Influence of Polyglycerol Polyricinoleate and Biopolymers on Physical Properties and Encapsulation Efficiency of Water-in-Oil-in-Water Emulsions Containing Mango Seed Kernel Extract

The influence of polyglycerol polyricinoleate (PGPR) and biopolymers (gelatin and sodium alginate) on the stabilization of water-in-oil (W/O) emulsions was investigated to improve the encapsulation efficiency (EE) of water-in-oil-in-water (W/O/W) emulsions containing mango seed kernel extract (MSKE). The physical properties and EE of the emulsions were found to depend more strongly on PGPR than on biopolymers. High EE values of MSKE were obtained when W/O emulsions stabilized by 4–8 wt% PGPR were incorporated with 1–5 wt% gelatin, or by 6–8 wt% PGPR incorporated with 0.5–1.5 wt% sodium alginate in the inner aqueous phase.     

Alginate/Polyoxyethylene and Alginate/Gelatin Hydrogels: Preparation,Characterization, and Application in Tissue Engineering

Hydrogels are attractive biomaterials for three-dimensional cell culture and tissue engineering applications. The preparation of hydrogels using alginate and gelatin provides cross-linked hydrophilic polymers that can swell but do not dissolve in water. In this work, we first reinforced pure alginate by using polyoxyethylene as a supporting material. In an alginate/PEO sample that contains 20 % polyoxyethylene, we obtained a stable hydrogel for cell culture experiments. We also prepared a stable alginate/gelatin hydrogel by cross-linking a periodate-oxidized alginate with another functional component such as gelatin. The hydrogels were found to have a high fluid uptake. In this work, preparation, characterization, swelling, and surface properties of these scaffold materials were described. Lyophilized scaffolds obtained from hydrogels were used for cell viability experiments, and the results were presented in detail.     

Sodium alginate/magnesium oxide nanocomposite scaffolds for bone tissue engineering

A simple 2‐step method, consisting of film casting and polyvinyl alcohol leaching, is proposed to prepare magnesium oxide (MO) nanoparticle‐reinforced sodium alginate scaffolds with right properties for bone tissue engineering. The cytocompatibility of the as‐prepared scaffolds was also evaluated using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium‐bromide yellow tetrazole assay test, wherein chondrocyte cells had been considered as target cells. According to the results, the ensuing sodium alginate nanocomposites, containing 4‐wt% MO nanoparticles, demonstrated the highest physical and mechanical properties after leaching step. The Young modulus of sodium alginate/4‐wt% MO was improved about 44%, in comparison with that of the pure alginate sample. Furthermore, incorporating MO nanoparticles up to 4 wt% controlled the liquid uptake capacity of scaffolds vis‐à‐vis the resultant pure sodium alginate sample. Moreover, with increasing the nanoparticle content, the antibacterial properties of scaffolds enhanced, but their degradation rates under in vitro conditions tapered off. With the introduction of 3‐ and 4‐wt% MO, the average diameter of the bacterial zone of the scaffold samples reduced to less than 10 mm², suggesting an insensitive antimicrobial performance, compared with the pure sodium alginate and the samples with 1‐ and 2‐wt% MO content, which exhibit antimicrobial sensitivity. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium‐bromide assay test also revealed the cultivated chondrocyte cells on the 4‐wt% MO nanoparticle‐reinforced scaffold possessed better interaction as well as appropriate cell attachment and proliferation than the pristine sodium alginate sample.     

The application of an optically switched dielectrophoretic (ODEP) force for the manipulation and assembly of cell-encapsulating alginate microbeads in a microfluidic perfusion cell culture system for bottom-up tissue engineering

This study reports the utilisation of an optically switched dielectrophoretic (ODEP) force for the manipulation and assembly of cell-encapsulating alginate microbeads in a microfluidic perfusion cell culture system for bottom-up tissue engineering. One of the key features of this system is the ODEP force-based mechanism, which allows a commercial projector to be coupled with a computer to manipulate and assemble cell-encapsulating microbeads in an efficient, manageable, and user-friendly manner. Another distinctive feature is the design of the microfluidic cell culture chip, which allows the patterned cell-encapsulating microbeads to be cultivated on site under culture medium perfusion conditions. For demonstrating its application in bottom-up cartilage tissue engineering, chondrocyte-encapsulating alginate microbeads varying in encapsulated cell densities were generated. The manipulation forces associated with operating the alginate microbeads were experimentally evaluated. The results revealed that the measured manipulation forces increased with increases in both the applied electric voltage and the number of cells in the alginate microbeads. Nevertheless, the observed manipulation force was found to be independent of the size of the cell-free alginate microbeads. It can be speculated that the friction force may influence the estimation of the ODEP force within the experimental conditions investigated. In this study, chondrocyte-encapsulating alginate microbeads with three different cell densities were manipulated and assembled in the proposed microfluidic system to form a compact sheet-like cell culture construct that imitates the cell distribution in the cross-section of native articular cartilage. Moreover, the demonstration case also showed that the cell viability of the cultured cells in the microfluidic system remained as high as 96 ± 2%. In this study, four sheet-like cell culture constructs were stacked to create a larger assembled cell culture construct. The cell distribution inside the cell culture construct was further confirmed by a confocal microscopy observation, which showed that the distribution was similar to that in native articular cartilage. As a whole, the proposed system holds great promise as a platform for engineering tissue constructs with easily tunable inner cell distributions.     

Sodium alginate/HPMC/liquid paraffin emulsified (o/w) gel beads,by factorial design approach; and in vitro analysis

The present study involved development of a novel sodium alginate (SA)/HPMC/light liquid paraffin emulsified (o/w) gel beads containing Diclofenac sodium (DS) as an active pharmaceutical ingredient and its site specific delivery by using hard gelatin capsule fabricated by enteric coated Eudragit L-100 polymer. Emulsified gel beads were formulated by 3-level factorial design, ionic gelatin method. The obtained beads were characterized by Fourier transform infrared, X-ray diffraction and Field emission scanning electron microscope analysis. The variables such as SA (X₁), HPMC (X₂), were optimized for drug loading and in vitro drug release with the help of response surface methodology (RSM). The RSM analysis predicted that SA was significant for both drug loading (p = 0.0005) and drug release (p = 0.0041). HPMC was only significant for drug release (p = 0.0154). The cross-product contribution (2FI) and quadratic model were found to be adequate and statistically accurate with correlation value (R²) of 0.9054 and 0.9450 to predict the drug loading and drug release respectively. An increase in concentration of HPMC and SA decreases the drug loading as well as the drug release. The obtained optimum values of drug loading and DS released were 7.43 % and 85.54 % respectively, which were well in agreement with the predicted value by RSM.     

Bacterial cellulose/gelatin composites: in situ preparation and glutaraldehyde treatment

Bacterial cellulose (BC)/GEL composites were prepared in situ by adding gelatin into BC-producing culture medium. The addition of gelatin interfered with the formation of the BC pellicle structure and thus made the BC yield and growth rate quite different from that of pure BC. Scanning electron microscope images showed that the width of cellulose ribbons became narrower than that of pure BC and the gelatin filled in the pores of BC to form a dense structure. The addition level of gelatin significantly influences the yield of BC/GEL composites. An optimum value of 0.5 wt/v% gelatin was attained, with which the highest yield of 0.0541 g/100 mL was achieved. Under this condition, the weight percentage of gelatin in BC/GEL composite was 65 wt%. BC/GEL composites were treated with glutaraldehyde to crosslink BC fibrils and gelatin. The crosslinking degree, determined by the concentration of glutaraldehyde and crosslinking time, could affect the swelling behavior, thermal stability and mechanical properties of composites. With increasing of the crosslinking degree, the crystallinity index and swelling behavior of the composites decreased. The increase in the crosslinking degree also descreased the composite’s strain at break in elongation but increased the compressive and tensile strength. Covalent bonding between BC and gelatin provides good strength retention to the glutaraldehyde-treated composites with a high crosslinking degree. Considering the cytocompatibility and properties of composites, the most appropriate concentration of glutaraldehyde and crosslinking time were 1.0 wt/v% and 24 h, respectively.     

Drying dissipative structures of arrowroot starch

Macroscopic and microscopic drying patterns of arrowroot starch (ARS) in diluted aqueous solution and gel state were investigated on a cover glass in order to know the molecular information of ARS and their interaction with the substrate. Thickness profiles of the dried film showed coexistence of the rather sharp broad ring and the very broad accumulation at the outside edge and the inner region, respectively. The sharpness parameters, S values from the outside peaks decreased sharply from 100 to 3 as initial concentration increased from 0.04 to 3 wt%. Furthermore, very low S values between one and two originating from the round hills were also observed at low concentrations, 0.04 to 0.2 wt%. The results support that stable gelation of ARS molecules does not take place at the ARS concentrations lower than ca. 2 wt% at 20 °C. It is highly plausible that ARS molecules existing near the substrate surface are adsorbed strongly on the substrate. Gelation of ARS molecules took place rapidly above 2 wt%. The S values increased sharply from 3 to 15 with increasing temperature from 5 to 20 °C, and kept constant around 15 at the higher temperatures up to 50 °C. Convectional diffusion of ARS decreased in the order of ARS > gelatin > poly (N-butyl acrylate), when comparison was made at the same weight percent at the lower concentrations than ca. 2 wt%. Above the concentration, stable gel structures of ARS were formed.     

Somatic Embryogenesis and Synthetic Seed Production—a Biotechnological Approach for True-to-Type Propagation and In Vitro Conservation of an Ornamental Bulbaceous Plant Drimiopsis kirkii Baker.

An efficient plant regeneration protocol through indirect somatic embryogenesis pathway via callus had been developed from the leaf explant of an ornamental bulbaceous plant Drimiopsis kirkii. Optimum friable calli were induced on Murashige and Skoog (MS) basal medium supplemented with 3.0 mg/l of 2,4-dichlorophenoxyacetic acid and 1.0 mg/l of α-naphthalene acetic acid (NAA). On subculturing the callus on MS medium supplemented with 2.5 mg/l of thidiazuron (TDZ), 73.3 % of the cultures responded with 20.4?±?0.3 somatic embryos (SEs) per 500 mg callus at different stages of development after 6 weeks of culture. The highest response of 86.7 % with 28.3?±?0.5 embryos per 500 mg callus was observed on MS medium supplemented with 2.5 mg/l TDZ and 1.0 mg/l NAA. SEs were encapsulated in calcium alginate beads for the production of synthetic seeds (SSs) and their storability was investigated. The highest SS germination (93.3 %) was observed in 1.0 % sodium alginate followed by 86.7 % germination with 2.5 % sodium alginate. The SSs were stored at three different temperatures (4, 15, and 24?ºC) up to 6 months. The SSs kept at 15 °C showed 64.4 % germinability even after 4 months of storage. Both nonencapsulated and encapsulated SE-derived plants were successfully transferred to soil with 93.3 and 88.3 % survival rate accordingly. Randomly amplified polymorphic DNA (RAPD) analysis revealed that there were no somaclonal variations among the plants produced via somatic embryogenesis and they are true-to-type to their parental plant. These results confirmed the most reliable methods, which can be further used for genetic transformation studies as well as for mass propagation of ornamental D. kirkii at a commercial level.     

Comprehensive studies on polymer electrolyte and dye-sensitized solar cell developed using castor oil-based polyurethane

Comprehensive characterization of new polymer electrolyte system prepared using polyurethane derived from castor oil polyol was undertaken. The castor oil polyol was synthesized via transesterification and reacted with 4,4′-diphenylmethane diisocyanate to form polyurethane. Polyurethane electrolyte films were prepared by addition of sodium iodide in different weight percentage with respect to the weight of the polymer. The electrolyte films were analyzed using Fourier transform infrared spectroscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, transference number measurement, and linear sweep voltammetry. Fourier transform infrared spectroscopy results confirmed the complexation between polymer and salt. Tan delta peak observed in the tan δ–temperature curve plotted using data obtained from dynamic mechanical analysis indicated that the glass transition temperature of polyurethane decreased with the addition of sodium iodide. The highest conductivity of 4.28 × 10^?7 S cm^?1 was achieved for the film with 30 wt% of sodium iodide. The performances of dye-sensitized solar cell using the electrolyte systems were analyzed in terms of short-circuit current density, open-circuit voltage, fill factor, and energy conversion efficiency. The polymer electrolyte with 30 wt% sodium iodide showed the best performance with energy conversion efficiency of 0.80%.     

Influence of different divalent metal ions on the properties of alginate microcapsules and microencapsulated cells

Different divalent metal ions (Ba²⁺, Sr²⁺, Ca²⁺, Zn²⁺) were selected as crosslinkers. The mechanical properties, cytocompatibility, histocompatibility, cell proliferation and long-term cultivation were investigated. The resulting microcapsules had good sphericity, smooth surface and particle size distribution of 300–400 μm. Sr²⁺ microcapsules exhibited a better mechanical strength. The molecular weights cut-off of all membranes were between 24 and 67 kDa. All microcapsules had no cytotoxicity. After intraperitoneal transplantation, the recovered microcapsules still maintained good mechanical strength and morphology with no fibrosis or macrophage aggregation phenomena. The microencapsulated PC12 cells showed no significant variation after recultivation following microcapsule breaking. The cell activity sequence of different microcapsules after 72 h was as follows: bare control cell >Sr²⁺ > Ca²⁺ > Ba²⁺ > Zn²⁺. After 9 weeks’ in vitro culture, the cell survival rate was higher than 80 %. This paper will be of scientific interests for the basic research and clinical application of alginate/chitosan microcapsules embedded with drugs or cells.     

Mechanical, thermal, and moisture absorption properties of nano-clay reinforced nano-cellulose biocomposites

In this research, fully environment-friendly, sustainable and biodegradable ‘green’ composites were fabricated. A novel material comprised of microfibrillated cellulose and laponite clay with different inorganic/organic ratios (m/m) was prepared. The composites were characterized by tensile, bending and water absorption tests as well as dynamic mechanical analysis. The morphologies of these nanocomposites were evaluated through scanning electron microscopy. Results showed considerable improvement of mechanical properties; specifically in elastic modulus, tensile strength and flexural modulus with the addition of nanoclay up to 7.5 wt% nano-clay. The modulus of elasticity increased significantly by about 26 % at 5 wt% nanocaly. The flexural modulus increased by about 90 % at 7.5 wt% nanoclay. However, with an increased load of clay in the nanocomposite, the mechanical properties decreased due to the agglomeration of excessive nanoclay. The storage modulus was significantly increased at high temperature with increasing the load of nanoclay.     

Designing Swellable Beads of Alginate and Gelatin for Controlled Release of Pesticide (Cypermethrin)

In the present study biopolymeric beads of sodium alginate and gelatin were prepared by employing CaCl₂ as a crosslinking agent. A series of such microspheres of different compositions were prepared by varying the amounts of sodium alginate, gelatin and CaCl₂ in the feed mixture. The beads were loaded with an insecticide like cypermethrin. The prepared loaded and unloaded beads were characterized by FTIR spectral and Environmental scanning electron microscopy (ESEM) techniques, to gain insight into the molecular structure and morphology of beads, respectively. The swelling experiments were performed for different composition of beads and at varying pH and temperature of the swelling media. The swelling controlled release of insecticide was also investigated for 8 days in bi-distilled water as a release medium. The release experiments were performed under the static and varying experimental conditions and the data obtained were fitted to Fick's equation to evaluate diffusion coefficients of insecticide. The results were further analyzed by Fick's power law equation, and the possible mechanisms of the insecticide release were explored at different experimental conditions. Soil–pot experiments were also performed to demonstrate the applicability of the present controlled release technique to agricultural fields.     

Diffusion Behavior of Microbial Transglutaminase to Induce Protein Crosslinking in Oil-in-Water Emulsions

Food-grade hydrogel particles composed of sodium alginate were used to investigate the diffusion behavior of microbial transglutaminase (mTG) to induce crosslinking of interfacially adsorbed protein. For this purpose, mTG-loaded hydrogel beads were mixed with caseinate-stabilized oil-in-water emulsions, whereas Bradford assay and ammonia measurements were utilized to monitor the enzyme-induced interfacial protein crosslinking. Different alginate (0.5–1.5%) and gelling concentrations (50–500 mM CaCl₂) were used to modulate the hydrogel mesh size and number of junction zones. The results indicated that mTG was able to diffuse out of alginate beads. However, a decrease in NH₃ concentration with increasing alginate and CaCl₂ levels was observed due to the formation of tight and dense bead structures. These results illustrate that the spatial distribution of molecules in complex matrices plays a key role on the enzyme accessibility     

Culture and Differentiation of Rat Neural Stem/Progenitor Cells in a Three-Dimensional Collagen Scaffold

A stable and fast method for constructing a neural-like tissue from rat neural stem/progenitor cells (rNS/PCs) based on three-dimensional (3D) collagen gel is described. First step, the collagen-embedded rNS/PCs expanded with the medium consisting of DMEM/F12/RPMI1640 (1:1:1) supplemented with EGF and bFGF was used to expand the cells in gel in 96-well plates until the average diameter of cell clusters was about 50–100 μm with the cell density higher than 10⁷ cells/mL. In the second step, the initial medium was replaced with NB/B-27 supplemented with bFGF and BDNF. The results show that cells in collagen presented neural-like morphology and maintained live cell rate around 82 % in neural network pattern at least for 42 days under static conditions. The cell–collagen constructs were detected by immunofluorescence and immunohistochemistry test after 42 days of culture, part of cells still maintained the character of rNS/PCs, and others differentiated into neurons, astrocytes, and oligodendrocytes. Our 3D neural-like tissue construct was similar to the neural tissue in morphology and cell compositions. They thus have a potential to be used for drug screening, detection of environment toxins, and replacement therapy.     

Genipin‐crosslinked gelatin hydrogel incorporated with PLLA‐nanocylinders as a bone scaffold: Synthesis,characterization, and mechanical properties evaluation

Nowadays, despite remarkable progress in developing bone tissue engineering products, the fabrication of an ideal scaffold that could meet the main criteria, such as providing mechanical properties and suitable biostability as well as mimicking the bone extracellular matrix, still seems challenging. In this regard, utilizing combinatorial approaches seems more beneficial. Here, we aim to reinforce the mechanical characteristics of gelatin hydrogel via a combination of Genipin‐based chemical cross‐linking and incorporation of the poly l ‐lactic acid (PLLA) nanocylinders for application as bone scaffolds. Amine‐functionalized nanocylinders are prepared via the aminolysis procedure and incorporated in gelatin hydrogel. The nanocylinder content (0, 1, 2, 3, and 4 wt%) and cross‐linking density (0.1, 0.5, and 1 wt/vol%) are optimized to achieve suitable morphology, swelling ratio, degradation rate, and mechanical behaviors. The results indicate that hydrogel scaffold cross‐linking by 0.5 wt% of Genipin shows optimized morphological feathers with a pore size of around 300 to 500 μm as well as an average degradation rate (40.09% ± 3.08%) during 32 days. Besides, the incorporation of 3 wt% PLLA nanocylinders into the cross‐linked gelatin scaffold provides an optimized mechanical reinforcement as compressive modulus, and compressive strength show a 4‐ and 2.6‐fold increase, respectively. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay indicates that the scaffold does not have any cytotoxicity effect. In conclusion, gelatin composite reinforced with 3 wt% PLLA nanocylinders cross‐linked via 0.5 wt/vol% Genipin is suggested as a potential scaffold for bone tissue engineering applications.     

Combinatorial effect of different alginate compositions, polycations, and gelling ions on microcapsule properties

Microencapsulation technology is commonly used to deliver cells and drugs for therapeutic applications. The encapsulation material has a direct influence over the properties of microcapsules and will eventually dictate the efficacy of this delivery system. In this study, the combinatory effect of different alginate compositions, polycations and gelling ions was investigated to determine their roles in affecting the properties of the microcapsules. A multifactorial relationship was found between the three factors, in which certain factors took priority over others in influencing the overall property of the microcapsules. As the size of the microcapsules was kept constant throughout the investigation, further insights into the role of fabrication parameters on microcapsules size were also obtained. From the results, poly-l-lysine-coated microcapsules fabricated from 40/60 sodium alginate and cross-linked with barium chloride were the most ideal for applications that require both good mechanical as well as diffusion properties.     

Biotransformation of <Emphasis Type="SmallCaps">l</Emphasis>-tyrosine to Dopamine by a Calcium Alginate Immobilized Mutant Strain of <Emphasis Type="Italic">Aspergillus oryzae</Emphasis>

The present research work is concerned with the biotransformation of l-tyrosine to dopamine (DA) by calcium alginate entrapped conidiospores of a mutant strain of Aspergillus oryzae. Different strains of A. oryzae were isolated from soil. Out of 13 isolated strains, isolate-2 (I-2) was found to be a better DA producer. The wild-type I-2 was chemically improved by treating it with different concentrations of ethyl methyl sulfonate (EMS). Among seven mutant variants, EMS-6 exhibiting maximal DA activity of 43 μg/ml was selected. The strain was further exposed with l-cysteine HCl to make it resistant against diversion and environmental stress. The conidiospores of selected mutant variant A. oryzae EMS-6 strain were entrapped in calcium alginate beads. Different parameters for immobilization were investigated. The activity was further improved from 44 to 62 μg/ml under optimized conditions (1.5 % sodium alginate, 2 ml inoculum, and 2 mm bead size). The best resistant mutant variable exhibited over threefold increase in DA activity (62 μg/ml) than did wild-type I-2 (21 μg/ml) in the reaction mixture. From the results presented in the study, it was observed that high titers of DA activity in vitro could effectively be achieved by the EMS-induced mutagenesis of filamentous fungus culture used.     

Thermoresponsive N-vinyl caprolactam grafted sodium alginate hydrogel beads for the controlled release of an anticancer drug

A series of thermoresponsive sodium alginate-g-poly(vinyl caprolactam) (NaAlg-g-PNVCL) beads were prepared as drug delivery matrices of 5-flurouracil (5-FU) crosslinked by glutaraldehyde (GA) in the hydrochloric acid catalyst. Graft copolymers of sodium alginate with vinyl caprolactam were synthesized using azobisisobutyronitrile as an initiator, and characterized by Fourier infrared spectroscopy, differential scanning calrimetry and X-ray diffraction for analysis of the amorphous nature drug in the beads, and by scanning electron microscopy for the spherical nature of the beads. Preparation condition of the beads was optimized by considering the percentage of encapsulation efficiency, swelling behavior of beads and their release data. Effects of variables such as GA concentration, drug/polymer ratio and catalyst concentration on the release of 5-FU were carried out at two different temperatures (25 and 37 °C) in simulated intestinal fluid for 12 h. It was observed that, drug release from the beads decreased with increasing drug/polymer (d/p) ratio, extent of crosslinking agent and catalyst concentration. The swelling degree of graft copolymer beads was found to be increased with decreasing of environmental temperature. In vitro release studies were performed at 25 and 37 °C for 12 h, and showed that thermoresponsive graft copolymer beads had higher drug release behavior at 25 °C than that at 37 °C, following Fickian diffusion transport mechanism with slight deviation.     

Biochemical Characterization of a GH43 β-Xylosidase from <Emphasis Type="Italic">Bacteroides ovatus</Emphasis>

Cartilage tissue engineering is believed to provide effective cartilage repair post-injuries or diseases. Biomedical materials play a key role in achieving successful culture and fabrication of cartilage. The physical properties of a chitosan/gelatin hybrid hydrogel scaffold make it an ideal cartilage biomimetic material. In this study, a chitosan/gelatin hybrid hydrogel was chosen to fabricate a tissue-engineered cartilage in vitro by inoculating human adipose-derived stem cells (ADSCs) at both dynamic and traditional static culture conditions. A bioreactor that provides a dynamic culture condition has received greater applications in tissue engineering due to its optimal mass transfer efficiency and its ability to simulate an equivalent physical environment compared to human body. In this study, prior to cell-scaffold fabrication experiment, mathematical simulations were confirmed with a mass transfer of glucose and TGF-β2 both in rotating wall vessel bioreactor (RWVB) and static culture conditions in early stage of culture via computational fluid dynamic (CFD) method. To further investigate the feasibility of the mass transfer efficiency of the bioreactor, this RWVB was adopted to fabricate three-dimensional cell-hydrogel cartilage constructs in a dynamic environment. The results showed that the mass transfer efficiency of RWVB was faster in achieving a final equilibrium compared to culture in static culture conditions. ADSCs culturing in RWVB expanded three times more compared to that in static condition over 10 days. Induced cell cultivation in a dynamic RWVB showed extensive expression of extracellular matrix, while the cell distribution was found much more uniformly distributing with full infiltration of extracellular matrix inside the porous scaffold. The increased mass transfer efficiency of glucose and TGF-β2 from RWVB promoted cellular proliferation and chondrogenic differentiation of ADSCs inside chitosan/gelatin hybrid hydrogel scaffolds. The improved mass transfer also accelerated a dynamic fabrication of cell-hydrogel constructs, providing an alternative method in tissue engineering cartilage.     

Oxidative stability and effect of stress factors on flaxseed oil-in-water emulsions stabilized by sodium caseinate–sodium alginate–chitosan interfacial membrane

The susceptibility of heart healthy ω-3 fatty acids to lipid oxidation has hindered its incorporation into healthful foods and beverages. In this study, plant-based flaxseed oil rich in ω-3 fatty acids were dispersed into primary, secondary and tertiary emulsion system. A primary emulsion containing sodium caseinate-stabilized cationic droplets was prepared by homogenizing flaxseed oil as oil phase and sodium caseinate solution as the aqueous phase in an ultrasonicator. A secondary emulsion comprising of sodium caseinate–sodium alginate anionic droplets were produced by diluting appropriate primary emulsion with alginate solution. Further, a tertiary emulsion composed of sodium caseinate–sodium alginate–chitosan-coated cationic droplets was produced by diluting secondary emulsion with chitosan solution. The resistance of primary, secondary and tertiary emulsions with the same lipid concentration to destabilization by thermal treatment (30–90 °C for 30 min), sodium chloride addition (≤70 mM NaCl) and oxidative degradation (hydroperoxide concentration and TBARS) was determined. The results showed that secondary emulsions could resist variation in environmental stresses of salt and heat as well as protect the oil phase from decomposition better than primary and tertiary emulsions. Interfacial engineering could be used to design emulsion system with desirable characteristics.