Alginate Additives and Coating Migration Control

In this study the feasibility of using alginate compounds in latex coating slurries to control migration so as to improve the coating properties of the latex is discussed. In the past, starch and casein have been used in an attempt to alleviate streaking, blade build-up and premature drying, but they have not performed in an entirely satisfactory way, particularly with higher concentrations of solids. Considerable evidence is presented to indicate that the use of alginate additives will enhance both the coating ability and the coating properties of latex, even when high concentrations of solids are present. In addition, a new method, using the Perkins-Elmer infrared spectrascope, for measuring migration is introduced. The greatest asst here is that the method can be used without other special equipment and can be applied after the coatings have been completely processed

The Effects of Carbon Nanotubes on Cells in a Synthetic Oxygen Carrier Enriched Alginate Scaffold

Abstract Huge progress has been made in the development of three dimensionally printed tissue structures. With the use of cells, three dimensional printers, and CAD drawing software, donor identical structures can be fabricated. However, cell scaffolds currently lack significant mechanical integrity which can result in reduced cellular survival, attachment, and nutrient delivery. For this reason, multiple strategies have been developed to increase and improve mechanical stability within engineered constructs without having to sacrifice cell viability. The hypothesis of this paper was that incorporating Perfluorotributylamine (PFTBA), a greenhouse gas, with single walled carbon nanotubes (SWCNT), a allotrope of carbon with a cylindrical nanostructure, into an alginate scaffold will not only increase mechanical integrity but also cell survival. The following objectives were proposed: 1. Fabricate and characterize cell laden scaffolds of alginate and 2. Assess the addition of perfluorotributylamine and various concentrations of carbon nanotubes inside of cell laden scaffolds of alginate. Three configurations of perfluorotributylamine and carbon nanotubes were explored in an effort to maximize mechanical properties and cytocompatibility. Perfluorotributylamine was combined with gelatin from bovine skin and phosphate buffered solution to form a PFTBA emulsion. This emulsion was added to each alginate scaffold to encompass 5% of the entire alginate scaffold. Single walled carbon nanotubes were added in increasing concentrations to have four scaffolds, one control, 0 µg/ml, .1 µg/ml, and 1 µg/ml. The results of this study indicate that the configuration of 5% PFTBA emulsion + 1 µg/ml SWCNT + alginate, provided the best cell viability results; Picogreen fluorescence of 8532, excellent viability in live/dead stain, and sufficient morphological features while the control scaffold, containing alginate only, provided the best mechanical properties after a 7 day period. The results contradict the hypothesis that mechanical properties will increase with increasing SWCNT concentration, but support the hypothesis of improved cell viability with the incorporation of PFTBA emulsion to increasing SWCNT concentration

Emulsan-Alginate Microspheres as a New Vehicle for Protein Delivery

A solution containing emulsan, a lipoheteropolysaccharide, and calcium was used to produce emulsan-alginate microspheres (EAMs). Optical, scanning electron microscopy and EDX (Energy Dispersive X-ray) analysis of the microspheres suggested different morphologies and compositions, respectively, when compared with microspheres prepared only from alginate. The EAMs were twice as stable in phosphate solution compared to alginate alone when assessed with blue dextran encapsulation. The EAMs were able to adsorb about twice the amount of BSA (Bovine Serum Albumin) compared to alginate alone. When azo-BSA was adsorbed on the emulsan-alginate microspheres, protein release could be triggered with enzymes. BSA released from the EAMs retained about of 78% of the -helix structure.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesLaboratorio de Nanobiomateriale

REVISÃO: EFEITO DO TRATAMENTO SOB ALTA PRESSÃO SOBRE AS PROPRIEDADES FUNCIONAIS DA PROTEÍNA DE SOJA E INTERAÇÃO PROTEÍNA POLISSACARÍDIOS

Neste trabalho de revisão de literatura foram abordados aspectos da composição da proteína de soja, suas propriedades funcionais e os efeitos do tratamento sob alta pressão sobre tais proteínas. As interações de proteínas e polissacarídios (carragena e pectina) também foram estudadas, assim como os efeitos do tratamentos sob alta pressão sobre essas interações. Os estudos revisados neste trabalho evidenciaram campo de aplicação da tecnologia de alta pressão para produtos a base de proteínas e polissacarídios. Essa tecnologia pode ser empregada para controlar ou modificar as propriedades funcionais tecnológicas das proteínas, assim como para o desenvolvimento de novos produtos e futuras aplicações

The physiology and biochemistry of the Laminaria Pallida/Carpoblepharis Minima and Ecklonia Maxima/Suhria Vittata associations from South-Western Cape waters, South Africa

Bibliography: leaves 129-140.The two laminarian brown algae Laminaria pallida Grev. ex. J. Ag. and Eoklonia maxima (Osb.) Papenf. are important both economically and as major components of the South-western Cape waters, South Africa. Growing attached to these brown algae are several different species of red algae two of which, Carpoblepharis minima Bart. and Suhria vittata (L.) J. Ag., were chosen and. the L. pallida/C. minima and. E. maxima/S. vittata associations were studied using physiological and biochemical methods. Carpoblepharis minima has only been observed on L. pallida, whereas S. vittata has been found attached to various substrates as well as to E. maxima

Analysis of carrageenans using capillary electrophoresis

This thesis reports the use of capillary electrophoresis (CE) for the analysis of carrageenans, anionic polysaccharides extracted from red seaweeds and widely used in the food industry for their gelling and thickening properties. The three main types, kappa, iota and lambda, differ in the number of sulfate groups and the presence or absence of a 3,6-anhydro bridge in the disaccharide residue repeat unit. CE separates analytes according to their charge to frictional coefficient ratios, therefore it is suitable to separate these biopolymers. In order to detect polysaccharides in CE, our approach consisted in derivatising the reducing ends of the saccharides by reductive arnination with a fluorophore, l-arninopyrene-3,6,8- trisulfonate (APTS). This allowed sensitive detection by laser induced fluorescence. Method development gave optimal conditions for separation using a polyvinyl alcohol coated capillary and a 25 mM ammonium acetate, pH 8.0 background electrolyte. The effects of changes of both instrumental parameters (temperature, injection mode, field strength) and, the composition of the BGE (concentration and pH) are reported, and explained in terms of the physical chemistry of the BGE and the biopolymers. The conditions of the derivatisation reaction were studied in order to minimise degradation due in particular to acid catalysis and to reduction of the reacting sites occurring in competition with derivatisation. Characterisation of the derivatised carrageenans by SEC-MALLS- RI was performed and showed that the extent of degradation occurring during the labelling reaction was a maximum of 40 % for kappa and 20 % for iota and lambda. The presence of the label APTS in excess and its reaction with the reagents during the labelling reaction produces peaks interfering with those from the carrageenan. A sample clean-up was therefore required before injection onto CEo A comparison was made of a range of clean-up procedures (centrifugation, dialysis, preparative SEC) to remove side products of the reaction and salts and to concentrate the carrageenans. Various seaweed extracts were analysed, including standards of carrageenans not available commercially. This study revealed that carrageenans are complex structures, and often occurring as hybrids between sUb-types. CE has the ability to characterise these hybrids, unlike spectroscopic methods which detect individual residues. When using actual food products, preliminary steps such as defatting and dialysis were found to be necessary to allow satisfactory detection of carrageenans. Finally the strategy for sample purification, derivatisation, clean-up and separation was successfully applied to additive mixtures used as raw materials in the food industry and to finished products (jelly, dairy products). CE has proved to be a fast and sensitive method to identify and provide semi-quantitative information on carrageenans present in such mixtures

Studies on plant gums of the acacia group

The results of a re-investigation of A.Senegal gum have led. to the rejection of the idea that its molecular structure is necessarily based on a "main chain" or "backbone" of (31,3- linked g-galactose residues. The concept that the A.Senegal gum molecule contains a "main chain" or "backbone," to which are attached short side chains, implies that there is one chain in the macromolecule which is unique in being very much longer than the others. Unequivocal evidence for the occurrence of such chains in A.Senegal gum molecules does not exist. In the case of A.arabica gum, all the evidence from structural investigations, and from the solution behaviour of the gum favours a dichotomously branched galactan framework for the basal units of the macromolecules. These findings suggest that it is no longer meaningful to interpret the structural features of these gums in terms of average repeating units. The results, however, may have a wider implication and significance. On re-examination, many plant gums (Smith & Montgomery, 1959) of' the substituted arabinogalactan type, and perhaps some of the arabinogalactans themselves (Timell, 1965), may be shown to exhibit dichotomous branching within their galactan frameworks.Although structural work has been carried out on gums from other Acacia species, including A.mollissima (Stephen, 1951; CHAPTER V - 125 - Young, 1963), A.pycnantha (Hirst & Perlin, 1954; Aspinall, Hirst & Nicolson, 1959), A.karroo (Charlson, Nunn & Stephen, 1955a), A.cyanophylla (Gharlson, Nunn & Stephen, 1955b), A.catechu (Hulyalkar, Ingle & Bhide, 1956, 1959), A.sundra (Mukherjee & Shrivastava, 1957, 1958, 1959; Shrivastava, 1962), A.seyal (Herbich, 1963), A.nilotica (Karamalla, 1965; Anderson & Karamalla, 1966b), A.nubica (Oree, 1966) and A.laeta (Smith, 1966), the investigations reported in this thesis represent the first exploratory steps towards interpreting molecular structures of Acacia gums at the molecular level

The use of bacterial polysaccharides in bioprinting

Brunel Research Innovation and Enterprise Fund; British Council/Newton Fund; British Society for Antimicrobial Chemotherapy; National Natural Science Foundation of China; China Postdoctoral Science Foundation; Fundamental Research Funds for Central Universities; Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry; Changchun Institute of Applied Chemistry; Chinese Academy of Science