Showing papers on "Gelatin published in 2004"
TL;DR: The findings of this study suggest that various biomaterials support the chondrogenic differentiation of hADAS cells, and that manipulating the composition of these tissue engineered constructs may have significant effects on their mechanical properties.
799 citations
TL;DR: The later gelatin extracts exhibited higher molecular order than earlier gelatin extracts, probably because the former contained surviving crosslinks or/and because renaturation of the low molecular weight gelatin fractions (later gelatin extracts) led to formation of more protein–protein linkages.
708 citations
TL;DR: In this article, the mass concentration-mechanical property relationship of the resulting nanofiber membranes was investigated, and it was found that the highest mechanical behavior did not occur to the nanofibrous membrane electrospun from the lowest or the highest mass concentration solution, instead, the matrix with the finest fiber structure and no beads on surface obtained from the 7.5% mass concentration exhibited the largest tensile modulus and ultimate tensile strength.
660 citations
TL;DR: Double‐network (DN) hydrogels with high mechanical strength have been synthesized using the natural polymers bacterial cellulose and gelatin, and an enhancement in the mechanical strength was also observed for the combination of BC with polysaccharides, such as sodium alginate, gellan gum, and ι‐carrageenan.
Abstract: Double-network (DN) hydrogels with high mechanical strength have been synthesized using the natural polymers bacterial cellulose (BC) and gelatin. As-prepared BC contains 90 % water that can easily be squeezed out, with no more recovery in its swelling property. Gelatin gel is brittle and is easily broken into fragments under a modest compression. In contrast, the fracture strength and elastic modulus of a BC–gelatin DN gel under compressive stress are on the order of megapascals, which are several orders of magnitude higher than those of gelatin gel, and almost equivalent to those of articular cartilage. A similar enhancement in the mechanical strength was also observed for the combination of BC with polysaccharides, such as sodium alginate, gellan gum, and ι-carrageenan.
619 citations
TL;DR: It was verified that the triple-helix content, calculated from the values of the enthalpy of denaturation associated to the endothermal transition at about 41 degrees C of gelatin, increases with the Bloom index, and these data are further supported by the results of the X-ray diffraction investigation.
436 citations
01 Sep 2004
TL;DR: In this article, the effect of chemical and enzymatic modifications on the solubility, mechanical properties, barrier properties, thermal properties and morphology of gelatin-based films was evaluated and compared.
Abstract: Protein films possess good gas barrier properties at low to intermediate relative humidity but reduced water vapor barrier properties, which limits their application. The introduction of chemical or enzymatic modifications could be an alternative to improve the cohesion properties of the polymeric matrix due to the formation of cross-linkages, thus improving the barrier characteristics and the mechanical resistance and decreasing the film solubility. The objective of this study was to evaluate and compare the effect of chemical and enzymatic modifications on the solubility, mechanical properties, barrier properties, thermal properties and morphology of gelatin-based films. The results indicated that the treatments resulted in 20% reduction in solubility for all the modified films, whereas the greatest reduction in water vapor permeability was observed for the enzymatic modified films (≅35%) as compared to the native film. The mechanical properties were only significantly affected by treatment with formaldehyde, where an increase of approximately 60% with respect to tensile strength was observed. Greater thermal stability, with an increase in the melting point, was observed for the chemically treated films, indicating a greater degree of cross-linking, as confirmed by the number of free e-amine groups remaining after the modification reactions. The morphological analyses indicated a loss of fibrillar orientation as a function of the introduction of cross-linking and the reduced percentage of renaturation of the modified films, as observed in the calorimetric assays. The results indicated that the effect of cross-linked protein films on water vapor permeability is always limited due to the inherent hydrophobic character of the protein and also on the morphology imposed by the modifications.
388 citations
TL;DR: A TEM image of core−shell structured bi-component nanofiber produced by a coaxial electrospinning technique is presented in this article, where the core and shell are polymers of gelatin and PCL, respectively.
Abstract: A TEM image of core−shell structured bi-component nanofiber produced by a coaxial electrospinning technique. The core and shell are polymers of gelatin and PCL, respectively. Variation of inner concentration during such a spinning process also resulted in tunable amount of gelatin encapsulated in the PCL-r-gelatin bi-component nanofibers.
361 citations
TL;DR: Characterisation of fish gelatin from cold water fish species, including rheological and optical rotation measurements, revealed that fish gelatin is heterogeneous in molecular compositions and that it mainly contains α- and β-chains.
357 citations
TL;DR: Dynamic light scattering analyses showed that such cross-linking results in denser polymeric networks and prevents extension of the peptide chains is when the pH is moved away from the isoelectric point.
322 citations
TL;DR: Paclitaxe-loaded gelatin nanoparticles represent a rapid release, biologically active paclitaxel formulation that can be used for intravesical bladder cancer therapy.
Abstract: Purpose: The present report describes the development of paclitaxel-loaded gelatin nanoparticles for use in intravesical therapy of superficial bladder cancer. The commercial formulation of paclitaxel contains Cremophor, which forms micelles and thereby entraps the drug and reduces its partition across the urothelium. Experimental Design: Paclitaxel-loaded gelatin nanoparticles were prepared using the desolvation method, and their physicochemical and biological properties were characterized. Results: The size of the particles ranged from 600 to 1,000 nm and increased with the molecular weight of the gelatin polymer. Under optimal conditions, the yield was >80%, and the drug loading was 0.7%. Wide-angle X-ray diffraction analysis showed that the entrapped paclitaxel was present in an amorphous state, which has higher water solubility compared with the crystalline state. Identical, rapid drug release from nanoparticles was observed in PBS and urine, with ∼90% released at 37°C after 2 hours. Treatment with a protease ( i.e ., Pronase) rapidly degraded the nanoparticles, with half-lives of 23.8 minutes, 0.6 minute, and 0.4 minute in the presence of 0.01, 0.05, and 0.25 mg/mL Pronase, respectively. The paclitaxel-loaded nanoparticles were active against human RT4 bladder transitional cancer cells; the IC 50 paclitaxel-equivalent concentrations were nearly identical to those of aqueous solutions of paclitaxel, i.e ., ∼30 nmol/L (equivalent to ∼25 ng/mL) for 2-hour treatments and ∼4 nmol/L for 96-hour treatments. In dogs given an intravesical dose of paclitaxel-loaded particles, the drug concentrations in the urothelium and lamina propria tissue layers, where Ta and T1 tumors would be located, were 7.4 ± 4.3 μg/g (mean ± SD; 3 dogs; 9 tissue sections), which were 2.6× the concentrations we reported for dogs treated with the Cremophor formulation. Conclusions: Paclitaxel-loaded gelatin nanoparticles represent a rapid release, biologically active paclitaxel formulation that can be used for intravesical bladder cancer therapy.
254 citations
TL;DR: Gelatin nanoparticles encapsulating pilocarpine HCl or hydrocortisone as model drugs were produced using a desolvation method, and the influence of a number of preparation parameters on the particle properties was investigated.
TL;DR: Release studies confirm that the rate of TGF-beta1 release and material degradation can be controlled by altering key parameters of these novel, in situ crosslinkable biomaterials, so that T GF-beta 1 release and scaffold degradation may be tailored to optimize cartilage repair.
TL;DR: Foam formation ability, foam stability, water-holding capacity and gel strength of shark cartilage gelatin were lower than the two porcine gelatins, but fat-binding capacity was higher in the shark Cartilage gelatin.
TL;DR: It is found that crosslinking gelatin hydrogels with carbodiimide or genipin could produce distinct crossl linking structures because of the differences in theirCrosslinking types.
Abstract: It was suggested in our previous studies that carbodiimide- and genipin-crosslinked gelatin hydrogels could be used as bioadhesives to overcome the cytotoxicity problem associated with formaldehyde-crosslinked gelatin hydrogels. In this study, we investigated the crosslinking structures of carbodiimide- and genipin-crosslinked gelatin hydrogels. We found that crosslinking gelatin hydrogels with carbodiimide or genipin could produce distinct crosslinking structures because of the differences in their crosslinking types. Carbodiimide could form intramolecular crosslinks within a gelatin molecule or short-range intermolecular crosslinks between two adjacent gelatin molecules. On the basis of gel permeation chromatography, we found that the polymerization of genipin molecules could occur under the conditions used in crosslinking gelatin hydrogels via a possible aldol condensation. Therefore, besides intramolecular and short-range intermolecular crosslinks, additional long-range intermolecular crosslinks could be introduced into genipin-crosslinked gelatin hydrogels. Crosslinking a gelatin hydrogel with carbodiimide was more rapid than crosslinking with genipin. Therefore, the gelation time for the carbodiimide-crosslinked gelatin hydrogels was significantly shorter than that of the genipin-crosslinked gelatin hydrogels. However, the cohesive (interconnected) structure of the carbodiimide-crosslinked gelatin hydrogels was readily broken because, unlike the genipin-crosslinked gelatin hydrogels, there were simply intramolecular and short-range intermolecular crosslinks present in the carbodiimide-crosslinked hydrogel. In the cytotoxicity study, the carbodiimide-crosslinked gelatin hydrogels were dissolved into small fragments in the cultural medium within 10 min. In contrast, the genipin-crosslinked gelatin hydrogels remained intact in the medium throughout the entire course of the study. Again, this may be attributed to the differences in their crosslinking structures. The genipin-crosslinked gelatin hydrogels were less cytotoxic than the carbodiimide-crosslinked gelatin hydrogels. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 4017–4026, 2004
TL;DR: The culture of human umbilical vein endothelial cells (HUVECs) in vitro proved that the cell proliferation ratio of both the aminolyzed and the biomacromolecules-immobilized PU membranes was improved greatly comparing with the control PU.
TL;DR: The results suggest that gelatin-mTG adhesives may offer the benefits of fibrin sealants without the need for blood products.
TL;DR: These studies show that the gelatin nanoparticles prepared by water-in-oil microemulsion systems are endocytosed by the fibroblasts without being toxic to cells even at high concentration of nanoparticles.
TL;DR: The improved mechanical properties of the composite cements with respect to the controls can be related to their reduced total porosity and more compact microstructure.
TL;DR: In this paper, the effect of gellan to gelatin ratio and NaCl concentration on the mechanical properties of composite films was studied using a Texture Analyzer. And the results suggest that modifying the ratio of gellian and gelatin improves the mechanical property of the composite film.
TL;DR: The results of this study show that PEGylated gelatin nanoparticles do possess long circulating properties and can preferentially distribute in the tumor mass after systemic delivery.
Abstract: Purpose: In order to develop a safe and effective systemically-administered biodegradable nanoparticle delivery system for solid tumors, the comparative biodistribution profiles of gelatin and poly(ethylene-glycol)(PEG)-modified (PEGylated) gelatin nanoparticles was examined in subcutaneous Lewis lung carcinoma (LLC)-bearing female C57BL/6J mice.Methods: Type-B gelatin and PEGylated gelatin nanoparticles were radiolabeled (125I) for the in vivo biodistribution studies after intravenous (i.v.) administration through the tail vein in LLC-bearing mice. At various time intervals, the mice were sacrificed and blood, tumor, and major organs harvested for analysis of radioactivity corresponding to the localization of the nanoparticles. Percent recovered dose was determined and normalized to the weight of the fluid or tissue sample. Non-compartmental pharmacokinetic analysis was performed to determine the long-circulating property and preferential tumor targeting potential of PEGylated gelatin nanoparticles in vi...
TL;DR: In this paper, a novel adsorbent, La3+-impregnated crosslinked gelatin, was prepared for the removal of fluoride from drinking water or agroindustrial wastewater by impregnation of cross-linked gelatin with La3+.
TL;DR: The data from this study suggested that chitosan-gelatin-hyaluronic acid scaffolds are suitable for preparing a bilayer skin substitute.
Abstract: Chitosan-gelatin-hyaluronic acid scaffolds for tissue regeneration were fabricated by freezing and lyophilizing methods. The scaffolds showed a higher water uptake and retention abilities than chitosan-gelatin scaffolds did. Fibroblasts cultured in chitosan-gelatin-hyaluronic acid scaffolds grew and proliferated well, and they exhibited a strong viability. Keratinocytes were co-cultured with fibroblasts in chitosan-gelatin-hyaluronic acid scaffolds to construct an artificial bilayer skin in vitro. The artificial skin obtained was flexible and had good mechanical properties. The data from this study suggested that chitosan-gelatin-hyaluronic acid scaffolds are suitable for preparing a bilayer skin substitute.
TL;DR: In this article, gelatin and acacia as walls and capsaicin as the core substance, microcapsules were prepared through the mixing of two solutions of oppositely charged polymers and were then treated with tannins.
Abstract: With gelatin and acacia as walls and capsaicin as the core substance, microcapsules were prepared through the mixing of two solutions of oppositely charged polymers and were then treated with tannins. The processing factors included the stirring rate and the types and dosages of the surfactants used in the preparation of the microcapsules. The morphology and size distribution of the microcapsules were analyzed with optical microscopy, environmental scanning electron microscopy, and laser particle size analysis. The microcapsules had a mean diameter of 20–30 μm, a maximal drug loading content of 19.84%, and an encapsulation efficiency of 88.21% with a good dispersion, even distribution, and round shape. The influence of the tannins on the morphology and structures of the microcapsules was also investigated, and their interaction mechanism was examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2669–2675, 2004
TL;DR: In this paper, Young's modulus of elasticity (E ) was used to determine the partition coefficients of compounds and the most rigid gel, gelatin gel, had the lowest partition coefficients for six compounds, while the starch and pectin gels showed a reduction in flavour release.
TL;DR: Fish gelatin gels, enzymatically crosslinked, did not melt after 30 min of heating in a boiling water bath, and the deformation of gels obtained from 5% gelatin solutions after a 24-h incubation with transglutaminase was the same as or slightly lower than in control samples (without enzyme).
TL;DR: In this article, the glass transition and crystallization temperatures of spray-dried powders were determined using differential scanning calorimetry, showing that proteins and water affect crystallization behavior of amorphous lactose differently.
Abstract: Water plasticization led to depression of the glass transition causing significant changes in the physico-chemical and crystallization properties in storage of lactose and lactose/protein (3:1) mixtures. Glass transition (T g ) and crystallization temperatures (T et ) were determined using differential scanning calorimetry. Whey protein isolate (WPI), albumin, and gelatin increased the T g of dry powders; when Na caseinate was used, a decrease was observed. In the presence of proteins and water, a decrease of T g af a w at ≤0.23 was observed. At a w a ≥0.33, proteins increased the T g . In the anhydrous state, T g decreased in the presence of proteins possibly because of browning. WPI, Na-caseinate, albumin, and gelatin delayed lactose crystallization in humidiffed samples, with albumin and gelatin delaying it more than WPI at all storage humidites. Temperature difference between an observed instant crystallization and glass transition (T x to T g ) was larger for humidified samples containing proteins than for lactose. Various proteins and water affect crystallization behavior of amorphous lactose differently in spray-dried powders. This should be considered in evaluating sugar cystallization properties in food products including dairy powders.
TL;DR: In this article, a mixture of fish gelatin and κ-carrageenan resulted in solutions and gels with varying degree of turbidity, depending on the concentration of polymers, pH, ionic strength and the nature of the added salt.
TL;DR: The AF4 method demonstrated the ability to comprehensively characterize polymeric gelatin bulk material as well as drug-loaded and unloaded nanoparticles in terms of size, size distribution, molecular weight, and loading efficiency.
Abstract: The physicochemical properties of nanosized colloidal drug carrier systems are of great influence on drug efficacy. Consequently, a broad spectrum of analytical techniques is applied for comprehensive drug carrier characterization. It is the primary objective of this paper to present asymmetrical flow field-flow fractionation (AF4), coupled online with multiangle light scattering detection, for the characterization of gelatin nanoparticles. Size and size distribution of drug-loaded and unloaded nanoparticles were determined, and data were correlated with results of state-of-the-art methods, such as scanning electron microscopy and photon correlation spectroscopy. Moreover, the AF4 fractionation of gelatin nanoparticulate carriers from a protein model drug is demonstrated for the first time, proposing a feasible way to assess the amount of loaded drug in situ without sample preparation. This hypothesis was set into practice by monitoring the drug loading of nanoparticles with oligonucleotide payloads. In this realm, various fractions of gelatin bulk material were analyzed via AF4 and size-exclusion high-pressure liquid chromatography. Mass distributions and high-molecular-weight fraction ratios of the gelatin samples varied, depending on the separation method applied. In general, the AF4 method demonstrated the ability to comprehensively characterize polymeric gelatin bulk material as well as drug-loaded and unloaded nanoparticles in terms of size, size distribution, molecular weight, and loading efficiency.
TL;DR: Further studies are required to improve the targeting efficiency of gelatin microspheres by modifying surface properties to overcome phagocytosis and by selecting suitable particle size to avoid the entrapment of micro Spheres in non-target organs.
TL;DR: Principal component analysis on matrix of height, width and total matrix were resulted in good differentiation between bovine and porcine gelatins.