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The carbon nanorings, possessing a radial π system, have garnered significant attention primarily due to their size‐dependent photophysical properties and the presence of a unique curved π‐conjugated cavity. This is evidenced by the rapid proliferation of publications. Furthermore, the integration of building blocks into CPP skeletons can confer [n]CPPs with novel and exceptional photophysical and electronic characteristics, as well as chiral properties and host‐guest interactions, thereby augmenting the diversity of [n]CPPs. Notably, the curved π surface structures and concave cavity of carbon nanorings enable them to host aromatic or non‐aromatic guests with a complementarily curved surface, resulting in interesting binary or ternary complexes. This review provides a comprehensive treatment of literature reports on binary and ternary complexes, focusing on both their host‐guest interactions and properties. It is important to note that the scope of this review is limited to host‐guest chemistry in binary and ternary complexes based on π‐conjugated carbon nanorings. [ABSTRACT FROM AUTHOR]

Aim: Objective of work was to compare role of β-Cyclodextrin (β-CD) and Nanosponges (NS) prepared with different cross-linking ratios and different drug loading ratios to enhance solubility and dissolution rate of Albendazole (ALB). Materials and Methods: Diphenyl Carbonate (DPC) was used as cross-linker for preparing NS with various β-CD and DPC ratios (1:2 and 1:4). Solvent evaporation was used to make binary complex. ALB and NS were dissolved in Dichloromethane (DCM) in 1:1 and 1:2 ratios and triturated until solvent evaporated. Phase solubility, saturation solubility and in vitro dissolution studies were performed. Solid state characterization as well as spectral and thermal analyses was done. Results: Stability constant for complexes ALB-β-CD, ALB-NS (1:2 ratios) and ALB-NS (1:4 ratios) were found to be 1715M-1±18.3, 1902M-1±29.5 and 1945M-1±30.1 respectively. Maximum solubility of all complexes was observed in fed state simulated intestinal fluid (FeSSIF). The increase was to the tune of 3-8 folds for all binary complexes at 1:1 and 1: 2 drug loading ratios. Dissolution rate increased by 47%-67% for drug loading ratio 1:1 and 55-71% for drug loading ratio 1:2 in FeSSIF in 150 min. Conclusion: β-CD based NS improved solubility of ALB. Presence of drug in molecular form in nanochannels and amorphization were responsible for increase in solubility. Nanosponges prepared in ratio 1:4 and drug loading in ratio 1:2 showed highest increase in solubility and dissolution rate. [ABSTRACT FROM AUTHOR]

The problem of oncological diseases has acquired a social and medical character. In this regard, the rapid development of new drugs and methods, as well as modification of existing methods in order to increase their effectiveness, is currently required. The paper aims to develop and study two promising agents for photodynamic therapy. We discussed a new binary complex based on the widely used photosensitizer chlorin E6 with europium, which can solve one of the main disadvantages of drugs for photodynamic therapy: it can be used to treat deeper tumors and act more effectively by transferring luminescence energy between europium and chlorin E6. Our other agent was copper-containing chlorophyllin. Chlorophyllin is a natural component, which is always promising in the development of new drugs. The optical and fluorescent parameters of the agents were determined using physicochemical methods; their ability to generate reactive oxygen species in the presence of two fluorescent probes was studied: 2ʹ, 7ʹ-dichlorodihydrofluorescein and dihydrofluorescein. Thus, we showed the effectiveness of chlorophyllin in comparison with chlorin E6 by 1.92 times at 50 μg / ml E6 and showed the effectiveness of the binary complex even at the minimum concentration of 10 μg / ml. Further research in cell cultures will develop the ways of the possible use of new substances as photosensitizers.

We obtained binary polyelectrolyte complexes containing chitosan from Bombyx mori and collagen with a mass ratio of 10:1; 10:2, and 10:3. During the interaction between the macromolecules, due to the compensation of the positive charges of chitosan with the negative charges of collagen, the zeta potential of the solutions of polyelectrolyte complexes changed from +15.2 to +5.67 mV. We revealed the dependence of the size characteristics of the particles of polyelectrolyte complexes on time and the ratio of macromolecules. An examination of the morphology of the films of polyelectrolyte complexes demonstrated that in the evaluated chitosan/collagen mass ratios, non-spherical nanosized particles up to = 60 nm form on the surface of the films. We evaluated the mechanism of formation of complexes by using Fourier-transform infrared spectroscopy and confirmed the findings with density functional theory and molecular dynamics. We found that the particle diameter is inversely proportional to the diffusion coefficient. The results show that the particles are almost uniformly distributed over the surface of the polymer matrix and have a unimodal character. We obtained reproducible results when using a chitosan/collagen mass ratio of 10:2 to dye natural silk. We found that the complexes contribute to increase the intensity and stability of colour relative to soap and friction. [ABSTRACT FROM AUTHOR]

Multiple sensitive eco‐friendly analytical techniques were applied for the assessment of two important fourth‐generation fluoroquinolones namely, gemifloxacin (GFX), and gatifloxacin (GTF). GFX, which is utilized as an essential adjunct therapy for the management of pneumonia in SARS‐CoV‐2 was determined by green indicating micellar liquid chromatographic in authentic powder and dosage forms. The separation was performed by using a reversed‐phase C18 column; the micellar mobile phase comprised of 12.5% n‐propanol, 0.15 M sodium lauryl sulfate, and 0.3% triethylamine in 0.02 M O‐phosphoric acid adjusted to pH 3.0 and pumped at 1 ml/min flow rate and detected at 266 nm by UV detection. The method was linear over the range of 4.0–90 μg.ml−1 with a recovery percentage of 99.81 ± 0.69. The acidic degradation behavior of GFX along with the kinetic investigation was evaluated as recommended by ICH‐stress conditions. The separation of the degradation product was performed in good elution time (less than 8 min), and the suggested technique has a good reproducibility (R.S.D. less than 1.0%) and provides an excellent resolution (Rs = 4.5) between GFX and its degradation product. Concerning the second drug, GTF, simple, extremely sensitive, and accurate spectrofluorimetric and spectrophotometric techniques were adopted for the determination of the drug in its pharmaceutical preparations. The suggested approaches utilize the concept of complex formation with eosin Y in an aqueous buffered solution. Regarding the spectrophotometric method (method I), the binary complex has a maximum absorption at 544 nm, while for spectrofluorimetric determination (method II) the formed complex was recorded at λem 491 nm after excitation at 286 nm. For both approaches, variables affecting the formation of the binary complexes were extensively investigated and optimized. The suggested techniques were shown to be rectilinear across the concentration range of 0.5–8 and 0.05–1 μg.ml−1, respectively, with recovery percentages of 100.34 ± 0.85 and 99.90 ± 0.81 for method (I) and method (II), respectively. In compliance with ICH guidelines, the analytical performance of the suggested techniques was thoroughly validated. Moreover, uniformity testing was also applied successfully for the evaluation of GFX by the proposed micellar liquid chromatographic method. To ensure the proposed methodology's greenness, The AGREE calculator software was adopted and the results obtained revealed an excellent greenness of the proposed approaches. [ABSTRACT FROM AUTHOR]

The triggering receptor expressed on myeloid cells-2 (TREM2), a pivotal innate immune receptor, orchestrates functions such as inflammatory responses, phagocytosis, cell survival, and neuroprotection. TREM2 variants R47H and R62H have been associated with Alzheimer's disease, yet the underlying mechanisms remain elusive. Our previous research established that TREM2 binds to heparan sulfate (HS) and variants R47H and R62H exhibit reduced affinity for HS. Building upon this groundwork, our current study delves into the interplay between TREM2 and HS and its impact on microglial function. We confirm TREM2's binding to cell surface HS and demonstrate that TREM2 interacts with HS, forming HS-TREM2 binary complexes on microglia cell surfaces. Employing various biochemical techniques, including surface plasmon resonance, low molecular weight HS microarray screening, and serial HS mutant cell surface binding assays, we demonstrate TREM2's robust affinity for HS, and the effective binding requires a minimum HS size of approximately 10 saccharide units. Notably, TREM2 selectively binds specific HS structures, with 6-O-sulfation and, to a lesser extent, the iduronic acid residue playing crucial roles. N-sulfation and 2-O-sulfation are dispensable for this interaction. Furthermore, we reveal that 6-O-sulfation is essential for HS-TREM2 ternary complex formation on the microglial cell surface, and HS and its 6-O-sulfation are necessary for TREM2-mediated ApoE3 uptake in microglia. By delineating the interaction between HS and TREM2 on the microglial cell surface and demonstrating its role in facilitating TREM2-mediated ApoE uptake by microglia, our findings provide valuable insights that can inform targeted interventions for modulating microglial functions in Alzheimer's disease., Competing Interests: Conflicts of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Three Schiff base ligands, L1H = (2-((benzo[d]thiazol-6-ylimino)methyl)-6-nitrophenol), L2H = (2-((benzo[d]thiazol-6-ylimino)methyl)-4,6-diiodophenol), L3H = (2-((benzo[d]thiazol-6-ylimino)methyl)-4-bromo-6-methoxyphenol) and their binary metal complexes, 1 [Cu(L1)2], 2 [Co(L1)2], 3 [Cu(L2)2], 4 [Co(L2)2], 5 [Cu(L3)2] and 6 [Co(L3)2], have been synthesized and characterized by elemental analysis, NMR, ESI mass, FT-IR, ESR, UV–Visible, magnetic susceptibility and TGA studies. The analytical and various spectral data suggested a square-planar geometry around the metal for all complexes with N2O2-donor atoms from the Schiff base ligands. Antimicrobial study was investigated against two Gram-positive, Bacillus amyloliquefaciens and Staphylococcus aureus, and one Gram-negative, Escherichia coli, bacteria as well as against two fungal species, Macrophomina phaseolina and Sclerotium rolfsii, by using Streptomycin and Mancozeb as standard drugs, respectively. The results revealed that metal complexes show more potent activity than free ligands and moderate compared to standard drugs. The free-radical scavenging ability of the complexes was evaluated by DPPH and ABTS assay methods using ascorbic acid as a standard antioxidant, complexes 1 and 2 showed good scavenging activity. DNA-binding titrations were also performed and indicated that all complexes bind to calf-thymus DNA via an intercalation mode. Additionally, the complexes exhibited good cleavage ability against the pBR322 DNA even at low concentrations in the presence of activators, H2O2 as well as UV light. [ABSTRACT FROM AUTHOR]

Highlights • Zein-hyaluronic acid binary complexes were fabricated by antisolvent coprecipitation. • Physicochemical and structural property of complexes were dependent on mass ratio. • Complex showed 2 types of microstructures: nanoparticle and particle-filled microgel. • Complex could encapsulate quercetagetin with high encapsulation efficiency (93.56%). • Quercetagetin-loaded complex exhibited anti-thermal degradation and control-release. Abstract The antisolvent coprecipitation method was utilized for fabricating the zein and hyaluronic acid complex at different mass ratios (100:5, 100:10, 100:15, 100:20, 100:25 and 100:30). Results showed that negatively charged zein-hyaluronic acid complex with small size (181.5 nm) was formed through the driving force of electrostatic attraction, followed by hydrogen bonding and hydrophobic effects. The incorporation of hyaluronic acid led to conformational change of zein, and improved its physical and thermal stability. Native hyaluronic acid showed a three-dimensional network structure, while zein-hyaluronic acid binary complex exhibited two different microstructures, including nanoparticles (zein: hyaluronic acid, above 100:20) and particle-filled-microgel (zein: hyaluronic acid, below 100:20). In addition, zein-hyaluronic acid complex was designed as a new delivery vehicle to anti- thermal degradation and control release of quercetagetin. These findings indicated that zein-hyaluronic acid complex would be a useful and promising delivery vehicle for embedding and protecting bioactive compounds. [ABSTRACT FROM AUTHOR]

Cyclodextrins (CDs) have been extensively utilized as host molecules to enhance the solubility, stability and bioavailability of hydrophobic drug molecules through the formation of inclusion complexes. It was previously reported that the use of co-solvents in such studies may result in ternary (host:guest:co-solvent) complex formation. The objective of this work was to investigate the effect of ethanol as a co-solvent on the inclusion complex formation between α-mangostin (α-MGS) and β-CD, using both experimental and theoretical studies. Experimental phase-solubility studies were carried out in order to assess complex formation, with the mechanism of association being probed using a mathematical model. It was found that α-MGS was poorly soluble at low ethanol concentrations (0–10% v/v), but higher concentrations (10–40% v/v) resulted in better α-MGS solubility at all β-CD concentrations studied (0–10 mM). From the equilibrium constant calculation, the inclusion complex is still a binary complex (1:1), even in the presence of ethanol. The results from our theoretical study confirm that the binding mode is binary complex and the presence of ethanol as co-solvent enhances the solubility of α-MGS with some effects on the binding affinity with β-CD, depending on the concentration employed.

Highlights • Inclusion complex of G with Epi-β-CD was prepared by freeze-drying method. • Stoichiometric ratio was determined through Jobs plot. • Analysis was done by FTIR, DSC, DTA and dissolution study. • The stability constant of the complex was found to be 15,871.3 M−1. • DE of complex was found to be 99.3% (7.4 times greater) than PM and pure G. Abstract Gefitinib is anticancer drug which is sparingly soluble in water. This limits its dissolution and bioavailability. Binary inclusion complex of gefitinib with Epi-β-CD was prepared by freeze-drying method. Stoichiometric ratio of 1:1 M was established by continuous variation (Job’s) plot. The stability constant of complex as determined by phase solubility study was found to be 15,871.3 M−1. Complex was characterized by FTIR, DSC, DTA and dissolution study. Results revealed that in complex the drug no longer exist in crystalline state and is converted into amorphous form; which shows higher dissolution efficiency as compared to crystalline drug. The solubilizing efficiency for freeze dried complex was found to be 175.57 and the relative drug crystallinity degree was 87.91% as estimated by thermal analysis. Complexation led to decrease in surface tension; from 54.8 dynes/cm (pure gefitinib) to 40.3 dynes/cm (FD complex) due to adsorption phenomenon. The results obtained in this study confirmed that complexation of gefitinib with Epi-β-CD is a prominent approach and suitable tool for tailoring the issue related to its delivery and can be explored for development of an effective delivery system. [ABSTRACT FROM AUTHOR]

Two simple, sensitive, rapid, validated and cost effective spectroscopic methods were established for quantification of antihistaminic drug azelastine (AZL) in bulk powder as well as in pharmaceutical dosage forms. In the first method (A) the absorbance difference between acidic and basic solutions was measured at 228 nm, whereas in the second investigated method (B) the binary complex formed between AZL and Eosin Y in acetate buffer solution (pH 3) was measured at 550 nm. Different criteria that have critical influence on the intensity of absorption were deeply studied and optimized so as to achieve the highest absorption. The proposed methods obeyed Beer ' s low in the concentration range of (2.0–20.0 μg·mL − 1 ) and (0.5–15.0 μg·mL − 1 ) with % recovery ± S.D. of (99.84 ± 0.87), (100.02 ± 0.78) for methods (A) and (B), respectively. Furthermore, the proposed methods were easily applied for quality control of pharmaceutical preparations without any conflict with its co-formulated additives, and the analytical results were compatible with those obtained by the comparison one with no significant difference as insured by student's t -test and the variance ratio F-test. Validation of the proposed methods was performed according the ICH guidelines in terms of linearity, limit of quantification, limit of detection, accuracy, precision and specificity, where the analytical results were persuasive. [ABSTRACT FROM AUTHOR]

Binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) with atenolol as hypertension drug and glycine have been determined pH metrically at room temperature and 0.01 M ionic strength (NaClO4) in aqueous solution. The formation of various possible species has been evaluated by computer program and discussed in terms of various relative stability parameters.

A novel supramolecular liquid crystal (LC) is synthesized from the binary complex of 4-decyloxy benzoic acid and cholesteryl acetate. Fourier transform infrared (FTIR) spectroscopic study confirms the formation of intermolecular hydrogen bond between the mesogens. Various mesophases and corresponding textural changes in the complex are observed by comparing with its constituents through polarizing optical microscopic (POM) studies. The thermal stability factor of smectic phase for present complex is calculated. An interesting observation of present work is that investigation of extended thermal span of mesomorphic phases, decreased enthalpy, a nematic phase with a high clearing point and a low melting point. This is due to an arrangement of molecular reorientations and the development of new associations by hydrogen bonding. Optical tilt angle for smectic C phase is determined and the same is fitted to a power law. [ABSTRACT FROM AUTHOR]

Binary complexes of Cu(II), Ni(II) and Co(II) were synthesized using two novel Schiff bases $$\mathbf{L}_{1}$$ = 2-(-(benzothiazol-6-ylimino)methyl)-4-chlorophenol (BTEMCP), $$\mathbf{L}_{2}$$ = 2-(-(benzothiazol-6-ylimino)methyl)-4-nitrophenol. The Schiff bases and metal complexes were characterized by analytical and spectral methods like elemental analysis, Mass, $$^{1}\hbox {H}$$ -NMR, $$^{13}\hbox {C}$$ -NMR, UV-Vis, IR, ESR, SEM, EDX, XRD and magnetic susceptibility measurements. From the analytical data, square planar geometry has been proposed for all the metal complexes. The binding interaction between the metal complexes and DNA was investigated by means of electronic absorption, fluorescence spectroscopy and viscosity measurements. The DNA cleavage ability of the metal complexes was also evaluated by agarose gel electrophoresis method. These studies revealed that the complexes showed an intercalative mode of binding to CT DNA and also effectively cleaved the supercoiled pBR DNA. The synthesised compounds were evaluated for in vitro antibacterial activity against Gram positive and Gram negative bacteria, and found that the metal complexes showed more potent biocidal activity than the Schiff bases. Graphical Abstract. : SYNOPSIS Six mononuclear metal complexes of benzothiazole Schiff bases were synthesized and characterized. The DNA interaction studies showed that all the complexes bind with CT-DNA through an intercalative mode. Supercoiled pBR322 DNA was effectively cleaved by the complexes . All the metal complexes exhibited better antibacterial activity than the Schiff bases from which they were prepared. [ABSTRACT FROM AUTHOR]

The effects of propylene glycol alginate (PGA) at different concentrations on the physical, conformational, thermal and morphological characteristics of zein particles were explored at pH 7.0. Results showed that the size of zein particles increased from nano-scale to micron-scale with the increasing proportion of PGA incorporation, consequently leading to greatly raised turbidity of zein colloidal dispersions. There was a large increase in fluorescence intensity of zein in the presence of PGA, indicating conformational change of zein. Results of X-ray diffraction and Fourier transform infrared spectroscopy revealed that the binary complex between zein and PGA was successfully generated due to the non-covalent interaction forces, mainly including hydrogen bonds and hydrophobic effects. The presence of PGA enhanced the physical and thermal stability of zein colloidal particles. The clumps and irregularly-shaped aggregates with large diameters were observed after the interaction between zein and PGA at mass ratios of 2:1 and 1:1. Findings in this work may help further understand the interaction theory between negatively charged proteins and polysaccharides and provide new insights into for the development of potential carriers for bioactive compounds in food system. [ABSTRACT FROM AUTHOR]

The anti-solvent co-precipitation method was used to fabricate the zein-propylene glycol alginate (PGA) binary complex with different mass ratios of zein to PGA (20:1, 10:1, 5:1, 2:1 and 1:1) at pH 4.0. Results showed that attractive electrostatic interaction between zein and PGA occurred and negatively charged binary complex with large size and high turbidity was formed due to the charge neutralization. Hydrogen bonding and hydrophobic effects were involved in the interactions between zein and PGA, leading to the changed secondary structure and improved thermal stability of zein. Aggregates in the irregular shape with large size were obviously observed in the AFM images. PGA alone exhibited a fine filamentous network structure, while zein-PGA binary complex showed a rough branch-like pattern and the surface of “branch” was closely adsorbed by lots of spherical zein particles. Q in zein-PGA binary complex dispersions presented the improved photochemical and thermal stability. The potential mechanism of a two-step process was proposed to explain the formation of zein-PGA binary complexes. [ABSTRACT FROM AUTHOR]

A simple and sensitive spectrophotometric method has been established for the determination of clemastine hydrogen fumarate (I), desloratadine (II), losartan potassium(III) and moxepril HCl(IV) based on binary complex formation with eosin. The method does not involve solvent extraction through the use of a non-ionic surfactant (methylcellulose). The color of the produced complex was measured at 552, 549 nm for (I), (II) while was measured at 540 nm for (III) and (IV). Appropriate conditions were established for the color reaction between eosin and the studied drugs to obtain maximum sensitivity. Under the proposed conditions, the method is applicable over concentration range of 1.25–11.25, 0.31–2.81, 2.5–20 and 1.25–15 μg/ml for (I), (II), (III) and (IV), respectively. The molar absorptivity (ε), sandell sensitivity, detection (LOD) and quantitation limits (LOQ) are calculated. Unlike other reported ion-pair techniques, the suggested methods have the advantage of being applicable for the determination of the four drugs in their pharmaceutical dosage forms without prior extraction with excellent recoveries.

A spectrofluorometric procedure was developed and fully validated for simple and sensitive determination of two antidepressant drugs; fluoxetine hydrochloride and paroxetine hydrochloride, in their pure forms and pharmaceutical formulations. The method is based on a binary complex formation with eosin Y in the presence of Teorell - Stenhagen buffer at pH 3.0. The quenching of the native fluorescence of eosin Y due to complex formation with the studied drugs was measured in the aqueous solution without extraction at 545 nm after excitation at 301 nm. At the optimum reaction conditions, the calibration graphs between the fluorescence quenching values (ΔF) and the drug concentrations were rectilinear over the ranges of 0.2–2.4 and 0.1–2.4 μg mL−1for fluoxetine and paroxetine respectively. The proposed method was successfully applied for the determination of the studied drugs in pharmaceutical formulations without interference from the common excipients. [ABSTRACT FROM AUTHOR]