Epidemiology of fragility fracture of the pelvic ring: a regional population-based study in Northern Japan.

Using a regional population-based dataset in Japan, we identified the epidemiological characteristics of patients with fragility fractures of the pelvic ring. The incidence rate was 35.5-121.2 per 100,000 population/year. Age-specific incidence increased after 75 years. This fracture is associated with worse prognosis in terms of walking function and life expectancy. PURPOSE: Fragility fracture of the pelvic ring (FFP) is common among older patients; however, little information is available on the epidemiology of FFP worldwide. We aimed to identify the epidemiological characteristics of patients with FFP using a regional population-based dataset in Japan. METHODS: This descriptive epidemiologic study analyzed data obtained from clinical information of patients diagnosed with FFP from January 1, 2011 through December 31, 2020 at a regional dominant hospital in Japan. We calculated the crude and age-adjusted annual incidences and the age-specific incidence and described epidemiological date, injury characteristics, walking ability before and after FFP, and mortality. Additionally, we investigated factors associated with walking ability. RESULTS: We identified 66 FFP patients, of whom 55 (83.3%) were female, with a mean age of 82.2 years. The crude annual incidence of FFP ranged from 35.5-121.2 per 100,000 population/year during the study period. The age-specific incidence of FFP increased after 75 and 80 years in females and males, respectively. In total, 44.4% of patients had declines in walking ability 1 year after their FFP injuries. Patients with declining walking ability were significantly older (p < 0.01), and age ≥ 80 years was significantly associated with the decline in walking ability (p < 0.01). The 1- and 5-year mortality rates were 15.4% and 39.9%, respectively. CONCLUSION: The incidence rate of FFP was 35.5-121.2 per 100,000 population/year. Age-specific incidence of FFP increased after 75 years. Our results indicate that FFP is associated with worse prognosis of walking function and life expectancy.

Epidemiology of distal radius fracture: a regional population-based study in Japan.

BACKGROUND: Distal radius fracture (DRF) is very common worldwide. In particular, aging countries have numerous patients with DRF, resulting in an urgent need for active preventive measures. As few epidemiological studies have investigated DRF in Japan, we aimed to identify the epidemiological characteristics of patients of all ages with DRF in Japan. METHODS: This descriptive epidemiologic study analyzed data obtained from clinical information of patients diagnosed with DRF from January 1, 2011, to December 31, 2020, at a prefectural hospital in Hokkaido, Japan. We calculated the crude and age-adjusted annual incidences of DRF and described the age-specific incidence, injury characteristics (injury location and cause, seasonal differences, and fracture classification), and 1- and 5-year mortality rates. RESULTS: A total of 258 patients with DRF were identified, of which 190 (73.6%) were female and the mean age (standard deviation) was 67.0 (21.5) years. The crude annual incidence of DRF ranged from 158.0 to 272.6 per 100,000 population/year, and the age-adjusted incidence among female patients demonstrated a significant decreasing trend during 2011-2020 (Poisson regression analysis; p = 0.043). The age-specific incidence differed by sex, with peaks at 10-14 years for males and 75-79 years for females. The most common cause of injury was a simple fall in patients > 15 year of age and sports injuries in patients ≤ 15 years of age. DRFs were most frequently sustained outdoors and were more common in the winter season. In patients > 15 years of age, the proportions of AO/OTA fracture types A, B, and C were 78.7% (184/234), 1.7% (4/234), and 19.6% (46/234), respectively, and 29.1% (68/234) of patients received surgical treatment for DRF. The 1- and 5-year mortality rates were 2.8% and 11.9%, respectively. CONCLUSIONS: Our findings were mostly consistent with previous global studies. Although the crude annual incidence of DRF was relatively high because of recent population aging, the age-adjusted annual incidence among female patients showed a significant decreasing trend during this decade.

Scallop aquaculture has a potential risk of natto-induced hypersensitivity reactions in a local area of northern Japan.

BACKGROUND: Fermented soybean (natto)-induced hypersensitivity reactions (natto allergy) are rare and can result in late-onset anaphylaxis. The allergen in natto is considered to be poly-γ-glutamic acid (PGA), and marine sports are a risk factor for natto allergy due to epicutaneous sensitization to PGA from cnidarian stings. However, no research on natto allergy in fishery workers has yet been performed. METHODS: We conducted a chart review of inpatients diagnosed with anaphylaxis due to natto at Hokkaido Prefectural Haboro Hospital between April 1, 2009, and August 31, 2020. We also administered self-report questionnaires about food hypersensitivity reactions to Japanese fishery workers, including members of the Kitarumoi Fishery Cooperative Association and part-time workers in this area, from February 1 to May 31, 2021. RESULTS: We found six inpatients (29 inpatients with food-induced anaphylaxis among approximately 11,000 community-dwelling residents) with late-onset anaphylaxis due to natto; all were involved in scallop aquaculture. The questionnaires revealed that 27 participants had natto allergy. We divided the fishery workers into a scallop aquaculture (Scallop) group (n = 211) and other fishery group (n = 106). The Scallop group was significantly associated with natto allergy after adjustments for confounders (OR: 5.73, 95% CI: 1.46-22.56) by logistic regression analysis. In the Scallop group, older age, experience in repairing nets, and a longer length of work experience were significantly related to participants with natto allergy (n = 23), but not participants without natto allergy (n = 181). CONCLUSIONS: Our results indicated an association between scallop aquaculture and natto allergy.

Effect of polyols on membrane structures of liposomes: A study using small-angle X-ray scattering data and generalized indirect Fourier transformation.

This study aimed to evaluate the membrane structure of distearoylphosphatidylcholine (DSPC) liposomes dispersed in water containing various types of polyols with low molecular weight such as glycerin (Gly), 1,3-butandiol (BG), and propylene glycol (PG). To clarify the detailed membrane structure, generalized indirect Fourier transformation (GIFT) analysis, which provides information about the bilayer spacing, bilayer thickness, number of lamellar layers, and membrane flexibility, was applied to small-angle X-ray scattering (SAXS) data of the present system. The GIFT results showed that the bilayer thickness of the DSPC liposomes followed the order Gly>>BG>PG. In addition, the membrane flexibility estimated by the Caille parameter was in the order Gly>>BG>PG; this result was supported by the gel-liquid crystal phase transition temperature (Tc) obtained by differential scanning calorimetry (DSC). These results, together with the Raman spectra, suggest that BG and PG incorporated into the bilayers of DSPC liposomes result in the formation of an interdigitated lamellar structure.

Direct entry of cell-penetrating peptide can be controlled by maneuvering the membrane curvature.

A biomembrane's role is to be a barrier for interior cytosol from an exterior environment to execute the cell's normal biological functions. However, a water-soluble peptide called cell-penetrating peptide (CPP) has been known for its ability to directly penetrate through the biomembranes into cells (cytolysis) without perturbating cell viability and expected to be a promising drug delivery vector. Examples of CPP include peptides with multiple arginine units with strong cationic properties, which is the key to cytolysis. Here we show the conclusive evidence to support the mechanism of CPP's cytolysis and way to control it. The mechanism we proposed is attributed to biomembrane's physicochemical nature as lamellar liquid crystal (Lα). Cytolysis occurs as the temporal and local dynamic phase transitions from Lα to an undulated lamellar with pores called Mesh1. We have shown this phase transfer of Lα composed of dioleoyl-phosphatidylcholine (DOPC) with water by adding oligo-arginine (Rx) as CPP at the equilibrium. Using giant unilamellar vesicle composed of DOPC as a single cell model, we could control the level of cytolysis of CPP (FITC-R8) by changing the curvature of the membrane through osmotic pressure modulation. The cytolysis of CPP utilizes biomembrane's inherent topological and functional flexibility corresponding to the stimuli.

Effect of Vesicle Size on the Cytolysis of Cell-Penetrating Peptides (CPPs).

A specific series of peptides, called a cell-penetrating peptide (CPP), is known to be free to directly permeate through cell membranes into the cytosol (cytolysis); hence, this CPP would be a potent carrier for a drug delivery system (DDS). Previously, we proposed the mechanism of cytolysis as a temporal and local phase transfer of membrane lipid caused by positive membrane curvature generation. Moreover, we showed how to control the CPP cytolysis. Here, we investigate the phospholipid vesicle's size effect on CPP cytolysis because this is the most straightforward way to control membrane curvature. Contrary to our expectation, we found that the smaller the vesicle diameter (meaning a higher membrane curvature), the more cytolysis was suppressed. Such controversial findings led us to seek the reason for the unexpected results, and we ended up finding out that the mobility of membrane lipids as a liquid crystal is the key to cytolysis. As a result, we could explain the cause of cytolysis suppression by reducing the vesicle size (because of the restriction of lipid mobility); osmotic pressure reduction to enhance positive curvature generation works as long as the membrane is mobile enough to modulate the local structure. Taking all the revealed vital factors and their effects as a tool, we will further explore how to control CPP cytolysis for developing a DDS system combined with appropriate cargo selection to be tagged with CPPs.

Key Process and Factors Controlling the Direct Translocation of Cell-Penetrating Peptide through Bio-Membrane.

Cell-penetrating peptide (CPP) can directly penetrate the cytosol (cytolysis) and is expected to be a potent vector for a drug delivery system (DDS). Although there is general agreement that CPP cytolysis is related to dynamic membrane deformation, a distinctive process has yet to be established. Here, we report the key process and factors controlling CPP cytolysis. To elucidate the task, we have introduced trypsin digestion of adsorbed CPP onto giant unilamellar vesicle (GUV) to quantify the adsorption and internalization (cytolysis) separately. Also, the time-course analysis was introduced for the geometric calculation of adsorption and internalization amount per lipid molecule consisting of GUV. As a result, we found that adsorption and internalization assumed to occur successively by CPP molecule come into contact with membrane lipid. Adsorption is quick to saturate within 10 min, while cytolysis of each CPP on the membrane follows successively. After adsorption is saturated, cytolysis proceeds further linearly by time with a different rate constant that is dependent on the osmotic pressure. We also found that temperature and lipid composition influence cytolysis by modulating lipid mobility. The electrolyte in the outer media is also affected as a chemical mediator to control CPP cytolysis by following the Hoffmeister effect for membrane hydration. These results confirmed the mechanism of cytolysis as temporal and local phase transfer of membrane lipid from Lα to Mesh1, which has punctured bilayer morphologies.

Phase Behavior and Polymerization of the Ternary Polymerizable Cationic Gemini Surfactant/Fatty Alcohol/Water System.

We studied the phase behavior of a ternary polymerizable gemini surfactant (PC11-6-11)/1-undecanol/water system and stabilized these liquid crystalline structures through the polymerization of surfactants. The addition of 1-undecanol to a PC11-6-11/water system formed bicontinuous cubic (V1) and reversed hexagonal (H2) liquid crystal phases in addition to hexagonal (H1) and lamellar (Lα) phases, which were also formed using the binary system of PC11-6-11/water. These new phases were formed because the fatty alcohol penetrated the palisade layer of the PC11-6-11 micelles. The polymerization of PC11-6-11 with a thermal initiator successfully preserved the Lα and H2 phases. Layered or honeycomb structures of these liquid crystals were clearly observed by transmission electron microscopy. The nanomaterials have potential applications as membranes for nano- or microfiltration and catalyst support materials.

Traditional uses, phytochemistry, and pharmacology of Ficus hispida L.f.: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Ficus hispida L.f. (Moraceae) has long been used as a traditional medicine in India, China, Sri Lanka, Australia, and Myanmar in the treatment of diarrhea, ulcer, anemia, diabetes, inflammation, and cancer. AIM OF THE REVIEW: This review provides a systematic comment on the botany, traditional uses, and phytochemical and pharmacological studies of F. hispida, with an aim to make critical update of the current knowledge and obtain opportunities for further therapeutic potential. MATERIALS AND METHODS: The information was derived from scientific literature databases including PubMed, Baidu Scholar, Google Scholar, Web of Science, and Science Direct. Additional information was gathered from books, Ph.D. and M.Sc. dissertations, and unpublished materials. RESULTS AND DISCUSSION: F. hispida is used especially in Chinese and Indian traditional medical systems as a remedy for skin disorders, respiratory diseases, and urinary diseases. Wound healing, anti-inflammatory, antinociceptive, sedative, antidiarrheal, antiulcer, antimicrobial, antioxidant, hepatoprotective, antineoplastic, and antidiabetic activities have been reported for crude extracts and isolated metabolites, but the methodologies in these studies often have inadequate design and low technical quality. More than 76 compounds have been isolated from F.hispida, including sesquiterpenoids and triterpenoids, flavonoids, coumarins, phenylpropionic acids, benzoic acid derivatives, alkaloids, steroids, other glycosides, and alkanes, but the method of bioassay-guided fractionation is seldom applied in the isolation from F. hispida. CONCLUSION: F. hispida is used widely in traditional medicines and has multiple pharmacological effects that could support traditional uses. However, pharmacological studies should be viewed with caution because of the inappropriate experimental design. More in vitro and in vivo research is urgently needed to study the molecular mechanisms and assess the effective and safe dose of F. hispida.

Vitellaria paradoxa nutshells from seven sub-Saharan countries as potential herbal medicines for treating diabetes based on chemical compositions, HPLC fingerprints and bioactivity evaluation.

The aim of the study was to determine the feasibility of the Vitellaria paradoxa nutshell as a new medicinal resource for treating diabetes. A total of forty-one compounds were identified by HPLC-DAD-Q-TOF-MS and phytochemical methods in V. paradoxa nutshell methanol extract. Based on HPLC fingerprints, four characteristic constituents were quantified and the origin of twenty-eight V. paradoxa nutshells from seven sub-Saharan countries was compared, which were classified into three groups with chemometric method. Twenty-eight samples contained high total phenolic content, and exhibited moderate-higher antioxidant activity and strong α-glucosidase inhibitory activity. Furthermore, all fractions and isolated compounds were evaluated for their antioxidant and α-glucosidase inhibitory activities, and α-glucosidase inhibitory action mechanism of four characteristic constituents including protocatechuic acid, 3, 5, 7-trihydroxycoumarin, (2R, 3R)-(+)-taxifolin and quercetin was investigated via molecular docking method, which were all stabilized by hydrogen bonds with α-glucosidase. The study provided an effective approach to waste utilization of V. paradoxa nutshell, which would help to resolve waste environmental pollution and provide a basis for developing potential herbal resource for treating diabetes.

Potent Anti-Proliferation on the Colon Cancer Cell Line (HT-29) of Liposomal Formulations Entrapped with Semi-Purified Job's Tears (Coix lacryma-jobi Linn.) Fractions.

Liposomes, entrapped with Job's Tears fractions, were prepared by the supercritical carbon dioxide fluid (scCO2) technique with and without sonication. Physical characteristics, which were the particle size, zeta potential, vesicular morphology, microviscosity and bioactivities including anti-proliferative, apoptotic and antioxidative activities of the S1L-S5L liposomal systems, were investigated. The potent anti-proliferative activity with the IC50 value of 4.44±2.31 ug/ml in a colon cancer cell (HT-29) was observed in the S5L. S5L also showed the apoptotic activity of 4.45±0.92% in an HT-29 cell. For antioxidative activities, the S3L showed the highest free radical scavenging activity and lipid peroxidation inhibition, whereas the S4L gave the highest metal chelating activity. This study has demonstrated the potent anti-proliferative activity on an HT-29 cell of the S5L liposomal formulation prepared by the scCO2 technique which can be further developed towards a novel anticancer drug.

C21 steroids from Streptocaulon juventas (Lour) Merr. induce apoptosis in HepG2.

Three new C21 steroids, i.e., (3ß,17α,20S)-pregn-5(6)-ene-3, 17, 20-triol-3-O-ß-d-digitalopyranosyl-(1 → 4)-ß-d-digitalopyranoside (4), (3ß,17α,20S)-pregn-5(6)-ene-3, 17, 20-triol-20-O-ß-d-glucopyranosyl-(1 → 6)-ß-d-glucopyranosyl-(1 → 2)-ß-d-digital-opyranoside (8), (3ß, 20R)-pregn-14(15)-ene-3, 20, 21-triol-3-O-ß-d-glucopy-ranoside (10), along with ten known C21 steroids were isolated from Streptocaulon juventas. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic techniques, mass spectrometry as well as comparison with the literature. All the isolated compounds were screened for their in vitro cytotoxicity against human liver cancer cells (HepG2) and the structure-activity relationships were also analyzed. Moreover, compounds 1-3, 5, 10-12, which displayed cytotoxic activities in HepG2 cells, were tested for the selective index (SI) by the ratio of cytotoxic effect on human hepatocytes (LO2) to that on HepG2. As a result, new compound 10 exhibited a good inhibitory activity against HepG2 with IC50 value 11.7 µM as well as high SI value 3.5. Furthermore, compound 10 could induce HepG2 cells apoptosis by flow cytometry.

Six underlying health conditions strongly influence mortality based on pneumonia severity in an ageing population of Japan: a prospective cohort study.

BACKGROUND: Mortality prediction of pneumonia by severity scores in patients with multiple underlying health conditions has not fully been investigated. This prospective cohort study is to identify mortality-associated underlying health conditions and to analyse their influence on severity-based pneumonia mortality prediction. METHODS: Adult patients with community-acquired pneumonia or healthcare-associated pneumonia (HCAP) who visited four community hospitals between September 2011 and January 2013 were enrolled. Candidate underlying health conditions, including demographic and clinical characteristics, were incorporated into the logistic regression models, along with CURB (confusion, elevated urea nitrogen, tachypnoea, and hypotension) score as a measure of disease severity. The areas under the receiver operating characteristic curves (AUROC) of the predictive index based on significant underlying health conditions was compared to that of CURB65 (CURB and age ≥ 65) score or Pneumonia severity index (PSI). Mortality association between disease severity and the number of underlying health conditions was analysed. RESULTS: In total 1772 patients were eligible for analysis, of which 140 (7.9%) died within 30 days. Six underlying health conditions were independently associated: home care (adjusted odds ratio, 5.84; 95% confidence interval, CI, 2.28-14.99), recent hospitalization (2.21; 1.36-3.60), age ≥ 85 years (2.15; 1.08-4.28), low body mass index (1.99, 1.25-3.16), neoplastic disease (1.82; 1.17-2.85), and male gender (1.78; 1.16-2.75). The predictive index based on these conditions alone had a significantly or marginally higher AUROC than that based on CURB65 score (0.78 vs 0.66, p = 0.02) or PSI (0.78 vs 0.71, p = 0.05), respectively. Compared to this index, the AUROC of the total score consisting of six underlying health conditions and CURB score (range 0-10) did not improve mortality predictions (p = 0.3). In patients with one or less underlying health conditions, the mortality was discretely associated with severe pneumonia (CURB65 ≥ 3) (risk ratio: 7.24, 95%CI: 3.08-25.13), whereas in patients with 2 or more underlying health conditions, the mortality association with severe pneumonia was not detected (risk ratio: 1.53, 95% CI: 0.94-2.50). CONCLUSIONS: Mortality prediction based on pneumonia severity scores is highly influenced by the accumulating number of underlying health conditions in an ageing society. The validation using a different cohort is necessary to generalise the conclusion.

Chemical Constituents of the Seed Cake of Camellia oleifera and Their Antioxidant and Antimelanogenic Activities.

There is a growing interest in the exploitation of agricultural byproducts. This study explored the potential beneficial health effects from the main biowaste, tea seed pomace of Camellia oleifera Abel (Theaceae), produced when tea seed is processed. Eighteen compounds were isolated from the 70% EtOH extract of the seed cake of C. oleifera. Their structures were determined by ESI-MS, 1 H- and 13 C-NMR together with literature data. All fractions and compounds were evaluated for the antioxidant and melanogenesis inhibitory activities. As the result, AcOEt fraction has the best in vitro antioxidant and antimelanogenesis activities, compounds 7 - 12 and 15 showed remarkable antioxidant activity, compounds 4, 6, 8, and 15 - 17 exhibited superior inhibitory activities against melanogenesis. Furthermore, tyrosinase inhibitory activity assay suggested that compound 8 could suppress melanogenesis by inhibiting the expression of tyrosinase.

Characterization of the micelle structure of oleic acid-based gemini surfactants: effect of stereochemistry.

In this study, we synthesize a novel oleic acid-based gemini surfactant with carboxylate headgroups, and study the effect of stereochemistry (anti- vs. syn-) on self-aggregation properties in water. We investigate these properties using phase diagrams, static surface tension, and one-dimensional and two-dimensional nuclear magnetic resonance (NMR) measurements. We find that a phase transition from a hexagonal liquid crystal (H1) phase to a lamellar liquid crystal (Lα) phase occurs at a lower surfactant concentration in the syn form, when compared with the anti form. In addition, the syn form gemini surfactant forms micelles with a close packing of the headgroups via hydrogen bonding. This was supported by static surface tensiometry; the area occupied by surfactant molecules at the air/aqueous solution interface is smaller for the syn form than for the anti form. We propose that, for the syn form gemini surfactant, the closer packing of the headgroups as well as the hydrogen bonding network around the micelle interface prevent water penetration into the hydrophobic part of the micelle.

Small Angle X-ray Scattering and Electron Spin Resonance Spectroscopy Study on Fragrance Infused Cationic Vesicles Modeling Scent-Releasing Fabric Softeners.

Industrially relevant systems for household and personal-care products often involve a large number of components. Such multiple component formulations are indispensable and effective for functionalization of the products, but may simultaneously provide more complex structural features compared to those in ideal systems comprising a smaller number of highly pure substances. Using cryogenic transmission electron microscopy (cryo-TEM), small angle X-ray scattering (SAXS), and electron spin resonance (ESR) spectroscopy, we have investigated effects of fragrance-incorporation into cationic vesicles on their bilayer structures and membrane-membrane interactions. Cationic vesicles were prepared from TEQ surfactant, whose major component was di(alkyl fatty ester) quaternary ammonium methosulfate, and fragrance components, l-menthol, linalool, and d-limonene, were infused into the vesicle membranes to model scent-releasing fabric softeners. The cryo-TEM images confirm formation of multilamellar vesicles (MLVs). Generalized indirect Fourier transformation (GIFT) analysis of the SAXS intensities based on the modified Caillé structure factor model reveals that incorporation of a more hydrophobic fragrance component leads to a more pronounced increase of the surface separation (water layer thickness). Furthermore, the fragrance-infused systems show longer-range order of the bilayer correlations and enhanced undulation fluctuation of the membranes than those in the TEQ alone system. The spin-label ESR results indicate different restricted molecular motions in the TEQ bilayers depending on the labeled position and their marked changes upon addition of the fragrance components, suggesting different mixing schemes and solubilization positions of the fragrance molecules in the TEQ bilayers. The present data have demonstrated how the infused fragrance molecules having different hydrophobicity and molecular architectures into the cationic vesicles affect the membrane structures and the intermembrane interactions, which may provide useful information for precisely controlling a fragrance-releasing property.

High-Power Abiotic Direct Glucose Fuel Cell Using a Gold-Platinum Bimetallic Anode Catalyst.

We developed a high-power abiotic direct glucose fuel cell system using a Au-Pt bimetallic anode catalyst. The high power generation (95.7 mW cm-2) was attained by optimizing operating conditions such as the composition of a bimetallic anode catalyst, loading amount of the metal catalyst on a carbon support, ionomer/carbon weight ratio when the catalyst was applied to the anode, glucose and KOH concentrations in the fuel solution, and operating temperature and flow rate of the fuel solution. It was found that poly(N-vinyl-2-pyrrolidone)-stabilized Au80Pt20 nanoparticles (mean diameter 1.5 nm) on a carbon (Ketjen Black 600) support function as a highly active anode catalyst for the glucose electrooxidation. The ionomer/carbon weight ratio also greatly affects the cell properties, which was found to be optimal at 0.2. As for the glucose concentration, a maximum cell power was derived at 0.4-0.6 mol dm-3. A high KOH concentration (4.0 mol dm-3) was preferable for deriving the maximum power. The cell power increased with the increasing flow rate of the glucose solution up to 50 cm3 min-1 and leveled off thereafter. At the optimal condition, the maximum power density and corresponding cell voltage of 58.2 mW cm-2 (0.36 V) and 95.7 mW cm-2 (0.34 V) were recorded at 298 and 328 K, respectively.

Physicochemical Understanding of Self-Aggregation and Microstructure of a Surface-Active Ionic Liquid [C4mim] [C8OSO3] Mixed with a Reverse Pluronic 10R5 (PO8EO22PO8).

Physicochemical studies on aqueous mixtures of ionic liquids (ILs) and reverse pluronics are limited. Self-aggregation dynamics and microstructure of a surface-active IL (SAIL), 1-butyl-3-methylimidazolium octylsulfate [C4mim] [C8OSO3], in the presence of a reverse pluronic, PO8EO22PO8 (known as 10R5), were studied using isothermal titration calorimetry (ITC), high-resolution nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS) methods. Also, cryo-/freeze-fracture transmission electron microscopy was employed to determine the microstructures of SAIL/10R5 mixtures. The ITC and NMR results revealed facilitation of SAIL aggregation in the presence of 10R5 forming mixed aggregates as well as free SAIL micelles. 2H spin relaxation rate data pointed out the onset of slow dynamics of the aqueous SAIL/10R5 mixture with an increase in either the former or the latter. Globular morphologies of the mixed species as well as their individual components were corroborated from the measurements. The preferential location of interaction of the SAIL with the 10R5 was identified from 13C NMR chemical shift findings to be in the interfacial region of the assembled SAIL. The formed species were mixed interacted aggregates but not mixed micelles that arise from mixed surfactants. The physicochemical information acquired herein would enrich the literature on the 10R5/SAIL mixed microheterogeneous systems having importance in the making of useful green drug carrier systems and templates for the synthesis of nanomaterials.

Photoinduced viscosity control of lecithin-based reverse wormlike micellar systems using azobenzene derivatives.

This report describes the controlled viscosity changes of photoresponsive reverse wormlike micellar systems formed by soybean lecithin (SoyPC), d-ribose, and azobenzene derivatives in decane. UV light irradiation produces a significant (150-fold) decrease in solution viscosity by triggering a structural transformation of the wormlike micelles. Subsequent visible light irradiation leads to recovery of the initial micellar structure and elevated solution viscoelasticity. This dramatic, reversible variation in solution viscosity by light irradiation can be applied to cosmetics, personal care products, and device components.