This study was intended to investigate the crosslinking characteristics of a new crosslinking agent-oxidized sodium alginate (ADA), which might provide an ideal biological crosslinking reagent for the construction of soft tissue bioprostheses. Glutaraldehyde and genipin, which have been typically used in developing bioprostheses, were used as controls. The porcine aortas were treated by these three crosslinking agents for 15 min to 72 h and the fixation index was determined. Subsequently, the mechanical property and cytocompatibility of fixed tissues were also tested. The results indicated that fixed tissues by ADA were comparable as glutaraldehyde and superior to genipin controls in fixative efficiency. It was also found that tissues fixed by ADA were comparable as genipin and superior to glutaraldehyde controls in cytocompatibility and were similar to natural tissues in mechanical property. The results of in vitro study demonstrated that ADA could be a promising crosslinking reagent for biological tissue fixation.
Alginates ; chemistry ; pharmacology ; Animals ; Aorta ; cytology ; metabolism ; Biocompatible Materials ; metabolism ; Cross-Linking Reagents ; chemistry ; pharmacology ; Extracellular Matrix ; metabolism ; Glucuronic Acid ; chemistry ; pharmacology ; Hexuronic Acids ; chemistry ; pharmacology ; Swine ; Tissue Engineering ; methods ; Tissue Fixation ; Tissue Scaffolds

To study the angiogenic activity of amphoteric brush-type copolymer complex of alginate-graft-PEI/pVEGF (Alg-g-PEI/pVEGF) in vivo, we evaluated the toxicity of Alg-g-PEI/pVEGF complexes to rMSCs and zebra fish first. Then, we used gel retardation assay to investigate the protection of complex to pDNA against DNase I, serum and heparin. For in vivo study, we evaluated the angiogenic activity of Alg-g-PEI/pVEGF complexes by using CAM and zebra fish as animal models, PEI 25K/pVEGF and saline as positive and negative controls. Our results show that Alg-g-PEI protected pVEGF from enzymolysis and displacement of heparin in some degree, and its complexes with pVEGF were less toxic to rMSCs and zebra fish. Alg-g-PEI/pVEGF complexes induced significant angiogenesis, which was dosage-dependent. In CAM, when the dosage of pVEGF was 2.4 microg/CAM, Alg-g-PEI group achieved the maximum of angiogenesis, and the area ratio of vessel to the total surface was 44.04%, which is higher than PEI 25K group (35.90%) and saline group (24.03%) (**P < 0.01). In zebra fish, the angiogenesis increased with the increase of N/P ratios of Alg-g-PEI/pVEGF complexes in our studied range; when N/P ratio was 110, the optimal angiogenesis was obtained with vessel length of 1.11 mm and area of 1.70 x 10(3) pixels, which is higher than saline group (0.69 mm and 0.94 x 10(3) pixels) (**P < 0.01) and PEI 25k group (0.82 mm and 1.11 x 10(3) pixels) (**P < 0.01). Our results demonstratethat Alg-g-PEI/pVEGF significantly induces angiogenesis in CAM and zebra fish, and has a great potential in therapeutic angiogenesis.
Alginates ; chemistry ; Angiogenesis Inducing Agents ; pharmacology ; Animals ; Chick Embryo ; Drug Carriers ; chemistry ; Genetic Vectors ; genetics ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Polyethyleneimine ; chemistry ; Polymers ; pharmacology ; toxicity ; Vascular Endothelial Growth Factor A ; chemistry ; Zebrafish

White-rot fungus manganese peroxidase (MnP) oxidizes a wide range of substrates, rendering it an interesting enzyme for potential applications. The stability of MnP can be improved by immobilization. With sodium alginate, gelatin, or chitosan as a carrier, and glutaraldehyde as the crosslinking agent, MnP was co-immobilized using the embed-crosslinked method and the adsorb-crosslinked method. The immobilization conditions and the partial properties of the three immobilized enzymes were investigated. When compared with the free enzyme, the optimum pH values and the temperatures of the three immobilized MnPs carried by alginate, gelatin, and chitosan were respectively shifted from 7.0 to 5.0, 5.0, 3.0 and from 35 degrees C to 75 degrees C , 55 degrees , 75 degrees C . The thermostabilities of the three immobilized MnPs were considerably better than that of the native enzyme. The chitosan-decreased by less than 5% even after repeated use for 6 - 9 times. The ability of decolorizing azo dyes in static and shaky situation by gelatin-immobilized MnP approached to the free enzyme, and there was no loss of enzyme activity during 2 repeated batch reactions.
Adsorption ; Alginates ; chemistry ; metabolism ; Biocatalysis ; drug effects ; Chitosan ; chemistry ; metabolism ; Dose-Response Relationship, Drug ; Enzymes, Immobilized ; chemistry ; metabolism ; Fungal Proteins ; chemistry ; metabolism ; Gelatin ; chemistry ; metabolism ; Glucuronic Acid ; chemistry ; metabolism ; Glutaral ; pharmacology ; Hexuronic Acids ; chemistry ; metabolism ; Hydrogen-Ion Concentration ; Kinetics ; Peroxidases ; chemistry ; metabolism ; Schizophyllum ; enzymology ; Substrate Specificity ; Temperature

Scutellarin is a flavonoid extracted from a traditional Chinese herb, Erigeron breviscapus. The present study investigated the effect of scutellarin on MUC5AC mucin production and the possible mechanism. Human bronchial epithelial 16 (HBE16) cells were pretreated with scutellarin for 60 min, and then exposed to human neutrophil elastase (HNE) or interleukin (IL)-13 for 12 hr. RT-PCR and ELISA were performed to measure the amount of MUC5AC mucin production. The results showed that scutellarin inhibited MUC5AC expression both in mRNA and protein level induced by HNE in a concentration-dependent manner. However, scutellarin failed to inhibit MUC5AC mucin production induced by IL-13. To investigate the intracellular mechanisms associated with the effect of scutellarin on MUC5AC mucin production, western blotting was carried out to examine the phosphorylation of protein kinase C (PKC), signal transducer and activator of transcription 6 (STAT6) and extracellular signal-regulated kinase 1/2 (ERK1/2). The phosphorylation of PKC and ERK1/2 was attenuated after treatment with scutellarin, whereas STAT6 was not significantly affected. Therefore, it is suggested that scutellarin down-regulates MUC5AC mucin production on HBE16 cells via ERK-dependent and PKC-dependent pathways.
Apigenin/chemistry/*pharmacology ; Cells, Cultured ; Dose-Response Relationship, Drug ; Down-Regulation ; Epithelial Cells/*drug effects/metabolism ; Erigeron/chemistry ; Glucuronic Acids/chemistry/*pharmacology ; Humans ; Interleukin-13/*pharmacology ; Leukocyte Elastase/*pharmacology ; Mitogen-Activated Protein Kinase 1/metabolism ; Mitogen-Activated Protein Kinase 3/metabolism ; Mucin 5AC/genetics/*metabolism ; Phosphorylation ; Protein Kinase C/metabolism ; Respiratory Mucosa/drug effects/*metabolism ; STAT6 Transcription Factor/metabolism ; Signal Transduction

The difference between absorption of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) after oral and oral cavity administration were studied respectively, and the compatible enhancer for oral cavity delivery system of both drugs was found. The LMWH and UFH films were prepared with two bioadhesive materials Carbopol and alginate sodium for oral cavity delivery. The activated partial thromboplastin time (APTT) was used to determine LMWH and UFH in plasma after oral, oral cavity and sc administration in rats. The results show that the enhancer (Labrasol) can increase the absorption of LMWH and UFH through oral cavity in rats but not obviously. The oral cavity iontophoretic delivery system is a useful method to improve the absorption of LMWH and UFH through oral cavity mucosa.
Absorption ; Acrylic Resins ; Administration, Oral ; Alginates ; chemistry ; Animals ; Anticoagulants ; administration & dosage ; pharmacokinetics ; Drug Carriers ; Drug Delivery Systems ; Glucuronic Acid ; chemistry ; Glycerides ; Heparin ; administration & dosage ; pharmacokinetics ; Heparin, Low-Molecular-Weight ; administration & dosage ; pharmacokinetics ; Hexuronic Acids ; chemistry ; Injections, Intradermal ; Iontophoresis ; Male ; Mouth ; Organic Chemicals ; pharmacology ; Partial Thromboplastin Time ; Polyvinyls ; chemistry ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To determine the effects of sodiun aescinate on Bcl-2 and Caspase-3 protein expression and neuronal apoptosis after focal cerebral ischemia reperfusion injury in rats. METHODS: One hundred male Wistar rats were subjected to middle cerebral artery occlusion (MCAO) and reperfusion. The rats were divided randomly into 4 groups: sham-operated group and MCAO and reperfusion model groups which were randomly divided into control group, saline group, and sodium aescinate group. The immunohistochemistry staining and microscope image were used to observe the dynamic Bcl-2 and Caspase-3 protein expression in the ischemic penumbra after the reperfusion. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining was performed for the detection of apoptosis. RESULTS: Bcl-2 protein expression in the sodium aescinate group was significantly higher than that of the saline group and control group (P < 0.05). While Caspase-3 protein expression in the sodium aescinate group was then compared with those of the saline group and control group, and showed the difference was significant (P < 0.05). Compared with the saline group and control group, the number of apoptotic cells in the sodium aescinate group was significantly reduced (P < 0.01). CONCLUSION Sodium aescinate increases Bcl-2 protein expression and decreases Caspase-3 protein expression,through which it can protect the ischemia brain on reperfusion injury.
Alginates ; pharmacology ; Animals ; Apoptosis ; drug effects ; Brain Ischemia ; metabolism ; pathology ; Caspase 3 ; Caspases ; biosynthesis ; genetics ; Glucuronic Acid ; pharmacology ; Hexuronic Acids ; pharmacology ; Male ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Wistar ; Reperfusion Injury ; metabolism ; pathology ; Saponins ; pharmacology

AIMTo evaluate the hypoglycemic effect of chitosan-coated and sodium alginate-coated insulin liposomes after oral administration in mice.

METHODSInsulin-liposomes were prepared by reverse-phase evaporation. Chitosan and alginate coating was carried out by mixing liposomal suspension with chitosan and sodium alginate solutions, followed by incubation. The particle size and morphology of insulin-liposomes were determined using laser light scattering instrument and transmission electron microscopy (TEM). The entrapment efficiency was analyzed using HPLC and ultracentrifuge. The protection of insulin from peptic and tryptic digestion was studied with HPLC. The hypoglycemic effects of polysaccharide-coated insulin liposomes were investigated using the glucose oxidase method after oral administration in mice.

RESULTSThe particle size of uncoated, chitosan-coated and alginate-coated insulin-liposomes was (138 +/- 31) nm, (230 +/- 20) nm and (266 +/- 19) nm, respectively. All insulin-liposomes were of spherical or ellipsoidal shape. The entrapment efficiencies were 81.6%, 73.5% and 68.7%, respectively. Insulin was protected from tryptic digestion by chitosan-coated liposomes and protected from peptic digestion by alginate-coated liposomes. The hypoglycemic effects of insulin-liposomes, coated with 0.1% chitosan and 0.1% sodium alginate, were observed.

CONCLUSIONChitosan-coated and sodium alginate-coated liposomes were shown to reduce peptic or tryptic digestion on insulin, and enhance enteral absorption of insulin.

Administration, Oral ; Alginates ; Animals ; Blood Glucose ; metabolism ; Chitin ; analogs & derivatives ; chemistry ; Chitosan ; Delayed-Action Preparations ; Drug Carriers ; Drug Delivery Systems ; Glucuronic Acid ; Hexuronic Acids ; Hypoglycemic Agents ; administration & dosage ; pharmacology ; Insulin ; administration & dosage ; pharmacology ; Liposomes ; Male ; Mice ; Particle Size ; Random Allocation ; Technology, Pharmaceutical ; methods