Showing papers on "Gelatin published in 2001"
TL;DR: The data suggest that the use of GTA at low concentration, which is desiderable to prevent toxicity, allows to modulate the physico-chemical properties of gelatin films, in order to obtain stable materials with a wide range of possible biomedical applications.
759 citations
TL;DR: In this article, the authors determined the water vapor permeability and the mechanical and thermal properties of edible films based on bovine hide and pigskin gelatins using a gravimetric method at 22°C.
560 citations
TL;DR: Results indicate that the purified peptide, P2, from gelatin hydrolysate of Alaska pollack skin is a natural antioxidant which has potent antioxidative activity.
Abstract: Gelatin extracted from Alaska pollack skin was hydrolyzed with serial digestions in the order of Alcalase, Pronase E, and collagenase using a three-step recycling membrane reactor. The fraction from the second step, which was hydrolyzed with Pronase E, was composed of peptides ranging from 1.5 to 4.5 kDa and showed high antioxidative activity. Two different peptides showing strong antioxidative activity were isolated from the hydrolysate using consecutive chromatographic methods including gel filtration on a Sephadex G-25 column, ion-exchange chromatography on a SP-Sephadex C-25 column, and high-performance liquid chromatography on an ODS column. The isolated peptides, P1 and P2, were composed of 13 and 16 amino acid residues, respectively; and both peptides contained a Gly residue at the C-terminus and the repeating motif Gly-Pro-Hyp. The antioxidative activities of the purified peptides were measured using the thiobarbituric acid method, and the cell viability was measured with MTT assay. The results showed that P2 had potent antioxidative activity on peroxidation of linoleic acid. Moreover, the cell viability of cultured liver cells was significantly enhanced by addition of the peptide. These results indicate that the purified peptide, P2, from gelatin hydrolysate of Alaska pollack skin is a natural antioxidant which has potent antioxidative activity.
478 citations
TL;DR: Findings indicate that the growth factor immobilized to the acidic gelatin hydrogel through ionic interaction was released in vivo as a result of hydrogels degradation.
Abstract: To develop a carrier for the controlled release of biologically-active growth factors, biodegradable hydrogels were prepared through glutaraldehyde cross-linking of gelatin with isoelectric points (IEP) of 5.0 and 9.0, i.e. 'acidic' and 'basic' gelatins, respectively. Radioiodinated growth factors were used to investigate their sorption and desorption from the hydrogel of both types of gelatin. Basic fibroblast growth factor (bFGF) and transforming growth factor-beta1 (TGF-beta1) were well sorbed with time to the acidic gelatin hydrogel, while less sorption was observed for the basic gelatin hydrogel. This could be explained in terms of the electrostatic interaction between the growth factors and the acidic gelatin. However, bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF), though their IEPs are higher than 7.0, were sorbed to the acidic gelatin hydrogel to a smaller extent than the two other growth factors. Under in vitro non-degradation conditions, approximately 20% of the incorporated bFGF and TGF-beta1 was desorbed from the hydrogels within the initial 40 min, followed by no further substantial desorption, whereas large initial desorption was observed for BMP-2 and VEGF. When implanted in the back subcutis of mice, gelatin hydrogels were degraded over time. Each growth factor was retained in vivo being incorporated in the acidic gelatin hydrogel: the smaller the in vitro desorption amount from the hydrogel, the longer the in vivo retention time. The in vivo profile of bFGF and TGF-beta1 retention was in good accordance with that of the hydrogel. These findings indicate that the growth factor immobilized to the acidic gelatin hydrogel through ionic interaction was released in vivo as a result of hydrogel degradation.
381 citations
TL;DR: The differential scanning calorimetry (DSC) result indicated that the paclitaxel trapped in the microspheres existed in an amorphous or disordered-crystalline status in the polymer matrix.
299 citations
TL;DR: In this study, synthesis of a novel polymeric bilayer wound dressing containing epidermal growth-factor (EGF) -loaded microspheres was aimed and Histological investigations showed that the prepared dressings were biocompatible and did not cause any mononuclear cell infiltration or foreign body reaction.
294 citations
TL;DR: Bovine skin gelatin was hydrolyzed with sequential protease treatments in the order of Alcalase, Pronase E, and collagenase using a three-step ultrafiltration membrane reactor and two different peptides showing strong ACE inhibitory activity were isolated from the hydrolysate using consecutive chromatographic methods.
Abstract: Bovine skin gelatin was hydrolyzed with sequenial protease treatments in the order of Alcalase, Pronase E, and collagenase using a three-step ultrafiltration membrane reactor. The molecular weight distributions of the first, second, and third hydrolysates were 4.8−6.6, 3.4−6.6, and 0.9−1.9 kDa, respectively. The angiotensin I converting enzyme (ACE) inhibitory activity of the third hydrolysate (IC50 = 0.689 mg/mL) was higher than that of the first and second hydrolysates. Two different peptides showing strong ACE inhibitory activity were isolated from the hydrolysate using consecutive chromatographic methods including gel filtration chromatography, ion-exchange chromatography, and reversed-phase high-performance liquid chromatography. The isolated peptides were composed of Gly-Pro-Leu and Gly-Pro-Val and showed IC50 values of 2.55 and 4.67 μM, respectively. Keywords: ACE inhibitory peptide; bovine skin; three-step ultrafiltration membrane reactor; gelatin hydrolysate
250 citations
TL;DR: The results suggest the potential application of gelatin microspheres crosslinked with GAL as a suitable drug delivery system for the subcutaneous administration and biocompatibility studies showed that the microsphere crosslinkers are well tolerated in vivo.
181 citations
TL;DR: A striking result is that, following extensive covalent crosslinking during cold-set gelation and afterwards in the melted state, the gelatin gel's characteristic thermoreversible character is almost completely lost.
168 citations
TL;DR: In this article, the phase transitions of pigskin gelatin were determined as a function of moisture content in the hygroscopic domain using the Gordon and Taylor model and the Flory-Huggins model.
166 citations
TL;DR: Despite the fact that gelatins are highly susceptible to proteolysis because of their unfolded structure, the recombinant protein was shown to be fully intact by SDS-PAGE, N-terminal sequencing, gel filtration chromatography and mass spectrometry.
Abstract: A custom-designed, highly hydrophilic gelatin was produced in Pichia pastoris. Secreted production levels in single-copy transformants were in the range 3-6 g/l of clarified broth and purification to near homogeneity could be accomplished by differential ammonium sulfate precipitation. Despite the fact that gelatins are highly susceptible to proteolysis because of their unfolded structure, the recombinant protein was shown to be fully intact by SDS-PAGE, N-terminal sequencing, gel filtration chromatography and mass spectrometry. Owing to its highly hydrophilic nature, the migration of the synthetic gelatin in SDS-PAGE was severely delayed. Esterification of the carboxylic amino acid side chains resulted in normal migration. The high polarity of the synthetic gelatin also accounts for its negligible surface activity in water at concentrations up to 5% (w/v), as determined by tensiometry. Circular dichroism spectrometry showed that the non-hydroxylated gelatin did not form triple helices at 4 degrees C. The spectrum was even more representative of the random coil conformation than the spectrum of natural non-hydroxylated gelatins.
TL;DR: GH with AgSD was found to show the best wound healing properties as a wound dressing resulting from histological findings and computerized morphometric analysis of epidermal healing.
Abstract: Novel cross-linked sponges composed of gelatin/alginate and gelatin/hyaluronate and chitosan/hyaluronate (GH, GA and CH, respectively) were prepared and compared. Six different sponges with or without silver sulfadiazine (AgSD) were applied on the full-thickness dorsal skin defect of Wistar rat. The histology and epidermal wound healing rates of the skin defects were investigated by light microscopy and computerized morphometry 5 and 12 days post-operatively. In our full-thickness wound model (diameter 1 cm), the AgSD-impregnated sponges showed good wound healing performances on the whole. However, there appeared meaningful differences of wound healing between the gelatin-based sponges (GH, GA) and the CH. GH with AgSD was found to show the best wound healing properties as a wound dressing resulting from histological findings and computerized morphometric analysis of epidermal healing.
TL;DR: There are electrostatic interactions between the above anions and chitosan in a certain region of solution pH that is related to the natural characteristics of the anions, and even in the pH region where anions can interact with chitOSan, no microspheres were formed.
Abstract: 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 cross-linking 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.
TL;DR: This work shows that increasing the comonomer concentration increases the CT-dose sensitivity of the polymer gel dosimeter, which can be further increased by replacing gelatin with agarose, and Varying the gelatin concentration however does not significantly change the CT -dose sensitivity.
Abstract: Changes in the linear attenuation coefficient of polymer gel dosimeters post-irradiation enable the imaging of dose distributions by x-ray computed tomography (CT). Various compositions of polymer gel dosimeters manufactured from acrylamide (AA), and N,N'-methylene-bis-acrylamide (BIS) comonomers and gelatin or agarose gelling agents were investigated. This work shows that increasing the comonomer concentration increases the CT-dose sensitivity of the polymer gel dosimeter. This can be further increased by replacing gelatin with agarose. Varying the gelatin concentration however does not significantly change the CT-dose sensitivity. Among the compositions studied, dose resolution (D(delta)95%) was found to be optimal for polymer gel dosimeters comprising 5% gelatin, 3% AA, 3% BIS and 89% water.
Patent•
09 May 2001
TL;DR: In this paper, the starch-based systems can completely replace gelatin in edible film-forming applications such as soft and hard gel capsules, which can be chemically modified starches which range in molecular weight from 100,000 to 2,000,000.
Abstract: Film-forming compositions are disclosed that can comprise, on a dry solids basis, 25 to 75 percent by weight of certain starch derivatives having a DE less than about 1, 25 to 75% plasticizer, and 0.1 to 15% hydrocolloid gum. The starch derviatives can be chemically modified starches which range in molecular weight from 100,000 to 2,000,000. These starch-based systems can completely replace gelatin in edible film-forming applications such as soft and hard gel capsules.
TL;DR: Light-colored, dry collagen was obtained and, after dissolving in warm water, turned into soluble gelatin this paper, and the type of acid used influenced the gelatin viscoelastic and gelling properties.
Abstract: Light-colored, dry collagen was obtained and, after dissolving in warm water, turned into soluble gelatin The type of acid used influenced the gelatin viscoelastic and gelling properties Acetic- and propionic-acid extracts produced the gelatins with the highest elastic modulus, viscous modulus, melting temperature, and gel strength, especially when skins were previously treated with dilute NaOH After such treatment, lactic acid was also shown to be suitable for collagen or gelatin extraction The lowest degree of turbidity was achieved by using citric acid, whereas propionic acid led to the most turbid gelatin No improvements of rheological properties were observed when acid concentration for extraction was increased above 005 M
TL;DR: Cast films presented thermal and mechanical properties, which make them good candidates as biodegradable self-fertilizing mulching films.
TL;DR: Microparticles prepared by complex coacervation to encapsulate eicosapentaenoic acid ethyl ester (EPA-EE) for incorporation into foods as a nutrition supplement showed a homogeneous distribution for both polymers, gelatin and acacia was observed inside the particle wall, and no influence of the different particle hardening procedures on the polymer distribution was found.
Abstract: Microparticles were prepared by complex coacervation to encapsulate eicosapentaenoic acid ethyl ester (EPA-EE) for incorporation into foods as a nutrition supplement. Gelatin and acacia were used in the coacervation process. With an increasing oil/polymer ratio, both yield and encapsulation rate decreased; with an increasing homogenization time, the yield remained constant while the encapsulation rate slightly increased. Several particle hardening techniques were examined and their influence on particle structure, yield and encapsulation rate were examined. Ethanol hardening was compared to cross-linking with dehydroascrobic acid with respect to both yield and encapsulation rate. The particle diameters for both formulations were similar (ethanol: 38.4 +/- 4.1 microm; cross-linking: 41.8 +/- 3.0 microm). Spray-drying of the coacervates led to the smallest particles (5.2 +/- 1.1 microm), lowest yield and encapsulation rate. All microencapsulation products were assayed for their storage stability over 4 weeks with respect to the oxidation of the encapsulated omega - 3 unsaturated fatty acid ester inside the particles. Hardening with ethanol showed the lowest amount of peroxides: particle wall cross-linking by dehydroascorbic acid and spray-drying were observed to be less protective. All microparticles were characterized for their internal structure with confocal laser scanning microscopy (CLSM) after fluorescence labelling of the polymers, in order to localize the oil phase and visualize the distribution of the polymers in the coacervates. With increasing homogenization time, the internal structure changed stepwise from a capsule structure (core/wall) towards a matrix structure. For all experiments, a homogeneous distribution for both polymers, gelatin and acacia was observed inside the particle wall. No influence of the different particle hardening procedures on the polymer distribution was found.
TL;DR: In this article, a thorough investigation was carried out on the propensity to biodegradation behavior of casting films based on waste gelatin (WG), after characterization of thermal and thermomechanical behaviour of the present blends, under incubation conditions aimed at simulating soil burial conditions.
TL;DR: The texture of high-methoxyl pectin gummy gels was quantified by instrumental and sensory techniques and their microstrucuture examined by light and transmission electron microscopy.
TL;DR: In preliminary in vivo experiments these drug- or adenovirus-immobilized stents were implanted in rabbit common carotid arteries, indicating that the gelatinous photogel effectively serves as a matrix or coating for a bioactive stent, which permits drug release as well as gene transfer.
Abstract: Hydrogel-coated metallic stents may provide supplementary functions such as local drug delivery and gene transfer in addition to mechanical dilation function. To this end, we used a photoreactive material consisting of gelatin macromer (multiple styrene-derivatized gelatin) and carboxylated camphorquinone (photo-initiator). A few minutes of visible light irradiation of a stent after dip-coating of an aqueous solution of the photoreactive material resulted in the formation of a homogeneously crosslinked gelatinous layer on the entire exterior surface of the stent. As the metal stent, gold stents under development were used. Rhodamine-conjugated albumin as a model drug or adenoviral vector expressing bacterial beta-galactosidase (AdLacZ) as a model gene were photo-immobilized in the gelatinous gel layer. In vitro experiments using hybrid tubular tissue, which is a self-shrinkaged, vascular smooth muscle cell-incorporated type-I collagen gel, as a vascular model, showed that the immobilized dye-derivatized albumin was released on and permeated into tissues, as observed by confocal laser microscopy, and that the cells transfected with immobilized AdLacZ produced beta-galactosidase up to almost 3 weeks, as observed by x-gal staining. In preliminary in vivo experiments these drug- or adenovirus-immobilized stents were implanted in rabbit common carotid arteries. Within 3 weeks of implantation, drug permeation and gene expression in the vascular tissues were observed, indicating that the gelatinous photogel effectively serves as a matrix or coating for a bioactive stent,which permits drug release as well as gene transfer. This intraluminal approach has the potential to realize drug and gene therapy in atherosclerotic plaque.
TL;DR: In this paper, the synthesis of full and semi-interpenetrating polymer networks (IPNs) based on poly(acrylic acid) and gelatin as polymers 1 and 2, which were crosslinked sequentially using N,N′-methylene bisacrylamide (BAm) and glutaraldehyde, respectively.
Abstract: This article describes the synthesis of full and semi-interpenetrating polymer networks (IPNs) based on poly(acrylic acid) and gelatin as polymers 1 and 2, which were crosslinked sequentially using N,N′-methylene bisacrylamide (BAm) and glutaraldehyde, respectively. Various samples were prepared by taking varying amounts of acrylic acid and gelatin in the initial feed. Sequential IPNs were prepared by first polymerizing and crosslinking acrylic acid in the presence of gelatin using redox initiators (ammonium persulphate and sodium metabisulphite) and BAm as a crosslinking agent. Gelatin present in the firm gels was then crosslinked using 4% glutaraldehyde. Characterization of these gels was done by measuring their swelling behavior as a function of pH, temperature, and time. Percent swelling increased with increasing amounts of acrylic acid. The swelling ratio was also determined in the pH range of 1 to 12. Acid/alkali or buffers were used for maintaining pH. A significant increase in the percent swelling was observed when pH of distilled water was above 10. On the other hand, in the case of buffer, the swelling ratio increased with increasing the pH, and a maxima was observed at pH 8.4. A further increase in pH resulted in a decrease in the swelling ratio. Thermal and morphological characterization was done using thermogravimetric analyzer and scanning electron microscopy, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 217–227, 2001
TL;DR: In this article, a new type of inorganic-organic hybrid materials incorporating gelatin and 3-(glycidoxypropyl) trimethoxysilane (GPSM) was prepared through sol-gel processing.
Abstract: A new type of inorganic-organic hybrid materials incorporating gelatin and 3-(glycidoxypropyl) trimethoxysilane (GPSM) was prepared through sol-gel processing. A solid-state 29Si NMR analysis indicated that all the methoxy silane groups of GPSM were polymerized to yield —Si—O—Si— bridging bonds. An amino acid analysis confirmed grafting reactions of GPSM against gelatin chains. The increasing GPSM/gelatin ratio stimulated gel formation, phase separation, and the density of GPSM-crosslinking of the gelatin chains as well as it changed the micro- and macro- structures and the viscoelastic properties of the final products.
TL;DR: In this paper, the authors investigated the properties of a polymer gel dosimeter post-irradiation using H-1-and C-13-NMR spectroscopy and FT-Raman spectrograms and showed that the nonlinear T-2 dependence against dose can be understood in terms of the fraction of protons in three different proton pools.
Abstract: H-1- and C-13-NMR spectroscopy and FT-Raman spectroscopy are used to investigate the properties of a polymer gel dosimeter post-irradiation. The polymer gel (PACT) is composed of acrylamide, N,N'-methylene-bisacrylamide, gelatin, and water. The formation of a polyacrylamide network within the gelatin matrix follows a dose dependence nonlinearly correlated to the disappearance of the double bonds from the dissolved monomers within the absorbed dose range of 0-50 Gy. The signal from the gelatin remains constant with irradiation. We show that the NMR spin-spin relaxation times (T-2) of PAGs irradiated to up to 50 Gy measured in a NMR spectrometer and a clinical magnetic resonance imaging scanner can be modeled using the spectroscopic intensity of the growing polymer network. More specifically, we show that the nonlinear T-2 dependence against dose can be understood in terms of the fraction of protons in three different proton pools. (C) 2000 John Wiley & Sons, Inc.
TL;DR: PLGA foams, treated and untreated, represent a promising scaffold for scaling up hepatocyte cultures and may be a substitute for transplantation in patients whose livers can regenerate.
Abstract: Techniques of liver replacement would benefit patients awaiting donor livers and may be a substitute for transplantation in patients whose livers can regenerate. Poly(lactic-co-glycolic acid) (PLGA) copolymers are biodegradable and have been shown to be useful as scaffolds for seeding and culturing various types of cells. In this study, foam disks were prepared from PLGA (lactic-to-glycolic mole ratio of 85:15) by lyophilization of benzene (5% w/v) solutions. These disks were then used as scaffolds for rat hepatocyte culture. Foams were coated with either a type I collagen gel (0.1% w/v), coated with gelatin (5% w/v), or treated with oxygen plasma (25 W, 90 s) to modify their surface chemistry and wettability. The disks were then seeded with rat hepatocytes (106/mL) and cultured for a period of 2 weeks. All surface treatments resulted in increased hydrophilicity, the greatest being obtained by collagen treatment (contact angle < 10°), and a minimal decrease in void fraction (5%). DNA content after a 2-wee...
TL;DR: In this paper, the structure and properties of the blend films were studied by infrared (IR) spectra, wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA).
Abstract: Blend films were prepared by blending 4 wt% sodium alginate and 5 wt% gelatin aqueous solutions and dried at room temperature for 2 days to obtain the transparent films. Their structures and properties were studied by infrared (IR) spectra, wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Significant changes in the shape and intensity of IR spectra absorption frequencies characteristic of either gelatin or sodium alginate were detected by IR analysis. The crystallinities of the blend films decreased with the increase of sodium alginate content. The thermal stability, mechanical properties of tensile strength, and breaking elongation of the blend films were improved by blending sodium alginate with gelatin. It is worth noting that the breaking elongation reached 16.6% when the weight ratio of sodium alginate to gelatin was 1:1, much higher than that of two components. The structure analysis indicated that the...
TL;DR: The higher amino group content, improved chain flexibility and favorable polymer conformation were suggested to be the main factors that contributed to the stronger mucoadhesive properties of aminated gelatin microspheres than that of gelatinmicrospheres.
TL;DR: The results support earlier reports of non-amino group crosslinking by formaldehyde in gelatin and support the possible mechanisms of this not-so-simple problem.
TL;DR: In this article, a new bone grafting material was developed using deglued bone, chitosan and gelatin, which is a byproduct of bone glue industries and has the close crystallographic similarities of hydroxyapatite was used as main component in the preparation of bone implant.
Abstract: With the aim of developing an ideal bone graft, a new bone grafting material was developed using deglued bone, chitosan and gelatin. Deglued bone (DGB) which is a by-product of bone glue industries and has the close crystallographic similarities of hydroxyapatite was used as main component in the preparation of bone implant. Chitosan was prepared from the exoskeleton of prawn (Pinaeus indicus, family Crustaceae) which is a by-product of seafood industries. Chitosan gives toughness to the product and do not allow the DGB particles to wither away when the implant is placed in the defect. Gelatin was used as binder for the preparation of DGB-chitosan composite. The DGB, chitosan and DGB-chitosan-gelatin composite, which were prepared in the laboratory, were analysed for their physicochemical properties by infrared spectroscopy, X-ray diffraction and scanning electron microscopy studies.
TL;DR: In vitro bioassay revealed that HGF molecules interacting with gelatin, still exhibited the biological activity, and it is possible that the HGF associating gelatin fragments of bioactivating, results in induced angiogenic effect.
Abstract: This paper investigates the controlled release of hepatocyte growth factor (HGF) by biodegradable gelatin hydrogels and their HGF-induced angiogenic effect. Hydrogels of different degradabilities were prepared through chemical crosslinking gelatin with varied amounts of glutaraldehyde. When the gelatin hydrogels were radioiodinated and subcutaneously implanted into the back of mice, the remaining radioactivity of the hydrogels decreased with time. However, the remaining period became longer when the concentration of glutaraldehyde used for hydrogel preparation increased. Following implantation of gelatin hydrogels incorporating 125I-labeled HGF, the HGF radioactivity retained in the mouse subcutis for longer time periods as the glutaraldehyde concentration becomes higher. The time profile of HGF remaining in every gelatin hydrogel was in good accordance with that of hydrogel degradation, indicating HGF release as a result of hydrogel biodegradation. The gelatin hydrogel incorporating HGF histologically in...