OBJECTIVETo prepare morphine-loaded chitosan microspheres by emulsion ionic cross-linking and investigate the effect of initial morphine quantity and different cross-linking degrees on drug loading, encapsulation efficiency and in vitro drug release.

METHODSChitosan (with a relative molecular mass of 50,000 and deacetylation degree no less than 90%) at 100 mg and morphine at 20, 30, 40, or 50 mg were dissolved by 2% acetate and dripped slowly into 15 ml soy-bean oil containing 0.75 ml Span80. After full emulsification at 35 degrees C; for 1.5 h, the mixture was dripped slowly into sodium tripolyphosphate (10 mg/ml) at the mass ratio of 5:1, 7:1, or 9:1 to allow cross-linking for 2 h. The drug loading, encapsulation efficiency and in vitro drug release of the preparations were measured.

RESULTSThe drug loading in the microsphere increased while the encapsulation efficiency reduced with the increment of the initial morphine quantity. High cross-linking degree resulted in prolonged release time of the drug loaded in the preparations.

CONCLUSIONThe microspheres loaded with morphine allows sustained release of morphine.

Chitosan ; administration & dosage ; Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; administration & dosage ; Microspheres ; Morphine ; administration & dosage

OBJECTIVETo optimize the preparation of genistein chitosan microspheres with central composite design (CCD).

METHODThe chitosan microspheres were prepared by the O/W/O multiple emulsion method. Second-order polynomial and linear equations were fitted to the data, and the resulting equations were used to produce response surface graphs and the best experiment conditions.

RESULTThe theoretical drug content was 13%-15%, the concentration of organic phase was 30%-40% and the concentration of oil phase was 68%-72%.

CONCLUSIONThe best experiment conditions can be obtained by central composite design and response surface methodology. The observed values agree well with model predicted values.

Antineoplastic Agents ; administration & dosage ; Chitin ; analogs & derivatives ; Chitosan ; Delayed-Action Preparations ; Genistein ; administration & dosage ; Mathematics ; Microspheres

A porous composite particle (CP) was fabricated by the methods of emulsification and cross-link based on chitosan, alginate and collagen protein, and the tranexamic acid-loaded composite particles (TACP) was prepared by immersing the composite particle into the solution of tranexamic acid and by freeze drying. In the hepatic and splenic hemorrhage model of rabbits, CP and TACP were randomly used as haemostatic agents, and the Suxiaozhixuefen (Flashclot) was used as control. The corresponding hemostatic time and bleeding amount were observed respectively. The hemostatic time of CP and Flashclot were (2.48 +/- 0.88) min and (3.07 +/- 0.84) min, respectively, no significant difference was observed. However, the hemostatic time of TACP was (1.90 +/- 0.75) min, which was significantly shorter than that of CP and Flashclot (P < 0.05). In the splenic bleeding model of rabbits, similar results were obtained with these three kinds of hemostatics. These results indicated that the CP based on chitosan, alginate and collagen protein displayed similar hemostatic efficiency to Flashclot. However, the TACP might be one of promising haemostatic powders due to its more excellent hemostatic efficiency.
Alginates ; administration & dosage ; pharmacology ; Animals ; Biocompatible Materials ; chemistry ; Chitosan ; administration & dosage ; pharmacology ; Collagen ; administration & dosage ; pharmacology ; Female ; Hemostatics ; administration & dosage ; pharmacology ; Male ; Rabbits ; Tranexamic Acid ; administration & dosage ; pharmacology

OBJECTIVETo prepare resveratrol chitosan nanoparticles with free amine groups on the surface so as to conjugate ligands, which will actively target to special tissues or organs.

METHODThe chitosan nanoparticles with free amine on the surface was prepared by sodium chloride precipitation. Nanoparticles with different solidification degrees were studied on turbidity, in vitro release, encapsulation efficiency, drug loading and diameter.

RESULTThe turbidity of nanoparticles with various solidification degrees decreased at different rates after ultrasonic or water bath heating treatment. All nanoparticles mentioned above obviously shew sustained release. The rate of release was slowed down with the increase of solidification agents. Solidification had no obvious effects on the encapsulation efficiency and drug loading. The diameter of chitosan nanoparticles with 200 microL solidification agents was 487 nm. The polydispersion was 0.144.

CONCLUSIONThe diameter of the prepared nanoparticles was relatively small. The amine on the surface was free, which offered the possibility of designing the acive target drug delivery system.

Chitosan ; chemistry ; Drug Compounding ; methods ; Drug Delivery Systems ; Nanostructures ; Particle Size ; Stilbenes ; administration & dosage ; chemistry

OBJECTIVETo assess the effect of cyclosporine A (CsA) loaded in chitosan conduit on bridging the sciatic nerve defects in a rat model.

METHODSA 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 μl carrier-drug dilution (10 μg/L CsA). In control group, the conduit was filled with the same volume of carrier dilution alone. The regene-rated fibers were studied 4, 8 and 12 weeks after surgery.

RESULTSThe functional study confirmed faster recovery of the regenerated axons in treatment group than control group (P<0.05). There was statistically significant difference of the gastrocnemius muscle weight ratios between treatment and control groups (P<0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group.

CONCLUSIONCsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative morphometric indices of sciatic nerve. It is easily available without any complications compared with its systemic administration.

Animals ; Chitosan ; Cyclosporine ; administration & dosage ; pharmacology ; Immunohistochemistry ; Nerve Regeneration ; drug effects ; Rats ; Sciatic Nerve ; chemistry ; injuries

Magnetic chitosan (CS) nano-spheres were prepared by the modified suspension cross-linking technique. The results demonstrated that the magnetic drug nano-spheres are mainly spherical in form with a size of 200 to 800 nm, and show good magnetic responsivity. Here, Doxorubicin was used as exam drug. Glutaraldehyde connects Doxorubicin to CS by the chemical bond (-N = C-), and the drug content is in range of 1% to 15% (w/w). The chemical bond is broken depending on pH, so pH is the important factor for the release of doxorubicin. The doxorubicin release was 22.0%, 13.4%, and 4.1% in the space of 7d, when pH was 1, 2, 4. So the nano-spheres are pH-sensitive magnetic targeting drug micro-spheres.
Chitosan ; chemistry ; Doxorubicin ; administration & dosage ; Drug Carriers ; chemical synthesis ; Drug Delivery Systems ; methods ; Magnetics ; Nanospheres ; chemistry

Nanoparticles had received much attention in the development of new kind of pharmaceutical formation because of the special nano-effectivity. Recently, some studies discovered the special functions of the nanoparticles in transdermal and transmucosal drug delivery systems. Even though the acting mechanism of the nanoparticles in these drug delivery systems are not known, these discoveries of the special function of the nanoparticles provide new developing prospect to the drug delivery systems. This paper mainly reviews the present studying results about the nanoparticles used in the transdermal and transmucosal drug delivery systems, including the lipid nanopaticles, natural polymer and the synthesized polymer nanoparticles.
Administration, Cutaneous ; Animals ; Chitosan ; Drug Delivery Systems ; Humans ; Lipids ; Liposomes ; Nanotechnology ; methods ; Polymers

The aim was to investigate the effect of particle size on transfection efficiency of chitosan (CS)-based nanoparticles. Nanoparticles were synthesized through complex coacervation CS with plasmid DNA (pDNA). Three kinds of pDNA/CS nanoparticles with different sizes (250, 580 and 1300 nm) were prepared by altering the adding rate and the vortexing time. The particle size, zeta potential and the stability in cultural medium were evaluated by zetasizer. The association efficiency was determined by spectrofluorophotometer. The combination of chitosan with pDNA as well as the ability to protect pDNA from nuclease degradation was analyzed by gel electrophoresis. The transfection efficiency of pDNA/CS nanoparticles in HEK293 cells was investigated by flow cytometry. Using CS grafted fluorescein isothiocyanate as a fluorescent marker, the adsorption features of the nanoparticles were visualized by fluorescence microscopy and the cellular uptake percent was quantitated by flow cytometry. The internalization process of the nanoparticles was visualized by confocal laser scanning microscopy (CLSM) using nanoparticles of the size of 250 nm. Results showed that the three kinds of pDNA/CS nanoparticles had no differences in zeta potential, association efficiency, protection ability, stability and transfection efficiency in HEK293. The nanoparticles were all adsorbed on cell surface in the form of aggregates, and similar cellular uptake percent as well as quantities were observed 4 h post-incubation with HeLa cells. CLSM images showed that the aggregates below 2 microm could be internalized by endocytosis. These results suggest that the transfection efficiency of pDNA/CS nanoparticles does not depend on particle size in the range from 250 nm to 1300 nm.
Chitosan ; administration & dosage ; chemistry ; metabolism ; DNA ; administration & dosage ; Endocytosis ; Genetic Vectors ; HeLa Cells ; Humans ; Nanoparticles ; Particle Size ; Plasmids ; Transfection

Animals ; Cations ; chemistry ; Chitin ; administration & dosage ; analogs & derivatives ; chemistry ; Chitosan ; DNA ; administration & dosage ; Gene Transfer Techniques ; Genetic Therapy ; Liposomes ; administration & dosage ; chemistry ; Polylysine ; administration & dosage ; chemistry

Chitosan, which is a biopolymer, composed of glucosamine units linked by beta-1, 4 glycoside bonds, is rich in shells of crustacean such as crabs and shrimps. Consumption of chitosan has been rapidly increased as a functional food. We examined effects of chitosan on the damages caused by lead (Pb) exposure in rats. Male Sprague-Dawley rats were divided into 8 groups (n = 64), then fed diets containing 3% cellulose (control) or 3% chitosan, each with 4 different lead doses (0 mg/d, 20 mg/d, 50 mg/d, and 100 mg/d) for 4 wks. Lead doses were given 3 times per week by oral administration. Blood lead levels in rats increased depending on the administered doses of lead. Rats fed chitosan diets showed lower blood lead concentration than did their respective controls. Effect of chitosan on the blood lead was more beneficial in rats exposed to lower lead (20 mg/d) than in rats exposed to higher lead (50 mg/d and 100 mg/d). Histological changes in erythrocytes and liver were also examined. Chitosan tended to reduce numbers of basophilic stippling erythrocytes and improve the histological liver changes in rats given various lead doses. The preventive effects of chitosan on liver damages were stronger in rats with higher lead than those with lower lead. These results indicate that chitosan has beneficial effects on both blood toxicological responses and histological damages of erythrocytes and liver induced by the administration of various lead doses.
Administration, Oral ; Animals ; Basophils ; Biopolymers ; Cellulose ; Chitosan* ; Diet ; Erythrocytes ; Functional Food ; Glucosamine ; Humans ; Liver ; Male ; Rats* ; Rats, Sprague-Dawley