This work reports the properties of dextran-spermine polycation (DSP) as a gene vector and its gene transfection efficiency in vitro. Oxidized dextran was reacted by reductive amination with spermine to obtain DSP, the resulted polycation was then incubated with plasmid pEGFP to form polyplexes by electrostatic interactions. DSP formed stable polyplexes when the weight ratio (DSP/DNA) varied from 4 : 1 to 20 : 1. The particle size and zeta potential of polyplexes were in the range of 162.6 - 187.9 nm and increased from + 8.45 mV to + 39.6 mV, respectively. DSP could effectively protect condensed DNA from DNase I degradation, and it showed strong buffering capacity in a certain pH range. The highest yields of transfection efficiency were found to be as high as Lipofectamine 2000 when the polyplexes were transfected to SMMC-7721 and BHK-21 cells at the weight ratio of 8 : 1. This research indicates that dextran-spermine polycation is a highly active gene vector in vitro.
Animals ; Cell Survival ; Cricetinae ; DNA ; administration & dosage ; Dextrans ; administration & dosage ; Genetic Vectors ; Spermine ; administration & dosage ; Transfection ; methods

OBJECTIVE: To determine the application of modified low-potassium dextran (LPD) solution in heart-lung transplantation. METHODS: We used the modified LPD as the lung flush solution of the donor in the first heart-lung transplantation procedure in Hunan. RESULTS: The patient survived 555 days after the surgery and severe infection, lung disfunction or severe graft rejection never occurred. CONCLUSION Modified LPD as lung flush solution of the donor during heart-lung transplantation demonstrates an excellent effect of lung protection.
Adult ; Dextrans ; administration & dosage ; Heart Defects, Congenital ; surgery ; Heart-Lung Transplantation ; methods ; Humans ; Male ; Organ Preservation Solutions ; Potassium ; administration & dosage

OBJECTIVETo study magnetic resonance enhancement features of inflammatory lymph nodes using different doses of ultrasmall superparamagnetic iron oxide (USPIO) particles in order to establish a standardized protocol for USPIO enhanced magnetic resonance imaging of lymph nodes.

METHODSA total of 12 healthy New Zealand rabbits were injected complete Freund's adjuvant in foot pad to establish popliteal inflammatory lymph node model. Different doses (45, 90, 135 micromol Fe/kg) of USPIO were injected intravenously. Magnetic resonance scans were performed before and after USPIO injection to observe the enhancement features of different groups. T2 signal intensity, T1 signal intensity, T2 x value, and T2 value were measured and T2 enhancement ratio was calculated at different time points.

RESULTSTwenty-four hours after USPIO injection, there was no statistical difference in T2 signal intensity and T2 enhancement ratio between 90 and 135 micromol Fe/kg dose groups, but both were superior to 45 micromol Fe/kg group (P < 0.05). There were no statistical differences in T2 signal intensity, T1 signal intensity, T2 value, and T2 enhance ratio among different postcontrast time delays from 6 to 24 hours in 90 micromol Fe/kg group (P > 0.05), and signal reduction of lymph nodes peaked 18 hours after USPIO injection. Better images were acquired with a postcontrast delay of 18-24 hours.

CONCLUSIONSLymph nodes can be enhanced well with a dose of 90 micromol Fe/kg. Postcontrast delay of 18-24 hours is appropriate for acquiring satisfactory enhancement images.

Animals ; Contrast Media ; administration & dosage ; Dextrans ; administration & dosage ; Image Enhancement ; methods ; Lymphadenitis ; diagnosis ; pathology ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; administration & dosage ; Male ; Rabbits ; Random Allocation

OBJECTIVETo establish an HPLC method for the determination of entrapment efficiency of sinomenine liposomes.

METHODThe liposomes and dissociated drugs were separated by sephadex filtration, mini-column centrifugation and dialysis. The methodology study and the optimization of determining condition were carried out at the same time.

RESULTSephadex filtration could effectively separate the sinomenine liposomes from dissociated sinomenine. The column recovery was 98.8%, the average entrapment efficiency of three tests was64.9%, RSD 2.67%.

CONCLUSIONThe method was simple, exact, and had a good reappearance. It can be used to examine the entrapment efficiency of sinomenine liposomes.

Dextrans ; Drug Carriers ; Drug Delivery Systems ; Filtration ; methods ; Liposomes ; Morphinans ; administration & dosage ; analysis ; isolation & purification ; Sinomenium ; chemistry ; Technology, Pharmaceutical ; methods

The aim of this study is to prepare cationic biodegradable dextran microspheres loaded with tetanus toxoid (TT) and to investigate the mechanism of protein loading. Positively charged microspheres were prepared by polymerization of hydroxylethyl methacrylate derivatized dextran (dex-HEMA) and dimethyl aminoethyl methacrylate (DMAEMA) in an aqueous two-phase system. The loading of the microspheres with TT was based on electrostatic attraction. The net positive surface charge increased with increasing amounts of DMAEMA. Confocal images showed fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) could penetrate into cationic dextran microspheres but not natural dextran microspheres. TT loading efficiency by post-loading was higher compared with by pre-loading. Even though TT is incorporated in the hydrogel network based on electrostatic interaction, still a controlled release can be achieved by varying the initial network density of the microspheres.
Delayed-Action Preparations ; Dextrans ; chemistry ; Drug Carriers ; chemistry ; Hydrogels ; chemistry ; Methacrylates ; chemistry ; Microscopy, Confocal ; Microspheres ; Particle Size ; Polymerization ; Serum Albumin, Bovine ; chemistry ; Tetanus Toxoid ; administration & dosage ; chemistry

OBJECTIVESTo analyze the technical aspects of uterine artery embolization with dextran microspheres and to evaluate the effectiveness of this technique as the primary treatment of uterine fibroids in a series of 38 patients.

METHODSThirty-eight volunteers (age range, 24-48 years; mean, 37.2 years) with symptoms caused by uterine fibroids (menorrhagia, mass-related symptoms, and pelvic pain) were randomly included in this study. The fibroids were single in 32 patients and multiple in 6 patients. According to the tumor location, subserous fibroids were found in 4 patients and interstitial or submucosal fibroids in 34. Tumor size was from 2 to 10.9 cm in diameter. We performed embolization with a single Headhunter catheter using the right-femoral artery approach, injection of dextran microspheres (225-450 micro m), and an absorbable gelatin sponge. Follow-up included clinical and sonographic examinations at one-month intervals for 6 months.

RESULTSEmbolization was successfully performed in all patients. Post-procedural pain control was good in 35 (92%) patients. In most patients, symptoms were improved at 3 months (36/38, 95%). Clinical failure of the treatment occurred in only 2 patients (2/38, 5%). Progressive reduction in leiomyoma size was revealed during sonographic follow-up, and the reduction rate at the sixth month after embolization was 68%. The tumor had vanished in five submucosal fibroid patients. Histopathological tests showed that the tumor was degenerative as fibrosis and hyalinosis.

CONCLUSIONSUterine artery embolization with dextran microspheres is a micro-invasive method for the treatment of uterine fibroids. It is clinically effective in most patients and induces a progressive reduction in the size of fibroids. Based on this study, we believe that this new technique is much more suitable for submucosal fibroids with massive menorrhagia.

Adult ; Dextrans ; administration & dosage ; Embolization, Therapeutic ; adverse effects ; Female ; Follow-Up Studies ; Humans ; Leiomyoma ; therapy ; Middle Aged ; Uterine Neoplasms ; therapy ; Uterus ; blood supply

PURPOSE: Poloxamer 407 (P407) thermo-sensitive hydrogel formulations were developed to enhance the retention time in the urinary bladder after intravesical instillation. MATERIALS AND METHODS: P407 hydrogels (P407Gels) containing 0.2 w/w% fluorescein isothiocyanate dextran (FD, MW 4 kDa) as a fluorescent probe were prepared by the cold method with different concentrations of the polymer (20, 25, and 30 w/w%). The gel-forming capacities were characterized in terms of gelation temperature (G-Temp), gelation time (G-Time), and gel duration (G-Dur). Homogenous dispersion of the probe throughout the hydrogel was observed by using fluorescence microscopy. The in vitro bladder simulation model was established to evaluate the retention and drug release properties. P407Gels in the solution state were administered to nude mice via urinary instillation, and the in vivo retention behavior of P407Gels was visualized by using an in vivo imaging system (IVIS). RESULTS: P407Gels showed a thermo-reversible phase transition at 4℃ (refrigerated; sol) and 37℃ (body temperature; gel). The G-Temp, G-Time, and G-Dur of FD-free P407Gels were approximately 10℃–20℃, 12–30 seconds, and 12–35 hours, respectively, and were not altered by the addition of FD. Fluorescence imaging showed that FD was spread homogenously in the gelled P407 solution. In a bladder simulation model, even after repeated periodic filling-emptying cycles, the hydrogel formulation displayed excellent retention with continuous release of the probe over 8 hours. The FD release from P407Gels and the erosion of the gel, both of which followed zero-order kinetics, had a linear relationship (r²=0.988). IVIS demonstrated that the intravesical retention time of P407Gels was over 4 hours, which was longer than that of the FD solution ( < 1 hour), even though periodic urination occurred in the mice. CONCLUSIONS: FD release from P407Gels was erosion-controlled. P407Gels represent a promising system to enhance intravesical retention with extended drug delivery.
Administration, Intravesical* ; Animals ; Dextrans ; Drug Liberation ; Fluorescein ; Hydrogel* ; Hydrogels* ; In Vitro Techniques ; Kinetics ; Methods ; Mice* ; Mice, Nude ; Microscopy, Fluorescence ; Optical Imaging ; Phase Transition ; Poloxamer* ; Polymers ; Urinary Bladder* ; Urination

Iron deficiency anemia (IDA) frequently occurs in infants and adolescents. IDA is the result of an interplay between increased host requirements, limited external supply, and increased blood loss. In outpatient clinics, we often see children with iron deficiency anemia. Most cases in children are caused by incomplete nutrient supplements and growth spurts. However, we can occasionally see patients with poor response despite iron supplementation. Failure of iron therapy occurs when a child does not receive the prescribed medication, when iron is given in a form that is poorly absorbed, or when there is a continuing unrecognized blood loss such as intestinal or pulmonary loss, or loss with menstrual periods. In addition, the therapeutic failure of iron medication may indicate that the original diagnosis of nutritional iron deficiency was incorrect. In this situation, we have to evaluate other etiologies of anemia. Recently, many cases relating H.pylori infection to iron deficiency anemia have been described in the literature and H.pylori infection has emerged as a cause of refractory iron deficiency anemia that is unresponsive to oral iron therapy. Also, iron deficiency anemia induced by athletics in adolescent females has been reported several times. In this article, the author reviews various etiologies of childhood iron deficiency anemia. The most important consideration in treatment of iron deficiency anemia is disclosure of the underlying cause and its recovery. Dietary habits should also be corrected. To supplement iron, 6 mg/kg of oral iron supplements (elemental iron) is recommended in ferrous salt form. If oral administration is not feasible, intravenous supplementation is recommended using forms such as iron dextran, iron gluconate, or iron sucrose.
Administration, Oral ; Adolescent ; Ambulatory Care Facilities ; Anemia ; Anemia, Iron-Deficiency ; Child ; Dextrans ; Disclosure ; Female ; Ferric Compounds ; Food Habits ; Glucaric Acid ; Gluconates ; Humans ; Infant ; Iron ; Sports ; Sucrose

In this paper, adriamycin-carboxymethyldextran magnetic nanoparticles (ADR-CMD MNPs) were prepared. After i.v. administration in mice, acute toxicity, cumulative toxicity and the distribution profiles of heart were studied both for free adriamycin(ADR) and ADR-CMD MNPs. The results showed conjugation with CMD MNPs, the acute toxicity of ADR was decreased significantly, the LD50 value of ADR-CMD MNPs was 5.06 times as high as that of the free ADR. Altogether, the cumulative toxicity of conjugate MNPs is significantly decreased as expressed by the mortality, the loss for both weight and leucocyte after repeated injection. Tissue distribution studies show the reduced cardiac uptake of ADR after i.v. which possibly contributes to minimizing the cardiotoxic effect of ADR.
Animals ; Dextrans ; Doxorubicin ; administration & dosage ; pharmacokinetics ; toxicity ; Drug Carriers ; Drug Delivery Systems ; Female ; Injections, Intravenous ; Magnetics ; Male ; Mice ; Myocardium ; metabolism ; Tissue Distribution

AIMTo prepare magnetoliposome (MLP) containing dextran-encapsulated magnetite (Fe3O4), and to examine its physicochemical properties and its in vivo behavior on ICR mice.

METHODSReverse phase evaporation method was used to formulate MLP and the Fe2+ concentration was measured by o-phenanthroline method. Then the basic properties of MLP and in vivo distribution were studied with the aid of 3H isotope as biomarker.

RESULTSThe mean diameter of MLP was 602.5 nm and the final concentration of encapsulated Fe3O4 was 88.1 mg x L(-1). Under natural conditions most of the MLP was taken up by spleen after the administration via tail vain, but its uptake was reduced under the magnetic field. There was a great difference in vivo distribution between the left and right lobes of the liver and the left and right kidneys in magnetic fields.

CONCLUSIONReverse phase evaporation method was utilized to prepare magnetoliposomes. The formulation was stable and encapsulated high amount of magnetite. The delivery system could be oriented to certain tissues under magnetic field and satisfying magnetic responsiveness was observed.

Animals ; Dextrans ; administration & dosage ; pharmacokinetics ; Drug Delivery Systems ; Female ; Ferrosoferric Oxide ; Iron ; administration & dosage ; pharmacokinetics ; Kidney ; metabolism ; Liposomes ; Liver ; metabolism ; Magnetics ; Male ; Mice ; Mice, Inbred ICR ; Nanotechnology ; Oxides ; administration & dosage ; pharmacokinetics ; Particle Size ; Spleen ; metabolism