Showing papers on "Gelatin published in 1988"

Gelation of aqueous gelatin solutions. I. Structural investigation

Abstract: We have investigated the structural modifications of aqueous gelatin solutions for various thermal treatments and different concentrations. The structure is explored at different microscopic levels, putting into evidence the conformational coil ~ helix transition of the proteic chains (by optical rotation), the supramolecular structure of the network (by electron microscopy) and the role of solvent (by proton nuclear magnetic resonance). The non-equilibrium nature of the gel phase is demonstrated as well as its disordered character. A phenomenological analysis of the kinetics of helix formation is proposed, followed by an attempt for a microscopic modelling of the mechanisms, based on the data presently known.

Macrophage phagocytosis of biodegradable microspheres composed of L-lactic acid/glycolic acid homo- and copolymers.

Abstract: A variety of biodegradable microspheres were prepared from L-lactic acid, DL-lactic acid, or glycolic acid homopolymers and copolymers of different molecular weights and monomer compositions. Phagocytosis of the microspheres by mouse peritoneal macrophages was studied in cell culture system using scanning electron microscopy as well as light microscopy. The diameter of microspheres prepared was less than 2 microns, regardless of the starting polymers. No dependence of the chemical nature of starting polymers was observed on the extent of phagocytosis of the microspheres by macrophages. Precoating the microspheres with water-soluble macromolecules such as proteins had great influence on phagocytosis by macrophages. It was demonstrated that precoating with bovine serum albumin and non-proteinaceous macromolecules reduced the phagocytosis of microspheres, while bovine gamma-globulin, human fibronectin, bovine tuftsin, and gelatin precoating enhanced the phagocytosis. This trend was not influenced by the presence of serum. Only in the case of gelatin precoating, the phagocytosis was greatly enhanced by the presence of serum as compared to precoating with other proteins. Microscopic observation clearly indicated that the phagocytosed microspheres were gradually degraded in the macrophage interior with the incubation time, leading to release of a fluorescent dye encapsulated in the microspheres. The rate of microsphere degradation in cells could be controlled by changing the molecular weight and the monomer composition of the copolymers comprising the microspheres.

Process for the preparation of a vessel prosthesis impregnated with crosslinked gelatin

Abstract: The invention relates to a process to prepare vessel prostheses formed from a porous basic body and an impregnating coating of crosslinked gelatin for sealing the pores Crosslinking takes place accompanied by the use of a diisocyanate The impregnating coating has good mechanical and physiological properties

Tissue-mimicking gelatin-agar gels for use in magnetic resonance imaging phantoms

Abstract: A new variety of tissue-mimicking materials for use in 1H nuclear magnetic resonance (NMR) phantoms has been developed and extensively tested, principally at 10 MHz and at room temperature. The materials can be formed with a broad range of T1's and T2's representative of soft tissues. They are mixtures of various percentages of agar, animal hide gelatin, water, and glycerol. Small concentrations of formaldehyde and n-propanol prevent melting through 100 degrees C and prevent bacterial invasion. The materials are easily produced. A thorough description of compositions and production procedures is given. T1's exhibit about a 5%/degrees C rise in temperature. T2's exhibit less than a 1% rise/degrees C. Long-term (12 months) stability is exhibited both for NMR properties and for absence of fluid extrusion. Preliminary results indicate that T1's depend on the Larmor frequency in a similar way to that observed in soft tissues.

Particle agglutination assays for rapid detection of fibronectin, fibrinogen, and collagen receptors on Staphylococcus aureus.

Abstract: Latex beads (0.8-micron diameter; Difco Laboratories) were coated with fibronectin, fibrinogen, collagen type I, or denatured collagen (gelatin) and evaluated in a particle agglutination assay (PAA) for the rapid detection of fibronectin, fibrinogen, or collagen binding to Staphylococcus aureus. These assays were compared with a commercial test for detecting the binding of fibrinogen and immunoglobulin G (Staphaurex). Bacterial cells (approximately 10(10) cells per ml) suspended in 0.02 M potassium phosphate buffer (pH 6.8) caused the clumping of standard fibronectin, collagen, gelatin, and fibrinogen latex suspensions within 2 min on glass slides. The test results were scored semiquantitatively from strongly positive ( ) to weakly positive (+) and negative (-) reactions. The negative PAA reactions corresponded to a median value of 11.5% relative to the binding of 125I-labeled protein to strain Cowan 1, indicating the high sensitivity of the test. The reactions with fibronectin and fibrinogen latex suspensions and with Staphaurex were optimal for cells grown on tryptic soy and brain heart infusion broth media. Blood agar was optimal for reactions with collagen and gelatin latex suspensions. Media containing high salts (mannitol salt agar and staphylococcus medium 110) enhanced the tendency of cells to autoaggregate. These assays were also clinically evaluated on 187 S. aureus isolates. The PAA reagents were stable, and the assays were highly specific, sensitive, and reproducible, thus making PAA suitable for the rapid screening of the binding of various bacterial pathogens to serum and connective-tissue proteins.

The modification of the triple helical structure of gelatin in aqueous solution I. The influence of anionic surfactants, pH-value, and temperature

Abstract: The modification of the triple helical structure in aqueous gelatin solutions by changing pH and adding alkyl sulphates at 298 K and after rechilling the solution to 283 K was investigated by CD-measurement. At 298 K the triple helical content at the IEP of the gelatin has its maximum value. It is only weakly affected by adding sodium dodecyl sulphate (SDDS) at concentrations <10−4 M/dm3. The unfolding of the triple helix affected by pH and SDDS is reversible by rechilling the solution. The triple helical content of gelatin solutions decreases at SDDS concentrations higher than 10−4 M/dm3. In all cases the decrease of the amount of triple helical structure is connected with an increase of the cis-configuration in single chains and leads to chain reversals. At sufficiently high SDDS concentrationsβ-sheets are formed. These changes are thermally irreversible. Sodium decyl sulphate (SDS) has a more minor influence than SDDS except in the range of the c.m.c. of SDS. At sufficiently high SDS concentrations,β-turns appear.

Water insoluble drugs coated by coacervated fish gelatin

Abstract: According to this invention, the combination of a solid particulate water insoluble drug with a solid fish gelatin coating is produced by coacervation of the fish gelatin. The fish gelatin being soluble at ambient temperatures provides a basis for relatively low temperature coacervation impossible with other gelatins. Coacervation is brought about by the addition of conventional coacervation agents and the coacervating suspension containing gelatin and the agents is rendered insoluble by the addition of a suitable fixative such as glutaraldehyde.

Method for double dipping gelatin coated caplets

Abstract: A novel capsule-like medicament and method for producing such medicaments are disclosed. The method provides a procedure for coating solid cores, such as caplets (16), with a first gelatinous coating (304) on one end (110), and then with a second gelatinous coating (306) on the other end (104) which is thicker than the first, to simulate the interlocking halves of a hollow capsule. The second, thicker gelatinous coating (306) can be provided with a single gelatin coating from a bath (38) having a higher viscosity than the bath used to provide the first gelatinous coating (304). Alternatively, the second gelatinous coating (306) can be provided by double dipping to provide layers of gelatinous material or gelatin.

Immobilization of cells in alginate beads containing cavities for growth of cells in airlift bioreactors

Abstract: Method and apparatus are provided for immobilizing and growing cells in airlift bioreactors to obtain increased cell density. Cells are immobilized by forming alginate beads containing cells and gelatin particles, and dissolving the gelatin by heating to form cavities in the beads entrapping the cells. In a growth chamber of an airlift bioreactor, introduced oxygen-containing gas circulates growth medium in contact with the beads resulting in oxygen transfer to cells in the cavities of the beads where growth of the cells occurs. Preferably, bead formation is carried out in the growth chamber by dripping an alginate-cell gelatin suspension into a calcium solution contained in the growth chamber. Growth medium is then supplied to the chamber, and oxygen-containing gas is introduced to result in circulation of the growth medium and growth of the cells.

Stabilized perfume-containing microcapsules and method of preparing the same

Abstract: Rupturable microcapsules made up of very small droplets or globules of perfume oil encapsulated with an inert polymeric wall are stabilized by providing ethyl cellulose in the perfume oil. This measure prevents escape of higher volatility components of the oil, which would otherwise occur during the preparation process. The stabilized microcapsules may be prepared by a liquid bath encapsulation method wherein ethyl cellulose is first dissolved in the starting oil, and the resulting solution is emulsified by mixing with a gelatin solution in water. The emulsion is then combined with a coacervant and cross-linking agent. Upon cooling the system, a gelatin-based wall coating is deposited around the emulsified particles. Fragrance characteristics of the starting perfume are preserved by this means.

Photographic element having polymer particles covalently bonded to gelatin

Abstract: A photographic element comprising a support having thereon a gelatin-containing layer, and a matting agent comprising polymer particles covalently bonded to the gelatin in the layer. The polymer particles may be individually covered with gelatin that is covalently bonded thereto and the gelatin that is covalently bonded to the particles may be cross-linked with the gelatin in the layer. There is also provided a process of preparing a photographic element comprising a matting agent and a layer comprising gelatin. In this process, the gelatin layer is coated onto a support, at least partially dried, and polymer particles are applied to the layer. The polymer particles are then covalently bonded to the gelatin in the layer.

Aqueous ink and process for its manufacture

Abstract: The invention relates to an aqueous ink for writing, drawing, or marking, which has as a dispersion stabilizer a degradation product of gelatin made by enzymatic action of a protease. The process of the invention is carried out by subjecting an aqueous gelatin solution to degradation by an enzyme, then inhibiting the enzyme, such as by heating to 90 degrees C. or above, before the degradation has proceeded to products which no longer have activity as dispersion stabilizers. Subsequently, colorants such as pigments can be added along with other desired additives.

Irradiation-sterilization of rat bone matrix gelatin.

Abstract: Bone matrix gelatin induces bone formation in muscle, and when implanted orthotopically it improves bone repair. Co-60 sterilization of bone gelatin impairs the protein-bound induction mechanisms. Gelatin samples nonirra-diated or irradiated by 25 or 50 kGy were implanted into a pouch in the abdominal wall of Sprague-Dawley rats, as well as into a 7-mm calvarial defect. Evaluation was done by histologic studies, histomorphometry of orthotopic implants, and determination of alkaline phosphatase in ectopic implants. Gelatin irradiated with 50 kGy was absorbed in the muscle bed without evidence of any specific host reaction. Irradiation of 25 kGy led to histologically confirmed ectopic bone formation, but the wet weight of the explants was only half that of the nonirradiated control samples. Alkaline phosphatase activity was equal in both of these groups. With orthotopic implantation, neither a histologic nor a morphometric effect was seen with 25 kGy. Loss of osteoinduction with 25-kGy irradiation is appare...

Grafting of gelatin during polymerization of methyl methacrylate in aqueous medium

Abstract: When methyl methacrylate is polymerized in aqueous medium in the presence of gelatin, graft copolymer macromolecules with gelatine backbones and poly(methyl methacrylate) (PMMA) grafts are formed. Due to the presence of graft copolymer, polymolecular micelles consisting of about 100 macromolecules are created. These micelles prevent macroscopic precipitation of PMMA. Fractionation in demixing solvents has been used to separate the components of the polymerization mixture, and the light-scattering method has been employed to determine their molecular weights. Each grafted macromolecule carries about one graft. The hypothesis of random grafting from gelatin backbones seems to explain most of the experimental observations.

Gelatin-grafted polymer particles

Abstract: There are disclosed polymer particles that are individually covered with a layer of gelatin that is covalently bonded thereto. The particles are useful as photographic matting agents.

Use of gelatin in the differential-pulse polarographic determination and identification of synthetic colouring matters in drugs and cosmetics

Abstract: A systematic study has been made of the effect of gelatin on the polarographic behaviour of 16 food and three cosmetic synthetic colouring matters. Gelatin was shown to have a pronounced effect on the peak currents, and a lesser effect on the peak potentials, of some of the colouring matters, and these effects could be used to partially identify and determine these colouring matters. Applications to the analysis of a coloured gelatin capsule, a lipstick and a blusher are described.

Interfacial tension of gelatin/sodium dodecylsulphate solutions against air, toluene, and diethylphthalate

Abstract: The adsorption isotherms between aqueous solutions of sodium dodecylsulphate and gelatin against air, toluene, or diethylphthalate were determined using the spinning drop method. The results qualitatively and quantitatively agreed with those found by surface tension measurements on sodium dodecylsulphate/gelatin solutions using the ring method in the version of Du Nouy. Interaction between gelatin and the surfactant will yield complexes which are more interfacially active than the components by themselves. The saturation of the interfaces occurs at lower concentrations than in solutions of the single components.

Soft film capsule mixed with alginic acid and production thereof

Abstract: PURPOSE: To obtain a soft film capsule mixed with alginic acid having excellent water resistance and heat resistance by crosslinking soft capsule covered with film comprising mixture of gelatin or lower methoxylpectine with specific amount of plasticizer and sodium alginate by positive ion. CONSTITUTION: 100 pts.wt. gelatin or lower methoxylpectine is uniformly blended with 10-50 pts.wt. plasticizer such as glycerin or sorbitol and 0.3-10 pts.wt. sodium alginate, then made to dried or semi-dried film, thus a capsule is formed. Next, said film is crosslinked using at least divalent positive ion, especially preferably calcium ion to afford the aimed material. Resultant capsule is useful for fields such as food processing, physic, quasi-drug or cosmetics and easily preservable in distribution process having excellent stability of quality and excellent functionality. Further, the capsule is efficiently produced in shortened manufacturing process and reducing cost of equipment with excellent productivity. COPYRIGHT: (C)1989,JPO&Japio

Aqueous gelatinizing agent and aqueous gel

Abstract: PURPOSE:To obtain the title gelatinizing agent providing an aqueous gel such as transparent gelatinous aromatic, gelatinous insecticide or gelatinous pet repellent, having stability in a wide temperature range, comprising a reaction product of gelatin, etc., and an olefin-maleic anhydride copolymer. CONSTITUTION:The aimed gelatinizing agent comprising a reaction product of gelatin or collagen and an olefin-maleic anhydride copolymer. The gelatin, etc., has preferably at least one free amino group and preferably 5,000-20,000 molecular weight. The copolymer has preferably 3,000-100,000 molecular weight.

Food casings based on cellulose containing cross-linked protein compounds

Abstract: The tube-shaped food casing, in particular artificial sausage casing for sausages of the raw-sausage type or boiling-sausage type, comprises a support tube based on cellulose hydrate, which support tube may be fibre-reinforced. The support tube contains a protein compound which is soluble or dispersible in alkali, resistant to hydrolysis and crosslinked with an alkali-resistant, reactive compound, preferably with aldehyde and/or dialdehyde. The protein compound is of animal or vegetable origin, preferably gelatin, soya bean protein, peanut protein or wheat protein, in particular casein. It is crosslinked, in particular, with formaldehyde, glyoxal, malonaldehyde and glutaraldehyde, preferably glyoxal. The support tube is produced by the viscose process, the protein compound together with the crosslinking agent being added to the viscose solution before coagulation. The crosslinking is effected during the final drying process.

Effect of gelatin-immobilization on the catalytic activity of enzymes and microbial cells

Abstract: The immobilization of enzymes and microbial cells within insolubilized gelatin involves both physical entrapment and covalent crosslinking, each one playing its role. The effect of this dual type of bonding on the kinetic parameters and activity yield of three enzymes (acid phosphatase, invertase and α-glucosidase) and of whole microbial cells belonging to three yeast species (Saccharomyces cerevisiae,Candida utilis andKluyveromyces marxianus) have been investigated.

Preparation and Characteristics of Gelatin Microspheres

Abstract: Gelatin microspheres are prepared by emulsification of a aqueous gelatin solution in a oily phase containing a surfactant, gelation by cooling, dehydration by isopropanol and cross-linking by formaldehyde. The pH, the gelatin concentration in the aqueous solution and the surfactant concentration in the oily phase have some influence on the size distribution of unloaded and loaded microspheres and on the drug contents of microspheres.

Immobilized luciferase for the quantitative determination of ATP

Abstract: Luciferase is immobilized on a membrane prepared from an absorbent albuminoid such as procine skin gelatin. The membrane may be formed by spreading a solution of porcine skin gelatin on a support and after incubation and drying removing the resultant membrane from the support. Preferably, the membrane is crosslinked with a solution of glutaraldehyde, and luciferase is immobilized by saturating the membrane with luciferase in the presence of dithiothreitol. The immobilized luciferase is particularly suitable for the quantitative determination of adenosine triphosphoric acid (ATP).

Granulated compositions of polysaccharides, process for their preparation and their use

Abstract: The present invention relates to granulated compositions of thickening and viscosity-raising polysaccharides having few anionic groups, wherein the polysaccharide particles are coated with hydrolyzed gelatin.