Showing papers on "Gelatin published in 1990"

X-ray diffraction of gelatin fibers in the dry and swollen states

Abstract: The aim of this x-ray diffraction investigation is to establish a comparison between the structure of collagen and that of gelatin gels. The gelatin gels are drawn into fibers, which are dried before use. The xray scattering patterns of the gelatin fibers show a close analogy with collagen, which provides evidence for the presence of bundles of triple helices in the dried, oriented gels. The mechanisms of swelling of the gelatin fibers are identified by investigating the humidity-sensitive position of the equatorial spots related to the side-by-side distance D of the triple helices. The distance D increases continuously as more water is added to the fibers; this is accompanied by a progressive loss of orientation of the triple helices with respect to the fiber axis. The temperature dependence of the x-ray patterns is also investigated. We discuss the implications of this study for understanding the gelation mechanisms and the structure of gelatin gels. Comparisons are made with other physical gels.

Proteolytic activities of human fibroblast collagenase: hydrolysis of a broad range of substrates at a single active site

Abstract: The action of human fibroblast collagenase (HFC) on six substrates of markedly different size, sequence, and conformation, including rat type I collagen, rat alpha 1(I) gelatin, beta-casein, and the three synthetic oligopeptides Gly-Pro-Gln-Gly-Ile-Ala-Gly-Gln, Asp-Val-Ala-Gln-Phe-Val-Leu-Thr-Pro-Gly, and Pro-Val-Gln-Pro-Ile-Gly-Pro-Gln, has been examined. The first peptide is a model for the collagenase cleavage site in the alpha 1(I) chain of type I collagen, while the latter two peptides are models for the autolytic activation and degradation sites in pro-HFC, respectively. The goal of these studies was to assess whether HFC hydrolyzes all of these disparate substrates at the same active site. Individual kinetic parameters for the hydrolysis of all six substrates have been determined. Gel zymography experiments using collagen, gelatin, and casein as substrates show that all three activities are associated solely with HFC rather than impurities. Recombinant HFC expressed in Escherichia coli also exhibits caseinase activity, reinforcing the view that this activity is not due to a contaminating protease from fibroblasts. The ratios of these activities agree within experimental error for several independent HFC preparations and do not change when two additional affinity purification steps are employed. The inhibition of the hydrolysis of these substrates by both 1,10-phenanthroline and Boc-Pro-Leu-Gly-NHOH is identical within experimental error. A series of assays carried out in the presence of pairs of these substrates clearly shows that they compete for the same active site.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of macroporous gelatin carriers for the cultivation of mammalian cells in fluidised bed reactors.

Abstract: A fluidised bed system for the cultivation of mammalian cells on a new type of macroporous gelatin microcarrier is described The volumetric cell densities achieved under controlled conditions for two ‘standard cell lines’ (VERO, CHO) were one order of magnitude higher compared to conventional techniques using spherical microcarriers The system can be potentially used for both anchorage dependent and independent cells

C-Gel composite food products

Abstract: Novel C-Gel food products comprising an aqueous gelatin kappa carrageenan matrix and a dispersed food product selected from the groups consisting of meat, seafood, vegetable, fruit, synthetic protein fiber, chocolate and mixtures thereof, in which the gelatin and carrageenan are present as a structurally firm continuous aqueous carrageenan/gelatin phase matrix at refrigeration temperature.

Wound dressing protocol utilizing collagen gelatin formed with iodine

Abstract: A stabilized collagen gel is disclosed as are methods of making this collagen gel which is useful as a wound dressing to prevent dehydration of the subject being treated and infection of the wound. The collagen gel of the invention is stabilized by combining collagen (preferably a pharmaceutical grade collagen, which is atelopeptide collagen), with iodine or a composition capable of generating iodine. The collagen is flowable on first mixing and undergoes a phase transition to form a stable gel with sufficient structural integrity to form a wound dressing.

Rheological Behaviour of Thixotropic Starch and Gelatin Gels

Abstract: Thixotropic behaviour of starch, gelatin and mixed starch/gelatin gels was investigated by different rheological methods by means of the rotational viscosimeter with coaxial cylinders. Influence of different factors (gel composition, preparation temperature, gel age, homogenization and viscosimeter rotor acceleration) on the coefficients of thixotropy and parameters of the flow equation was considered. The recovery of destructed gels was followed by Doherty-Hurd method, but also a modified method was developed and applied for determination of some specificities in the rheological behaviour of starch and gelatin gels.

Gelatin hard capsule containing crystalline hydrate of oral cephalosporin

Abstract: An antibacterial, 7β-[(Z)-2-(2-aminothiazol-4-yl)-4-carboxybut-2-enoylamino]-3-cephem-4-carboxylic acid is stable in a (di or tri)-hydrate crystal form. A pharmacologically effective amount of this hydrate is filled in a gelatin hard capsule and sealed by a band of gelatin to make a stable composition for clinical use after storage for a long time.

Preparation of Gelatin: Phenytoin Sodium Microsphers: An IN VITRO and IN VIVO Evaluation

Abstract: In this study phenytoin sodium microspheres were formulated with biodegradable acid-treated gelatin. The microspheres were subjected to in vitro and in vivo testing. The percent drug retained in the microspheres, as well as its release from the microspheres, was tested. In vitro data revealed a decrease in percent druq retained in the microspheres with an increase in addition of glutaraldehyde to the microsphere formulations. The statistically most consistent drug release was observed from formulations containing 10 g of gelatin and 2 g of phenytoin sodium. From this formulation the slowest release was observed when 5 ml of glutaraldehyde were added to the various formulations, whereas the fastest release was observed when no glutaraldehyde was added. In vivo studies consisted of administering phenytoin sodium in microsphere form and an aqueous solution v i a various routes of administration and determining phenytoin plasma concentration vs. time profiles in female Sprague Dawley Rats. Computer fi...

Emulsifying Effects of Food Macromolecules In Presence of Ethanol

Abstract: The influence on droplet size of ethanol present during homogenization was investigated for emulsions stabilized by macromolecular emulsifiers: sodium caseinate, whey protein isolate, gelatin and gum arabic. Emulsions produced with polysaccharide gum arabic had increasing droplet size as ethanol concentration increased, in contrast to the protein-stabilized emulsions which had decreasing droplet size (up to 20 % ethanol for gelatin and 30 % ethanol for the milk proteins), followed by increasing droplet size with increasing ethanol concentration. Interfacial tension measurements indicated that the emulsifying property of the macromolecules depended on adsorption at the oil-water/alcohol interface during emulsification.

Interpenetrating hydrogel networks. I. The gelatin–polyacrylamide system†

Abstract: In situ polymerization of acrylamide–bisacrylamide mixture in concentrated aqueous gelatin solutions followed by the subsequent crosslinking of gelatin itself with glutaraldehyde yields interpenetrating hydrogel networks. The surface morphology, swelling, and thermal behavior of the samples of different composition were investigated. The swelling characteristics of the hydrogel could be manipulated by varying gelating and acrylamide ratio.

Controlled release of nifedipine from gelatin microspheres and microcapsules: in vitro kinetics and pharmacokinetics in man.

Abstract: Nifedipine was embedded in a gelatin matrix to develop a prolonged release dosage form. The effects of polymer/drug ratio, size of the beads, cross-linking with formaldehyde and ethylcellulose coating of the gelatin microspheres on the in vitro release rate of the drug were investigated. The data were analysed according to different laws that can govern the release mechanism: first-order, Higuchi square root of time, spherical matrix and zero-order. The in vitro release kinetics of nifedipine from gelatin microspheres were mainly first-order; from formaldehyde hardened gelatin microspheres, complied with the diffusion model for a spherical matrix, and from ethylcellulose-coated gelatin microspheres, obeyed zero-order kinetics. These findings suggest the possibility of modifying the formulation in order to obtain the desired controlled release of the drug for a convenient oral sustained delivery system. The pharmacokinetic parameters of nifedipine, after adminstration of a single oral dose of nifed...

Pharmaceutical capsules containing panetidine

Abstract: The invention relates to a pharmaceutical composition in the form of a gelatin capsules consisting of a filling containing as active ingredient ranitidine or a physiologically acceptable salt thereof surrounded by a gelatin shell. The filling is formulated based on a non-aqueous matrix consisting of at least one fatty acid glyceride and/or mineral oil or paraffin. Preferably the matrix contains at least one surfactant. The matrix is essentially hydrophobic in character but is also sufficiently hydrophilic to permit dispersion and dissolution of the capsule filling in the gastrointenstinal tract.

Enteric soft capsule for health food

Abstract: PURPOSE: To obtain an enteric soft capsule for health foods such as royal jelly by adding and blending a calcium salt, and a water-soluble saccharides crosslinkable with calcium ions with a film base composed of gelatin and a plasticizer CONSTITUTION: An enteric soft capsule is readily obtained by blending a film base composed of gelatin and a plasticizer with a calcium salt or a natural calcium agent (preferably eggshell or shell) consisting essentially of the afore mentioned calcium salt and water-soluble saccharides (preferably gelan gum) crosslinkable with calcium ions The resultant enteric soft capsule can be pro duced by a rotary type production process for the soft capsule COPYRIGHT: (C)1992,JPO&Japio

Gelatin coated tablets and method for producing same

Abstract: Pharmaceutical tablets having increased slipperiness and swallowability are provided. The enhanced swallowability is imparted by an overcoat of a low bloom gelatin, which overcoat has a lower coefficient of friction than other known coatings.

Methylene blue sensitized dichromated gelatin holograms: influence of the moisture on their exposure and diffraction efficiency

Abstract: Dependence of the moisture of the plate on the hologram characteristics is studied for methylene blue sensitized dichromated gelatin The maximum diffraction efficiency increases, and the exposure to obtain a certain amount of diffraction efficiency is reduced for the red light when the moisture of the gelatin layer is properly controlled during exposure The photochemical reaction of the plate is briefly discussed, and the result of the double exposed hologram is also presented

Nucleation, propagation, and direction of triple helix formation in collagens I, III, and IV and in gelatin as monitored by electron microscopy

Abstract: In vivo, the formation of the triple-helical structure is one of the important posttrans lational events. A prerequisite for the correct folding of an intact triple helix is the correct alignment and association of three polypeptide chains. As demonstrated for collagens I and 111, this is facilitated by carboxy-terminal propeptides and disulfide bridges.I4 The mechanism of collagen folding was described by a zipper model that proceeds from the Cto the N-terminus at a rather uniform rate, determined by the cis/trans isomerization of proline peptide bonds.’-’ Folding is disturbed in certain pathological conditions and in mutated collagens such as 01 (osteogenesis imperfecta) collagens.’-’ The extent of triple helix reformation is also decisive for the properties of gelatins! Methods for monitoring triple helix formation are therefore of both biological and technical importance. In the past collagen folding was monitored mainly by changes of proteolytic susceptibility, spectroscopic signals, or changes of other solution properties? Visualization of refolded molecules and intermediates was obviously desirable. In this study we show that the folding process of collagens may be monitored by electron microscopy. Triple helices as well as globular domains in collagens were visualized by electron microscopy after spraying and rotary shadowing and could be readily distinguished from randomly coiled polypeptide chains that are not visible or barely visible by this technique. Collagens were completely unfolded by thermal denaturation and then exposed to refolding conditions at zero time. Samples were sprayed and inspected at various time intervals, and the localization and length distribution of the growing triple helices were determined. Results for collagen I11 (FIG. 1) confirmed previous models’*2 of a zipperlike growth of the triple helix starting at the disulfide knot located at the Cterminal end of the molecules. As indicated by broad and bimodular length distributions of intermediates (FIG. 1) the rate of zippering, however, was not as uniform as assumed previously. Integration over all sizes yielded the total fraction of refolded

Glassy oxide network passivation of dichromated gelatin holograms

Abstract: A passivated dichromated gelatin film in which the film includes a glassy oxide network to provide passivation and structural strengthening. The glassy oxide network is formed simultaneously with the gelatin formation via a sol-gel process.

Composite graft optical polymer

Abstract: A holographic recording material, comprising a dichromated gelatin-polymer graft, is used in a volume hologram. The gelatin may comprise naturally occurring gelatin primarily made up of glycerin, proline, and hydroxyproline. The polymerizable monomers used to make up the gelatin polymer graft may comprise 2-hyroxyethylmethacralate, acrylamide, acrylic acid, or vinyl acetate.

Continuous in-line preparation of photographic gelatin solutions

Abstract: A process for the in-line preparation of gelatin solutions comprising (a) mixing gelatin particles with an aqueous solution to wet the gelatin forming a gelatin-aqueous solution mixture, (b) heating rapidly said mixture to a temperature capable of digesting gelatin in said mixture, and (c) maintaining the digested gelatin at said temperature for a period to dissolve the gelatin particles into the aqueous solution. The process provides gelatin solutions for photographic uses in an improved manner without the general dissolution problems. The process is quick and is accomplished in-line, preferably continuously.

Water-in-oil dispersion

Abstract: The present invention is concerned with a plastic dispersion containing from 5-65 wt. % of a continuous fat phase and from 95-35 wt. % of a gelling polysaccharide containing dispersed aqueous phase, wherein the gelling polysaccharide is selected from the group consisting of agar, pectin and mixtures thereof and present in a concentration exceeding the critical concentration and which aqueous phase contains further 0.004 to 10.0 wt. % of protein. We have found that the present dispersion displays essentially the same in-mouth break down behaviour as a gelatin based dispersion.

Photoresist dichromate composition containing gelatin coated particles

Abstract: A negative-working photoresist composition comprising, in admixture, (a) dye-loaded or dye-precursor-loaded polymeric particles individually covered with a layer of gelatin that is covalently bonded thereto and (b) a radiation-sensitive dichromate is useful in the preparation of continuous tone dyed imaging elements such as color filter arrays for use in solid state color image sensing devices.

Rigid capsule for medicine and production thereof

Abstract: PURPOSE: To obtain the title capsule having low equilibrium water content in film and capable of preventing crack, deterioration, etc., due to water content after filling of chemical without causing brittleness even under low-temperature conditions. CONSTITUTION: An aqueous solution of a base agent obtained by blending (A) a water soluble cellulose, preferably a cellulose ether (e.g. hydroxypropylmethyl cellulose substituted with an alkyl group and/or hydroxyalkyl group and used as a base with (B) a gelling agent, e.g. tamarind seeds, polysaccharides, pectin, gelatin, especially carrageenan and (C) a gelling assistant, e.g. potassium ion and/or ammonium ion in the case of carrageenan and containing 5-25wt.% of the ingredient A, 0.1-0.5wt.% of the ingredient B and 0.01-0.50wt.% of the ingredient C is prepared and a pin for forming capsule is dipped in the above- mentioned aqueous solution and the pin is pulled up and the aqueous solution of base attached to the outer surface is gelled to form capsule film. COPYRIGHT: (C)1991,JPO&Japio

Glutaraldehyde Crosslinked Gelatin with Polyacrylamide Grafts

Abstract: Persulfate-initiated grafting of crosslinked gelatin with acrylamide in aqueous medium is investigated. the high percentages of grafting are explained as a direct consequence of the heterophase nature of grafting. Optimum reaction conditions for a high percentage of grafting together with low homopoymer yields are discussed.

Comparative behaviour of L-929 fibroblastic and human endothelial cells onto crosslinked protein substrates.

Abstract: Studies were carried out to compare the behaviour of human umbilical vein endothelial cells (HUVEC) and L-929 fibroblastic cells towards proteins crosslinked by glutaraldehyde (GTA) or carbodiimide (CDI) proposed for coating of vascular prostheses. CDI crosslinking of bovine serum albumin used alone, or mixed with gelatin, allowed higher rates of cell growth and DNA synthesis than GTA crosslinking independent of cells. Assessment of the plating efficiency revealed a similar behaviour of both cells towards membranes and reference plastic surface in terms of percentages of bound cells. HUVEC proliferation onto CDI crosslinked gelatin and/or albumin membranes did not differ significantly whereas the growth of L-929 was enhanced onto gelatin albumin membranes in comparison with both gelatin membranes and the reference surface. The analysis of DNA synthesis corroborated the results of the growth curves and elicited a delay of the growth phases in HUVEC cultured onto CDI crosslinked membranes, unlike the L-929 fibroblast.