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Abstract: Dissolution behavior and molecular conformation of waxy maize amylopectin in aqueous DMSO solutions containing different amounts of water and salts (NaCl or CaCl2 up to 0.2 M) were characterized using multi-angle laser light scattering (MALLS; micro-batch mode) and dynamic light scattering (DLS) detectors. The solubility of amylopectin decreased and the molecular size measured increased when the water content in the DMSO increased, indicating that amylopectin chains tended to be less dissociated or aggregate by the excess amount of water. The amylopectin in aqueous DMSO solutions (10–50% water) had a spherical shape with a regular star structure, but the individual amylopectin chains were not affected by water content. Minor addition of salts facilitated the dissolution of amylopectin in aqueous DMSO solutions, possibly due to water cluster formation by the salt ions. However, a minute presence of salts (0.01 and 0.05 M) could induce the chain association even in 90% DMSO solution. [Copyright &y& Elsevier]

Abstract: Waxy maize starch was dispersed (14.7% solids) in an aqueous sulfuric acid solution (3.16M), and hydrolyzed by stirring for up to 7 days at 40°C with ultrasonic treatments at different vibration amplitudes (20 and 40%) and durations (30 and 60min/day). The amount of starch nanoparticles in the hydrolyzates isolated after 7 days, measured by a dynamic light scattering detector, was raised from 20% to 70% by an ultrasonic treatment (20% amplitude, 30min). The aggregation of nanoparticles possibly occurring during the hydrolysis was effectively prevented by the ultrasonication. Alternatively, ultrasonic treatments were applied to the re-dispersed suspension of the large microparticles of starch hydrolyzates (2 days) precipitated by a mild centrifugation (500rpm, 10min). By an ultrasonic treatment at 60% vibration amplitude for 3min, the microparticles could be completely transformed to nanoparticles. The inherent crystalline structure of waxy maize starch (A-type in X-ray diffraction) remained after the ultrasonic treatments during acid hydrolysis, but it was disrupted by the ultrasonic treatments for the re-dispersed microparticles. [Copyright &y& Elsevier]

Abstract: An alcohol-free oil/water hyaluronic acid nanoemulsion was developed to be applied as transdermal carrier for active lipophilic ingredient. In vitro hemolysis, skin penetration and histological examinations were carried out using α-tocopherol as model ingredient to assess skin permeability and bioavailability. Without any chemical enhancers, nanoemuslion performed desirable skin permeable capacity, being able to penetrate across stratum corneum and diffuse deeper into dermis compared with the control group (ethanol solution) via follicular and intercellular pathway. Penetration mechanism was preliminarily studied and suggested to be closely concerned with transmembrane concentration gradient, carrier characteristics and penetration enhancers. No irritation has been found in dermis and skin surface indicated hyaluronic acid nanoemulsions could be successfully used as purcutaneous delivery carrier of active lipophilic ingredient and favorable for drug and cosmetic applications. [Copyright &y& Elsevier]

Abstract: Amylosucrase (AS), maltooligosyltrehalose synthase (MTS), and maltooligosyltrehalose trehalohydrolase (MTH) were used in combined cross-linked enzyme aggregates (combi-CLEAs) to achieve one-step bioconversion of sucrose to trehalose. Combi-CLEAs of three enzymes were successfully established with acetone and glutaraldehyde (GA) as a precipitant and a cross-linker, respectively. The optimum enzyme ratio was 8:0.5:0.5 (AS, 4mg:MTS, 0.25mg:MTH, 0.25mg). To improve trehalose production, bovine serum albumin was co-aggregated with enzymes as a proteic feeder. The trehalose production yield of combi-CLEAs was about 8% in each cycle on the basis of substrate added up to 400mM. Finally, the combi-CLEAs used in this experiment showed reusability of about five cycles without any activity loss. [Copyright &y& Elsevier]

Abstract: In this study, high molecular weight hyaluronic acid in powder form (HMW-HA, with average molecular weight of 1042kDa) was degraded to low molecular (LMW-HA, 200–230kDa) by several methods, and the changes in molecular structure and antioxidative activities brought about by each degradation method were compared. The degradation methods used were electron beam irradiation (EB), gamma ray irradiation (GM), microwave irradiation (MW), and thermal treatment (TH). The FT-IR spectra showed no substantial changes of the spectral pattern between HMW and LMW-HAs. However, the UV absorbance of LMW-HA by MW was considerably greater at 265nm indicating the formation of more double bonds. The antioxidative activities of all LMW-HA samples were found to have risen, but the MW-treated LMW-HA showed the most significant increase due to a newly formed double bond. EB- and GM-treated LMW-HA showed the lowest polydispersity and little change in UV spectra from those of HMW-HA. [Copyright &y& Elsevier]