Introduction Of Gelatin Research Articles

Improving the Stability of Water-in-Oil Emulsions with Medium Internal Phase by the Introduction of Gelatin.

The water-in-oil (W/O) emulsion with a medium aqueous phase may be limited in food and cosmetics due to its poor stability and high cost. Herein, this work proposed a facile strategy to improve the W/O emulsion stability by introducing gelatin. The influence of different gelatin concentrations (0, 0.5%, 1.0%, 2.0%, and 4.0%) on the stability and properties of W/O emulsions was mainly investigated. Results showed that the obtained emulsions still belonged to W/O emulsions after adding gelatin to the aqueous phase. As the gelatin concentration increased (0~4.0%), the interfacial tension decreased, which is conducive to promoting the interface adsorption of polyglycerol polyricinoleate (PGPR). Furthermore, introducing gelatin also improved the water-holding capacity (WHC) (33.50~6.32%) and viscosity of W/O emulsions and reduced the droplet size (37.47~8.75 μm) of emulsions. The enhanced interfacial adsorption and aqueous gelation induced by gelatin addition promoted the formation of a tight overall emulsion network structure by the interaction between the interfacial adsorbed PGPR, as well as PGPR and gelatin in the aqueous phase. The enhancement of the overall network effectively improved the storage stability (35 d), thermal stability (20 min, 80 °C), and freeze-thaw stability (10 cycles) of emulsions, especially at 4.0% gelatin concentration. Hence, this study can provide guidance for the improvement and regulation of the stabilities of W/O emulsions.

Technique for reducing the surgical porosity of small-diameter vascular grafts

High surgical porosity (SP) is one of the causes of significant blood loss, as well as hematoma formation. So, reducing the SP of small-diameter vascular grafts (VGs) is a crucial task.The objective of this work was to develop a technology for the formation of polycaprolactone (PCL)-based small-diameter VGs with a bioactive coating with reduced SP.Materials and methods. Porous VGs with an inner diameter of 3 mm were fabricated by electrospinning from 5% PCL solution with addition of 5–30% gelatin (PCL/G) on an NANON-01A unit (MECC CO, Japan). Bioactive coating was applied by sequential incubation of VGs in solutions of bovine serum albumin, heparin and platelet lysate with fixation in a glutaric aldehyde solution. The surface structure and mechanical properties of the samples were investigated. Functional properties of the bioactive VGs were evaluated in relation to their interaction with cell cultures in vitro.Results. It was found that introduction of gelatin into the working solution reduces SP from 30.4 ± 1.5 mL/(cm2 ·min) to 2.8 ± 0.5 ml/(cm2 ·min). It was shown that at a PCL/gelatin ratio of 9 : 1, the outer and inner sides of the bioactive VGs samples are characterized by surface uniformity (no defects), mechanical properties close to blood vessels of the same diameter (Young’s modulus 6.7 ± 2.1 MPa, tensile strength 26.7 ± 4.9 N and elongation to break 423 ± 80%) and ability to support adhesion and proliferation of human umbilical vein endothelial cell line, EA.hy926.Conclusion. Introduction of 10% gelatin content (by the polymer weight) into PCL solution reduces the SP of small-diameter VGs, leads to uniformity in their inner and outer surface, improvement in their mechanical properties without reducing their ability to support adhesion and proliferation of vascular endothelial cells.

Stretchable Organohydrogel with Adhesion, Self-Healing, and Environment-Tolerance for Wearable Strain Sensors.

Stretchable hydrogels as landmark soft materials have been efficiently utilized in the field of wearable sensing devices. However, these soft hydrogels mostly cannot integrate transparency, stretchability, adhesiveness, self-healing, and environmental adaptability into one system. Herein, a fully physically cross-linked poly(hydroxyethyl acrylamide)-gelatin dual-network organohydrogel is prepared in a phytic acid-glycerol binary solvent via a rapid ultraviolet light initiation. The introduction of gelatin as the second network endows the organohydrogel with desirable mechanical performance (high stretchability up to 1240%). The presence of phytic acid not only synergizes with glycerol to impart environment-tolerance to the organohydrogel (from -20 to 60 °C) but also increases the conductivity. Moreover, the organohydrogel demonstrates a durable adhesive performance toward diverse substrates, a high self-healing efficiency through heat treatment, and favorable optical transparency (transmittance of 90%). Furthermore, the organohydrogel achieves high sensitivity (gauge factor of 2.18 at 100% strain) and rapid response time (80 ms) and could detect both tiny (a low detection limit of 0.25% strain) and large deformations. Therefore, the assembled organohydrogel-based wearable sensors are capable of monitoring human joint motions, facial expression, and voice signals. This work proposes a facile route for multifunctional organohydrogel transducers and promises the practical application of flexible wearable electronics in complex scenarios.

A versatile nanofibrous facemask filter for triboelectric nanogenerator-based self-powered respiratory monitoring with efficient filtration and excellent antibacterial capacities

Respiration, as a basic human physiological process, can be used as a vital indicator for early disease diagnosis. Moreover, the prevention of respiratory diseases caused by particulate matter and bacteria is of great importance. Herein, a smart face mask with self-powered real-time respiratory monitoring, efficient filtration and excellent antibacterial activity was fabricated by electrospinning. By applying polyvinylidene fluoride (PVDF)/ε-poly (L-lysine)(ε-PL) and poly (ε-caprolactone)(PCL)/gelatin nanofibrous membranes as contact electrification pairs, the triboelectric nanogenerator assembled into a face mask could detect different breathing frequencies and intensities without external power supply. The electrical output performance was increased with the increment of PVDF concentration and the introduction of gelatin. Efficient filtration of particulate matter was achieved under a low pressure drop. Furthermore, PVDF/ε-PL nanofibrous membrane also exhibited excellent antibacterial activity, thus reducing the risk of respiratory infection. The prepared smart face mask is hopeful for personal healthcare management and prevention of respiratory diseases.

Isolation of dicarboxy cellulose nanocrystal from spent fungi substrate and redispersion with gelatin

Dicarboxylic cellulose nanocrystals (DCNCs) from spent fungi substrate were freeze-dried with gelatin to obtain nanoscale-powder that was easy to redisperse and store. The agglomeration of nanocellulose during the drying process led to its performance degradation, which was the major limit to its productization and economy. In this study, The DCNCs were obtained via the sequential periodate-chlorite process without any mechanical component, and its structural and morphological properties were characterized by the transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD results showed the cellulose I structure was maintained, however, the crystallinity index decreased because of the oxidation. The TEM analysis revealed that DCNC behaved rod-shaped with the average length and width of 281.47 nm and 20.8 nm, respectively. The gelatin and nanocellulose were homogenized through different conditions, then washing with hot water after the freeze-drying. Under the conditions of gelatin 2%, pH 7, and homogeneous (16000 r/min, 20 min), the redispersed DCNC suspension with the best light transmittance and stability was obtained. The introduction of gelatin not only minimized aggregation during the dehydration but also ensured excellent redispersion kinetics and stability. This study would provide an efficient and convenient route for the redispersion and storage of nanocellulose, aiming to realize its industrial application.

The Influence of Transglutaminase on Minced Muscular Fish Tissue Structure Formation After the Application of Various Protein Substrates

This research aimed to examine the effect of a microbial transglutaminase preparation (Activa® GS, Ajinomoto Co., Inc, Japan) on the structure formation of the myofibrillar protein system of a deep-sea fish species – the giant grenadier – after the addition of various protein substrates. The low content of proteins and their low water-holding capacity in this fish, subjected to various processing methods, leads to significant losses in the initial mass and decreased gelation ability in the muscle tissue system. Various concentrations of transglutaminase were used but these did not ensure the restructuring of the initial muscle tissue of the grenadier. Additional protein substrates with different molecular weights and amino acid composition were added, including gelatin, milk casein, hydrolysates of the skin and milt of the fish, and whole bivalves, which were used to create a firm structure. It was shown that the introduction of gelatin and casein at a concentration of 5% led to the formation of a firm, thermostable structure under the action of the enzyme, while hydrolyzed proteins with low molecular weight at their various concentrations enhanced the expression of water and formation of the fluid consistency. The ability of gastrointestinal tract proteases (pepsin and trypsin) to digest did not depend on the formation of protein-to-protein cross-linking in these combined products. The influence on the growth of the Tetrahymena pyriformis ciliates test culture also showed the high degree of product availability. The technology of molded products based on fermented minced muscle tissue of grenadier with added casein, both in the form of semi-finished products and in the form of ready-to-eat products, was developed.
 Keywords: transglutaminase, muscle tissue, structure formation, deep-sea fish

Chitosan/PVA Based Membranes Processed by Gamma Radiation as Scaffolding Materials for Skin Regeneration.

Some of the current strategies for the development of scaffolding materials capable of inducing tissue regeneration have been based on the use of polymeric biomaterials. Chitosan, in particular, due to its recognized biological activity has been used in a number of biomedical applications. Aiming the development of chitosan-based membranes with improved cell adhesion and growth properties to be used as skin scaffolds allowing functional tissue replacement, different formulations with chitosan of different molecular weight, poly (vinyl alcohol) and gelatin, were evaluated. To meet the goal of getting ready-to-use scaffolds assuring membranes’ required properties and sterilization, preparation methodology included a lyophilization procedure followed by a final gamma irradiation step. Two radiation dose values were tested. Samples were characterized by TGA, FTIR, and SEM techniques. Their hydrophilic properties, in vitro stability, and biocompatibility were also evaluated. Results show that all membranes present a sponge-type inner structure. Chitosan of low molecular weight and the introduction of gelatin are more favorable to cellular growth leading to an improvement on cells’ morphology and cytoskeletal organization, giving a good perspective to the use of these membranes as potential skin scaffolds.

Development of wound therapy in nursing care of infants by using injectable gelatin-cellulose composite hydrogel incorporated with silver nanoparticles

Nano silver material has been regarded as a kind of promising candidate for biomedical application due to its low cytotoxicity and striking antibacterial activity. In this study, an injectable silver-gelatin-cellulose ternary hydrogel dressing was prepared by the introduction of gelatin and aminated silver nanoparticles into the carboxylated cellulose nanofibers for efficient wound therapy in infant nursing. The produced silver nanoparticles and composite hydrogel were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), and X-ray diffraction (XRD) techniques. The as-synthesized silver-cellulose-gelatin ternary hydrogel demonstrated high porosity and satisfactory antibacterial activity. In vitro cytocompatibility measurement revealed the very low toxic nature of such composite hydrogel dressing. Additionally, the in vivo assessment in mice confirmed that the silver-cellulose-gelatin ternary dressing possessed improved wound healing ability. Hence, this study strongly supports the possibility of using this novel silver-gelatin-cellulose ternary dressing for efficient cutaneous wound healing in nursing care of infants.

Effect of gelatin on electrodeposition of tellurium from alkaline electrolyte

The effect of gelatin as an additive on tellurium (Te) electrodeposition process was studied by linear sweep voltammogram (LSV) and electrochemical impedance spectroscopy (EIS) in alkaline electrolyte (NaOH). It was found that deposition, corrosion and recrystallization occurred almost simultaneously during Te electrodeposition process, resulting in a porous structure of Te products. Gelatin helped to improve the corrosion resistance and limited current density, and reduce the bath potential at the same current density. LSV showed that the physical adsorption of gelatin on the Titanium (Ti) plate affected the electrodeposition process of Te. EIS results indicated that the gelatin had little effect on the electron transfer of Te electrodeposition but disturbed the diffusion of TeO32−. Equivalent circuit and deposition model of Te electrodeposition process with and without gelatin were deduced. Furthermore, high purity Te products were deposited and obtained on Ti plate from electrolyte with different content of gelatin by chronopotentiometry (CP) for 48 h at 80 A∙m−2, which indicated that moderate amount of gelatin could increase both bath potential and current efficiency of Te electrodeposition. Morphological, structural and pure characterizations of Te products were studied by x-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), respectively. Introduction of gelatin could not change the morphology of Te products but acted as a grain refiner, that increased the purity of Te products.

Mechanically Biomimetic Gelatin-Gellan Gum Hydrogels for 3D Culture of Beating Human Cardiomyocytes.

To promote the transition of cell cultures from 2D to 3D, hydrogels are needed to biomimic the extracellular matrix (ECM). One potential material for this purpose is gellan gum (GG), a biocompatible and mechanically tunable hydrogel. However, GG alone does not provide attachment sites for cells to thrive in 3D. One option for biofunctionalization is the introduction of gelatin, a derivative of the abundant ECM protein collagen. Unfortunately, gelatin lacks cross-linking moieties, making the production of self-standing hydrogels difficult under physiological conditions. Here, we explore the functionalization of GG with gelatin at biologically relevant concentrations using semiorthogonal, cytocompatible, and facile chemistry based on hydrazone reaction. These hydrogels exhibit mechanical behavior, especially elasticity, which resembles the cardiac tissue. The use of optical projection tomography for 3D cell microscopy demonstrates good cytocompatibility and elongation of human fibroblasts (WI-38). In addition, human-induced pluripotent stem cell-derived cardiomyocytes attach to the hydrogels and recover their spontaneous beating in 24 h culture. Beating is studied using in-house-built phase contrast video analysis software, and it is comparable with the beating of control cardiomyocytes under regular culture conditions. These hydrogels provide a promising platform to transition cardiac tissue engineering and disease modeling from 2D to 3D.

Influence of added gelatin on the rheological properties of a Fucus vesiculosus extract

The influence of gelatin from bovine skin on the rheological properties of hydrogels in an extract from the alginate-containing algae Fucus vesiculosus was studied. The shear rate and dynamic mechanical analyses were used to determine the rheological properties. FT-IR spectroscopy showed that the main structural component of the Fucus extract was sodium alginate. The changes of the rheological properties of the extract with the introduction of gelatin are explained using the framework of the alginate–gelatin complexation model. The Fucus extract showed a weakly expressed non-Newtonian behaviour since the flow index in the Ostwald–De Waele equation is 0.91–0.94. The introduction of gelatin (1.0 wt.%) into the extract at 24 °C led to the formation of a hydrogel, whereas the extract itself cannot form a gel with these conditions. Further increasing the concentration of gelatin led to an exponential increase in the yield stress, plastic viscosity and apparent viscosity of the hydrogels. The introduction of gelatin into the Fucus extract at 4 °C led to a non-additive increase in the elastic modulus (G′), and a decrease in the tan δ of the hydrogels, i.e., strengthening of the elastic properties and weakening of viscous properties in these systems. The changes in the rheological parameters of a Fucus extract after the introduction of gelatin can be explained by an increase in the concentration of triple helices in the macromolecular chains of the gelatin, which are the elastic elements in the 3D mixed gel network.

Study of hemocompatibility and endothelial cell interaction of tecoflex-based electrospun vascular grafts

Ensuring long-term functioning and efficient endothelialization of small diameter vascular grafts (VG) is an urgent task of tissue engineering. A solution may be to use electrospun VGs prepared from blends polyurethane with gelatin and/or bivalirudin. Here, properties of 3D matrices were explored by SEM, contact angle measurements and IR spectroscopy, and their interaction with blood and endothelial cells was studied. Introduction of gelatin into matrices enhanced adhesion and proliferation of endotheliocytes and enabled adhesion of platelets, whereas bivalirudin inhibited platelet adhesion while having no negative effect on the adhesion and proliferation of endothelial cells.

Influence of gelatin on crystallisation and hydrophilicity of poly(vinyl alcohol)/gelatin blend films

Gelatin has been incorporated into poly(vinyl alcohol) (PVA) hydrogels obtained by a crosslinking technique of repeated freezing and thawing. The crystallisation and hydrophilicity of PVA/gelatin blend films in the presence of gelatin were investigated using Fourier transform infrared, X-ray diffraction and contact angle measurement. The introduction of gelatin increases the degree of crystallinity of uncross-linked PVA/gelatin films obtained by casting/evaporation method. Compared with the uncross-linked films, the freeze–thawed PVA/gelatin hydrogels exhibited an enhanced degree of crystallinity. With the increase of the proportion of gelatin present in the film, the degree of crystallinity of cross-linked PVA/gelatin hydrogels increases first and then decreases. Water contact angle studies indicated that all these materials have good hydrophilicity, and the water contact angles of hydrogel increased with the increase of gelatin content and cross-linking treatment.

Lecithin-Linker Microemulsion Gelatin Gels for Extended Drug Delivery

This article introduces the formulation of alcohol-free, lecithin microemulsion-based gels (MBGs) prepared with gelatin as gelling agent. The influence of oil, water, lecithin and hydrophilic and lipophilic additives (linkers) on the rheological properties and appearance of these gels was systematically explored using ternary phase diagrams. Clear MBGs were obtained in regions of single phase microemulsions (μEs) at room temperature. Increasing the water content in the formulation increased the elastic modulus of the gels, while increasing the oil content had the opposite effect. The hydrophilic additive (PEG-6-caprylic/capric glycerides) was shown to reduce the elastic modulus of gelatin gels, particularly at high temperatures. In contrast to anionic (AOT) μEs, the results suggest that in lecithin (nonionic) μEs, the introduction of gelatin “dehydrates” the μE. Finally, when the transdermal transport of lidocaine formulated in the parent μE and the resulting MBG were compared, only a minor retardation in the loading and release of lidocaine was observed.

Fabrication of protein‐doped PLA composite nanofibrous scaffolds for tissue engineering

AbstractBACKGROUND: Electrospinning is known as a novel fabrication method to form nanofibrous scaffolds for tissue‐engineering application. Previously, many natural biopolymers of protein have been electrospun. However, keratin has not attracted enough attention. In this study, keratin and gelatin were co‐electrospun with polylactide (PLA), respectively.RESULTS: The resulting nanofibers were characterized by a field emission scanning electron microscope (FE‐SEM), an attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR), and an electron spectroscopy for chemical analysis (ESCA). The biodegradation of mats in the presence of trypsin solution was studied. Cell attachment experiments showed that NIH 3T3 cells adhered more and spread better onto the PLA/keratin and PLA/gelatin nanofibrous mats than that onto the blank PLA mats. MTT and BrdU assay showed that PLA/keratin and PLA/gelatin nanofibrous mats could both accelerate the viability and proliferation of fibroblast cells as compared to PLA nanofibrous mats.CONCLUSION: The present study suggests that the introduction of gelatin and keratin can both improve cell‐material interaction, especially, the former is more effective. Copyright © 2008 Society of Chemical Industry

Preparation of alginate-gelatin capsules and its properties

Capsules based on alginate and gelatin prepared by extrusion method could increase the cell numbers of Lactobacillus casei ATCC 393 to be 108 CFU·g−1 in the wet state of the capsules. The capsules were spherical, smooth-surfaced and non-aggregated with a diameter of (4.0 ± 0.3) mm. The behavior of the samples were quite similar at low relative humidity (33%, 52%) and the ratio of weight change reached 93%. Four kinds of capsules in simulated gastric fluid (SGF) exhibited shrinkage while the beads eroded accompanied with slight swelling in simulated intestinal fluid (SIF). The pH values affected the stability of the capsules and with the increase in pH, the capsules changed from shrank then swelled and finally, broke into pieces. The capsules behaved differently under different ion intensities and the introduction of gelatin weakened the stability of capsules compared with the alginate ones. Cells of L. casei ATCC 393 could be continuously released from the capsules in the simulated gastrointestinal tract (GIT) and the release amounts and speeds in SIF were much higher and faster than those in SGF.

New Contact Lens Based on Chitosan/Gelatin Composites

A series of chitosan/gelatin composite films were prepared by solvent evaporation and characterized for oxygen permeability, optical transmittance, water absorptivity and mechanical properties. The results indicate that the introduction of gelatin was beneficial to increasing water absorption and that oxygen and solute permeability of chitosan composite film was improved. Chitosan/gelatin composite films are more permeable, transparent, flexible and biocompatible films and could potently be used for contact lens material.

Chitosan/gelatin microspheres prepared by modified emulsification and ionotropic gelation

Chitosan microspheres were prepared by an emulsion-phase separation technique without the use of chemical cross-linking agents; alternatively, ionotropic gelation was employed in a w/o emulsion. The possibility of three kinds of anions (tripolyphosphate, citrate and sulphate) to interact with chitosan was investigated by turbidimetric titration. The results indicate that there are electrostatic interactions between the above anions and chitosan in a certain region of solution pH(1.0-7.5 for sulphate/chitosan, 4.5-7.5 for citrate/chitosan and 1.9-7.5 for tripolyphosphate/chitosan), that is related to the natural characteristics of the anions. Out of the pH region where anions interact with chitosan, no microspheres were formed. However, even in the pH region where anions can interact with chitosan, only irregular microparticles were obtained in the case of the conventional emulsification and ionotropic gelation method, while spherical microspheres with diameters in the range of tens of microns were obtained when a modified process was employed. The key point of the modified process is the introduction of gelatin and allowing the ionic crosslinking process of chitosan/gelatin w/o emulsions to take place under coagulation conditions at a low temperature. The surface of sodium sulphate cross-linked chitosan/gelatin and sodium citrate cross-linked chitosan/gelatin microspheres was very smooth, but large gaps were observed on the surface of tripolyphosphate/chitosan microspheres. The increase of stirring speed led to a decrease in diameter and a narrowing in size distribution.

CATHODE SURFACE CHANGES IN THE PRESENCE OF GELATIN DURING ELECTRODEPOSITION OF COPPER

Measurements of the cathode polarization during electrodeposition of copper from acid copper sulphate solutions indicate that introduction of gelatin into the electrolyte decreases the area of the cathode available for deposition, or active area, owing to adsorption of gelatin on the active centres. This decrease in area causes an increase in the true current density, with a resulting increase in cathode polarization, the former being assumed the main factor in causing an increase in the rate of nuclear formation and decrease in grain size.