Self‐Assembled Nanogel of Hydrophobized Dendritic Dextrin for Protein Delivery

Highly branched cyclic dextrin derivatives (CH‐CDex) that are partly substituted with cholesterol groups have been synthesized. The CH‐CDex forms monodisperse and stable nanogels with a hydrodynamic radii of ≈10 nm by the self‐assembly of 4–6 CH‐CDex macromolecules in water. The CH‐CDex nanogels spontaneously trap 10–16 molecules of fluorescein isothiocyanate‐labeled insulin (FITC‐Ins). The complex shows high colloidal stability: no dissociation of trapped insulin is observed after at least 1 month in phosphate buffer (0.1 M , pH 8.0). In the presence of bovine serum albumin (BSA, 50 mg · mL^?1), which is a model blood system, the FITC‐Ins trapped in the nanogels is continuously released (≈20% at 12 h) without burst release. The high‐density nanogel structure derived from the highly branched CDex significantly affects the stability of the nanogel–protein complex.

     

Microencapsulation of Fish Oil by Simple Coacervation of Hydroxypropyl Methylcellulose

To improve the oxidative stability and application of fish oil, it was microencapsulated by simple coacervation followed by spray drying. Simple coacervation took place by adding malt dextrin into the emulsion of fish oil and hydroxypropyl methylcellulose （HPMC） solution. Influences of several process parameters on the microencapsulation were evaluated and the oxidative stability and microstructure of microcapsules were analyzed. Results showed that the coacervation could be observed only when dextrose equivalent value （DE value） of malt dextrin, concentration of HPMC solution and fish oil percentage in microcapsules were no more than 20. 5% and 40%, respectively. Moreover, microencapsulation efficiency was higher at HPMC solution concentration of 4% and fish oil percentage of less than 30%. The oxidative stability of fish oil was improved by the microencapsulation and done best in the ease of replacing malt dextrin by 40% with acacia. Scanning electronic microscopic photographs showed that the microcapsule obtained was a round, smooth and hollow microcapsule with its wall made up of innumerable small and solid submicrocapsules with the core of fish oil.     

Improvement in Solubility of Poorly Water Soluble Drug by Cogrinding with Highly Branched Cyclic Dextrin

We investigated the enhancement of the solubility of glibenclamide (GCM), a poorly water soluble anti-diabetes drug, by cogrinding it with highly branched cyclic dextrin (HBCD) using a ball mill. Highly branched cyclic dextrin (HBCD) is a novel cyclic glucan produced from waxy corn starch by the cyclization reaction of a branching enzyme. When GCM crystals were coground with HBCD for 2 h, the solubility of GCM was improved to 12.4 μg/ml, while the concentration of HBCD was 5.0 mg/ml. Additionally, the GCM solubilized with HBCD was chemically stable in aqueous solution for at least 1 week at room temperature. The peak intensity assigned to crystalline GCM disappeared after cogrinding it by observing its powder X-ray diffraction pattern, which means that the crystalline structure of GCM could be disrupted. In the DSC measurement, the ground mixture showed a single endothermic peak, even though a temperature depression of the endothermic peak due to GCM crystal was observed. After the cogrinding, two sharp peaks assigned to sulfonylurea and benzoyl carbonyl stretching bands varied to broaden the peak to around 1640 cm⁻¹ in the C=O stretching region. These results suggested the formation of solid dispersion between GCM and HBCD.     

Waterborne epoxy adhesive derived from epoxidized soybean oil and dextrin: Synthesis and characterization

In the present study, waterborne epoxy (WBE) was prepared and the parameters involved in the synthesis of WBE have been optimized based on physicochemical analysis. A dextrin-based curing agent (DCA) was synthesized from dextrin and trimellitic anhydride at variable molar ratios, reaction temperature, reaction duration, and solvent. Furthermore, the optimized composition of DCA and WBE system was used as adhesive in wood bonding. A comparative analysis of DCA-cured-bonded system was studied with phenol-formaldehyde (PF)-bonded adhesive system. From all the analyses, the performance characteristic WBE–DCA adhesive system was found comparable with that of PF-bonded system.     

Structural and mechanical properties of edible films from composite mixtures of starch,dextrin and different types of chemically modified starch

Abstract

Recent regulations restricting the use of one-use-plastics open the possibility to develop starch-based edible packaging material. The objective of this work was to determine the effect of three different modified starches on starch and dextrin composite edible films by a mixture design approach on edible films’ mechanical properties. The amylose content of chemically modified starches influenced their swelling capacities, where higher amylose content was inversely related to water-power uptake and directly related to film thickness. CMS3 Nifrastarch-TS edible films, with higher amylose content, presented higher puncture force and tensile strength, but lower puncture deformation and elongation, related to a less smooth surface, according to atomic force micrographs. The use of CMS1 Gelamil-100, with lower amylose content, decreased stiffness but increased films’ stretching, presenting higher surface smoothness film topography. The use of commercial chemical modified starches in combination with starch and dextrin will allow to control of edible film thickness and hence, mechanical properties, depending on food covering necessities.     

Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.     

β-环糊精交联聚合物的合成及其在水处理中的应用

以环氧氯丙烷为交联剂,在碱性介质中将β-环糊精固载化,合成了不溶于水的β-环糊精交联聚合物,同时考察了β-环糊精交联聚合物对模拟水样中的微污染物（无机重金属离子及有机酚类、胺类）的吸附性能。实验结果表明：β-环糊精交联聚合物对无机重金属离子（Pb^2 ,Cu^2 ,Cd^2 ,Zn^2 ）及苯酚、苯胺的去除效果良好,前者的去除率达到83.60%以上,其中Pb^2 的去除率高达95.62%,苯酚、苯胺的去除率达到95%以上。     

糊精介质中西酞普兰的毛细管电泳手性分离与定量测定

以糊精作为毛细管电泳手性分离选择剂,对药物西酞普兰对映体的分离进行研究。考察了糊精浓度、缓冲液体系离子强度和pH及分离电压对对映体分离的影响。在糊精7．0％（m／V）、磷酸盐80mmol／L（pH5．4）的运行缓冲液中,分离电压20kV时,西酞普兰对映体分离度达3．9,同时对拆分机理进行了初步探讨。测定S-（＋）-西酞普兰原料药中R-（-）异构体的含量,在0．05～4．00g／L浓度范围内线性关系良好,R-（-）．西酞普兰与S-（＋）-西酞普兰的检出限分别为25．3mg／L和27．3mg／L,线性相关系数均在0．9970以上;RSD低于3．2％。