Sodium Salicylate Research Articles

Thalamo-cortical neural mechanism of sodium salicylate-induced hyperacusis and anxiety-like behaviors

Tinnitus has been identified as a potential contributor to anxiety. Thalamo-cortical pathway plays a crucial role in the transmission of auditory and emotional information, but its casual link to tinnitus-associated anxiety remains unclear. In this study, we explore the neural activities in the thalamus and cortex of the sodium salicylate (NaSal)-treated mice, which exhibit both hyperacusis and anxiety-like behaviors. We find an increase in gamma band oscillations (GBO) in both auditory cortex (AC) and prefrontal cortex (PFC), as well as phase-locking between cortical GBO and thalamic neural activity. These changes are attributable to a suppression of GABAergic neuron activity in thalamic reticular nucleus (TRN), and optogenetic activation of TRN reduces NaSal-induced hyperacusis and anxiety-like behaviors. The elevation of endocannabinoid (eCB)/ cannabinoid receptor 1 (CB1R) transmission in TRN contributes to the NaSal-induced abnormalities. Our results highlight the regulative role of TRN in the auditory and limbic thalamic-cortical pathways.

Exploring the effects of naringenin on cell functioning and energy synthesis in the hippocampus of male Wistar rats with chronic tinnitus, by examining genetic indicators such as Bax, Bcl-2, Tfam, and Pgc-1α

BackgroundThe pivotal factors, including neural plasticity, oxidative stress, neuronal inflammation, and apoptosis, play a significant role in the pathogenesis of tinnitus. The balance between Bax/Bcl-2 genes is an important factor in determining the rate of apoptosis. Pgc-1α and Tfam genes are fundamental regulators of mitochondrial biogenesis. Naringenin possesses significant antioxidant, neuroprotective, anti-inflammatory, anti-apoptotic, and antiviral properties, and its compounds are effective on cell signaling pathways. AimsIn light of the aforementioned information, we endeavored to evaluate the impact of naringenin on the expression levels of Bax, Bcl-2, Pgc-1α, and Tfam genes in the hippocampus of male Wistar rats with chronic tinnitus. Material and MethodsTo demonstrate the existence of tinnitus, all rats were instructed to complete an “active avoidance test” utilizing a conditioning box. The expression levels of genes mentioned above were assessed using real-time PCR. ResultsThe sodium salicylate at a dosage of 350 mg/kg showed an upregulation in the expression level of Bax and a downregulation in the expression level of the Bcl-2 gene (p < 0.001). Furthermore, the sodium salicylate displayed significantly higher expression levels of Tfam and Pgc-1α (p < 0.001) genes. The naringenin, at a dose of 100 mg/kg, led to a decrease in Bax gene expression (p < 0.05) and an increase in Bcl-2 gene expression (p < 0.05). On the other hand, naringenin restored the expression level of both Tfam (p < 0.001) and Pgc-1α (p < 0.01) genes. ConclusionsOur research findings demonstrate that sodium salicylate-induced tinnitus leads to enhanced apoptosis and mitochondrial biogenesis within the hippocampus. Additionally, our evidence recommends that naringenin can reduce apoptosis effectively and maintain a balanced mitochondrial state.

Strategy of Constructing Ratio-Dependent Coordination Polymer probes and Their Film Application with a Smart Phone for Detection of Lomefloxacin Hydrochloride and Sodium Salicylate.

Lomefloxacin hydrochloride (LMFX) and sodium salicylate (SS) are important targets for real-time detection due to their widespread uses in daily life; accurate and portable monitoring of LMFX and SS is crucial for human health concerns accordingly. Developing a precise and smart platform for determination of the above analytes remains a significant challenge. Herein, a high-sensitivity platform incorporating a luminescence electrospinning film, self-designed smart-phone app, and portable 3D printing device has been developed to identify LMFX and SS. In this work, two heterometallic coordination polymers with two-dimensional layer structures have been synthesized based on 2,2'-oxidiacetic acid ligand (H2oda), namely, [LnPb(oda)2(CH3COO)]n [Ln = Eu (IMU-1); Tb (IMU-2)]. IMU-1 and IMU-2 were ratio-dependent luminescence probes, which could selectively and sensitively sense with LMFX and SS, respectively. Additionally, the synthesized electrospinning films incorporating IMU-1 and IMU-2 were employed to identify LMFX and SS. Both films could rapidly photograph and color-capture through a portable 3D printing device, along with a self-designed smart-phone app that enabled convenient and quick determination of the concentrations of the above analytes. Remarkably, the mechanism exploration indicated that electron transfer from ligands to analytes affected the antenna effect and further utilized the intrinsic luminescence of analytes along with the luminescence quenching of Ln3+ ions. Furthermore, a strategy for constructing ratio-based fluorescent probes by exploiting the luminescence of analytes and Ln3+ ions in host coordination polymers is proposed. This work provides a new insight by combining luminescence probes, portable devices, and a smart-phone app for real-time detection of drugs and food additives.

Study of the proton transfer during acidification of sodium salicylate based on ReaxFF molecular dynamics simulation

Salicylic acid(SA) is known for its pain-relieving and fever-reducing abilities and has a very broad range of applications, being an important ingredient in a wide variety of products such as pharmaceuticals, skin care products, agrochemicals, dyes, colorants, preservatives, and more. SA is mainly synthesized by the Kolbe-Schmitt method in industrial production, but there is still no standardized description of the mechanism of this reaction. The Kolbe-Schmitt reaction mechanism is divided into three steps, and the reaction mechanism of the first two steps has been fully investigated, while the reaction mechanism of Sodium salicylate (SS) acidification, as the last step in the synthesis of SA by the Kolbe-Schmitt process, has not been investigated, so we used the Reactive force-field molecular dynamics simulation (ReaxFF MD) method to simulate and reveal the reaction mechanism of the mixed solution of SS and sulfuric acid, followed by an orthogonal design to explore the effects of different factors on the yield of SA. Through the investigation, it was found that the reaction of SS with sulfuric acid mixed solution was divided into the following four stages in total: hydration reaction, proton transfer reaction, association reaction and dissociation reaction, respectively. It is concluded that the SA yield in SS acidification reaction is affected by the factors in the following order: concentration > pressure > time > temperature, where concentration and pressure significantly affect the SA yield. It is hoped that the present study can supplement the relevant understanding of the reaction mechanism of the Kolbe-Schmitt process, and at the same time have some practical significance and application value for the improvement and optimization of the synthetic SA process.

Amelioration Potency of a Nano-Therapeutic Drug in Rats with Uninephrectomy and Cisplatin-induced Toxicity

While physicians describe drugs to treat diseases, these medications may have cytotoxic effects on certain organs, necessitating the use of some drugs to ameliorate such adverse effects. The study was conducted to investigate the protective behavior of nanoemulsified sodium salicylate on uninephrectomized rats injected with cisplatin to induce nephrotoxicity. Fifty adult male albino rats, aged five weeks and weighing approximately 100-120 g, were divided into five groups. The first group received 200 mg/kg/day i.p normal saline for 30 days. The second group was administrated 200 mg/kg/day of nanoemulsified salt of salicylic acid for 30 days. The third group, comprising uninephrectomized rats, was injected with two doses of cisplatin (20 mg/kg body weight) on alternate days from the start of the experiment to induce nephrotoxicity. The fourth group, also uninephrectomized, received 200 mg/kg/day i.p of nanoemulsified sodium salicylate for 30 days. The fifth group, uninephrectomized and treated with 200 mg/kg/day sodium salicylate nanoemlusion for 21 days, was subsequently injected with two doses of cisplatin, followed by continued nanoemulsified sodium salicylate treatment until day 30 from the start of the study. The results showed a significant increase in tissue inhibitor metalloproteinase 1 (TIMP-1), Hyaluronic acid (HA), malondialdehyde, kidney injury molecule -1(KIM-1), and nitric oxide in the nephrotoxic group injected with cisplatin compared to the control group. Additionally, there was an elevation in the mRNA expression of nephrotoxic group with uninephrectomy. However, nephrotoxic rats treated with nanoemulsified sodium salicylate exhibited only a modest increase in TIMP-1, HA, and KIM-1 levels, along with elevated expressions of podocin and nephrin compared to the healthy control group. These findings suggest that nanoemulsified sodium salicylate exerts a protective effect against cisplatin-induced nephrotoxicity in uninephrectomized.

Temperature-dependent physicochemical studies of sodium salicylate in aqueous solutions of ionic liquids {[BMIm]Br and [EMIm]Cl}

The current study explores the impact of two different imidazolium based ionic liquids, having diverse side chains and anions: 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) and 1‑butyl‑3-methylimidazolium bromide ([BMIm]Br) on the thermodynamic and transport properties of sodium salicylate. This inquiry examines the sodium salicylate's density, sound velocity, and viscosity within aqueous solutions of these ionic liquids across a temperature range of 283.15 K to 313.15 K at atmospheric pressure. Various parameters, including apparent molar volume (Vϕ), limiting apparent molar volume (Voϕ), transfer volume (ΔtrV∘ϕ), limiting apparent molar expansibility (E∘∅), Hepler's constant, apparent molar isentropic compression (Kϕ,s), limiting apparent molar isentropic compression (K∘ϕ,s), transfer parameter of isentropic compression (ΔtrK∘ϕ,S), and viscosity B-coefficient, were computed from experimental values. Additionally, we have analyzed the trends in computed parameters, considering the interactions between `solute and solvent along with solute-solute interactions in the systems under investigation. Our results suggest a predominance of hydrophilic-hydrophilic and ion-hydrophilic interactions within studied systems. The observed magnitudes of these parameters affirm a stronger interaction between sodium salicylate and [BMIm]Br in comparison to those with [EMIm]Cl.

Photobiomodulation with near-infrared laser for tinnitus management: preliminary animal experiments and randomized clinical trials.

This study investigates the effectiveness of photobiomodulation therapy (PBMT) in treating chronic high-frequency tinnitus with the TINI device, a near-infrared (830nm) laser. The study includes preliminary animal experiments with 28 mice and a randomized controlled trial with 56 participants to examine the functional and molecular changes in the auditory system that PBMT may cause. The animal model used sodium salicylate to induce tinnitus, followed by PBMT, which showed promising reductions in the behavioral evidence of tinnitus and a reversal of tinnitus-associated upregulation of vesicular glutamate transporters 2 expression in the ipsilateral dorsal cochlear nucleus (p < 0.05). In the clinical trial, participants with chronic high-frequency tinnitus received trans-tympanic application of the TINI device. The results did not show a significant difference in tinnitus score at the final time point when compared to the sham group. However, questionnaires revealed significant improvements in tinnitus symptoms and psychological outcomes following treatment with the TINI device compared to before treatment (p < 0.05). These findings suggest that while PBMT has potential benefits, its clinical effectiveness may be unclear due to its complex nature and interaction with other conditions. Further research is required to optimize treatment parameters and gain a complete understanding of the therapeutic potential of PBMT in managing tinnitus.

Sodium salicylate as a green fluorescent probe for ultrasensitive determination of vonoprazan fumarate via fluorescence switch off strategy; greenness assessment

A green, simple and sensitive spectrofluorometric approach for determining vonoprazan fumarate in bulk and pharmaceutical dosage form by turning off the fluorescence of sodium salicylate is developed. The addition of vonoprazan fumarate reduced linearly the fluorescence intensity of 0.4 mM sodium salicylate at λem 408 nm and at λex 330 nm. The approach was found to be linear in the 50.0–3000.0 ng/mL range. The limits of detection and quantification were 10.97 and 33.23 ng/mL, respectively. The presented method proved its suitability in determination of vonoprazan fumarate in its pure and pharmaceutical dosage form. This method employs water as the exclusive solvent and utilizes safe reagents, evaluated using the Analytical Eco Scale, Green Analytical Procedure Index (GAPI), and carbon footprint. In contrast, previous methods relied on toxic reagents and required extended heating times, resulting in higher environmental impact. The novel method not only enhances analytical efficiency but also aligns with green chemistry principles, offering a sustainable solution for routine pharmaceutical analysis.

Effect of concentration and wavelength of excitation on the photophysics of salicylate anion in acetonitrile and water

Sodium salicylate (NaSA) molecule exists as salicylate anion in acetonitrile (ACN) and water solvents, and exhibits large Stokes shifted fluorescence due to excited state intramolecular proton transfer (ESIPT), with decay times of ∼5 ns in ACN and ∼3.9 ns in water by 300 nm (absorption maxima) excitation. Previous studies report both ground and excited state enol-keto tautomerization in ACN, but only excited state tautomerization in water at 10−4 M. However, the current work explores the effect of concentration and excitation wavelengths on the photoinduced dynamics of ESIPT in the salicylate anion. On increasing the concentration of NaSA, no change in absorption spectra appears in both the solvents, and emission spectra of NaSA in water remain unaffected by changes in concentration or excitation wavelength, whereas, a slight red shift and decrease in FWHM appears in ACN. Time-domain fluorescence measurements show predominantly single-exponential decay throughout the emission profile by 300 nm excitation above the 10−5 M concentration in both the solvents, while by 375 nm excitation, multi-exponential fluorescence decay is observed at low concentrations, and as the concentration of NaSA increases, this decay behaviour tends to converge towards a single exponential decay. These results suggest that solute–solvent interactions stabilize the ground-state intermolecular hydrogen-bonded species at low concentrations, while higher concentrations weaken these interactions, leading to emission solely from the salicylate anion. Peak fit analysis of excitation spectra confirms enol-keto tautomerization in both the solvents, with the keto form being more stabilized in ACN. These findings underscore that in ACN, behaviour of NaSA is influenced by both concentration and excitation wavelength and contrary to previous reports, the keto form of the molecule is also present in water, though at a very low concentration and an increase in non-radiative transitions in water cause fluorescence quenching.

Small Organic Molecule‐Assisted Mesoscopic Self‐Assembly of SnO2 Nanoparticles: An Efficient Catalyst for the Synthesis of β‐Nitroaldol

AbstractOver the past few decades, huge number of mesoporous materials have been synthesized by using supramolecular assembly of ionic/non‐ionic surfactants as structure‐directing agents (SDAs). Here, we report a facile synthetic strategy to fabricate self‐assembled SnO2 nanoparticles with well‐defined nanocrystalline spherical morphology and mesoporosity using sodium salicylate as a SDA and stabilizing agent. The mesophases of the materials were investigated by powder X‐ray diffraction, TEM and N2 sorption studies. TEM results show that the mesopores are formed by the assembly of ultrasmall SnO2 NPs with broad range of interparticle voids and N2 sorption studies agreed well with this TEM data. This synthesis strategy facilitated the generation of SnO2 NPs with increased surface area and pores of nanoscale dimensions with a large number of exposed surface‐active sites. The photoinduced electron transfer in these materials was investigated by the fluorescence quenching study with pyranine, which suggested the presence of surface Lewis basicity. The materials showed excellent catalytic activity for the synthesis of β‐nitroaldol through the reaction of benzaldehyde and nitromethane. The heterogeneous nature of the catalyst could be attributed to the high surface area, presence of numerous surface active sites, and structural robustness of the self‐assembled SnO2 nanostructure. The catalysts exhibited negligible loss in activity after several catalytic cycles.

Micellization, interaction forces and physicochemical parameters of tetradecyltrimethylammonium bromide in aqueous solution of crystal violet dye: Assessment of the influences of temperature, electrolytes and hydrotrope

The present study explores the interactions between tetradecyltrimethylammonium bromide (TTAB) and crystal violet (CV) dye in aq. Na-based electrolytes (NaCl, NaOAc, Na2SO4) and hydrotrope (sodium salicylate (NaSal)) media using conductometric technique. Physicochemical parameters (critical micelle concentration (CMC), degree of counter ion binding (β)) and thermodynamic variables (ΔGmo, ΔHmo, and ΔSmo)) were estimated. The CMC values of the study system were reduced with the increase of the concentrations of three Na-salts and the CMC values increased with the content of NaSal while the values increased with the escalation temperature. The spontaneous micellization of the TTAB+CV mixture was characterized by negative ΔGmo values. The ΔHmo and ΔSmo values expose the existence of hydrophobic interaction between TTAB and CV dye in aq. medium while these values connote the presence of electrostatic interaction along with hydrophobic interaction in aq. salts and NaSal media. Moreover, the molar heat capacity (ΔCm0), the thermodynamic of transfer (ΔGm,tr0, ΔHm,tr0 and ΔSm,tr0) and enthalpy–entropy compensation parameters for TTAB+CV mixture were estimated and analyzed with proper reasoning. The findings contribute to a deeper understanding of the interaction dynamics between TTAB and CV dye in aq. solutions of salts and NaSal environments, providing valuable insights for applications in relevant fields.

Identifying tinnitus in mice by tracking the motion of body markers in response to an acoustic startle.

Rodent models of tinnitus are commonly used to study its mechanisms and potential treatments. Tinnitus can be identified by changes in the gap-induced prepulse inhibition of the acoustic startle (GPIAS), most commonly by using pressure detectors to measure the whole-body startle (WBS). Unfortunately, the WBS habituates quickly, the measuring system can introduce mechanical oscillations and the response shows considerable variability. We have instead used a motion tracking system to measure the localized motion of small reflective markers in response to an acoustic startle reflex in guinea pigs and mice. For guinea pigs, the pinna had the largest responses both in terms of displacement between pairs of markers and in terms of the speed of the reflex movement. Smaller, but still reliable responses were observed with markers on the thorax, abdomen and back. The peak speed of the pinna reflex was the most sensitive measure for calculating GPIAS in the guinea pig. Recording the pinna reflex in mice proved impractical due to removal of the markers during grooming. However, recordings from their back and tail allowed us to measure the peak speed and the twitch amplitude (area under curve) of reflex responses and both analysis methods showed robust GPIAS. When mice were administered high doses of sodium salicylate, which induces tinnitus in humans, there was a significant reduction in GPIAS, consistent with the presence of tinnitus. Thus, measurement of the peak speed or twitch amplitude of pinna, back and tail markers provides a reliable assessment of tinnitus in rodents.

In vitro Ascertainment of Interactions between Kanamycin and Adjuvants against Various Bacterial Species

Background: In recent times, there has been incontrovertible evidence regarding the propensity of various bacteria that barge through the immune system of an already debilitated individual. In this regard, combination therapy presents us with a more effective approach than conventional monotherapy. A specific combination of antibiotics exhibits a synergistic antibacterial effect, which can be seen with kanamycin, which shows moderate antibacterial activity alone but acts synergistically with particular adjuvants, displaying a high degree of antibacterial activity Objective: This study aimed to carry out an in vitro evaluation of the interaction between kanamycin and adjuvants against various bacterial species. Methods: The interaction between kanamycin and adjuvants against various bacterial isolates was determined by checkerboard assay, and the synergistic interactions were further evaluated by time-kill kinetic assay under in vitro settings. Results: The interaction between kanamycin and citric acid was found to be synergistic against all strains of E. coli. Both kanamycin and citric reduced their MICs by at least 4 fold in combination. This synergistic interaction was further confirmed by the time-kill kinetic assay. The result of time kill kinetic assay of combination revealed that at MIC, there was a 2.36 log10 CFU/ml reduction compared to kanamycin (the most active antimicrobial agent alone), at 24 hours at 2 fold MIC, 2.41 log10 CFU/ml reduction was seen in comparison to kanamycin at 24 hours at its one fold MIC. For other bacterial species, the combination of citric acid and kanamycin showed additive or indifferent interactions. In the case of our second combination (kanamycin and sodium salicylate), all the bacterial species displayed additive and indifferent interaction. Conclusion: It has been concluded that the combination of kanamycin and citric acid (adjuvant) demonstrated a remarkable synergistic interaction against E. coli.

Deoxycholic acid inducing chronic atrophic gastritis with colonic mucosal lesion correlated to mucosal immune dysfunction in rats

The present study aimed to explore the underlying mechanism of bile reflux-inducing chronic atrophic gastritis (CAG) with colonic mucosal lesion. The rat model of CAG with colonic mucosal lesion was induced by free-drinking 20 mmol/L sodium deoxycholate to simulate bile reflux and 2% cold sodium salicylate for 12 weeks. In comparison to the control group, the model rats had increased abundances of Bacteroidetes and Firmicutes but had decreased abundances of Proteobacteria and Fusobacterium. Several gut bacteria with bile acids transformation ability were enriched in the model group, such as Blautia, Phascolarctobacter, and Enterococcus. The cytotoxic deoxycholic acid and lithocholic acid were significantly increased in the model group. Transcriptome analysis of colonic tissues presented that the down-regulated genes enriched in T cell receptor signaling pathway, antigen processing and presentation, Th17 cell differentiation, Th1 and Th2 cell differentiation, and intestinal immune network for IgA production in the model group. These results suggest that bile reflux-inducing CAG with colonic mucosal lesion accompanied by gut dysbacteriosis, mucosal immunocompromise, and increased gene expressions related to repair of intestinal mucosal injury.

One-Pot Synthesis of Silicon Quantum Dots-Based Fluorescent Nanomaterial and Its Application.

Conventionally obtained silicon quantum dots (Si QDs) generally suffer from the disadvantages of a cumbersome preparation process, large fluctuation in the quality of Si QDs, poor water solubility, and aggregation-caused quenching (ACQ) phenomenon. Here we report a facile one-pot strategy to synthesize a novel Si QDs-based fluorescent nanomaterial in which Si QDs are confined into dendritic mesoporous silica, named as SiQDs@DMSNs. The prepared SiQDs@DMSNs, with adjustable particle sizes ranging from 140 to 300 nm, emit blue fluorescence around 410 nm upon excitation by ultraviolet light at a wavelength of 300 nm. It is found that the addition of sodium salicylate (NaSAL) plays a crucial role in the in situ generation of Si QDs. The obtained SiQDs@DMSNs exhibit excellent fluorescence intensity, water solubility, and stability, facilitating easy surface modification, without being limited by the ACQ phenomenon. It is expected to be widely used in many fields such as biosensors, nanomedicines, in vivo imaging, fingerprint identification, and anticounterfeiting labels.

Beneficial effect of metformin on tolerance to analgesic effects of sodium salicylate in male rats.

Tolerance to the analgesic effects of opioids and non-steroidal anti-inflammatory drugs (NSAIDs) is a major concern for relieving pain. Thus, it is highly valuable to find new pharmacological strategies for prolonged therapeutic procedures. Biguanide-type drugs such as metformin (MET) are effective for neuroprotection and can be beneficial for addressing opioid tolerance in the treatment of chronic pain. It has been proposed that analgesic tolerance to NSAIDs is mediated by the endogenous opioid system. According to the cross-tolerance between NSAIDs, especially sodium salicylate (SS), and opiates, especially morphine, the objective of this study was to investigate whether MET administration can reduce tolerance to the anti-nociceptive effects of SS. Fifty-six male Wistar rats were used in this research (weight 200-250 g). For induction of tolerance, SS (300 mg/kg) was injected intraperitoneally for 7 days. During the examination period, animals received MET at doses of 50, 75, or 100 mg/kg for 7 days to evaluate the development of tolerance to the analgesic effect of SS. The hot plate test was used to evaluate the drugs' anti-nociceptive properties. Salicylate injection significantly increased hot plate latency as compared to the control group, but the total analgesic effect of co-treatment with SS + Met50 was stronger than the SS group. Furthermore, the effect of this combination undergoes less analgesic tolerance over time. It can be concluded that MET can reduce the analgesic tolerance that is induced by repeated intraperitoneal injections of SS in Wister rats.

Enhancement of aqueous solubility of hesperidin and naringenin utilizing hydrotropic solubilization technique: characterization and in vitro evaluation

The therapeutic potential of two important flavonoids, i.e. hesperidin and naringenin, remains unutilized due to pharmacokinetics issues, especially poor aqueous solubility. Hydrotropic solid dispersions with different agents like sodium salicylate, niacinamide, benzoic acid, and urea etc. can change the solubility profile of poorly soluble drugs. The current study investigated the potential of different hydrotropic agents in improving the solubility of both natural bioactives. The hydrotropic solid dispersion in 1:3 w/w drug: sodium salicylate ratio showed maximum solubility and dissolution amongst all the tested hydrotropes. This novel and economical approach could be explored for other poorly soluble pharmaceuticals.

Corrosion protection and antibacterial performance of a chitosan/salicylate coating electrogenerated on a magnesium alloy

In this work, chitosan and chitosan/salicylate coatings were prepared by EPD on AZ91D Mg alloy to improve the corrosion resistance of the substrate in a simulated physiological solution. The effect of two concentrations of salicylate on the morphology and anticorrosive behaviour of the coatings was evaluated. The results showed that the addition of 0.50 g/L sodium salicylate to the chitosan formulation decreased the corrosion rate of the chitosan coating from 0.0025 ± 0.0003 to 0.0007 ± 0.0004 mA cm−2. From the results of electrochemical impedance spectroscopy (EIS) and Fourier Transform Infrared (FTIR) analysis, it can be concluded that the presence of salicylate in the coating leads to a self-healing effect that contributes to an improved corrosion protection. In addition, the presence of salicylate in the coating has been shown to increase antibacterial activity against both Gram-positive and Gram-negative bacteria. It has been demonstrated that salicylate can be released from the coating, which has an anti-inflammatory effect. In this way, a novel chitosan/salicylate coating was developed for the first time on a Mg alloy for bactericidal effect, release of salicylate and corrosion protection in simulated physiological solution. So far, chitosan and salicylate have not been investigated as a combination for the development of multifunctional coatings on Mg alloys. In addition, the self-healing effect of salicylate ions in a chitosan coating was established for the first time.

Fabrication, encapsulation and controlled release of multilayer capsule based on thermosensitivity and host‐guest interaction

AbstractAs an efficient means of material carrying, multilayer capsules are widely used in medicine, agriculture, food safety and other fields. Here, we report a kind of temperature‐triggered multilayer capsule with chitosan‐sodium dodecyl benzene sulfonate (CS‐SDBS) as the shell and gelatin bead containing α‐cyclodextrin (α‐CD@gelatin) as the core. The α‐CD@gelatin/CS‐SDBS multilayer capsules can simultaneously encapsulate various substances, such as drugs, fluorescent materials, and nanoparticles. The encapsulated substances do not interfere with each other because they are located in different layers. Both the temperature‐sensitive property of gelatin and the host‐guest interaction between α‐CD and SDBS are utilized to achieve temperature‐controlled release of substances in the multilayer capsules. The release rate can be adjusted by the α‐CD amount in the gelatin beads. The controlled drug release and chemical detection of the multilayer capsules are studied with sodium salicylate, iodine, and purple cabbage pigment as the carriers. The results show that the α‐CD@gelatin/CS‐SDBS multilayer capsules have excellent capabilities of encapsulation and controlled release, which are beneficial for their application in the fields of substance encapsulation, drug‐controlled release, and chemical detection.

Phase separation, aggregation, and complexation of triton-X100 and bovine serum albumin mixture: A combined cloud point and UV–visible spectroscopic approaches

Phase separation and aggregation behaviour of triton X-100 (TX-100) and bovine serum albumin (BSA) mixture were investigated using cloud point and UV–visible spectroscopic techniques. The effects of various hydrotropes (HYTs) - namely, sodium salicylate (SS), sodium benzoate (SB), glycerol (Glyc), and 4-aminobenzoic acid (4-ABA) - on the cloud point (CP) of TX-100 + BSA were determined. The obtained CP values for the mixed system in the presence of HYTs followed the order:CPH2O+4−ABA<CPH2O+Glyc<CPH2O+SB<CPH2O+SS. The measured critical micellization concentration (CMC) values of the TX-100 + BSA mixture were found to be significantly altered with varying amounts of BSA. The calculated free energy of clouding and micellization indicated the non-spontaneous nature of the phase transition and the spontaneous association of the TX-100 + BSA mixture. The non-spontaneity of phase separation decreased with increasing concentrations of HYTs. The enumerated values of ∆Hco and ∆Sco were consistently recorded as negative and positive magnitudes, respectively, in all aqueous HYTs media. The clouding process occurred due to a combination of hydrophobic and electrostatic interactions. The binding constant of the mixed system was determined employing the UV–vis spectroscopic method using the Benesi-Hildebrand equation.