Search Results (8)

This study investigated the influence of β-cyclodextrin (βCD) on the micellization behavior of two bile salt surfactants, sodium deoxycholate (NaDC) and sodium cholate (NaC), in aqueous solutions. Tensiometry, conductometric, and spectrofluorimetric techniques were employed to determine critical micelle concentrations (CMCs) in the presence of varying concentrations of βCD, as well as in the presence of inorganic salts (NaCl and CsCl). The results showed that βCD forms inclusion complexes with both bile salts, leading to an increase in their CMCs, consistent with a competitive interaction between micelle formation and complexation. The inclusion constants, determined graphically, revealed stronger complexation for NaDC than NaC, attributed to differences in hydrophobic surface area. Salt addition decreased the CMC of both surfactants, with CsCl having a more pronounced effect. However, salt presence also modulated the inclusion complex formation, suggesting specific ion effects influence the availability and behavior of βCD. These findings contribute to the understanding of bile salt–cyclodextrin interactions and their modulation by electrolytes, with implications for drug delivery and supramolecular chemistry. Full article

Background: Phytocarriers are advanced drug delivery systems that use biocompatible and biodegradable materials to enhance the efficacy, stability, and bioavailability of natural products. The sea buckthorn (Hippophae rhamnoides L.) berry extract is rich in essential fatty acids and antioxidants, including vitamin C, vitamin E, and anthocyanins, which contribute to its wide-ranging health benefits. In this study, we assessed the morphology, intracellular delivery, and anti-inflammatory effect of sodium cholate (NaC) and sodium deoxycholate (NaDC)-based phytocarriers loaded with ethanolic extract from sea buckthorn berries (sea buckthorn carrier nanostructures, further defined as phytocarriers). Methods: Negative and electron cryo-microscopy were used to analyze hollow and loaded nanocarriers. The cyto-compatibility of nanocarriers was assessed by endpoint (LDH and MTS) and real-time cell assays, on both human fibroblasts (HS27) and human normal monocytes (SC). The anti-inflammatory effect of hollow and loaded nanocarriers was tested by multiplexing. Results: The negative and electron cryo-microscopy analyses showed that NaC-based phytocarriers were spherical, whilst NaDC-based phytocarriers were predominantly polymorphic. Moreover, the NaDC-based phytocarriers frequently formed large lipid networks or “plaques”. Although 24 h cytotoxicity testing showed both types of nanocarriers are biocompatible with human fibroblasts and monocytes, based on a long-term real-time assay, NaDC delayed fibroblast proliferation. NaC sea buckthorn phytocarriers did not impair fibroblast proliferation in the long term and they were uptaken by cells, as shown by hyperspectral microscopy. NaC nanocarriers and NaC sea buckthorn phytocarriers induced an anti-inflammatory effect, lowering IL-8 cytokine production in normal human monocytes as soon as 4 h of treatment lapsed. Conclusions: NaC-derived phytocarriers loaded with sea buckthorn alcoholic extract are a cell-compatible delivery system with anti-inflammatory properties. Full article

Caffeic acid phenylethyl ester (CAPE) is a natural polyphenol extracted from propolis, which is reported to have several pharmacological effects such as antibacterial, antitumor, antioxidant and anti-inflammatory activities. Hemoglobin (Hb) is closely related to the transport of drugs, and some drugs, including CAPE, can lead to a change in Hb concentration. Herein, the effects of temperature, metal ions and biosurfactants on the interaction between CAPE and Hb were studied using ultraviolet-visible spectroscopy (UV−Vis), fluorescence spectroscopy, circular dichroism (CD), dynamic light scattering (DLS) and molecular docking analysis. The results showed that the addition of CAPE led to changes in the microenvironment of Hb amino acid residues as well as the secondary structure of Hb. Hydrogen bonding and van der Waals force were found to be the main driving forces for the interaction between CAPE and Hb through fluorescence spectroscopy and thermodynamic parameter data. The results of fluorescence spectroscopy also showed that lowering the temperature, adding biosurfactants (sodium cholate (NaC) and sodium deoxycholate (NaDC)) and the presence of Cu²⁺ increased the binding force between CAPE and Hb. These results provide useful data for the targeted delivery and absorption of CAPE and other drugs. Full article

Viscosity, speed of sound (u), and density (ρ) have been measured in aqueous glycyl glycine solution over a temperature range from 293.15 to 313.15 K with a 5 K interlude to evaluate the volumetric and compressibility properties of bio-surfactants, namely sodium cholate (NaC; 1–20 mmol∙kg⁻¹) and sodium deoxycholate (NaDC; 1–10 mmol∙kg⁻¹). Density and viscosity findings provide information on both solute–solute and solute–solvent types of interactions. Many other metrics, such as apparent molar adiabatic compression $({\kappa }_{S,\phi })$, isentropic compressibility $({\kappa }_S)$, and apparent molar volume $(V_{\phi })$, have been calculated from speed of sound and density measurements, utilising experimental data. The results show that the zwitterionic end group in the glycyl glycine strongly interacts with NaDC and NaC, promoting its micellization. Since the addition of glycyl glycine causes the bio-surfactant molecules to lose their hydrophobic hydration, the observed concentration-dependent changes in apparent molar volume and apparent molar adiabatic compression are likely attributable to changes in water–water interactions. Viscous relaxation time ($\tau$) increases significantly with a rise in bio-surfactant concentration and decreases with increasing temperature, which may be because of structural relaxation processes resulting from molecular rearrangement. All of the estimated parameters have been analysed for their trends with regard to the different patterns of intermolecular interaction present in an aqueous glycyl glycine solution and bio-surfactant system. Full article

D- and L-arginine-based polyamidoamino acids, called D- and L-ARGO7, retain the chirality and acid/base properties of the parent α-amino acids and show pH-dependent self-structuring in water. The ability of the ARGO7 chiral isomers to selectively interact with chiral biomolecules and/or surfaces was studied by choosing sodium deoxycholate (NaDC) as a model chiral biomolecule for its ability to self-assembly into globular micelles, showing enantio-selectivity. To this purpose, mixtures of NaDC with D-, L- or D,L-ARGO7, respectively, in water were analysed by circular dichroism (CD) spectroscopy and small-angle neutron scattering (SANS) at different levels of acidity expressed in terms of pD and concentrations. Differences in the CD spectra indicated chiral discrimination for NaDC/ARGO7 mixtures in the gel phase (pD 7.30) but not in the solution phase (pD 9.06). SANS measurements confirmed large scale structural perturbation induced by this chiral discrimination in the gel phase yet no modulation of the structure in the solution phase. Together, these techniques shed light on the mechanism by which ARGO7 stereoisomers modify the morphology of NaDC micelles as a function of pH. This work demonstrates chirality-dependent interactions that drive structural evolution and phase behaviour of NaDC, opening the way for designing novel smart drug delivery systems. Full article

Potentiometric sensors have a great influence on the determination of most various compounds in their matrices. Therefore, efficient and new sensors were introduced to measure sodium Deoxycholate (NaDC) as a bile acid salt. These sensors are based on NaDC imprinted polymer (MIP) as sensory element. The MIP beads were synthesized using thermal polymerization pathway, in which acrylamide (AAm), ethylene glycol dimethacrylate (EGDMA), NaDC, and benzoyl peroxide (BPO) were used as the functional monomer, cross-linker, template, and initiator, respectively. The proposed sensors were fabricated using a coated screen-printed platform and the sensing membrane was modified by single-walled carbon nanotubes (SWCNTs) as an ion-to-electron transducer. The sensors exhibited high sensitivity that reached 4.7 × 10⁻⁵ M of near-Nernestian slope (−60.1 ± 0.9 mV/decade, r² = 0.999 (n= 5)). In addition, the sensors revealed high selectivity, long lifetime, high potential stability, and conductivity that ensure reproducible and accurate results over a long time. MIP characterization was performed using Fourier Transform-Infrared (FT-IR) and a scanning electron microscope (SEM). Regarding the interaction of NaDC with serum albumin (SA), albumin is determined in human serum samples as human serum albumin (HSA), which was collected from different volunteers of different ages and gender. Full article

Au nanoparticles (NPs) were prepared by UV light irradiation of a mixed solution of HAuCl₄ and sodium deoxycholate (NaDC) under alkaline condition, in which NaDC served as both reducing agent and capping agent. The reaction was monitored by circular dichroism (CD) spectra, and it was found that the formed gold NPs could catalyze the oxidation of NaDC. A CD signal at ~283 nm in the UV region was observed for the oxidation product of NaDC. The intensity of the CD signal of the oxidation product was enhanced gradually with the reaction time. Electrospray ionization (ESI) mass spectra and nuclear magnetic resonance (NMR) spectra were carried out to determine the chemical composition of the oxidation product, revealing that NaDC was selectively oxidized to sodium 3-keto-12-hydroxy-cholanate (3-KHC). The chiral discrimination abilities of the micelles of NaDC and its oxidation product, 3-KHC, were investigated by using chiral model molecules R,S-1,1′-Binaphthyl-2,2′-diyl hydrogenphosphate (R,S-BNDHP). Compared with NaDC, the micelles of 3-KHC displayed higher binding ability to the chiral model molecules. In addition, the difference in binding affinity of 3-KHC micelles towards R,S-isomer was observed, and S-isomer was shown to preferentially bind to the micelles. Full article

The two main steps of the membranolytic activity of detergents: 1) the partitioning of detergent molecules in the membrane and 2) the solubilisation of the membrane are systematically investigated. The interactions of two bile salt molecules, sodium cholate (NaC) and sodium deoxycholate (NaDC) with biological phospholipid model membranes are considered. The membranolytic activity is analysed as a function of the hydrophobicity of the bile salt, ionic strength, temperature, membrane phase properties, membrane surface charge and composition of the acyl chains of the lipids. The results are derived from calorimetric measurements (ITC, isothermal titration calorimetry). A thermodynamic model is described, taking into consideration electrostatic interactions, which is used for the calculation of the partition coefficient as well as to derive the complete thermodynamic parameters describing the interaction of detergents with biological membranes (change in enthalpy, change in free energy, change in entropy etc). The solubilisation properties are described in a so-called vesicle-to-micelle phase transition diagram. The obtained results are supplemented and confirmed by data obtained from other biophysical techniques (DSC differential scanning calorimetry, DLS dynamic light scattering, SANS small angle neutron scattering). Full article