The emergence and pitfalls of international tissue banking.

The rapid growth of tissue banking and associated international organisations following the fall of the Berlin wall in 1991 is described. This surge in collaboration led to a world-wide constructive movement to use and to produce human tissues. As the years progressed industrialisation, led by the USA, improved the quality of tissue allografts but led higher costs and consolidation within the developing industry. The growth of litigation more than kept pace with the industrial progress. One landmark case is described, the outcome of which could revolutionise the current practices now applied to eliminate possible viral contamination of implanted tissue grafts.

Conformational Transition of Polyelectrolyte As Influenced by Electrostatic Complexation with Protein.

Conformation and conformational transitions are essential for the biological and technological functions of natural polyelectrolytes, for example, DNA. This study aims to clarify how the conformational transition of natural polyelectrolyte is affected and tuned by electrostatic complexation with protein as encountered in many biological processes. A model protein/polyelectrolyte system, ß-lactoglobulin (ß-lg) and κ-carrageenan (κ-car), was used for the investigation. The effect was found to be determined by the molecular state of ß-lg/κ-car electrostatic complexation and the molecular weight of protein. ß-lg/κ-car complexation in soluble state had a subtle effect on the coil-to-helix transition of κ-car, while that in insoluble state greatly suppressed it. On the basis of the McGhee-Hippel theory, a quantitative model was successfully developed to describe the effect of protein/polyelectrolyte electrostatic complexation on the conformational transition of polyelectrolyte. The model can also provide additional information on the change of tertiary structure of ß-lg upon electrostatic complexation with κ-car. Moreover, it was found that ß-lg or its hydrolysates with a molecular weight larger than 2000 Da hindered the conformational transition of κ-car, while those with a molecular weight lower than 1000 Da promoted it. The observations offer a promising approach to control the conformational transition and related properties of polyelectrolytes for technological applications.

Effect of acidification on the protection of alginate-encapsulated probiotic based on emulsification/internal gelation.

BACKGROUND: The method of emulsification/internal gelation is commonly used to prepare alginate microspheres for lactic acid bacteria (LAB). This paper focused on the influence of acidification parameters, i.e. acid/Ca molar ratio and acidification time, on the physical properties and cell protection efficiency of microspheres and their correlations. RESULTS: With increasing acid/Ca molar ratio and acidification time, the average diameter of microspheres decreased and their mechanical strength increased. Interestingly, wet alginate microspheres shrank in simulated gastric juice (SGJ) while they swelled in bile salts solution (BS). The shrinkage or swelling ratio decreased with increasing mechanical strength. Correlation analysis showed that the encapsulated cell survivals in both SGJ and BS were positively correlated with the mechanical strength of microspheres but negatively with the shrinkage or swelling ratio. BacLight LIVE/DEAD assay suggested that the viability of encapsulated cells in fresh, SGJ-treated and BS-treated microspheres was closely related to cell membrane integrity. CONCLUSION: Acidification is a key step during microsphere preparation, which strongly affected the physical properties of alginate microspheres, resulting in different cell protection efficiency. The resulting well-protected LAB can be applied in probiotics foods. © 2016 Society of Chemical Industry.

An international survey of tissue banking: a preliminary report.

International Atomic Energy Agency is currently carrying out a survey on the tissue banking activities from the tissue banking organisations worldwide. The purpose of the survey is to establish regional and global overview of the current tissue banking activities and practices in order to assist the International Atomic Energy Agency to provide further guidance about the use of radiation technology to sterilise tissues as well as to promote better collaboration between the regional tissue banking associations. The survey is an on-going exercise and the preliminary data is presented here. This exercise is not completed and the authors urge the remaining tissue banks to participate in the survey.

Complexation of bovine serum albumin and sugar beet pectin: structural transitions and phase diagram.

The complexation between bovine serum albumin (BSA) and sugar beet pectin (SBP) was studied in situ by coupling glucono-δ-lactone (GDL) induced acidification with dynamic light scattering and turbidity measurements. Individual measurements at specific pHs and mixing ratios were also carried out using zeta potentiometry, gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), and isothermal titration calorimetry (ITC). These investigations together enabled the establishment of a phase diagram of BSA/SBP and the identification of the molecular events during protein/polysaccharide complexation in relation to the phase diagram, which showed five regions: (I) a stable region of mixed individual soluble polymers, (II) a stable region of intramolecular soluble complexes, (III) a quasi-stable region of intermolecular soluble complexes, (IV) an unstable region of intermolecular insoluble complexes, and (V) a second stable region of mixed individual soluble polymers, on lowering pH. We found for the first time that the complexation could take place well above the critical pH(c), the value that most previous studies had regarded as the onset occurrence of complexation. A model of structural transitions between the regions was proposed. The borderline between region II and region III represents the BSA/SBP stoichiometry for intramolecular soluble complex at a specific pH, while that between region III and region IV identifies the composition of the intermolecular insoluble complex. Also studied was the effect of NaCl and CaCl(2) on the phase diagram and structural transitions.

The challenges of litigation in US courts and the actions tissue banks can take to meet those challenges.

The growth of tissue banking from local non-profit organizations to national and multi-national corporations has increased the likelihood of litigation against tissue banks. The acquisition of tissue banks by corporate entities, many of whom are based in the US, means that tissue banks need to be prepared for the challenge of litigation in the US courts. The purpose of this paper is to help tissue banks meet those challenges by describing the nature of US litigation, the most common types of lawsuits against tissue banks and the steps that tissue banks can take to prepare for litigation in the US.

Interfacial and emulsion-stabilizing properties of zein nanoparticles: differences among zein fractions (α-, ß-, and γ-zein).

According to the solubility in the binary solvent of ethanol water, zein can be classified into α-, ß-, γ-, and δ-zein, and the difference in amino acid compositions of these fractions is believed to affect their physicochemical properties and functionalities. This research comparatively analyzed main zein fractions, namely the α-zein fraction, ß-zein fraction, and γ-zein fraction, on the formation, surface adsorption, and emulsifying properties of their anti-solvent-induced particles. Results showed that all zein fractions were able to form spherical particles through an anti-solvent procedure, and formed particles possessed different surface charge and surface hydrophobicity. γ-Zein fraction particles had the biggest size and lowest surface hydrophobicity, the highest interfacial adsorption speed, and formed the strongest viscoelastic interfacial film, as analyzed through the interfacial rheology results, while ß-zein fraction particles exhibited the poorest interfacial activity. These physicochemical differences were reflected in their emulsifying properties, whereby the γ-zein fraction particle-stabilized emulsion had the maximum tolerance to salt (50, 100, and 200 mM NaCl) and pH (4.0, 7.0, and 9.0). The excellent interfacial properties of the γ-zein fraction presented in this research would afford a new strategy for the effective application of zein.

Interaction of gum arabic with fatty acid studied using electron paramagnetic resonance.

Electron paramagnetic resonance (EPR) is here used to study the interaction between gum arabic and a fatty acid. The EPR spectra of 5-doxyl stearic acid (5-DSA), a spin-labeled fatty acid analog, displayed increasingly anisotropic line features upon addition of gum arabic, indicating a strong immobilization of the nitroxyl moiety when the fatty acid is bound to gum arabic. To understand the nature of the interaction, EPR measurements were carried out at different pHs and using two fractions of gum arabic separated by hydrophobic interaction chromatography (HIC). 5-DSA bound favorably to the hydrophobic fraction, which contains mainly glycoprotein, and a small amount of high molecular weight arabinogalactan protein (AGP). Binding occurred to a less extent to the hydrophilic fraction, which contains essentially arabinogalactan (AG). Such a hydrophobic binding mechanism is further supported by a sharp drop in the binding when pH is raised above the pK(a) value of 5-DSA (approximately pH 5). This is because the ionization of carboxylic groups would lead to increased polarity and hydrophilicity of the fatty acid. A secondary effect involving the formation of ionic hydrogen bonds between carboxylic groups in fatty acid and lysine residues in gum arabic might also contribute. This is consistent with the reduction in binding ability when the pH was elevated above the pK(a) value of lysine residue (approximately pH 10). The biological significance of these findings is considered.

pH-Induced structural transitions in whey protein isolate and ultrasonically solubilized Persian gum mixture.

The present work evidently reports that ultrasonic depolymerization strongly enhanced complex coacervation between Persian gum (PG) and whey protein isolate (WPI). PG was sonicated at 60 °C, operating frequency of 20 kHz and nominal power output of 800 W for various times followed by mixing with WPI. Acid-induced interaction between the two biopolymers was studied by turbidity, light scattering, zeta potential and viscosity measurements over a wide pH range. Sonication of intact PG (IPG) for 10 min considerably reduced the molecular weight from 4.12 × 106 to 0.76 × 106 g/mol. Besides, ultrasonic fragmentation of water insoluble fraction of PG drove protein containing chains into the soluble phase. Sonicated PG (SPG) was shown to be more flexible with higher number of carboxyl groups available for electrostatic interaction with WPI, such that the complete neutralization did not occur even at protein to polysaccharide ratio of 50: 1. Additionally, scattered light intensity and viscosity measurements revealed two maxima in the pH ranges of 4.4-4.85 and 3.27-4.0, being highly intense for the gum sonicated for 10 min and longer. Considering the pH-behavior of WPI components, the former peak was related to interpolymer complex formation between ß-lactoglobulin and long chain fraction of SPG, while the latter was attributed to intrapolymer association of α-lactalbumin with the short chain oligosaccharides arising from ultrasonic degradation of PG.

Novel strategy for enhancing the color intensity of ß-Carotene: Enriching onto the oil-water interface.

A novel strategy to enhance the color intensity of ß-carotene (BC), namely, "interfacial enriching", was developed in this work. As the sole emulsifier in W/O emulsion, BC particles were enriched onto the droplet surface through emulsifying process. By increasing the concentration of BC in oil phase from 1 mg/g to 5 mg/g, the average droplet size of the emulsion decreased from 92.2 ± 5.1 µm to 34.0 ± 5.4 µm. Too low (e.g. ≤ 1 mg/g) or too high (e.g. ≥25 mg/g) concentration of BC in the oil phase yielded an insufficient coverage or flocculation of the droplets. By enriching onto the interface, the color intensity of BC were enhanced apparently at the reflectance wavelength ranging from 500 nm to 700 nm, compared with that of the BC encapsulated within the emulsion droplets. This enhancement was due to the higher availability of incident light for the BC particles on the interface than that of the BC particles buried inside the droplets.

In situ nanomechanical properties of natural oil bodies studied using atomic force microscopy.

Natural oil bodies (OBs) from plant organs represent an important category of functional ingredients and materials in a variety of industrial sectors. Their applications are closely related to the membrane mechanical properties on a single droplet level, which remain difficult to determine. In this research, the mechanical properties of the membranes of OBs from soybean, sesame, and peanut were investigated in-situ by atomic force microscopy (AFM). Different regions of the force-deformation curves obtained during compression were analyzed to extract the stiffness Kb or Young's modulus of the OB membranes using Hooke's law, Reissner theory, and the elastic membrane theory. At higher strains (ε = 0.15-0.20), the elastic membrane theory breaks down. We propose an extension of the theory that includes a contribution to the force from interfacial tension based on the Gibbs energy, allowing effective determination of Young's modulus and interfacial tension of the OB membranes in the water environment simultaneously. The mechanical properties of the OBs of different sizes and species, as well as a comparison with other phospholipid membrane materials, are discussed and related to their membrane compositions and structures. It was found that the natural OBs are soft droplets but do not rupture and can fully recover following compressive strains as large as 0.3. The OBs with higher protein/oil ratio, have smaller size and stronger mechanical properties, and thus are more stable. The low interfacial tension due to the existence of phospholipid-protein membrane also contributes to the stability of the OBs. This is the first report measuring the mechanical properties of OB membranes in-situ directly.

Iron encapsulated microstructured gel beads using an emulsification-gelation technique for an alginate-caseinate matrix.

Iron-deficiency anemia is an important health problem in global public issues, and development of iron fortifiers in diets is essential for the decrease of iron deficiency. However, there are problems for iron fortification in food because the common bioavailable iron compounds would contribute to iron-promoted lipid oxidation and unpleasant iron odor, presenting an adverse food quality. Ferrous fumarate loaded microstructured gel beads were prepared by an emulsification-gelation method using an alginate-caseinate matrix, and the gel network was formed by crosslinking of Ca2+ or Fe2+. Internal gelated beads showed relatively symmetrical and homogeneous spheres with no adhesion due to the simultaneous release of Fe2+ to initiate gelation in situ. External gelated beads displayed an irregular and adhesive structure, probably because the random contact between Na-ALG and Ca2+ occurred on the droplet surface, and the immediately gelated hardening layer provided a delay for further Ca2+ diffusion. The gel beads exhibited a lag phase in the promotion of lipid oxidation of the emulsion and restrained the iron odor release from ferrous fumarate. Ferrous ion release from microstructured gel beads in the simulated gastric juice was obviously delayed before a more progressive high release in the simulated intestinal juice, beneficial for iron absorption in the duodenum. The iron encapsulated microstructured gel beads might be developed as a promising safe iron fortifier by relieving lipid oxidation and iron odor.

Trivalent iron induced gelation in Artemisia sphaerocephala Krasch. polysaccharide.

Artemisia sphaerocephala Krasch. polysaccharide (ASKP) has attracted growing attention in the field of food and medical engineering due to its biological activity and colloidal property. In this study, the binding between ASKP and ferric ions was found and the binding mechanism was explored. The results showed that ASKP could form a hydrogel with three-dimensional network structure in the presence of ferric ions. Ferric ions could specifically bind with the carboxyl and hydroxyl groups of the high molecular weight fraction of 60P with the binding stoichiometry of [M3+]/[repeating unit] = 2.5. The possible mechanism of the formation of ASKP-Fe3+ complex was proposed as two binding modes of monodentate and bridging binding. ASKP-Fe3+ complex exhibited higher thermal stability than ASKP revealed with DSC thermograms. The study indicated that ASKP would be a novel gelation biopolymer and the ASKP-Fe3+ complex hydrogel could be exploited as a new iron fortifier.

The evolution and impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in the Latin American region.

Since 1993, the IAEA supported the establishment or the consolidation of seven tissue banks in the region. As a direct or indirect consequence of the implementation of the IAEA program, more than 53 tissue banks are now operating in the participating countries. The fast development of tissue banks in the Latin America region under the ARCAL Agreement and with the financial and technical support of the IAEA program made it necessary to train new tissue bank operators and medical personnel. In general, 90 tissue bank operators and medical personnel were trained in the training centre of Buenos Aires. Another six tissue bank operators and medical personnel were trained in the International Training Centre of Singapore. The main impact of the IAEA program in the region was the following: the establishment or consolidation of fifty-three tissue banks in nine countries in the region; the implementation of five national projects, allocating $1,006,737 dollars for this purpose and of one regional project allocating $284,741 dollars for this purpose; the use of the IAEA Standards, the IAEA Code of Practice and the IAEA Public Awareness Strategies in several tissue banks in the region; the application of quality control and quality assurances manuals in all of the participating countries.

The evolution and impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Asia and the Pacific region.

The Asia and the Pacific region was within the IAEA program on radiation and tissue banking, the most active region. Most of the tissue banks in the Asia and the Pacific region were developed during the late 1980s and 1990s. The initial number of tissue banks established or supported by the IAEA program in the framework of the RCA Agreement for Asia and the Pacific region was 18. At the end of 2006, the number of tissue banks participating, in one way or another in the IAEA program was 59. Since the beginning of the implementation of the IAEA program in Asia and the Pacific region 63,537 amnion and 44,282 bone allografts were produced and 57,683 amnion and 36,388 bone allografts were used. The main impact of the IAEA program in the region was the following: the establishment or consolidation of at least 59 tissue banks in 15 countries in the region (the IAEA supported directly 16 of these banks); the improvement on the quality and safety of tissues procured and produced in the region reaching international standards; the implementation of eight national projects, two regional projects and two interregional projects; the elaboration of International Standards, a Code of Practice and a Public Awareness Strategies and, the application of quality control and quality assurances programs in all participating tissue banks.

The impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Asia and the Pacific and the Latin American regions.

The technical assistance program of the International Atomic Energy Agency (IAEA) for its member states in the framework of the implementation of its program on radiation and tissue banking focuses on ensuring the availability of quality radiation-sterilised tissue grafts. The IAEA also helps its member states to develop quality control capabilities in order to ensure the safe use of the processed tissues in certain medical treatments. The majority of developing countries does not have such capacity, and must import expensive sterilised tissues from developed countries. The IAEA's core contribution to its program on radiation and tissue banking in Asia and the Pacific and the Latin American regions is a technology for sterilisation by gamma radiation and a training program for tissue bank operators and medical personnel. The Agency develops capabilities for radiation sterilisation of tissue grafts, both for reducing the pre-processing bacterial load, and as a terminal sterilisation process. Sterilising tissue grafts offers a clear advantage in terms of safety. Moreover, compared to alternative sterilisation methods, radiation sterilisation is considered particularly safe in relation to environmental concerns, and the deposition of harmful residuals in the tissue, which occurs for example in the use of chemical such as ethylene oxide gas. Radiation sterilisation, thus, has become the method of choice for an increasing number of tissue banks. Radiation sterilisation of tissue grafts is a critical component in the chain connecting donors to recipients of high quality tissue grafts. Due to this fact, the IAEA has evolved as the only organisation in the UN System with expertise related to tissue banking.

Ultrasonic degradation of Persian gum and gum tragacanth: Effect on chain conformation and molecular properties.

The present study introduces the ultrasonic modification of two Iranian native gum exudates, Persian gum (PG) and gum tragacanth (GT) for the first time. They were sonicated at a constant frequency of 20 kHz and temperature of 60 °C for various times (0, 2, 5, 10, 20, 30 and 40 min) and the changes in their molecular properties were investigated using oven drying, gel permeation chromatography-multiangle laser-light scattering (GPC-MALLS), rheometery and FTIR analysis. Results indicated that the soluble dry mass of both hydrocolloids was extensively enhanced (from less than 10% at time zero to more than 90% at the end of treatment time) by sonication. Moreover, the molecular weight and viscosity of gums dispersions were decreased with the increase of the treatment time. Fracture in polysaccharide chains was confirmed by analysis of the molecular weight parameters. Calculation of chain breaks and polydispersity index (PDI) revealed that scissions occurred at the backbone as well as the side branches. PG, owing to its higher molecular weight, displayed more extensive and faster degradation than GT. However, the chain rupture of GT was twice more than that of PG at the end of sonication time. The specific volume for gyration (SVg) and molecular density (ρ) showed that intact PG contains compactly packed molecules with greater number of cross-linked bonds compared to GT. Furthermore, the conformational changes into semi-flexible chains and worm-like coils were determined for both gums after 40 min sonication. Variation of the molecular density along with the results of FTIR analysis demonstrated that ultrasonication broke C-O-C bonds in both PG and GT leading to more flexible chains.

All-Natural Food-Grade Hydrophilic-Hydrophobic Core-Shell Microparticles: Facile Fabrication Based on Gel-Network-Restricted Antisolvent Method.

Hydrophilic-hydrophobic core-shell microparticles are highly appealing for a variety of industrial applications (foods, pharmaceutics, cosmetics, biomedicines, etc.) owing to their unique properties of moisture resistance and controlled release. However, the fabrication of such structured microparticles proves to be nontrivial due to the difficulty in assembling two materials of distinctly different hydrophilicities and hydrophobicities. This paper reports a facile method to fabricate hydrophilic-hydrophobic core-shell microparticles using all-natural food-grade polysaccharides and proteins, based on a novel principle of gel-network-restricted antisolvent precipitation. Immersion of microgel beads prepared from hydrophilic polysaccharides (i.e., alginates, κ-carrageenan, agarose) into a hydrophobic protein solution (i.e., zein in 70% aqueous ethanol) enables slow and controllable antisolvent precipitation of a protein layer around the microbead surface, leading to the formation of a hydrophilic-hydrophobic core-shell structure. The method applies to various gelling systems and can easily tailor the particle size and shell thickness. The resulting freeze-dried microparticles demonstrate restricted swelling in water, improved moisture resistance, and sustained release of encapsulants, with great potential in applications such as protection of unstable and/or hygroscopic compounds and delivery and controlled release of drugs, bioactives, flavors, etc. The method is rather universal and can be extended to prepare more versatile core-shell structures using a large variety of hydrophilic and hydrophobic materials.