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PubMed2005

Optimization and characterization of chitosan-coated alginate microcapsules containing albumin.

In order to obtain small microcapsules with high protein encapsulation efficiency and extended release characteristics various processing factors were studied. Bovine serum albumin-loaded alginate microcapsules were prepared by an emulsion method and further incubated in chitosan. Many process factors were tested including the concentration and molecular weight of alginate, the concentration and pH of chitosan, and surfactants, etc. Microcapsules were achieved with diameters less than 2 microm, high encapsulation efficiency (> 80%) and high loading rate (> 10% w/w). The results also showed that the initial BSA amount of 20%-30% loaded alginate microcapsules coated with 0.2%-0.5% chitosan solutions at pH 4 by the two-stage procedure present the best sustained releasing characteristics.

2-Propanol↗
PubMed2003

[Study on PVA-alginate co-immobilization of Xanthomonas ampelina TS206].

Ice nucleation activity and anti-leaking capability are both important technical parameters in INA (Ice nucleation active bactetia) bacteria immobilization which can be adopted on freezing concentrate. Both PVA and alginate are good medium for immobilization. They can be used on co-immobilization of ice nucleation-active bacteria (Xanthomonas ampelinaTS206). The results showed that quantity of embedding affects ice nucleation activity greatly. The order of importance to comprehensive scores of technical standard should be concentration of Sodium alginate > Boric acid > PVA > CaCl2. The optimized concentration are PVA 8%, sodium alginate 1%, CaCl2 1.1% and boric acid 5%. A conclusion can be draw that ice nucleation activity increases with the number of beads and shows little pertinency with the time of immobilization, whereas anti-leaking capability can be influenced faintly by the number of beads and the time of immobilization.

Alginates↗
PubMed2005

[Experimental study of cartilage reconstruction using directed inducing MSCs-alginate complex].

OBJECTIVE: To evaluate the practicability of cartilage reconstruction using directed inducing bone marrow stem cells(MSCs)- alginate complex. METHODS: The MSCs were seperated by gradient centrifugation on Percoll, then were induced into chon-drogenic differentiation. After 14 days,immunohistochemical techique was applied to detect the expression of collagen type II. Then, the MSCs and calcium alginate were mixed to form a complex and were planted under the skin of nude mice. Histochemical or immuno-histochemical tests were made at 4 weeks and 8 weeks later. RESULTS: The MSCs showed the positive result of collagen type II. There were chondrcytes and cartilage lacuna at 4 weeks later, and chondrocytes and the collagen secreted by them became more at 8 weeks later. But, the MSCs without directed inducing did not show the character of the chondrocyte. CONCLUSION: The way of using directed inducing MSCs-alginate complex can form cartilage; it is possible to repair the defect of cartilage in clinical practice.

Alginates↗
PubMed2006

Administration of an alginate based gastric reflux suppressant on the bioavailability of omeprazole.

BACKGROUND & OBJECTIVE: Omeprazole treats gastro-oesophageal reflux disease (GORD) by inhibition of acid secretion whereas alginate based reflux suppressants work by forming a low density raft of near neutral pH which floats on the stomach contents and physically impedes gastro-oesophageal reflux. There is limited pharmacokinetic information regarding possible drug interaction between these two types of products, although these may be frequently co-prescribed to improve symptom control in GORD patients. This study was designed to determine whether the administration of a 10 per cent w/v liquid alginate suspension affected the pharmacokinetic profile of omeprazole. METHODS: This was a randomized, two-treatment, two-sequence, two-period crossover study in 26 volunteers. Each treatment was dosed for 3 consecutive days with a washout period of 7 days between dosing periods. Blood samples for pharmacokinetic analysis were taken over the 24 h period following the final dose of omeprazole. RESULTS: Geometric means and ratios were as follows: C(max) was 555 for omeprazole/alginate and 558 for omeprazole alone (ratio 99.55%, 90% confidence interval 82.75-119.75%; AUC(0-t) was 2050 for omeprazole/alginate and 2094 for omeprazole alone (ratio 97.90%, 90% confidence interval 87.83-109.12%); AUC(0-a) was 2247 for omeprazole/alginate and 2231 for omeprazole alone (ratio 100.74%, 90% confidence interval 90.05-112.70%). Mean values for T(max), K(el) and T(1/2) were also similar for the two treatment regimens. INTERPRETATION & CONCLUSION: As the 90 per cent confidence intervals for the geometric mean ratios for C(max), AUC(0-t), and AUC(0-alpha) are all contained within the bioequivalence interval of 80-125 per cent, it can be concluded that the administration of this liquid alginate suspension does not affect the pharmacokinetic profile of omeprazole.

Adolescent↗
PubMed2006

Solubility and stability of curcumin in solutions containing alginate and other viscosity modifying macromolecules. Studies of curcumin and curcuminoids. XXX.

The solubility, chemical- and photochemical stability of curcumin in aqueous solutions containing alginate, gelatin or other viscosity modifying macromolecules have been investigated in order to obtain an alternative to the use of surfactants or cyclodextrins. The solubility of curcumin in aqueous solution at pH 5 increased by a factor > or = 10(4) in the presence of 0.5% (w/v) alginate (various qualities) or gelatin compared to plain buffer, while propylene glycol alginate ester, cesapectin and sodium carboxymethyl cellulose did not have a similar solubilizing effect. The solubilization was slightly influenced by pH, ionic strength and type and concentration of buffer salts. The macromolecules do, however, not stabilize towards hydrolytic- or photolytic degradation of curcumin.

Alginates↗
PubMedDate not supplied

[Trypsin interaction with sodium alginate].

The formation of an insoluble product of the interaction of trypsin and sodium alginate at pH 3-9 was studied. The optic density of the system was in an extreme relation to the composition. The insoluble phase was enriched in trypsin. The dispersion phase formed as a result of the electrostatic interaction between alginate macroanion and trypsin macrocation. The interaction brought about the formation of ATn, where n=90-900 (with an accuracy of the term Mw/Mn of alginate). The relation between the composition of the complex and pH was nonmonotonous.

Alginates↗
PubMed1991

[Calcium alginate as a nasal pack].

Alginates are highly absorbent, gel-forming materials with haemostatic properties. The aim of this study was to compare calcium alginate to Telfa as a postoperative nasal pack in a prospective randomised clinical trial. Eighty two patients entered the trial. There were 55 males and 27 females whose ages ranged from 13 to 74 years (mean 34.7 years). Immediate postoperative bleeding was controlled in all cases irrespective of the pack used. There was no difference in the incidence of postoperative complications between the two groups. Calcium alginate is a safe and effective alternative to Telfa as a postoperative nasal pack.

Adolescent↗
PubMedDate not supplied

[Medical rugosity (Ra) of the surface of stone models from alginate impressions using two processes: manual spatulation and vacuum mechanical spatulation].

The differences in superficial smoothness of 108 stone models, obtained from three marks of alginates, manipulated by two different techniques of spatulation (a. manual; and b. mechanic with vibration under vacuum), were studied. The 108 stone models (resultant from the factorial product: 3 alginates x 2 techniques x 6 stones x 3 replica = 108) were analysed by means rugosimeter (Talisurf 10). The results showed that the superficial smoothness of the models was not affected significantly by any of the two techniques tested. The alginate Jeltrate offered the best results, and the group represented by the stones Moldaroc/Gaúcha III/Durastone T/Castone was better than the Vel-Mix, and the Vel-Mix statistically better than the Glastone.

Alginates↗
PubMed1989

[Compatibility between stone and alginate].

The compatibility between three alginates and three die stones was measured with a surface analyser and observed in the scanning electron microscope. For all nine combinations of alginate and die stone, the relief of the roughness standard was only partly reproduced. The compatibility of certain combinations was so poor that these should be avoided. Thus, Blueprint should not be poured with white Vel-Mix. Furthermore, it is recommendable to use combinations of alginate and die stone that result in the highest Ra-values possible.

Alginates↗
PubMed1988

[Reduction of postprandial gastroesophageal reflux with sodium alginate in suspension. Multicenter pH study in 21 patients].

The purpose of this study was to ascertain the pharmacological effectiveness of sodium alginate liquid in the treatment of gastroesophageal acid reflux. The pharmacological test selected was 3 hours postprandial oesophageal pH, because of the physico-chemical properties of this drug. Twenty-one patients of both sexes were included in this study. The initial pH measurement served both as inclusion criteria, by confirming the presence of gastric acid reflux, and as reference for the evaluation of the effect of sodium alginate liquid by a second pH determination after treatment. After treatment with sodium alginate liquid, the number and mean duration of episodes of reflux, as well as the time spent at each pH level, had significantly decreased as compared to the initial value. The gastroesophageal reflux score was significantly reduced during the second hour in recumbent posture, but none of the different parameters studied separately (number and mean duration of episodes of reflux and time spent at each pH level) was significantly decreased. This study demonstrates the pharmacological effectiveness of the drug during the post prandial period and indicates that it is more effective in upright than in supine position.

Adult↗
PubMed1983

Inhibition of bacterial binding to mouse macrophages by Pseudomonas alginate.

Alginate, an acetylated polymer of D-mannuronic and L-guluronic acid obtained from a mucoid strain of Pseudomonas aeruginosa was shown to inhibit the binding of an isogenic non-mucoid revertant to mouse peritoneal and pulmonary macrophages. Inhibition of bacterial binding by the alginate was also demonstrated in tests with other non-mucoid P. aeruginosa strains and a strain of Staphylococcus albus. Since the mucoid form of P. aeruginosa eventually predominates in chronic P. aeruginosa infection in patients with cystic fibrosis, it is postulated that the alginate's inhibition of binding gives mucoid forms a selective advantage over non-mucoid forms against macrophage defence mechanisms in the lung.

Alginates↗
PubMed1981

[Use of ionizing radiation for sterilizing alginate dressings containing various antibacterial preparations].

The effect of various doses of ionizing radiation on activity of antibacterial drugs contained in polymer alginate coatings was studied. Sensitivity of P. aeruginosa, E. coli, Staph. aureus, Proteus and B. subtilis used as the test organisms to the drugs and their combinations after radiation sterilization was determined on liquid nutrient media with the method of serial dilutions and agar diffusion and the use of the respective reference antibiotics. The coatings were irradiated in an isotope unit with 60Co at a dose of 7 Krad/min. The data are indicative of the possible use of ionizing radiation for sterilization of pharmaceutical alginate coatings in trade packings. Combined effect of antimicrobial substances and ionizing radiation plays an important role in the efficiency of radiation sterilization. Sterility of the majority of the drugs was achieved after irradiation in doses of 0.5-1 Mrad. The bactericidal activity of gentamicin, mafenid, polymyxin M and neomycin contained in the alginate coatings sterilized with gamma-radiation in doses of 1-2.5 Mrad did not decrease immediately and 1 year after irradiation.

Alginates↗
PubMedDate not supplied

Using double-poured alginate impressions to fabricate bleaching trays.

Esthetic and diagnostic treatment often requires two casts of one arch, one for baseline and one for alterations (diagnostic wax-up, bleaching tray, occlusal analysis). The purpose of this study was to compare the accuracy of stone casts generated from a second pour of a properly handled alginate impression with first-poured casts. A maxillary dentoform was indexed with six reference spaces (#8-15, 9-2, 2-15, and incisal-to-gingival of #3, 9, 14). Irreversible hydrocolloid (Jeltrate) impressions were made in perforated steel trays by a single investigator. Impression material was spatulated for 1 minute. The seated impression and dentoform were wrapped in a damp paper towel to simulate intraoral conditions, and allowed to set for 2 minutes. Upon separation, the impression was stored in a damp towel for 5 minutes. The impression was poured in cast stone (Microstone) according to the manufacturer's instructions. The stone-filled impression was immediately rewrapped in a damp paper towel and allowed to set for 45 minutes at room temperature. Upon removal of the stone, the impression was rinsed with cold water, shaken dry, and repoured in the same manner. Ten impressions were made: the first five impressions were poured to make casts for Group A, then repoured as described above for casts for Group B. The remaining five impressions were poured once to make casts for Group C. The six spaces of each cast were measured three times in random order using a dial caliper and the space average calculated for the cast. At each space, analysis of variance showed no significant difference among Groups A, B, or C (P < 0.05). When alginate impressions that have been poured with cast stone are kept moist during stone setting and repoured within 45 minutes, two casts can be generated from one impression with the same degree of accuracy as two casts made from taking two separate impressions, providing the alginate does not tear during first cast removal.

Alginates↗
PubMed1998

[Functional properties of alginates and their use in therapeutic-prophylactic nutrition].

Adsorbability of alginic acid and its salts extracted from brown seaweeds and character of their biological action were studied. The results of clinical tests alginic acid and its salts as well as of preparations and food-stuffs, prepared from Laminaria japonica Arech, were reflected. The potentialities of use of alginates and food-stuffs containing them in therapeutic nutrition was shown.

Alginates↗
PubMed1998

A prospective randomized study of calcium alginate (Sorbsan) versus standard gauze packing following haemorrhoidectomy.

Post-haemorrhoidectomy pain is problematical but may be reduced by using less bulky haemostatic dressings in the anal canal. Fifty consecutive patients undergoing haemorrhoidectomy were prospectively randomized to receive either paraffin gauze/cotton gauze roll on calcium alginate (Sorbsan) roll as a post-operative pack. Post-operative pain was assessed at 6 h, on removal of rectal packing and at first bowel action. Haemorrhage was monitored at 6 h and removal of pack. There was no difference in the hospital stay between the two groups. Pain was significantly reduced at the time of removal/spontaneous discharge of rectal packing (P < 0.0001) and first post-operative bowel action (P = 0.0008) in the calcium alginate group. There was no significant difference in post-operative haemorrhage between the two groups. Calcium alginate dressings following haemorrhoidectomy effectively reduce post-operative pain compared to more bulky anal packs.

Alginates↗
PubMed1994

Detection of alginate lyase by activity staining after sodium dodecil sulfate-polyacrylamide gel electrophoresis and subsequent renaturation.

A slab gel electrophoretic method for the study of bacterial alginate lyase has been developed. By incorporating alginate in acrylamide gels, the method is based on renaturation of the enzyme after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, subsequent staining with cetylpyridinium chloride, and quantification of the spot by densitometric scanning. The molecular mass of alginate lyase can be determined from its position in the gel.

Azotobacter↗
PubMed2000

Influence of Sodium Periodate and Tyrosinase on Binding of Alginate to Adlayers of Mytilus edulis Foot Protein 1.

Mytilus edulis foot protein 1 (Mefp-1) is the most well-characterized component of this sea mussel's adhesive plaque. The plaque is a condensed, heterogeneous mixture consisting of a large proportion of cross-linked biopolymers that bonds the mussel to a chosen mooring. Mefp-1 is densely populated with lysine and L-3,4-dihyroxyphenylalanine (L-dopa) residues incorporated into a repeating amino acid sequence motif. It has been proposed that one plaque cross-linking reaction is the nucleophilic addition of the epsilon-amino groups of the lysine residues into the oxidized catechol (o-diphenol) functionality (quinone) of the L-dopa residues. In order to determine if this reaction occurs in adlayers of Mefp-1, a previously developed assay for epsilon-amino groups was applied. Adlayers of Mefp-1 were exposed to an oxidant, either the enzyme, mushroom tyrosinase, or sodium periodate. Binding of alginate to adlayers was used to probe for accessibility of epsilon-amino groups. It was found that lysine residues lose the ability to bind alginate after exposure to sodium periodate, but that this loss is not clearly due to a reaction with L-dopa residues. There is a slight decrease of binding of alginate to adlayers of Mefp-1 exposed to either active or thermally deactivated mushroom tyrosinase, probably due to the obstruction of binding sites by bound enzyme. Adsorption kinetics of mushroom tyrosinase onto adlayers of Mefp-1 for active and thermally inactivated enzyme were nearly identical. Attenuated total reflection Fourier transform infrared spectroscopy was used to characterize these interactions at a germanium (Ge) interface. Copyright 2000 Academic Press.

Journal Article↗
PubMed1995

Microencapsulation of DNA within alginate microspheres and crosslinked chitosan membranes for in vivo application.

Calf thymus DNA was microencapsulated within crosslinked chitosan membranes, or immobilized within chitosan-coated alginate microspheres. Microcapsules were prepared by interfacial polymerization of chitosan, and alginate microspheres formed by emulsification/internal gelation. Diameters ranged from 20 to 500 microns, depending on the formulation conditions. Encapsulated DNA was quantified in situ by direct spectrophotometry (260 nm) and ethidium bromide fluorimetry, and compared to DNA measurements on the fractions following disruption and dissolution of the microspheres. Approximately 84% of the DNA was released upon core dissolution and membrane disruption, with 12% membrane bound. The yield of encapsulation was 96%. Leakage of DNA from intact microspheres/capsules was not observed. DNA microcapsules and microspheres were recovered intact from rat feces following gavage and gastrointestinal transit. Higher recoveries (60%) and reduced shrinkage during transit were obtained with the alginate microspheres. DNA was recovered and purified from the microcapsules and microspheres by chromatography and differential precipitation with ethanol. This is the first report of microcapsules or microspheres containing biologically active material (DNA) being passed through the gastrointestinal tract, with the potential for substantial recovery.

Animals↗