Deoxycholate Solution Research Articles

Bio-surfactant mediated sustainable exfoliation of MoS2 and in-situ preparation of Ag@MoS2 nanocomposites for photocatalysis under sunlight in aqueous medium

Exfoliation of MoS2 has been performed in the aqueous solution of bio-based surfactant choline deoxycholate, ([Cho][Doc]), employing low-energy bath sonication. The ability of [Cho]+ to reduce the Ag+ under sunlight accompanied by the templating effect of [Doc]− has been exploited to decorate the exfoliated MoS2 in a single step. The dimensions as well as the extent of adherence of Ag NPs to MoS2 in Ag@MoS2 nanocomposites (NCs) have been controlled by adjusting the concentration of [Cho][Doc]. The prepared NCs have been characterized by UV–vis spectroscopy, atomic force microscopy (AFM), dynamic light scattering (DLS), zeta-potential measurements (ζ-potential), X-ray diffraction (XRD), Raman spectroscopy, X-ray photon spectroscopy (XPS), transmission (TEM) and high-resolution transmission electron microscopy (HR-TEM). The NCs have shown enhancement in photocatalytic activity compared to bare Ag NPs under sunlight in an aqueous medium. It has been observed that the Schottky junction between metallic Ag NPs and semiconductor MoS2 in NCs shows efficient charge separation by generating a continuum-charged region resulting in increased catalytic activity of NCs. The present work is expected to serve as a platform for preparing photocatalytic NCs sustainably employing various other 2D materials.

Assessment of nuclear material elimination by different methods of dermis decellularization

We carry out a comparative assessment of the degree of nuclear material disintegration and elimination in the samples of decellularized porcine dermis after using chemical, detergent and enzymatic decellularization methods. Decellularized dermis materials are promising materials as wound dressings. The chemical method (Protocol No. 1) was performed using NaOH and H2 O2 solutions; the detergent method (Protocol No. 2) involved the solutions of Triton X-100 and sodium deoxycholate in combination with Na2 -EDTA; the enzymatic method (Protocol No. 3) was based on the solutions of trypsin Versene and porcine pan creatic DNase. Subsequently, we analyzed the DNA amount in decellularized and native dermis (control group) samples. The results of this analysis showed positive results in all three protocols. It was found that the detergent method have advantages over other methods of producing decellularized dermis matrices.

CO2/N2-switchable sol–gel transition based on NaDC/NaCl solution: Experiments and molecular dynamics simulations

The CO2/N2-triggered switchable sol–gel transition based on sodium deoxycholate (NaDC) and sodium chloride (NaCl) aqueous solutions has been investigated using both experiments and molecular dynamics (MD) simulations. The effects of CO2 on the phase behavior, viscosity, pH, electrical conductivity, and microstructure of the NaDC/NaCl mixed system were explored. The mixed system exhibits a recycled CO2/N2 response, and switching between solution state and gel state with six orders of magnitude variation in shear viscosity was achieved within a narrow pH range of 7.82–7.20. The FT-IR and 1H NMR spectra of the mixed system before and after CO2 bubbling were measured. The experimental results indicate that NaDC is not directly protonated to deoxycholic acid by the small amount of CO2 present; instead, an acid salt structure with a strong hydrogen bond, that is, [RCOOH⋯OOCR]−, is formed. MD simulation results reveal that, in the aqueous mixed NaDC/NaCl/CO2 system, three types of bridging hydrogen bonds between two deoxycholate (DC−) anions and one H3O+ or HCO3− ion are key factors for the formation of hydrogels. These bridging hydrogen bonds promote the formation of DC− pairs bridged by H3O+ or HCO3− ions (including the acid salt structure) and are beneficial to the growth of micelles and formation of hydrogels. It is worth noting that the bridging hydrogen bond connected by HCO3− ions is an aspect of CO2-induced hydrogels that distinguishes them from acid-induced hydrogels. In addition, the results indicate that CO2 and NaCl have a synergistic effect when inducing hydrogel formation. Based on experiments and MD simulations, a CO2/N2-switchable sol–gel transition mechanism for an aqueous mixed NaDC/NaCl system has been proposed.

Oxidation of Sodium Deoxycholate Catalyzed by Gold Nanoparticles and Chiral Recognition Performances of Bile Salt Micelles.

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.

Decellularization of the mouse ovary: comparison of different scaffold generation protocols for future ovarian bioengineering

BackgroundIn order to preserve fertility in young women with disseminated cancer, e.g. leukemia, an approach that has been suggested is to retransplant isolated small follicles within an ovarian matrix free from malignant cells and with no risk for contamination. The present study evaluates the first step to create a bioengineered ovarian construct that can act as growth-supporting tissue for isolated small follicles that are dependent on a stroma for normal follicular maturation. The present study used the intact mouse ovary to develop a mouse ovarian scaffold through various protocols of decellularization.Material and methodsPotential Immunogenic DNA and intracellular components were removed from whole mouse ovaries by agitation in a 0.5% sodium dodecyl sulfate solution (Protocol 1; P1), or in a 2% sodium deoxycholate solution (P2) or by a combination of the two (P3). The remaining decelluralized ovarian extracellular matrix structure was then assessed based on the DNA- and protein content, and was further evaluated histologically by haematoxylin and eosin-, Verhoeff’s van gieson- (for elastin), Masson’s trichrome- (for collagens) and Alcian blue (for glycosaminoglycans) staining. We also evaluated the decellularization efficiency using the mild detergent Triton-X100 (1%).ResultsSodium dodecyl sulfate efficiently removed DNA and intracellular components from the ovarian tissue but also significantly reduced the integrity of the remaining ovarian extracellular matrix. Sodium deoxycholate, a considerably milder detergent compared to sodium dodecyl sulfate, preserved the ovarian extracellular matrix better, evident by a more distinct staining for glycosaminoglycan, collagen and elastic fibres. Triton-X100 was found ineffective as a decellularization reagent for mouse ovaries in our settings.ConclusionsThe sodium dodecyl sulfate generated ovarian scaffolds contained minute amounts of DNA that may be an advantage to evade a detrimental immune response following engraftment. The sodium deoxycholate generated ovarian scaffolds had higher donor DNA content, yet, retained the extracellular composition better and may therefore have improved recellularization and other downstream bioengineering applications. These two novel types of mouse ovarian scaffolds serve as promising scaffold-candidates for future ovarian bioengineering experiments.

Effect of Maltodextrin and Temperature on Micellar Behavior of Bile Salts in Aqueous Medium: Conductometric and Spectrofluorimetric Studies

Abstract Conductivity and fluorescence probe techniques have been employed to study the micellar behavior of bile salts i.e. sodium cholate (1–20 mmol⋅kg−1) and sodium deoxycholate (0.5–10.0 mmol⋅kg−1) in aqueous solutions of maltodextrin (0.0, 0.5, 1.1, and 1.6 mmol⋅kg−1) at different temperatures. The influence of maltodextrin on the micellization behavior of bile salts has been determined in terms of critical micelle concentration (CMC) values obtained from conductivity measurement. The variation in CMC values has been discussed by considering the alteration in the hydrophobic environment of maltodextrin-sodium cholate/sodium deoxycholate complex imparted by the carbohydrate molecules. In order to substantiate the CMC values determined from conductivity method, the fluorescence probe study of aqueous sodium cholate and sodium deoxycholate solutions in presence of fluorescent, pyrene has also been carried. The CMC values obtained from both techniques are in full agreement with each other. Moreover, application of charged pseudo-phase separation model has been made to discuss the thermodynamics of the system.

Environmental stimuli induced phase transition in the aqueous mixture solution of Gemini surfactants and sodium deoxycholate

The phase behavior in a mixture of a cationic Gemini surfactant (12-2-12) and an anionic sodium deoxycholate (SDC) in the aqueous solution was reported here. The microstructures of formed aggregates have been investigated by rheology, small angle X-ray scattering and transmission electron microscopy. Mediated by the hydrophobic and electrostatic interactions of 12-2-12 and SDC, the wormlike micelles and lamellar aggregates were formed successively with increasing the SDC concentration. Due to the presence of hydroxyl and carboxylate groups on SDC, these aggregates were temperature and pH responsive. At low SDC concentrations, the wormlike micelles could be transformed into lamellar aggregates at lower pH. While at high SDC concentrations, the lamellar aggregates would be transformed into wormlike micelles at elevated temperatures. The Gemini surfactant structure also played an important role here on such environment-responsive phase transitions. The obtained results suggest the possibility to form smart aggregates by utilizing simple molecules with certain functional groups.

Skin Necrosis Following Adipocitolitic Solution Injections

Injectable fat-reduction techniques emerged in the world literature in 2001, when Patricia Rittes, a dermatologist in Sao Paulo, Brazil, reported reduction of infraorbital fat after direct, transcutaneous injection of phosphatidylcholine (PC) combined with sodium deoxycholate (DC) solution.1 Despite lack of approval by any regulatory body, PC/DC combinations have been used off-label by healthcare practitioners to reduce subcutaneous fat in selected patients.2,3 In Europe, the only drug with CE marking (approval) for the reduction of localized fat is Aqualyx (Marllor International; San Giovanni in Marignano, Italy).4 Currently, it is approved in approximately 50 countries. Aqualyx is a DC-based solution with a lactose-based delivery system, formulated to control and enhance the action of external ultrasound waves for the microcavitation of adipose tissue.5 It does not contain PC. Aqualyx was designed for the medical treatment (reduction) of localized adipose tissue5 and is sold exclusively to physicians trained in intralipotherapy, the injection technique for its insertion.6 The product has been in clinical use since 2009 for the nonsurgical reduction of localized adiposity, lipohypertrophy, subcutaneous lipohyperplasia, and “buffalo hump”.6-8 Aqualyx is an aqueous microgelatinous solution comprised of the following: polymer of 3:6-anhydro-L-galactose and D-galactose; buffer systems; 3-alpha-12alpha-dihydroxy-5-beta-24-oico cholanic acid sodium salt; and saline solution.7,8 The solution appears similar in composition to DC, but it is considered a medical device—not a drug. A claim regarding this matter has been submitted to the Italian Ministry of the Health.8 Aqualyx is marketed as a 2-step product: immediately following injection (step 1), it is recommended that external ultrasonography be performed (step 2).5 However, …

Toxic influence of detergents on human mesenchimal stromal cells during graft repopulation

Detergents are effective decellularization agents in order to obtain cell-free matrixes. However, the toxicity of residual detergent prevents the adhesion of cells to the matrix and the realization of their functions. In this study, the degree of influence of residual detergents on mesenchymal stromal cells after a series of washes was investigated. The human pulmonary valve were treated in three ways: 1% solution of sodium dodecyl sulfate, 1% solution of sodium deoxycholate and a combination of these solutions with the reduction of the concentration to 0.5%. After each of 8 steps washing buffer were collected. We investigated influence of residual detergents on cytotoxicity and effect on the metabolic activity of MSCs. Histologic analysis showed sufficient tissue decellularization in all groups. Matrixes were washed by successive incubations with 200 ml of phosphate buffer. Detergent concentrations in all samples ceased to be toxic only to the 4-cycle wash, and had no effect on the metabolism and viability of human MSCs. After 4-8 washing cycles decellularized pulmonary trunk fragments were successfully settled by mesenchymal stromal cells. Thus, a few successive washing fabrics pulmonary valve after decellularization reduce residual detergent to a safe level and lead to successful repopulation of acellular scaffolds with MSCs.

Engineering of a Secretory Active Three-Dimensional Lacrimal Gland Construct on the Basis of Decellularized Lacrimal Gland Tissue.

Lacrimal gland (LG) insufficiency is a main cause for severe dry eye leading to pain, visual impairment, and eventually loss of sight. Engineering of transplantable LG tissue with secretory capacity is a desirable goal. In this study, a three-dimensional decellularized LG (DC-LG) scaffold with preserved LG morphology was generated by treatment with 1% sodium deoxycholate and DNase solution using porcine LG tissue. To address clinical applicability, the primary in vitro culture of secretory active LG cells from a small tissue biopsy of 1.5 mm diameter was introduced and compared with an established isolation method by enzymatic digestion. Cells from both isolation methods depicted an epithelial phenotype, maintained their secretory capacity for up to 30 days, and exhibited progenitor cell capacity as measured by aldehyde dehydrogenase-1 activity, side population assay, and colony-forming units. Cells from passage 0 were reseeded into the DC-LG and secretory active cells migrated into the tissue. The cells resembled an LG-like morphology and the constructs showed secretory activity. These results demonstrate the possibility of engineering a secretory competent, three-dimensional LG construct using LG cells expanded from a small tissue biopsy and DC-LG as a matrix that provides the native structure and physiological niche for these cells.

Human growth hormone‐loaded nanogels composed of cinnamoyl alginate, cinnamoyl Pluronic F127, and cinnamoyl poly(ethylene glycol)

ABSTRACTCinnamoyl alginate (CinAlg), cinnamoyl Pluronic F127 (CinPlu), and cinnamoyl poly(ethylene glycol) (CinPEG) could be self‐assembled into nanogels, possibly due to hydrophobic interaction among cinnamic acid (CA) residues. The nanogels were nearly spherical particles on TEM photographs. The photodimerization of CA residue had little effect on the integrity and the size of nanogel. The stability of the nanogels in blood plasma for 48 h at 37°C did not depend on UV irradiation, however they were stable in deoxycholate solution (1 and 10 mM) only when they were UV‐treated. Human growth hormone (hGH) could readily be loaded in the nanogel under an acidic condition possibly due to the electrostatic interaction between hGH and CinAlg. hGH hardly released from the nanogel at body temperature (37°C) when the release medium was at acidic condition (e.g., pH 3.0, pH 5.0; <10% in 170 h). However, it readily released at the same temperature when the medium was at physiological pH (e.g., pH 7.4; around 45% in 170 h) and at an alkaline condition (e.g., pH 9.0; >50% in 170 h). However, slow release of hGH was observed for 100 h possibly due to the layer of thermally condensed Pluronic F127 chains. In addition, initial burst release was suppressed as the CinPlu content increased. For example, the release degree at pH 9 in 60 min decreased from 15.3 to 5.9% as the CinPlu content increased from 20 to 60%. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42446.

Magnesium octa[(4′-benzo-15-crown-5)oxy]phthalocyaninate in water micellar solutions of sodium deoxycholate

Aggregation of magnesium octa-[(4′-benzo-15-crown-5)oxy]phthalocyaninate (Mgcr8Pc) in solutions of biocompatible anionic surfactant, sodium deoxycholate (SDC), was studied. It was shown using the electron absorption spectra that formation of Mgcr8Pc monomers in micellar solutions of SDC is affected by both increased surfactant concentration and by changes in the ionic strength of solution after sodium chloride is added. The effect of the chemical structure of biocompatible anionic surfactant on monomerization of crown-containing phthalocyanines was identified; this fact opens new possibilities for using this family of compounds for fluorescent diagnosis and photodynamic therapy.

Separation of Metallic and Semiconducting Single-Walled Carbon Nanotubes by Density Gradient Ultracentrifugation

In this paper, SWNTs synthesized by an improved arc discharge method were chemically purified, and then sonically dispersed in an aqueous cosurfactant solution of sodium deoxycholate and sodium dodecyl sulfate. Density gradient ultracentrifugation showed that the separation of such chemically purified SWNTs by diameter or electronic type could be improved by optimizing rotation speed, time and temperature. UV-vis-NIR absorbance and Raman scattering spectra showed that the purity of the metallic SWNTs was estimated to be 74% mainly composed of (9,9) tube, and the purity of the semiconducting SWNTs to be 98% mainly composed of (15,8) tube.

Analyzing Surfactant Structures on Length and Chirality Resolved (6,5) Single-Wall Carbon Nanotubes by Analytical Ultracentrifugation

The structure and density of the bound interfacial surfactant layer and associated hydration shell were investigated using analytical ultracentrifugation for length and chirality purified (6,5) single-wall carbon nanotubes (SWCNTs) in three different bile salt surfactant solutions. The differences in the chemical structures of the surfactants significantly affect the size and density of the bound surfactant layers. As probed by exchange of a common parent nanotube population into sodium deoxycholate, sodium cholate, or sodium taurodeoxycholate solutions, the anhydrous density of the nanotubes was least for the sodium taurodeoxycholate surfactant, and the absolute sedimentation velocities greatest for the sodium cholate and sodium taurodeoxycholate surfactants. These results suggest that the thickest interfacial layer is formed by the deoxycholate, and that the taurodeoxycholate packs more densely than either sodium cholate or deoxycholate. These structural differences correlate well to an observed 25% increase in fluorescence intensity relative to the cholate surfactant for deoxycholate and taurodeoxycholate dispersed SWCNTs displaying equivalent absorbance spectra. Separate sedimentation velocity experiments including the density modifying agent iodixanol were used to establish the buoyant density of the (6,5) SWCNT in each of the bile salt surfactants; from the difference in the buoyant and anhydrous densities, the largest hydrated diameter is observed for sodium deoxycholate. Understanding the effects of dispersant choice and the methodology for measurement of the interfacial density and hydrated diameter is critical for rationally advancing separation strategies and applications of nanotubes.

Procedure for Decellularization of Porcine Heart by Retrograde Coronary Perfusion

Perfusion-based whole organ decellularization has recently gained interest in the field of tissue engineering as a means to create site-specific extracellular matrix scaffolds, while largely preserving the native architecture of the scaffold. To date, this approach has been utilized in a variety of organ systems, including the heart, lung, and liver (1-5). Previous decellularization methods for tissues without an easily accessible vascular network have relied upon prolonged exposure of tissue to solutions of detergents, acids, or enzymatic treatments as a means to remove the cellular and nuclear components from the surrounding extracellular environment(6-8). However, the effectiveness of these methods hinged upon the ability of the solutions to permeate the tissue via diffusion. In contrast, perfusion of organs through the natural vascular system effectively reduced the diffusion distance and facilitated transport of decellularization agents into the tissue and cellular components out of the tissue. Herein, we describe a method to fully decellularize an intact porcine heart through coronary retrograde perfusion. The protocol yielded a fully decellularized cardiac extracellular matrix (c-ECM) scaffold with the three-dimensional structure of the heart intact. Our method used a series of enzymes, detergents, and acids coupled with hypertonic and hypotonic rinses to aid in the lysis and removal of cells. The protocol used a Trypsin solution to detach cells from the matrix followed by Triton X-100 and sodium deoxycholate solutions to aid in removal of cellular material. The described protocol also uses perfusion speeds of greater than 2 L/min for extended periods of time. The high flow rate, coupled with solution changes allowed transport of agents to the tissue without contamination of cellular debris and ensured effective rinsing of the tissue. The described method removed all nuclear material from native porcine cardiac tissue, creating a site-specific cardiac ECM scaffold that can be used for a variety of applications.

Oxidation‐induced the Formation of Vesicles from Ferrocene Derivative Superamphiphiles

AbstractThe stimuli‐responsive vesicles were prepared via electrochemical oxidation on the mixture solution of ferrocenylmethyl‐trimethylammonium iodide (FcMI) and sodium deoxycholate (NaDC). The vesicle structure and morphology are characterized respectively by transmission electron microscopy (TEM), dynamic light scattering (DLS) and atomic force microscopy (AFM). The vesicle shells can be clearly observed by TEM with the thickness ranging from several to several tens of nanometers and their outer diameters at the range of 50‐200 nm. The formation of vesicular structures is also supported via AFM measurements, and the ratio of the diameter and height of the nanospheres was estimated to be ca. 10, indicating the shell collapse. The obtained results are significant for the preparation of smart supramolecular aggregates.

Construction and transformation of stimuli-responsive vesicles from the ferrocene derivative supramolecular amphiphiles

The tough stimuli-responsive vesicles were prepared via electrochemical oxidation on the mixture solution of ferrocenylmethyl-trimethylammonium iodide (FcMI) and sodium deoxycholate (NaDC). The vesicle structure and morphology are characterized respectively by transmission electron microscopy (TEM), dynamic light scattering (DLS) and atomic force microscopy (AFM). The vesicle shells can be clearly observed by TEM with the thickness ranging from several to several tens of nanometers and their outer diameters at the range of 50–200nm. The formation of vesicular structures is also supported via AFM measurements. Such tough vesicles made up of ferrocene and deoxycholate blocks are redox-responsive, and their assembly or disassembly behaviors may be controlled by electrochemical methods through the change of ferrocene states between the neutral hydrophobic and the hydrophilic ferrocenium cation. In addition, the stimuli-responsive vesicles can also be formed from the supramolecular inclusion complex between the ferrocene blocks and the β-cyclodextrin hosts, which can then be transformed into nanotubes with time. The obtained results are significant for the preparation of smart supramolecular aggregates.

The separation single-wall carbon nanotubes on length by sepharose gel

The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM and Raman were used to characterize the length of nanotube bundles. The results show that the longer nanotubes were eluted out first, and then the shorter tubes were followed by the sodium dodecyl sulfate. However, the separated order was totally reversed by the sodium deoxycholate. By this method, the process generated nanotube fractions not only were narrower in length distributions, but also could control the separation orders by changing the eluents. Moreover, the separation principle was also discussed.

Micellization in sodium deoxycholate solutions

NMR self-diffusion, tensiometry, and measurement of solubilization capacity are employed to comparatively study micellization in aqueous solutions of a facial amphiphilic compound, sodium deoxycholate (NaDC), and a conventional micelle-forming sodium dodecyl sulfate. Based on the two-state model, which is commonly used to analyze the data of NMR diffusometry, a method is proposed for determining variable sizes of NaDC micelles. It is shown that, in the concentration range from the critical micelle concentration to 0.1 M, the sizes of NaDC micelles monotonically increase. At comparable sizes of molecules of the examined surfactants, NaDC micelles are characterized by noticeably smaller aggregation numbers and solubilization capacity than sodium dodecyl sulfate due to the rigid structure of NaDC molecules, their facial amphiphilicity, and a low value of hydrophilic-lipophilic balance.

Surfactant free fractions of metallic and semiconducting single-walled carbon nanotubes via optimised gel chromatography

We report the procedure of sorting/purification of carbon nanotubes by electronic type using chromatographic column with sodium dodecylsulfate (SDS) and sodium deoxycholate (DOC) solutions as the eluents. The non-commercial agarose gel in different concentrations has been tested in the process. It was found that in optimal gel concentration the fractionation resulted in ∼96.2% yield of semiconducting species. Importantly, to get surfactant-free fractions the post-separation purification procedure has been carried out. The UV–vis–NIR and Raman spectroscopy have been utilised for the samples analysis. High resolution transmission microscopy and thermogravimetric analysis allowed to study the sample morphology and purity, respectively.