Thermoresponsive in situ forming and self-healing double-network hydrogels as injectable dressings for silymarin/levofloxacin delivery for treatment of third-degree burn wounds.

Our study aimed to introduce a novel double-cross-linked and thermoresponsive hydrogel with remarkable potential for accelerating third-degree burn wound healing. Burn injuries are recognized as challenging, critical wounds. Especially in third-degree burns, treatment is demanding due to extended wounds, irregular shapes, significant exudation, and intense pain during dressing changes. In this work, hydrogels made of zwitterionic chitosan and dialdehyde starch (ZCS and ZDAS) were created to deliver silymarine (SM) and levofloxacin (LEV). The hydrogels were effortlessly produced using dynamic Schiff base linkages and ionic interactions between ZCS and ZDAS at appropriate times. The pore uniformity, gel fraction, and commendable swelling properties can imply a suitable degree of Schiff base cross-link. The hydrogel demonstrated outstanding shape retention, and significant self-healing and flexibility abilities, enabling it to uphold its form even during bodily movements. After injecting biocompatible hydrogel on the wound, a notable acceleration in wound closure was observed on day 21 (98.1 ± 1.10 %) compared to the control group (75.1 ± 6.13 %), and histopathological analysis revealed a reduction of inflammation that can be linked to remarkable antioxidant and antibiotic properties. The results demonstrate the hydrogel's efficacy in promoting burn wound healing, making it a promising candidate for medical applications.

pH-Responsive Injectable Multifunctional Pluronic F127/Gelatin-Based Hydrogels with Hydrogen Production for Treating Diabetic Wounds.

Diabetic chronic wounds remain a major clinical challenge with long-term inflammatory responses and extreme oxidative damage. Hence, a pH-responsive injectable multifunctional hydrogel [Gel/CUR-FCHO/Mg (GCM) micromotors] via a Schiff base reaction between gelatin and benzaldehyde-grafted Pluronic F127 drug-loaded micelles (FCHO) was fabricated for the first time. Dynamic Schiff base linkage endowed the GCM hydrogel with the ability to be self-healing, injectable, and pH-responsive for on-demand drug delivery at the wound site. Curcumin (CUR), a hydrophobic drug with antioxidative, anti-inflammatory, and antibacterial activities, was encapsulated into the hydrogel matrix by micellization (CUR-FCHO micelles). Simultaneously, magnesium-based micromotors (Mg micromotors) were physically entrapped into the system for providing active hydrogen (H2) to scavenge reactive oxygen species and alleviate inflammatory responses. As a result, the GCM micromotor hydrogel displayed an inherent antibacterial property, extraordinary antioxidative performance, and remarkable biocompatibility. In the diabetic mouse with a full-thickness cutaneous defect wound, the GCM hydrogel could remodel the inflammatory microenvironment and stimulate vascularization and collagen deposition, thereby facilitating wound closure and enhancing tissue regeneration, which offered a promising therapeutic option for diabetic chronic wound management.

Loading of green-synthesized cu nanoparticles on Ag complex containing 1,3,5-triazine Schiff base with enhanced antimicrobial activities.

The physicochemical properties of materials change significantly in nanometer dimensions. Therefore, several methods have been proposed for the synthesis of nanoparticles. Plant extracts and essential oils are applied as natural and economic resources to prepare nanomaterials especially metal nanoparticles. In this project, a green, simple and efficient method has been designed for the synthesis of Cu nanoparticles using Purple cabbage extract as a reducing and stabilizing agent. They were successfully loaded onto a new Ag complex containing 1,3,5-triazine Schiff base as ligand to form Cu@Ag-CPX nanocomposite. Phytochemical contents of extract were identified by standard qualitative analyses. The chemical structure of all synthesized compounds was characterized using spectral data. In FT-IR, coordination of C=N bond of Schiff base ligand to Ag+ ions shifted the absorption band from 1641 to 1632 cm-1. The UV-Vis spectrum of Cu@Ag-CPX nanocomposite shown the peak related to Cu nanoparticles in the region of around 251 nm. 5:7 molar ratio of Cu to Ag in Cu@Ag-CPX was determined using ICP-OES. The FESEM, TEM, and DLS techniques provided valuable insights into the morphology and size distribution of the nanocomposite, revealing the presence of rods and monodispersed particles with specific diameter ranges. These analyses of the nanocomposite displayed rods with diameters from 40 to 62 nm as well as monodispersed and uniform particles with average diameter of 45 nm, respectively. The presence of elements including carbon, nitrogen, oxygen, Cu and Ag was proved by EDX-EDS analysis. The XRD pattern of Cu@Ag-CPX shown the diffraction peaks of Cu and Ag particles at 2θ values of 10°-80°, and confirmed its crystalline nature. The inhibitory properties of the synthesized compounds were evaluated in vitro against four Gram-negative and two Gram-positive bacteria, as well as two fungal strains. The MIC, MBC and MFC values obtained from microdilution and streak plate sensitivity tests were ranged from 128 to 4096 µg ml-1. While Cu nanoparticles and Ag complexes were effective against some pathogens, they were not effective against all them. However, the growth of all tested microbial strains was inhibited by Cu@Ag-CPX nanocomposite, and makes it as a new promising antimicrobial agent. Modification of nanocomposite in terms of nanoparticle and complex can improve its blocking activities.

Antimicrobial screening involving Helicobacter pylori of nano-therapeutic compounds based on the amoxicillin antibiotic drug.

Nano-structure Cu(II) complex [Cu(AMAB)2 ]Cl2 with Schiff base (AMAB) derived from the condensation between 4-(dimethylamino)benzaldehyde and amoxicillin trihydrate was prepared. (AMAB) Schiff base and its Cu(II) complex were identified and confirmed by different physicochemical techniques. The Schiff base (AMAB) was coordinated to copper ion through carbonyl oxygen and imine nitrogen donor sites. X-ray powder diffraction shows a cubic crystal system of the Cu(II) complex. The density functional theory was used to optimize the structure geometries of the investigated compounds. The molecular docking of the active amino acids of the investigated proteins' interactions with the tested compounds was evaluated. The bactericidal or bacteriostatic effect of the compounds was screened against some bacterial strains. The activity of Cu-chelate against Gram-negative bacteria was mainly more effective than its (AMAB) ligand and vice versa in the case of Gram-positive bacteria. The biological activity of the prepared compounds with biomolecules calf thymus DNA (CT-DNA) was determined by electronic absorption spectra and DNA gel electrophoresis technique. All studies revealed that the Cu-chelate derivative exhibited better binding affinity to both CT-DNA than the AMAB and amoxicillin itself. The anti-inflammatory effect of the designed compounds was determined by testing their protein denaturation inhibitory activity spectrophotometrically. All obtained data supported that the designed nano-Cu(II) complex with Schiff base (AMAB) is a potent bactericide against H. pylori, and exhibits anti-inflammatory activity. The dual inhibition effects of the designed compound represent a modern therapeutic approach with extended spectrum of action. Therefore, it can act as good drug target in antimicrobial and anti-inflammtory therapies. Finally, H. pylori resistance to amoxicillin is absent or rare in many countries, thus amoxicillin nanoparticles may be beneficial for countries where amoxicillin resistance is reported.

Novel pyrimidine Schiff bases and their selenium-containing nanoparticles as dual inhibitors of CDK1 and tubulin polymerase: design, synthesis, anti-proliferative evaluation, and molecular modelling.

Nanotechnology-based strategies can overcome the limitations of conventional cancer therapies. Hence, novel series of pyrimidine Schiff bases (4-9) were employed in the synthesis of selenium nanoparticle forms (4NPs-9NPs). All selenium nano-sized forms exerted greater inhibitions than normal-sized compounds, far exceeding 5-fluorouracil activity. Compound 4 showed effective anti-proliferative activity against MCF-7(IC50 3.14 ± 0.04 µM), HepG-2(IC50 1.07 ± 0.03 µM), and A549(IC50 1.53 ± 0.01 µM) cell lines, while its selenium nanoform 4NPs showed excellent inhibitory effects, with efficacy increased by 96.52%, 96.45%, and 93.86%, respectively. Additionally, 4NPs outperformed 4 in selectivity against the Vero cell line by 4.5-fold. Furthermore, 4NPs exhibited strong inhibition of CDK1(IC50 0.47 ± 0.3 µM) and tubulin polymerase(IC50 0.61 ± 0.04 µM), outperforming 4 and being comparable to roscovitine (IC50 0.27 ± 0.03 µM) and combretastatin-A4(IC50 0.25 ± 0.01 µM), respectively. Moreover, both 4 and 4NPs arrested the cell cycle at G0/G1 phase and significantly forced the cells towards apoptosis. Molecular docking demonstrated that 4 and 4NPs were able to inhibit CDK1 and tubulin polymerase binding sites.

Characterization and antivibrio activity of chitosan-citral Schiff base calcium complex for a calcium citrate sustained release antibacterial agent.

Vibrio parahemolyticus is the "Number one killer" of seafood products. Anti-vibrio agents having low cost and high-safety are urgently needed to supplement the application needs. This work attempted to prepare CS-CT-CCa complex with citral (CT), chitosan (CS) and calcium citrate (CCa) as raw material by microwave-assisted high-pressure homogenization. Additionally the coordination structure and morphology of Bridge-CS-CT-Schiff base/OH-CCa were verified. The prepared CS-CT-CCa had a well-dispersed property (the size: 3.55~9.33 µm and the zeta potential: +38.7~+67.5 mV) and an excellent sustained released ability (sustained release up to 180 min). MIC, Glucose assay, MDA assay, biofilm formation inhibition assay, SEM, swimming and swarming motility assay demonstrated that CS-CT-CCa had strong (MIC of 128 µg/mL) and sustained (more than 12 h) inhibitory effects against V. parahaemolyticus. Meanwhile, CS-CT-CCa could increase the membrane permeability of V. parahaemolyticus and inhibit their biofilm-forming ability in a dose-dependent manner. It could be inferred that the antibacterial activities against V. parahaemolyticus caused inhibition of biofilm formation, swimming and swarming motilities. This study provided necessary data for the further design and development of chitosan antibacterial agents, food and feed additives.

An effective uranium removal using diversified synthesized cross-linked chitosan bis-aldehyde Schiff base derivatives from aqueous solutions.

Three new cross-linked chitosan derivatives were yielded through intensification of chitosan with diverse types of bis-aldehydes. The prepared cross-linked chitosan was characterized by FTIR, 1H NMR, XRD, and TGA techniques. TGA indicated an improvement in thermal stability of the cross-linked chitosan compared with pure chitosan. Batch adsorption experiments showed that the three novel cross-linked chitosan bis-aldehyde derivatives possessed good adsorption capacity against U(VI) in the order of BFPA > BFB > BODB (adsorption capacity of the three adsorbents for U(VI) reaches 142, 124, and 114 mg/g respectively) and the adsorption isotherm and kinetic were well described by the Langmuir and the pseudo-second-order kinetic model, respectively. In addition, the prepared cross-linked chitosan bis-aldehyde derivatives were examined as U(VI) catcher from waste solutions.

Novel biocompatible and sensitive visual sensor based on aggregation-induced emission for on-site detection of radioactive uranium in water and live cell imaging.

In consideration of the severe hazards of radioactive uranium pollution, the rapid assessment of uranium in field and in vivo are urgently needed. In this work a novel biocompatible and sensitive visual fluorescent sensor based on aggregation-induced emission (AIE) was designed for onsite detection of UO22+ in complex environmental samples, including wastewater from Uranium Plant, river water and living cell. The AIE-active sensor (named as TPA-SP) was prepared with a "bottom-up" strategy by introducing a trianiline group (TPA) with a single-bond rotatable helix structure into the salicylaldehyde Schiff-base molecule. The photophysical properties, cytotoxicity test, recognition mechanism and the analytical performance for the detection of UO22+ in actual water samples and cell imaging were systematically investigated. TPA-SP exhibited high sensitivity and selectivity toward UO22+ as well as outstanding anti-interference ability against large equivalent of different ions in a wide effective pH range. A good linear relationship in the UO22+ concentration range of 0.05-1 µM was obtained with a low limit of detection (LOD) of 39.4 nM (9.38 ppb) for uranium detection. The prepared visual sensor showed great potential for fast risk assessment of uranium pollution in environmental systems. In addition, our results also indicated that the TPA-SP exhibited very low cytotoxicity in cells and demonstrated great potential for uranium detection in vivo.

The selective encapsulation and stabilization of cinnamaldehyde and eugenol in high internal phase Pickering emulsions: Regulating the interfacial properties.

This work aimed to investigate the encapsulation and stabilization mechanism of cinnamaldehyde and eugenol in high internal phase Pickering emulsions (HIPPEs) through regulating their interfacial rheological properties and interfacial microstructure. With the incorporation of cinnamaldehyde, the Schiff base reaction between the cinnamaldehyde and proteins favored the formation of the predominantly elastic and solid-like interfacial layers. In contrast, the hydrogen bonds between eugenol and proteins resulted in the transformation of interfacial layers to viscous dominant with weak viscoelastic responses. Thus, cinnamaldehyde-loaded HIPPEs had a better storage stability than eugenol-loaded HIPPEs, and the retention rate was increased by about 15 %∼20 %. The addition of tea camellia seed oil inhibited the mobility of immobilized water and improved the retention rates of cinnamaldehyde and eugenol by approximately 6 % and 12 % (30 days at 25 °C), respectively. These findings will be beneficial for the development and design of effective essential oil encapsulation systems in the food industry.

Antibacterial-renew dual-function anti-biofouling strategy: Self-assembled Schiff-base metal complex coatings built from natural products.

Marine biological fouling has caused huge economic losses and environmental problems. Therefore, it was essential to develop effectively environment-friendly biofouling resistance technology. Here, inspired by the natural module of bacterial secretions, animal and plant extracts, we synthesized Schiff based compounds through Tobramycin (TOB) from Streptomyces and Protocatechualdehyde (PR) from black fern. Furthermore, a dynamic self-renewal Schiff based metal composite coating- (Fe/TOB-PR)n was prepared via layer by layer self-assembly (LBL) method. It was proved to be a versatile coating, which could adhere to different types of substrates. Hydrolytic degradation tests showed that the degradation of the (Fe/TOB-PR)20 coating was regular and controlled. Moreover, compared with the blank glass substrate, the antibacterial rate of (Fe/TOB-PR)20 reached 97 % after 24 h, and the test further shows that the durability of the antibacterial performance benefits from the greater coating thickness. Such coatings displayed excellent anti-bacteria and anti-algae adhesion properties which was attributed to the renewal of the surface and the generation of antibacterial substance (TOB) in the coating. Further, the coating eventually degraded to natural micromolecule monomer, avoiding the occurrence of microplastics. It provides research ideas for fabricating environment-friendly anti-biofouling coatings.

Design, Synthesis, Characterization, Catalytic, Fluorometric Sensing, Antimicrobial and Antioxidant Activities of Schiff Base Ligand Capped AgNPs.

In recent days, the usage of biological and non-biological pollutants increased which poses a significant threat to environmental and biological systems. Therefore, the present aim is to develop effective methods to treat such pollutants by using highly stable and small-sized Schiff base ligand capped silver nanoparticles (AgNPs) with a face-centered cubic (fcc) crystalline structure and the size range is 5-10 nm. The potent role of the resulting synthesized AgNPs was found to be on multiple platforms such as catalyst, sensor, antioxidant, and antimicrobial disinfectant. The synthesized AgNPs were characterized through UV-vis spectroscopy, PL, FTIR, XRD, SEM, and TEM. The FTIR spectrum of AgNPs exhibited the interacted functional groups of Schiff base and size was estimated by XRD and TEM. AgNPs were able to catalytically degrade approximately 95% of methylene blue (MB), rhodamine B (RhB), and eosin Y (EY) dyes within 80 min of reaction time using NaBH4. The fluorometric sensor studies of synthesized AgNPs showed selective sensing of the potentially hazardous Fe2+ ion in water. As an antimicrobial agent, the AgNPs are effective against both Gram-positive and Gram-negative bacteria; as well as fungi, with the zones of clearance as approximately compatible with standard drugs. The AgNPs displayed a greater ability to scavenge free radicals, especially DPPH when compared with AgNPs and ascorbic acid. Thus, the results of this study validate the triple role of AgNPs derived via a simple synthesis as a catalyst, sensor, antioxidant, and antimicrobial agent for effective environmental remediation.

Synthesis and Investigation of the Analgesic Potential of Enantiomerically Pure Schiff Bases: A Mechanistic Approach.

Schiff bases are a class of organic compounds with azomethine moiety, exhibiting a wide range of biological potentials. In this research, six chiral Schiff bases, three 'S' series (H1−H3) and three 'R' series (H4−H6), were synthesized. The reaction was neat, which means without a solvent, and occurred at room temperature with a high product yield. The synthesized compounds were evaluated for analgesic potential in vivo at doses of 12.5 and 25 mg/kg using acetic-acid-induced writhing assay, formalin test, tail immersion and hot plate models, followed by investigating the possible involvement of opioid receptors. The compounds H2 and H3 significantly (*** p < 0.001) reduced the writhing frequency, and H3 and H5 significantly (*** p < 0.001) reduced pain in both phases of the formalin test. The compounds H2 and H5 significantly (*** p < 0.001) increased latency at 90 min in tail immersion, while H2 significantly (*** p < 0.001) increased latency at 90 min in the hot plate test. The 'S' series Schiff bases, H1−H3, were found more potent than the 'R' series compounds, H4−H6. The possible involvement of opioid receptors was also surveyed utilizing naloxone in tail immersion and hot plate models, investigating the involvement of opioid receptors. The synthesized compounds could be used as alternative analgesic agents subjected to further evaluation in other animal models to confirm the observed biological potential.

Royal jelly plus coenzyme Q10 supplementation improves high-intensity interval exercise performance via changes in plasmatic and salivary biomarkers of oxidative stress and muscle damage in swimmers: a randomized, double-blind, placebo-controlled pilot trial.

Background: Excessive production of free radicals caused by many types of exercise results in oxidative stress, which leads to muscle damage, fatigue, and impaired performance. Supplementation with royal jelly (RJ) or coenzyme Q10 (CoQ10) has been shown to attenuate exercise-induced oxidant stress in damaged muscle and improve various aspects of exercise performance in many but not all studies. Nevertheless, the effects of treatments based on RJ plus CoQ10 supplementation, which may be potentially beneficial for reducing oxidative stress and enhancing athletic performance, remain unexplored. This study aimed to examine whether oral RJ and CoQ10 co-supplementation could improve high-intensity interval exercise (HIIE) performance in swimmers, inhibiting exercise-induced oxidative stress and muscle damage. Methods: Twenty high-level swimmers were randomly allocated to receive either 400 mg of RJ and 60 mg of CoQ10 (RJQ) or matching placebo (PLA) once daily for 10 days. Exercise performance was evaluated at baseline, and then reassessed at day 10 of intervention, using a HIIE protocol. Diene conjugates (DC), Schiff bases (SB), and creatine kinase (CK) were also measured in blood plasma and saliva before and immediately after HIIE in both groups. Results: HIIE performance expressed as number of points according to a single assessment system developed and approved by the International Swimming Federation (FINA points) significantly improved in RJQ group (p = 0.013) compared to PLA group. Exercise-induced increase in DC, SB, and CK levels in plasma and saliva significantly diminished only in RJQ group (p < 0.05). Regression analysis showed that oral RJQ administration for 10 days was significantly associated with reductions in HIIE-induced increases in plasmatic and salivary DC, SB, and CK levels compared to PLA. Principal component analysis revealed that swimmers treated with RJQ are grouped by both plasmatic and salivary principal components (PC) into a separate cluster compared to PLA. Strong negative correlation between the number of FINA points and plasmatic and salivary PC1 values was observed in both intervention groups. Conclusion: The improvements in swimmers' HIIE performance were due in significant part to RJQ-induced reducing in lipid peroxidation and muscle damage in response to exercise. These findings suggest that RJQ supplementation for 10 days is potentially effective for enhancing HIIE performance and alleviating oxidant stress. Abbreviations: RJ, royal jelly; CoQ10, coenzyme Q10; HIIE, high-intensity interval exercise; DC, diene conjugates; SB, Schiff bases; CK, creatine kinase; RJQ, royal jelly plus coenzyme Q10; PLA, placebo; FINA points, points according to a single assessment system developed and approved by the International Swimming Federation; ROS, reactive oxygen species; 10H2DA, 10-hydroxy-2-decenoic acid; AMPK, 5'-AMP-activated protein kinase; FoxO3, forkhead box O3; MnSOD, manganese-superoxide dismutase; CAT, catalase; E, optical densities; PCA, principal component analysis; PC, principal component; MCFAs, medium-chain fatty acids; CaMKKß, Ca2+/calmodulin-dependent protein kinase ß; TBARS, thiobarbituric acid reactive substances; MDA, malondialdehyde.

Magnetic covalent-organic frameworks-based extraction followed by UHPLC-MS/MS for determination and pharmacokinetic study of trace angoroside C in rat plasma after oral administration of Xuanbo Shuangsheng Granule.

The composition of the traditional Chinese medicine compound preparation is complex, while the content of each active ingredient is extremely low, which brings difficulties to the plasma concentration detection. In this study, the magnetic covalent-organic frameworks were synthesized by a simple one-step Schiff base reaction and applied for the specific extraction of trace angoroside C in rat plasma prior to ultra-high-performance liquid chromatography-tandem mass spectrometry detection. The synthesized magnetic covalent-organic frameworks have high magnetic responsiveness (35.67 emu·g-1 ), large surface area (110.9 m2 ·g-1 ), and strong stability. The as-prepared material can quickly extract angoroside C from plasma with high extraction efficiency, be easily separated with a magnet afterward, and can be reused for at least five times. The established method was systematically validated showing good linearity (0.1-5 ng·ml-1 ), low limit of quantification (0.1 ng·ml-1 ), good accuracy (93.18-105.36%), and good precision (percentage relative standard deviation 3.60-10.90%). Finally, the method was used to the pharmacokinetic study of trace angoroside C in rats after oral administration of Xuanbo Shuangsheng Granule.

A diselenium-bridged covalent organic framework with pH/GSH/photo-triple-responsiveness for highly controlled drug release toward joint chemo/photothermal/chemodynamic cancer therapy.

Here, a novel joint chemo/photothermal/chemodynamic therapy was developed using a pH/GSH/photo triple-responsive 2D-covalent organic framework (COF) drug carriers for passive target treatment of tumors with extraordinarily high efficiency. The well-designed COF (DiSe-Por) with simultaneous dynamic diselenium and imine bonds, synthesized by the copolymerization of 4,4'-diselanediyldibenzaldehyde (DiSe) with 5,10,15,20-(tetra-4-aminophenyl)-porphyrin (Por) via Schiff base chemistry, which was applied as the host for effective encapsulation and highly controlled release of anticancer drug (DOX), was stable under normal physiological settings and can effectively accumulate in tumor sites. After being internalized into the tumor cells, the unique microenvironment i.e., acidic pH and overexpressed GSH, triggered substantial degradation of DiSe-Por-DOX, promoting DOX release to kill the cancer cells. Meanwhile, the breaking of Se-Se bonds boosted the generation of intracellular ROS, disturbing the redox balance of tumor cells. The highly extended 2D structure endowed the drug delivery system with significant photothermal performance. The rise of temperature with external laser irradiation (808 nm) further promoted drug release. Additionally, the phototherapy effect was further augmented after the loading of DOX, guaranteeing an almost complete drug release to tumor tissue. As a result, the triple-responsive drug delivery system achieved a synergistic amplified therapeutic efficacy with a growth inhibitory rate of approximately 93.5% for the tumor xenografted in nude mice. Moreover, the body metabolizable and clearable DiSe-Por-DOX presented negligible toxicities toward major organs in vivo. All these characteristics verified the great potential of DiSe-Por-DOX nanosheets for multi-modality tumor treatment, accelerating the application range of COFs in biomedical fields.

Exploitation of a rod-shaped, acid-labile curcumin-loaded polymeric nanogel system in the treatment of systemic inflammation.

Curcumin is proven to have potent anti-inflammatory activity, but its low water solubility and rapid degradation in physiological conditions limit its clinical use, particularly in intravenous drug delivery. In this study, we fabricated rod-shaped, acid-labile nanogels, using high biosafe and biocompatible polymers, for intravenous application in systemic inflammation treatment. The constituent polymers of the nanogels were prepared via the conjugation of vitamin B6 derivatives, including pyridoxal and pyridoxamine, onto poly(glutamate) with ester bonds. The aldehyde groups of the pyridoxal and amine groups of the pyridoxamine on the polymers enable crosslinking using a Schiff base during the solvent evaporation procedure for the preparation of the rod-shaped nanogels. Our study is the first to introduce this linkage, which is generated from two vitamin B6 derivatives into a nanogel system. It is also the first to fabricate a rod-shaped nanogel system via simple solvent evaporation. Under acidic conditions, such as those encountered in the endosomes and lysosomes within inflammatory macrophage cells spread in the whole body, imine bonds are cleaved and release payloads. The nanogel polymers were successfully synthesized and characterized, and the formation and disappearance of the Schiff base under neutral and acidic conditions were also confirmed using Fourier transform infrared spectroscopy. Following curcumin encapsulation, the long, rod-shaped nanogels were able to rapidly internalize into macrophage cells in static or adhere to cells under the flows, release their payloads in the acid milieus, and, thus, mitigate curcumin degradation. Consequently, curcumin-loaded, rod-shaped nanogels displayed exceptional anti-inflammatory activity both in vitro and in vivo, by efficiently inhibiting pro-inflammatory mediator secretion. These results demonstrate the feasibility of our acid-labile, rod-shaped nanogels for the treatment of systemic inflammation.

New Acetamidine Cu(II) Schiff base complex supported on magnetic nanoparticles pectin for the synthesis of triazoles using click chemistry.

In this project, the new catalyst copper defines as Fe3O4@Pectin@(CH2)3-Acetamide-Cu(II) was successfully manufactured and fully characterized by different techniques, including FT-IR, XRD, TEM, FESEM, EDX, VSM, TGA, and ICP analysis. All results showed that copper was successfully supported on the polymer-coated magnetic nanoparticles. One of the most important properties of a catalyst is the ability to be prepared from simple materials such as pectin that's a biopolymer that is widely found in nature. The catalytic activity of Fe3O4@Pectin@(CH2)3-Acetamide-Cu(II) was examined in a classical, one pot, and the three-component reaction of terminal alkynes, alkyl halides, and sodium azide in water and observed, proceeding smoothly and completed in good yields and high regioselectivity. The critical potential interests of the present method include high yields, recyclability of catalyst, easy workup, using an eco-friendly solvent, and the ability to sustain a variety of functional groups, which give economical as well as ecological rewards. The capability of the nanocomposite was compared with previous works, and the nanocomposite was found more efficient, economical, and reproducible. Also, the catalyst can be easily removed from the reaction solution using an external magnet and reused for five runs without reduction in catalyst activity.

Preparation and characterization of vanillin-chitosan Schiff base zinc complex for a novel Zn2+ sustained released system.

In this work, a novel sustained released system (VCSB-Zn(II)) for zinc supplements was built by vanillin-chitosan Schiff base (VCSB) chelated with Zn2+ to improve the zinc trace element utilization ratio. Samples were characterized by FT-IR, 1H NMR, XRD, SEM, and TGA. The results showed that VCSB exhibited a more excellent chelation capacity of Zn2+ than chitosan. The chelation capacity of VCSB was about 1.7 times more than that of chitosan, corresponding to 50.96 mg/g and 29.91 mg/g, respectively. Furthermore, VCSB-Zn(II) showed excellent sustained released performance at simulated gastric fluid because of the acid slow-dissolving ability. And the higher the CN content of VCSB, the higher the cumulative release rate (Ri) of Zn2+, the highest Ri reached 77.81%. The sustained released curves were described by the first-order and Korsmeyer-Peppas equation, which described the Zn2+ sustained released performance caused by the dissolution of VCSB-Zn(II) and Fick diffusion. This Zn2+ sustained released system shows great potential in the application in the field of trace elements supplements for animals.

Development of Chromium(III) Selective Potentiometric Sensors for Its Determination in Petroleum Water Samples Using Synthesized Nano Schiff Base Complex as an Ionophore.

BACKGROUND: Many analytical techniques, such as X-ray fluorescence spectrometry, inductively coupled plasma-atomic emission spectrometry, and even traditional spectroscopic and fluorimetric methods, are used for the measurement of Cr(III) ions. These methods are sophisticated and very expensive, so the cheapest and low-cost ion selective electrodes were used. OBJECTIVE: The quantification of Cr(III) ions in various samples of petroleum water using ion selective electrodes was suggested. Nano chromium modified carbon paste sensor (MCPE) and nano chromium modified screen printed sensor (MSPE) based on Schiff base Cr(III) complex are developed. METHOD: The developed nano Cr(III) Schiff base chelate was characterized using elemental, spectroscopic, and thermal analysis techniques. The proposed nano Cr(III) has good properties for antibacterial and antifungal activity. The modified carbon paste and screen-printed sensors were fabricated for determination of Cr(III) ion. RESULTS: The proposed MCPE (sensor I) and MSPE (sensor II) obeys Nernstian equation upon incorporating nano Cr(III) ionophore in the paste at 25°C with a trivalent cationic slope of 18.8 ± 0.2 and 20.0 ± 0.4 mV/decade. They have showed fast response time around 8 and 5 s, and they may be used for at least 98 and 240 days without significant changes in MCPE and MSPE potential, respectively. The sensors I and II showed good selectivity for Cr(III) ion toward a wide variety of metal ions or anions as confirmed by potentiometric selectivity coefficients values. The detection and quantification limits were defined alongside the other process validation parameters. The results have been compared well to those obtained by atomic absorption spectrometry (AAS), and the data of F- and t-test indicated no significant difference between the proposed and AAS methods. CONCLUSIONS: These sensors have been used to determine Cr(III) ions in genuine spiked different petroleum well water samples with satisfactory percentage recoveries, low standard, and relative standard deviation values using direct potentiometric and standard addition methods. The proposed method of producing nano Cr(III) complex as a sensor material possesses the distinct advantages of being simple, easily reproducible, appropriate for operation, and highly selective and sensitive. HIGHLIGHTS: Modified carbon paste and screen-printed electrodes were fabricated based on nano Cr(III) complex as ionophore. The electrodes follow Nernstian behavior, and they optimized according to IUPAC recommendation. They showed a high selectivity for Cr(III) ion over many bi- or trivalent metal ions and anions. The results obtained compared well with those obtained using AAS. They successfully applied for determination of Cr(III) in petroleum water samples.

Determination of antimicrobial and antimutagenic properties of some Schiff bases.

In this study, we aimed to investigate for the first time antimicrobial and antimutagenic activities new two Schiff bases, obtained from a primary amine (p-toluidine, o-toluidine) and an aldehyde (Helicin). Synthesized compounds characterized with elemental analysis, fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry. 1H-13C nuclear magnetic resonance spectroscopy. Antimutagenic activity was evaluated by micronuclei assay. Antimicrobial activity of Schiff bases have been demonstrated against pathogenic four Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermis, Micrococcus luteus, Bacillus cereus) and four Gram-negative bacteria (Pseudumonas aeroginosa, Salmonella typhi H, Brucella abortus, Escherichia coli) and two yeasts (Candida albicans and Saccharomyces cerevisiae). The results showed that both Schiff bases have antimutagenic activity. Especially, high concentration (20 µM) of (E)-2-(hydroxymethyl)-6-(2-((p-tolylimino)methyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol (Compound I) and (E)-2-(hydroxymethyl)-6-(2-((o-tolylimino)methyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol (Compound II) have strong antimutagenic activity against aflatoxin B1. On the other hand, both of studied compounds were found effective against pathogenic bacteria and yeasts. Compound I exhibited more activity against P. aeroginosa, S aureus, S.typhi H and C. albicans comparable to Compound II and standard antibiotics. Additionally, Compound II showed better inhibitory activity than Compound I against Candida albicans and Br. Abortus. Therefore, these compounds can be used in phytotherapeutic due to theirs antimutagenic and antimicrobial activities.