Effect of Adding Lecithin and Nonionic Surfactant on α-Gels Based on a Cationic Surfactant-Fatty Alcohol Mixture.

α-Gels are often used as base materials for cosmetics and hair conditioners. α-Gel-based commercial products typically contain many types of additives, such as polymers, electrolytes, oily components, and other surfactants, in addition to the three basic components. However, few systematic studies have been conducted on the effect of such additives on α-gels. In this study, we chose surfactant as an example to initiate the effect of such additives on the structure and rheological properties of α-gel samples formulated using cetyl alcohol (C16OH) and cetyltrimethylammonium chloride (CTAC). Optical microscopy analysis demonstrated that the size of the vesicles in the α-gel samples in this study was decreased via the addition of hydrogenated soybean lecithin (HSL) and penta(oxyethylene) cetyl ether (C16EO5), a nonionic surfactant, to them. Rheological measurements revealed that at high C16OH/CTAC ratios, the viscosity and yield stress of the α-gel samples decreased owing to the addition of surfactants to them. Conversely, at low C16OH/CTAC ratios, the opposite tendency was observed. Small-angle X-ray scattering analysis indicated that for the α-gel samples with high C16OH/CTAC ratios, the addition of HSL or C16EO5 to them decreased the interlayer spacing of their lamellar bilayer stack, which led to the changes in the rheological properties of the α-gel samples.

Cetyltrimethylammonium bromide-nanocrystalline cellulose (CTAB-NCC) based microemulsions for enhancement of topical delivery of curcumin.

Low bioavailability and poor water solubility have limited the utilization of curcumin in conventional dosing methods. As an alternative, microemulsions as drug carrier can improve curcumin delivery. A cetyltrimethylammonium bromide-nanocrystalline cellulose (CTAB-NCC)-based microemulsion was developed and its potential use as a topical delivery method for curcumin was investigated. The effect of microemulsion's particle size and its microstructure as well as the presence of the CTAB-NCC nanoparticle on the topical delivery of curcumin was studied. In vitro permeation studies showed higher penetration rate of curcumin from the oil-in-water type-microemulsions. The skin permeation profile of curcumin followed Higuchi release kinetics. Furthermore, use of the (CTAB-NCC)-based microemulsion enhanced curcumin accumulation in the skin and these system showed non cytotoxicity effect on L929 cell line. These results showed the potential of (CTAB-NCC)-based microemulsions as controlled-release topical systems for the delivery of curcumin and potentially other lipophilic drugs.

Assessing magnetic and inductive thermal properties of various surfactants functionalised Fe3O4 nanoparticles for hyperthermia.

This work reports the fabrication of magnetite (Fe3O4) nanoparticles (NPs) coated with various biocompatible surfactants such as glutamic acid (GA), citric acid (CA), polyethylene glycol (PEG), polyvinylpyrrolidine (PVP), ethylene diamine (EDA) and cetyl-trimethyl ammonium bromide (CTAB) via co-precipitation method and their comparative inductive heating ability for hyperthermia (HT) applications. X-ray and electron diffraction analyses validated the formation of well crystallined inverse spinel structured Fe3O4 NPs (crystallite size of ~ 8-10 nm). Magnetic studies confirmed the superparamagnetic (SPM) behaviour for all the NPs with substantial magnetisation (63-68 emu/g) and enhanced magnetic susceptibility is attributed to the greater number of occupations of Fe2+ ions in the lattice as revealed by X-ray photoelectron spectroscopy (XPS). Moreover, distinctive heating response (specific absorption rate, SAR from 130 to 44 W/g) of NPs with similar size and magnetisation is observed. The present study was successful in establishing a direct correlation between relaxation time (~ 9.42-15.92 ns) and heating efficiency of each surface functionalised NPs. Moreover, heat dissipated in different surface grafted NPs is found to be dependent on magnetic susceptibility, magnetic anisotropy and magnetic relaxation time. These results open very promising avenues to design surface functionalised magnetite NPs for effective HT applications.

Facile modification of graphene oxide and its application for the aqueous uranyl ion sequestration: Insights on the mechanism.

Graphene oxide (GO) has been proved with favorable affinity to U(VI), while some drawbacks such as poor dispersity and low adsorption performance limit its application. Herein, cetyltrimethylammonium bromide (CTAB) modified graphene oxide (MGO) composites were successfully fabricated, characterized and compared with graphene oxide (GO) in the sequestration of U(VI) in aqueous solutions. The results showed that maximum adsorption rate of MGO (99.21%) was obviously higher than that of GO (66.51%) under the same initial condition. Simultaneous introduction of C-H and NO coupled with the enhanced dispersity of GO after modification were mainly responsible for the updated performance verified with multiple characterization techniques. Based on the results of kinetics and isotherms investigations, the experimental data were best described by Pseudo-first-order kinetic model and Redlich-Peterson isotherm model. The results of ΔH, ΔS and ΔG show that adsorptive behaviors of uranyl ion on MGO are endothermic and spontaneous. The study provides a feasible alternative to the chemical modification of GO and enhancing the performance towards uranyl ion removal from solution.

Toxicity assessment of palladium oxide nanoparticles derived from metallosurfactants using multi assay techniques in Allium sativum.

In today's world, nanotechnology is reaching practically every ground and entering the human lifestyle by becoming a part of it. Thus, it is vital to check the cytotoxic and genotoxic effects of nanosubstances on plants, as they are the base constituent of ecosystem. The present work deals with the toxicity evaluation of metallosurfactant derived palladium oxide nanoparticles towards Allium sativum (Garlic cloves). The nanoparticles were prepared using microemulsion quenching method (a softer approach) using palladium metallosurfactants as precursors. The three ligands used were cetyltrimethylammonium chloride (CTAC), dodecylamine (DDA) and hexadecylamine (HEXA). Further, their characterization was done using TEM, Size Distribution curve, FESEM, EDS, XRD and Zeta potential. Garlic (Allium sativum) cloves were used to investigate the cytotoxicity and genotoxicity of fabricated PdO NPs. To check the cytotoxicity, optical microscopy was employed and for the genotoxic assessment, different parameters such as chromosomal aberrations in the mitosis, circular dichroism, and gel electrophoresis were utilized. From mitosis study, chromosomes aberrations were confirmed such as chromosomes stickiness, breakage, C-Mitosis, delay in anaphase, spindle fibre abnormality, laggard, vagrant and condensed chromosomes. Morphology of A. sativum clove, rooting and shooting pattern in the presence of PdO nanosuspension was observed. From all the experiments, it was concluded that all the three PdO nanosuspension are toxic in nature to both the cells and to genome, although, bishexadecyltrimethyl ammonium palladium tetrachloride (PdCTAC) Ns was found to be the most cytotoxic and genotoxic. Gel electrophoresis also confirmed the complete degradation of DNA in the presence of PdCTAC Ns.

Exploring the Interactions of Ruthenium (II) Carbosilane Metallodendrimers and Precursors with Model Cell Membranes through a Dual Spin-Label Spin-Probe Technique Using EPR.

Dendrimers exhibit unique interactions with cell membranes, arising from their nanometric size and high surface area. To a great extent, these interactions define their biological activity and can be reported in situ by spin-labelling techniques. Schiff-base carbosilane ruthenium (II) metallodendrimers are promising antitumor agents with a mechanism of action yet to explore. In order to study their in situ interactions with model cell membranes occurring at a molecular level, namely cetyltrimethylammonium bromide micelles (CTAB) and lecithin liposomes (LEC), electron paramagnetic resonance (EPR) was selected. Both a spin probe, 4-(N,N-dimethyl-N-dodecyl)ammonium-2,2,6,6-tetramethylpiperidine-1-oxyl bromide (CAT12), able to enter the model membranes, and a spin label, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) covalently attached at newly synthesized heterofunctional dendrimers, were used to provide complementary information on the dendrimer-membrane interactions. The computer-aided EPR analysis demonstrated a good agreement between the results obtained for the spin probe and spin label experiments. Both points of view suggested the partial insertion of the dendrimer surface groups into the surfactant aggregates, mainly CTAB micelles, and the occurrence of both polar and hydrophobic interactions, while dendrimer-LEC interactions involved more polar interactions between surface groups. We found out that subtle changes in the dendrimer structure greatly modified their interacting abilities and, subsequently, their anticancer activity.

Facile synthesis of mesoporous alumina using hexadecyltrimethylammonium bromide (HTAB) as template: simplified sol-gel approach.

Herein the authors present the synthesis of surface functionalised mesoporous alumina (MeAl) for textural characterisation by a simplified sol-gel method obtained by using hexadecyltrimethylammonium bromide as a template. Etoricoxib (ETOX) was used as a model drug for the study. Alumina supported mesoporous material containing drug was characterised using instrumental technique namely Brunauer-Emmett-Teller surface area, Fourier transform-infrared, differential scanning calorimetry, transmission electron microscopy, X-ray diffraction, and field emission scanning electron microscopy. Diffusion study using a dialysis bag method used to check the release pattern of ETOX-loaded-MeAl. Results of characterisation study revealed the successful surface functionalisation of the drug on nanocomposite. The IC50 value obtained from cell viability study demonstrated the non-toxic behaviour of synthesised drug-loaded mesoporous alumina up to the tested concentration range. The present work has demonstrated that synthesised MeAl showed excellent stability with an expanded surface area suitable for carrier material for drug delivery system.

Eco-friendly walnut shell powder based facile fabrication of biogenic Ag-nanodisks, and their interaction with bovine serum albumin.

Walnut shell biomass was used for the extraction of juglone by water as a solvent at room temperature. Upon addition of AgNO3 to a dye solution, prefect transparent pale brown color develops within the reaction time. UV-visible spectroscopy revealed the appearance of surface plasmon absorption (SRP) peak at 410 nm for spherical silver nanoparticles (AgNPs). Transmission electron microscopy suggested the formation of spherical and truncated triangular nano-plate geometry of AgNPs with average diameter 25 nm. Juglone-surfactant interactions (micellization and incorporation) have been studied spectrophotometrically by using cationic cetyltrimethylammonium bromide (CTAB). The presence of CTAB has significant impacts on size, shape and the size distribution of AgNPs. The nucleation, growth, and adsorption processes depend on the [CTAB]. It also catalyzes the Ag+ ions reduction by juglone with a rate enhancement of ca. 100-fold. Activation parameters (activation energy, enthalpy of activation and entropy of activation) were evaluated to the synthesis of silver nano-disks. Antioxidant activity of juglone was accessed by the scavenging effect on DPPH radical. Silver nanoparticles was also used as quencher to determine their interaction with bovine serum albumin (BSA). The quenching constant were found to be 1.4 × 103 M-1 L s-1 and 4.8 × 103 M-1 L s-1 for two BSA concentrations.

Air assisted - vesicle based microextraction (AAVME) as a fast and green method for the extraction and determination of phenolic compounds in M. officinalis L samples.

In this research, a simple, rapid, and efficient air assisted - vesicle based microextraction (AAVME) approach was developed for the extraction of phenolic compounds and their analysis in different Melissa officinalis L. samples. The extraction method is based injection an aqueous mixture of CTAB and 5-methyl salicylic acid, into the hydroalcoholic plant extract in a conical test tube to form a cloudy solution. Suction and dispersion were then applied to accelerate the dispersion process. After centrifugation, the sediment phase was removed and injected into HPLC system. The optimized extraction conditions were as 450 µL of a mixture of CTAB and 5-methyl salicylic acid (3:5 mol ratios), 10.0 mL sample solution at pH 8.0 and 30 suction-dispersion cycles. Under these extraction conditions, the proposed method was able to provide a good linearity (R2 ≥ 0.9994) within the range of 0.5-2500.0 ng mL-1, low detection limits (0.1-0.5 ng mL-1), good extraction replicability (relative standard deviations below 3.5%, n = 7), and enrichment factors of 97-118. Finally, the developed method was successfully used for determining the mentioned analytes in Melissa officinalis samples. Recoveries for all compounds in real samples were between 82.5% and 91.8.

Effects of modified sediments from a eutrophic lake in removing phosphorus and inhibiting phosphatase activity.

Phosphorus is one of the main limiting and strong influencing factors of eutrophication, and phosphorus controlling in lake is of great significance for eutrophication. To do this, sediment materials were taken from Dianchi Lake, a typically eutrophic lake, and modified by hexadecyltrimethylammonium bromide (CTAB) and ZnSO4 to remove phosphorus and inhibit alkaline phosphatase activity (APA). Results indicated that phosphorus removal efficiencies of sediments modified by CTAB (S-CTAB), ZnSO4 (S-Zn), and oxidized sediments (OS) were higher than that of the raw sediment (RS). Ability to absorb phosphorus varied, following the order S-Zn>S-CTAB>OS>RS. Sorption was influenced by ionic strength, with the former decreasing with the increase of the latter. Freundlich model well described the sorption isotherm, with an R2 ranging from 0.9168 to 0.9958. Furthermore, compared with the raw sediments, the maximum phosphorus sorption capacities of S-Zn and S-CTAB increased by 12.2% and 124.5%, respectively. Results of desorption studies suggest that the desorption rate of S-Zn was from 3.88 to 13.76%, lower than that of other sediment materials. APA was inhibited by S-CTAB and S-Zn at the same time, with inhibition rates from 29.6% and 61.0% when the concentrations of S-CTAB and S-Zn were 10 nmol L-1 and 0.2 nmol L-1, respectively. This study provides new insights into phosphorus removal and phosphatase activity inhibition in water treatment.

Poly(d,l-lactic-co-glycolic acid) (PLGA) hollow fiber with segmental switchability of its chains sensitive to NIR light for synergistic cancer therapy.

This work introduces a new fibrous system for synergistic cancer therapy. The system consists of poly(d,l-lactic-co-glycolic acid) (PLGA) fibers with a core encapsulating an anticancer drug and a shell entrapping gold nanorods (AuNRs) as a photothermal agent. On exposure to NIR light, the photothermal agent generates heat to raise the local temperature of the fibers. If the temperature is above a glass transition (Tg) of the polymer, the polymer chains will be mobile, increasing free volume in size within the shell. As a result, a rapid release of the drug can be achieved. When NIR light is turned off, the release will stop with inactivity of the photothermal agent, followed by freezing the segmental motion of the polymer chains. The on-off switching of NIR light in a time-controllable manner allows a repeated and accurate release of the drug, leading to the significant enhancement of anticancer activity in combination with the hyperthermia effect arising from the photothermal agent.

BSA-bioinspired gold nanorods loaded with immunoadjuvant for the treatment of melanoma by combined photothermal therapy and immunotherapy.

The development of therapeutic methods that can effectively delay tumor growth, inhibit tumor metastases, and protect the host from tumor recurrence still faces challenges. Nanoparticle-based combination therapy may provide an effective therapeutic strategy. Herein, we show that bovine serum albumin (BSA)-bioinspired gold nanorods (GNRs) were loaded with an immunoadjuvant for combined photothermal therapy (PTT) and immunotherapy for the treatment of melanoma. In this work, cetyltrimethylammonium bromide (CTAB)-coated GNRs were successively decorated with polyethylene glycol (PEG) and BSA, and loaded with an immunoadjuvant imiquimod (R837). The synthesized mPEG-GNRs@BSA/R837 nanocomplexes under near-infrared (NIR) irradiation could effectively kill tumors and trigger strong immune responses in treating metastatic melanoma in mice. Furthermore, the nanocomplex-based PTT prevented lung metastasis and induced a strong long-term antitumor immunity to protect the treated mice from tumor recurrence. The nanocomplex-based PTT in combination with immunotherapy may be potentially employed as an effective strategy for the treatment of melanoma and other metastatic cancers.

Rapid, simple and potentially universal method for DNA extraction from Opuntia spp. fresh cladode tissues suitable for PCR amplification.

In Opuntia spp., the cladode tissues contain many polysaccharides and secondary metabolites that interfere with obtaining high-quality deoxyribonucleic acid (DNA), using currently available methods. To circumvent this problem, three commercial kits, three modified versions of the conventional cetyltrimethylammonium bromide method (CTAB) method and one combined method were tested in Opuntia ficus-indica, O. robusta, O. dillenii and O. elata species. We obtained a rapid and simple protocol that allows the extraction of DNA from all the tested species with good DNA yield and purity, namely, the combined method. With this method (DNeasy® Plant Mini Kit combined with the CTAB method), DNA yields from 13.2 ± 7.8 to 15.9 ± 11.3 µg g-1 of fresh tissue were obtained in the four Opuntia species. The purity, evaluated by the ratio A260/A280 ratio, ranged from 1.67 ± 0.12 to 2.01 ± 0.25, revealing low levels of problematic metabolites. The extracted DNA quality was confirmed by amplifying a set of nuclear microsatellites obtained for the genus. Reliable reproducible bands and electropherogram profiles were obtained. The combined method has potential to be universal for good-quality DNA extraction in cacti, particularly in the Opuntia genus and other difficult-to-extract species.

Plant Genomic DNA Extraction for Selected Herbs and Sequencing their Internal Transcribed Spacer Regions Amplified by Specific Primers.

This study was focused on plant genomic DNA extraction and sequencing from five commonly used medicinal herbs, namely Impatiens balsamina, Ficus deltoidea, Centella asiatica, Andrographis paniculata and Orthosiphon aristatus. This molecular technique is another highly reliable alternative for plant species identification besides phytochemical profiling. Three cetyl hexadecyltrimethylammonium bromide (CTAB) based methods with slight modification on incubation time, salt content and other additives were used for DNA extraction. The CTAB method of Doyle and Doyle produced higher DNA concentration from L balsamina, most probably due to the presence of ammonium acetate in the washing buffer and longer incubation time (2 h). The CTAB based method was suitable for A. paniculata because a high DNA concentration of acceptable quality was obtained for all the modified methods. However, Ο. aristatus was likely to have a lower DNA concentration (33-87 µg/g) and quality, probably due to the high concentration of phenolic compounds, particularly rosmarinic acid. The extracted genomic DNA was effectively amplified by a polymerase chain reaction using a universal primer of internal transcribed spacer (ITS), particularly AB 101 and AB 102 at the optimum annealing temperature of 48°C. The DNA sequences were analyzed by phenetic analysis and it was found that they have high similarity with the nucleotide sequences of ITS regions for similar plant species in the GenBank database of the National Center for Biotechnology Information.