase in the amount of non-oxidised segments in the polymer. Finally, the antibacterial activity of the coating against the Gram positive Staphylococcus aureus and Staphylococcus epidermidis bacteria was evaluated. Both strains resulted sensitive to the modified coatings, obtaining a slightly better result against S. aureus.

Decreasing the toxicity of paraquat through the complexation with sodium salicylate: Stoichiometric analysis.

Over the last decades, paraquat (1,1'-dimethyl-4,4'-bipyridilium dichloride; PQ) has been involved in numerous fatalities especially attributed to suicide attempts. Previously, it was shown that salicylates, namely sodium salicylate (NaSAL) and lysine acetylsalicylate (LAS) may form complexes with PQ, which may contribute to prevent its toxicity. The direct chemical reactivity between PQ and NaSAL was previously studied by liquid chromatography/electrospray ionization/mass spectrometry/mass spectrometry, showing the formation of complexes, though reported data was not fully conclusive. In the present study, the structure of the complex of PQ with NaSAL is fully characterized by crystallography. It was observed that PQ is complexed with 4 NaSAL molecules. Since formulations containing PQ and salicylates have been proposed, these results point that the stoichiometry of 1:4 (PQ:salicylates) should be considered to optimize prevention of PQ-mediated toxic effects.

Effect of sodium salicylate and sodium deoxycholate on fibrillation of bovine serum albumin: comparison of fluorescence, SANS and DLS techniques.

The impact of biocompatible additives on the fibrillation and defibrillation of proteins provides valuable insight into the development of suitable formulations for the treatment of protein-related diseases or the storage of proteins in the laboratory. We have studied the effects of the addition of sodium deoxycholate (NaDC) and sodium salicylate (NaSal) on the fibrillation of bovine serum albumin (BSA) using fluorescence, circular dichroism, dynamic light scattering (DLS) and small angle neutron scattering (SANS). Spectroscopic studies indicate that the additives are adsorbed on the surfaces of proteins and change their secondary structures, irrespective of the sequence of addition. DLS and SANS studies show that the addition of either NaSal or NaDC to native proteins slows down or arrests the formation of fibrils. However, the additives do not defibrillate preformed fibrils when added after fibril formation. Thus, NaSal and NaDC can act as potential adjuvants for the prevention of fibril formation in BSA solutions.

Polyethylenimine-grafted cellulose nanofibril aerogels as versatile vehicles for drug delivery.

Aerogels from polyethylenimine-grafted cellulose nanofibrils (CNFs-PEI) were developed for the first time as a novel drug delivery system. The morphology and structure of the CNFs before and after chemical modification were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Water-soluble sodium salicylate (NaSA) was used as a model drug for the investigation of drug loading and release performance. The CNFs-PEI aerogels exhibited a high drug loading capability (287.39 mg/g), and the drug adsorption process could be well described by Langmuir isotherm and pseudo-second-order kinetics models. Drug release experiments demonstrated a sustained and controlled release behavior of the aerogels highly dependent on pH and temperature. This process followed quite well the pseudo-second-order release kinetics. Owing to the unique pH- and temperature-responsiveness together with their excellent biodegradability and biocompatibility, the CNFs-PEI aerogels were very promising as a new generation of controlled drug delivery carriers, offering simple and safe alternatives to the conventional systems from synthetic polymers.

Determination of vitamin B6 using an optimized novel TCPO-indolizine-H2O2 chemiluminescence system.

Indolizine derivatives are of great interest as fluorescent emitters for peroxyoxalate chemiluminescence. The reaction of peroxyoxalates such as bis-(2,4,6-trichlorophenyl) oxalate (TCPO) with H2O2 can transfer energy to fluorescer via the formation of dioxetanedione intermediate. Four indolizine derivatives were used as a novel fluorescer in the chemiluminescence (CL) systems in this study. The relationship between CL intensity and the concentration of fluorescer, peroxyoxalate, sodium salicylate and hydrogen peroxide was investigated. Optimum conditions were obtained for four fluorescers and it was found that the indolizine can be used as an efficient green fluorescence emitter. Vitamin B6 induces a sharp decrease in the CL intensity of the TCPO-hydrogen peroxide-sodium salicylate system. A simple, rapid and sensitive CL method for the determination of vitamin B6 has been developed. The results showed a linear relationship between vitamin B6 concentration and peroxyoxalate CL intensity in the range 7.0 × 10(-8) -1.0 × 10(-4) . A detection limit of 2.3 × 10(-8) M and relative standard deviation (RSD) of < 4.5% were obtained.

Structural determinants of the catalytic inhibition of human topoisomerase IIα by salicylate analogs and salicylate-based drugs.

We previously identified salicylate as a novel catalytic inhibitor of human DNA topoisomerase II (topo II; EC 5.99.1.3) that preferentially targets the alpha isoform by interfering with topo II-mediated DNA cleavage. Many pharmaceuticals and compounds found in foods are salicylate-based. We have now investigated whether these are also catalytic inhibitors of topo II and the structural determinants modulating these effects. We have determined that a number of hydroxylated benzoic acids attenuate doxorubicin-induced DNA damage signaling mediated by the ATM protein kinase and inhibit topo II decatenation activity in vitro with varying potencies. Based on the chemical structures of these and other derivatives, we identified unique properties influencing topo II inhibition, including the importance of substitutions at the 2'- and 5'-positions. We extended our findings to a number of salicylate-based pharmaceuticals including sulfasalazine and diflunisal and found that both were effective at attenuating doxorubicin-induced DNA damage signaling, topo II DNA decatenation and they blocked stabilization of doxorubicin-induced topo II cleavable complexes in cells. In a manner similar to salicylate, we determined that these agents inhibit topo II-mediated DNA cleavage. This was accompanied by a concomitant decrease in topo II-mediated ATP-hydrolysis. Taken together, these findings reveal a novel function for the broader class of salicylate-related compounds and highlight the need for additional studies into whether they may impact the efficacy of chemotherapy regimens that include topo II poisons.

Evaluation of a sieve classification method for characterization of low-dose interactive mixtures.

This study investigated a sieve classification method for evaluating carrier materials and particle size fractions, which could be a valuable tool in the early development of pharmaceutical dosage forms containing low-dose interactive mixtures. When developing new products based on interactive mixtures, it is essential to ensure that the drug particles are successfully deagglomerated and have adhered to the carrier particles. In this study, the effect on the demixing potential (DP) of low-dose interactive mixtures was assessed for various carrier particle sizes and surface textures. The model drug used was sodium salicylate and the tested carriers were lactose, mannitol, and isomalt. The results showed that the lowest DPs, i.e. the most mechanically stable mixtures, were obtained with lactose. Furthermore, for interactive mixtures, small carrier particles and/or a narrow carrier particle size range are essential for obtaining a low DP and high homogeneity. Calculation of the DP provided a reliable estimate of the quality of the low-dose interactive mixtures used in this study.

Transcutaneous immunization system using a hydrotropic formulation induces a potent antigen-specific antibody response.

BACKGROUND: Transcutaneous immunization (TCI) is a novel vaccination strategy, which is expected to have therapeutic applications. However, to develop effective TCI systems, a simple, non-invasive and safe transdermal formulation is required. This study developed a novel TCI system utilizing the co-administration of a liposoluble absorption enhancer, propylene glycol monocaprylate (PGMC) and hydrosoluble protein antigen without pretreatment of any typical adjuvants and disruption of the skin. Novel transdermal formulations were also prepared with sodium salicylate (NaSal) as a hydrotropic agent to improve the solubility of poorly water-soluble substances. METHODOLOGY/PRINCIPAL FINDINGS: The TCI system, which used a transdermal formulation containing hen lysozyme (HEL) and PGMC, solubilized with NaSal, resulted in a substantial HEL-specific antibody response in an HEL dose-dependent manner even in the absence of potent adjuvants, such as cholera toxin (CT). We also investigated whether NaSal activates antigen-presenting cells in vitro to clarify the mechanisms of antibody production by the hydrotropic formulation. NaSal enhanced the expression of MHC class II molecules and increased the production of IL-12 and TNF-α in dendritic cells, which were stimulated by lipopolysaccharide in vitro, indicating that NaSal had an effective adjuvant-like property. Moreover, the use of NaSal in the TCI system did not induce an HEL-specific, IgE-dependent anaphylactic reaction. CONCLUSION/SIGNIFICANCE: Our TCI system using a hydrotropic formulation effectively and safely induced the intended immune response, and this system thus represents a new advantageous method that will result in improved TCI strategies.

Failure of film formation of viscoelastic fluid: dynamics of viscoelastic fluid in a partially filled horizontally rotating cylinder.

The dynamics of a viscoelastic Maxwell fluid is studied in a partially filled cylinder rotating around a horizontal axis. At low rotational velocity, the fluid behaves in the same manner as a viscous fluid. A thin fluid film is pulled up from the edge of a fluid bump at the bottom of the cylinder, and it covers the inner wall of the cylinder completely. As a result, a steady state is the coexistence of the film and the bump of the fluid. When the rotational velocity of the cylinder is increased, the film formation fails and the bump of fluid rolls steadily at the bottom of the cylinder. This failure of film formation has never been observed in the case of a viscous fluid. At higher rotational velocity, the bump of the fluid starts to oscillate at the bottom of the cylinder. Then, the fluid bump again rolls steadily with a further increase in the rotational velocity. The failure of film formation is explained in terms of the elastic behavior of the viscoelastic fluid near the boundary between the film and the bump regions. The theoretical prediction shows good agreement with the experimental results. We further estimate the condition for which a viscoelastic fluid displays dynamically nonwetting behavior; i.e., the absence of fluid film at any value of rotational velocity.

Chemiluminescence characteristics of furan derivatives as blue fluorescers in peroxyoxalate-hydrogen peroxide system.

Furan derivatives (synthesized and purified in organic laboratories) are a great interest as fluorescent emitters for peroxyoxalate chemiluminescence. Reaction of peroxyoxalates such as bis-(2,4,6-trichloro-phenyl) oxalate with H(2)O(2) can transfer energy to fluorophore via formation of dioxetanedione intermediate. Furan derivatives used as a novel fluorescer in this study which produces a blue light in the chemiluminescence systems. The relationship between the chemiluminescence intensity and concentrations of TCPO, sodium salicylate, hydrogen peroxide and the fluorescer has been investigated. The linear ranges for Furan derivatives were 0.25-5 × 10(-4) M and 0.1-5 × 10(-4) M (A and B compounds, respectively). Kinetic parameters for the peroxyoxalate-chemiluminescence were also calculated from the computer fitting of the corresponding chemiluminescence intensity/time profiles.

Self-assembled mesoporous γ-Al2O3 spherical nanoparticles and their efficiency for the removal of arsenic from water.

We report a highly efficient synthetic strategy for self-assembled mesoporous γ-Al(2)O(3) materials using sodium salicylate as template. The mesoporous γ-Al(2)O(3) samples synthesized following this strategy have high surface areas (231-497 m(2)g(-1)), consist of crystalline tiny spherical nanoparticles of dimensions ca. 2-10nm and showed high affinity for the adsorption of arsenic from the contaminated aqueous solutions. Efficient synthesis strategy, exceptionally high surface area and high adsorption efficiency of these mesoporous γ-Al(2)O(3) materials for the dissolved arsenic from the contaminated aqueous solutions (in the form of oxyanions of arsenic) could find potential utility in the purification of polluted water.

Poly(amidoamine) dendronized hollow fiber membranes: synthesis, characterization, and preliminary applications as drug delivery devices.

Poly(amidoamine) (PAMAM) dendrons were prepared from hollow fiber membranes (HFM) consisting of bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) in a stepwise manner. The prepared HFM were characterized by Fourier transform infrared spectroscopy, elemental analysis, and scanning electron microscopy. The drug loading efficiency and release behavior of the PAMAM dendronized HFM were evaluated using sodium salicylate, sodium methotrexate, and Congo red as model drugs. The results suggest that PAMAM dendronized HFM can be effectively loaded with a variety of drugs and prolong the release of these drugs. The drug loading and release characteristics of the HFM depend on the generation of PAMAM dendrons grafted on the membranes. The prepared PAMAM dendronized BPPO HFM are promising scaffolds in drug delivery and tissue engineering.