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PubMed2000

Raffinose improves the function of rat pulmonary grafts stored for twenty-four hours in low-potassium dextran solution.

OBJECTIVES: The perfect strategy for pulmonary graft preservation remains elusive. Experimental work supports the use of perfusates, such as Euro-Collins, University of Wisconsin, and low-potassium dextran solutions. We use low-potassium dextran solution in our clinical program, but we aim for continued improvement. The trisaccharide raffinose has been shown to be responsible for the efficacy of University of Wisconsin perfusate in lung preservation. Raffinose is superior to a variety of other saccharides for this purpose. We tested the hypothesis that the addition of raffinose to low-potassium dextran solution might further improve graft function. METHODS: In a randomized blinded study with a rat left lung transplant model, donor lungs were flushed with either standard low-potassium dextran solution or low-potassium dextran solution modified by the addition of 30 mmol/L raffinose (n = 5 for each group). Alprostadil (prostaglandin E(1), 500 microg/L) was added to the perfusates in accordance with our clinical practice. Grafts were stored inflated at 4 degrees C for 24 hours. After transplantation, recipients were ventilated with a fraction of inspired oxygen of 1 and a positive end-expiratory pressure of 2 cm H(2)O. Graft function was evaluated by measuring oxygenation at 2 hours after graft reperfusion, peak airway pressure throughout the reperfusion period, and the wet/dry lung weight ratio. RESULTS: The group receiving low-potassium dextran solution with raffinose demonstrated significantly higher oxygenation (oxygen tension, 370 +/- 45 mm Hg vs 150 +/- 64 mm Hg; P =.0025), lower peak airway pressures at 2 hours after lung reperfusion (11 +/- 2.7 mm Hg vs 16 +/- 2.4 mm Hg; P <.001), and a lower wet/dry weight ratio (4.7 +/- 1.26 vs 11 +/- 5. 0; P =.017). CONCLUSION: Modification of low-potassium dextran solution with the trisaccharide raffinose resulted in a significant improvement in graft function in this model and merits further evaluation with respect to the mechanisms involved.

Animals↗

PubMed2001

In vitro biocompatibility of biodegradable dextran-based hydrogels tested with human fibroblasts.

The cytotoxicity of dextran T40, methacrylated dextran (dex-MA) and hydroxyethyl-methacrylated dextran (dex-HEMA), dextran-based hydrogel discs and microspheres, and their degradation products, was studied by measuring the cell proliferation inhibition index (CPII) on human fibroblasts in vitro. In addition, during the 72 h incubation period light-microscopic observations were performed daily. After 24 h of incubation with dextran and dex-HEMA polymers, the cells showed elongated or spider-like forms, some lipid droplets and intracellular granula, indicative of pinocytosis and internalization of the polymers. During the next two days, the fibroblasts' appearance did not change. Methacrylic acid (MAA), formed by hydrolysis of dex-HEMA, did not influence the cell morphology. Dex-HEMA polymer solutions with a low and high degree of substitution (DS) at 100 mg/ml caused a CPII of 30-40% after 72 h. This is less than 10% growth inhibition per cell cycle and statistically not different from the CPII induced by 100 mg/ml dextran T40. Growth inhibition induced by MAA was also low. The various dex-MA hydrogel discs caused similar low growth inhibition. Interestingly, hydrogel microspheres of dex-MA and dex-(lactate-)HEMA caused a CPII of only 0-20% after 72 h. The results presented in this study demonstrate that methacrylate-derivatized dextran hydrogels show good biocompatibility in vitro making these degradable biomaterials promising systems for drug delivery purposes.

Biocompatible Materials↗

PubMed2002

A novel porous cells scaffold made of polylactide-dextran blend by combining phase-separation and particle-leaching techniques.

In this study, a kind of biodegradable material was developed by blending polylactide (PLA) with natural biodegradable dextran, and a novel sponge-like scaffold made of it was fabricated thereof using solvent-casting and particle-leaching technique. To obtain a uniform blend of PLA and dextran by simple solvent-casting method, hydroxyls of dextran should be protected via trimethylsilyl (TMS) groups to make dextran soluble in organic solvents. Benzene was found among the few solvents that could dissolve this TMS-protected dextran (TMSD) well, however, it was not a good solvent for PLA. Therefore, a homogeneous mixed solution of PLA and TMSD could be obtained when a mixture of dichloroform (DCM) and benzene (v/v = 6/4) was used. By this technique, PLA-dextran blend films and even PLA films were observed a microporous structure (pore size around 5-10 microm) formation throughout the films under scanning electron microscope (SEM). Scaffolds that were prepared by dissolving PLA and TMSD in mixed solvent of DCM and benzene and using salt as porogen, were observed the formation of micropores (pore size around 5-10 microm) in the cellular walls of macropores (pore size around 100-200 microm). This microporous structure was closely related to the phase separation occurring during films or foams formation, which was mainly due to the different solubility of PLA and TMSD in benzene, as well as the different evaporation rates of DCM and benzene. In comparison with PLA, the surface and bulk hydrophilicity of PLA-dextran blend films or foams were significantly improved after the TMS groups were removed in methanol, and the results of cell culture on these polymeric substrates exhibited an enhancement on cell attachment and proliferation.

3T3 Cells↗

PubMed1999

Insolubilization of water-soluble dextran.

In order to clarify the insolubilization mechanism of water-soluble dextran, comparison of water-soluble dextran and insoluble particles was carried out by detailed structural and surface chemical studies. The precipitate that form in bottled dextran solutions are composed of dextran itself, resulting from the interaction of dextran molecules (e.g., the formation of hydrogen bonds). Interaction of dextran molecules derived from a crystallized domain causes insolubilization from aqueous solution. In addition, the adsorption of dextran molecules on the air-liquid interface is the first step of insolubilization.

Calorimetry, Differential Scanning↗

PubMed1990

An in vitro and clinical comparison of corneal storage with chondroitin sulfate corneal storage medium with and without dextran.

The safety and efficacy of 1% dextran in Chondroitin Sulfate Corneal Storage Medium (CSM) in reducing corneal swelling after 4 degrees C storage was assessed in a corneal endothelial cell culture system. No difference was found in 3H-thymidine incorporation by cells incubated in either CSM-dextran medium or CSM medium alone. Subsequently, 21 pairs of corneas, stored in either CSM or CSM-dextran from 30 to 112 hours, were transplanted into 42 eyes of 42 patients, paired by diagnostic group and procedure. All CSM grafts and 19 of 21 CSM-dextran grafts were clear at 4 months with no primary donor failures in either group. Intraoperative corneal thickness was significantly greater in the CSM group (0.82 +/- 0.07 mm) than the CSM-dextran group (0.76 +/- 0.06 mm); however, the two groups did not differ thereafter. No differences in all endothelial morphometric parameters were noted between the two groups pre- and postoperatively. Average endothelial cell loss by 4 months was 13.0 +/- 16.4% for the CSM group and 16.4 +/- 15.5% for the CSM-dextran group. The addition of dextran to CSM medium results in significant intraoperative corneal thinning without adversely affecting endothelial DNA synthesis in vitro and endothelial survival in vivo.

Adult↗

PubMed2002

Time-programmed pulsatile release of dextran from calcium-alginate gel beads coated with carboxy-n-propylacrylamide copolymers.

Time-programmed release of macromolecular drugs was achieved by utilization of calcium-alginate gel beads modified with coated copolymer layers. Modified calcium-alginate gel beads coated with poly(carboxy-n-propylacrylamide-co-dimethylacrylamide) [poly(CNPAAm-co-DMAAm)] (22.7 mol% of CNPAAm) of varying coating thickness from 25 to 125 microm were developed as drug carriers. Model macromolecular drugs used were fluorescein isothiocyanate (FITC)-labeled dextrans with different molecular weights ranging from 9400 to 145000. FITC-dextran release was strongly dependent on both copolymer coating thicknesses and the dextran molecular weights. Release of FITC-dextran (MW 9400) followed Fickian diffusion according to t(1/2) dependence, indicating that the drug diffusion is the main driving force for release of dextran MW 9400. Release of higher molecular weight FITC-dextrans (71,00 and 145,00) exhibited a burst-effect preceded by a preset lag time. These release profiles were governed by the dissociation of calcium ions from polyguluronate sequences in alginate molecules along with the diffusion of sodium ions into the gel bead core. This created osmotic pressure inside the gel, inducing breakage of the coated copolymer layer and accelerated drug release. Burst release of macromolecular drugs thus occurred after a certain lag period. The lag time was regulated by the copolymer coat thickness. A pulsatile release of FITC-dextran was demonstrated by combining a series of modified alginate gel beads in a single batch.

Acrylic Resins↗

PubMed1999

Synthesis and pharmacokinetics of a novel macromolecular prodrug of Tacrolimus (FK506), FK506-dextran conjugate.

A novel macromolecular prodrug of Tacrolimus (FK506), FK506-dextran conjugate, was developed and its physico-chemical, biological and pharmacokinetic characteristics were studied. The conjugate was estimated to contain 0.45% of FK506 and the coupling molar ratio was approximately 1:1 (dextran-FK-506). Adsorption experiments using ion exchangers indicated that FK506-dextran conjugate acted as a weakly negatively charged macromolecule. Low molecular weight radioactive compound(s), which was eluted in the same fractions as [(3)H]FK506, was released from [(3)H]FK506-dextran conjugate by chemical hydrolysis with a half-life of 150 h in phosphate buffer. In vitro immunosuppressive activity of the conjugate, as assessed by the rat lymphocyte stimulation test, was almost comparable to that of free FK506, suggesting that biologically active FK506 could be liberated from the conjugate. In vitro biodistribution studies demonstrated that conjugation with the dextran derivative dramatically changed the pharmacokinetic properties of FK506 after intravenous injection in rats. AUC of the FK506-dextran conjugate was almost 2000 times higher than that of free FK506 and organ uptake clearances of the conjugate were significantly smaller than those of the free drug. Thus, the present study has demonstrated that the FK506-dextran conjugate behaves as a prodrug of FK506 with an extended blood circulating time and can be expected to have an improved therapeutic potency.

Animals↗

PubMed1999

Targeting of tumor necrosis factor to tumor by use of dextran and metal coordination.

Tumor targeting of recombinant human tumor necrosis factor alpha (TNF) and consequently an enhanced anti-tumor effect were achieved through conjugation with dextran having metal chelating, diethylenetriaminepentaacetic acid (DTPA) residues based on metal coordination. A simple mixing with the DTPA-dextran in an aqueous solution containing Cu2+ enabled TNF to coordinately conjugate to dextran. Following intravenous (i.v.) injection into tumor-bearing mice, the TNF-DTPA-dextran conjugate caused a significantly higher tumor accumulation of TNF and the longer retention period than free TNF or its mixture with the DTPA-dextran. Intravenous injection of the TNF-DTPA-dextran conjugate suppressed tumor growth to a significantly greater extent than that of free TNF at a lower injection dose. It is concluded that dextran conjugation based on Cu2+ coordination is a promising way to enhance the anti-tumor effect of TNF as a result of its passive tumor targeting.

Animals↗

PubMed1999

Sodium ferric gluconate complex in sucrose: safer intravenous iron therapy than iron dextrans.

Use of recombinant human erythropoietin in patients with end-stage renal disease has highlighted iron deficiency as the major cause of resistant anemia. The current mainstay of intravenous (i.v.) iron replacement therapy, iron dextran, has been shown in prior studies to have a risk of serious life-threatening anaphylaxis of just under 1 per 100 patients exposed. The current study assessed the safety profile of an alternative i.v. iron, sodium ferric gluconate complex in sucrose (Ferrlecit), as compared with iron dextrans. Sodium ferric gluconate complex in sucrose, a unique chemical preparation, has been in use since 1959, principally in Europe, at a rate of approximately 2.7 million i.v. doses per year (1992 to 1996) in Germany and Italy alone. For iron dextran, usage in the United States was comparable--principally renal hemodialysis--and estimated from market sources at 3.0 million doses per year (1995). From 1976 to 1996, there were 74 allergic adverse events reported for sodium ferric gluconate complex in sucrose to the World Health Organization (WHO), German Health Bureau, and the manufacturer (all combined). For the years 1992 to 1996, sodium ferric gluconate complex in sucrose had an allergy event reporting rate of 3.3 allergy episodes per million doses per year compared with a similar rate of 8.7 reported allergy events per million doses per year for iron dextran in the United States in 1995. Case fatalities for sodium ferric gluconate complex in sucrose and iron dextran within these reports were then compared. For sodium ferric gluconate complex in sucrose, there were no reports of deaths over the entire period (1976 to 1996). However, for iron dextrans, there were 31 fatalities among 196 allergy/anaphylaxis cases reported in the United States between 1976 and 1996, yielding a case-fatality rate of 15.8%. These data show that sodium ferric gluconate complex in sucrose, when compared with iron dextrans in comparably sized patient usage populations with similar total rates of reporting of allergic events, has a significantly lower reported mortality rate (P < 0.001). Thus, the data justify usage of sodium ferric gluconate complex in sucrose as the safer iron replacement therapeutic agent.

Anaphylaxis↗

PubMed1989

High-performance size-exclusion chromatographic procedure for the determination of fluoresceinyl isothiocyanate dextrans of various molecular masses in biological media.

A high-performance size-exclusion chromatographic procedure, using Nucleosil Diol, for the quantitative analysis of fluoresceinyl isothiocyanate dextrans of various molecular masses (10,000-150,000) in biological media was developed. The influence of the molecular mass and the degree of substitution of the conjugates on the chromatographic behaviour are discussed. In addition to quantitation, the molecular mass of the conjugates with degree of substitution below 1.6 could be estimated from the chromatograms. Linear standard calibration curves were obtained at concentrations down to 0.050 micrograms ml-1 in rabbit plasma and urine and homogenates of rabbit liver, lymph node and muscle when the derivative (degree of substitution 0.85) was monitored by fluorescence detection (lambda ex = 493 nm, lambda em = 520 mm). The fluoresceinyl isothiocyanate dextrans were found to be stable for more than three days at 37 degrees in all biological media under investigation. A pH-rate profile for the alkaline hydrolysis of fluoresceinyl isothiocyanate dextrans was constructed. The applicability of the method to pharmacokinetic studies was demonstrated by recording the plasma concentration-time profile of a fluoresceinyl isothiocyanate dextran T-70 conjugate following intravenous injection to a rabbit. In relation to future pharmacokinetic investigations on dextran conjugates, the results reported indicate that labelling of the parent dextran with fluoresceinyl isothiocyanate and monitoring of the fluoresceinyl isothiocyanate dextran conjugate throughout the organism using the described method is a promising development.

Animals↗

PubMed1998

Does dextran 40 improve the early patency of autogenous infrainguinal bypass grafts?

PURPOSE: We determined whether the administration of dextran 40 would increase the early (30-day) patency of autogenous infrainguinal bypass grafts. METHODS: During a 4-year period, 244 patients undergoing 273 autogenous infrainguinal bypass grafts were prospectively enrolled into and completed this study. Patients were randomized into two groups; one of the groups received a 72-hour infusion of dextran 40 after surgery, and the other did not. Comparisons were made between those patients who did and did not receive dextran 40 with respect to risks factors, demographics, and early graft patency. RESULTS: One hundred twenty-six procedures were accompanied by the use of dextran; 147 were not. There was no significant difference between the two groups with respect to patient age, gender, perioperative risk factors, indication for surgery, or location of bypass graft (popliteal vs tibial). Among those patients receiving dextran, there were eight early occlusions (6.4%) and four deaths (3.2%); 89.7% of the patients were alive with patent grafts 30 days after surgery. In the group not receiving dextran, there were 10 early occlusions (6.8%) and 3 deaths (2%); 90.5% of the patients were alive with patent grafts 30 days after surgery. There was no significant difference between the two groups with respect to rate of early occlusion (p = 1.00), death (p = 0.71), or 30-day patency (p = 0.84). CONCLUSIONS: The administration of dextran 40 does not increase the early patency of autogenous infrainguinal bypass grafts. Its routine use during these procedures cannot be recommended.

Adult↗

PubMed1990

Does dextran 40 reduce early graft thrombogenicity? An experimental investigation on patency and platelet deposition on prosthetic graft materials in sheep.

The mechanism by which dextran 40 reduces early graft thrombogenicity has not been fully elucidated. Dextran improves haemaodynamics, reduces platelet aggregation, alters fibrin formation and enhances thrombus lysis. In this experimental investigation on sheep using a low flow model, the thrombogenicity of various grafts was studied when either a dextran or saline infusion was given. Bilateral carotid interposition grafts with expanded polytetrafluorethylene (ePTFE) on one side and dacron on the other (random allocation) were inserted in 12 sheep. The sheep were randomly divided into two groups, one given a dextran infusion and the other saline. A tendency for improved graft patency was seen in the dextran 40 treated animals (P less than 0.05 at 3 h). However, platelet accumulation did not differ markedly between the dextran 40 and saline treated groups. On the other hand there was a clear reduction of platelet accumulation on ePTFE grafts compared to dacron grafts (P less than 0.01). A large part of the radioactivity measured from the dacron graft was located within the graft wall. Further studies to clarify the mechanism of action of dextran are needed.

Animals↗

PubMed2001

[(99m)Tc]MAG(3)-mannosyl-dextran: a receptor-binding radiopharmaceutical for sentinel node detection.

Technetium-99m-labeled benzoyl-mercaptoacetylglycylglycyl-glycine-mannosyl-dextran ([(99m)Tc]MAG(3)-mannosyl-dextran) is a receptor-binding radiotracer that binds to mannose-binding protein, a receptor expressed by recticuloendothelial tissue. This agent is composed of a 10.5-kilodalton molecule of dextran and multiple units of mannose, and benzoyl-mercaptoacetylglycylglycyl-glycine (BzMAG(3)). The tetraflorophenol-activated ester of BzMAG(3) and the imidate of thiomannose were used to covalently attach BzMAG(3) and mannose to an amino-terminated conjugate of dextran. This yielded a 19-kilodalton macromolecule consisting of 3 BzMAG(3) and 21 mannose units per dextran. Dynamic light scattering was used to measure a mean diameter of 5.5 nanometers for BzMAG(3)-mannosyl-dextran and 0.28 microns for filtered Tc-99m sulfur colloid. A preliminary sentinel node detection study employing right fore and hind footpad injections of [(99m)Tc]MAG(3)-mannosyl-dextran and left fore and hind footpad injections of filtered Tc-99m sulfur colloid demonstrated greater sentinel lymph node uptake by the receptor-binding agent.

Animals↗

PubMed2001

The potentiation of human C1-inhibitor by dextran sulphate is transient in vivo: studies in a rat model.

C1-inhibitor (C1-Inh) is an important regulator of inflammatory reactions because it is a potent inhibitor of the contact and complement system. C1-Inh application in inflammatory disease is, however, restricted because of the high doses required. The glycosaminoglycan-like molecule dextran sulphate (DXS) enhances C1-Inh function in vitro. Hence, we investigated whether co-administration with dextran sulphate reduces the amount of C1-Inh required, through enhancement in vivo. C1-Inh potentiation was measured in a newly developed C1s-inactivation assay that is based on activation of C4 by purified C1s. Activated C4 in rat plasma was quantified with a newly developed ELISA. Human C1-Inh (2.5 microM) inhibited C1s in rat plasma 55-fold faster in the presence of dextran sulphate (15 kDa, 5 microM). To study the stability of the complex in vivo, rats were given a mixture of C1-Inh (10 mg/kg) and dextran sulphate (3 mg/kg). C1-Inh activity during 5 h was analyzed ex vivo with the C1s inactivation assay. The noncovalent C1-Inh-dextran sulphate complex resulted in a transient enhancement of the inhibitory capacity of C1-Inh, lasting for 60-90 min. Dextran sulphate did not affect plasma clearance of C1-Inh. We conclude that the enhanced inhibitory capacity of C1-Inh complexed to dextran sulphate is transient in vivo. Hence, co-administration of these compounds seems a feasible approach to achieve short-term inhibition of complement in vivo.

Animals↗

PubMed2000

In vitro fermentability of dextran, oligodextran and maltodextrin by human gut bacteria.

Anaerobic batch culture fermenters were used for a preliminary screening of the in vitro utilization by human gut microflora of dextran and novel oligodextrans (I, II and III) produced in the University of Reading (UK). Glucose and fructooligosaccharides (FOS) were used as reference carbohydrates. As expected, FOS acted as a good prebiotic in that it selectively increased numbers of bifidobacteria in the early stages of the fermentation. Dextran and oligodextrans each resulted in an enrichment of bifidobacteria in the batch cultures, with high levels of persistence up to 48 h. They also produced elevated levels of butyrate ranging from 5 to 14.85 mmol/l. To more effectively simulate conditions that prevail in different regions of the large intestine, a three-stage continuous culture cascade system was used to study further the fermentation of dextran, a low-molecular-mass oligodextran (IV) and maltodextrin. Oligodextran IV was shown to be the best substrate for bifidobacteria and lactobacilli with steady-state populations of bifidobacteria and lactobacilli being higher in all three vessels of the gut model than the respective populations resulting from dextran and maltodextrin. A maximum difference of 1.9 log was observed in vessel 1 for both bifidobacteria and lactobacilli in the case of dextran fermentation, with 1.4 log and 0.8 log in vessel 3 were the maximum differences for bifidobacteria and lactobacilli when maltodextrin was used as the carbohydrate source. Moreover, dextran and oligodextran appeared to stimulate butyrate production, with a maximum production up to 25.39 mmol/l in vessel 3 when fermenting dextran, followed by 21.70 mmol/l in the case of oligodextran IV and only 12.64 mmol/l in the case of maltodextrin.

Bifidobacterium↗

PubMed1999

A fluorescence-based glucose biosensor using concanavalin A and dextran encapsulated in a poly(ethylene glycol) hydrogel.

A fluorescence biosensor is described that is based on a photopolymerized poly(ethylene glycol) (PEG) hydrogel incorporating fluorescein isothiocyanate dextran (FITC-dextran) and tetramethylrhodamine isothiocyanate concanavalin A (TRITC-Con A) chemically conjugated into the hydrogel network using an alpha-acryloyl, omega-N-hydroxysuccinimidyl ester of PEG-propionic acid. In the absence of glucose, TRITC-Con A binds with FITC-dextran, and the FITC fluorescence is quenched through fluorescence resonance energy transfer. Competitive glucose binding to TRITC-Con A liberates FITC-dextran, resulting in increased FITC fluorescence proportional to the glucose concentration. In vitro experiments of hydrogel spheres in a solution of 0.1 M phosphate-buffered saline (pH 7.2) and glucose were conducted for multiple TRITC-Con A/FITC-dextran ratios. Hydrogels were characterized on the basis of the percent change in fluorescence intensity when FITC-dextran was liberated by increasing glucose concentrations. The optimum fluorescent change between 0 and 800 mg/dL was obtained with a TRITC-Con A/FITC-dextran mass ratio of 500:5 micrograms/mL PEG. Fluorescent response was linear up to 600 mg/dL. At higher concentrations, the response saturated due to the displacement of the majority of the FITC-dextran and to concentration quenching by free FITC-dextran. Dynamic fluorescent change upon glucose addition was approximately 10 min for a glucose concentration step change from 0 to 200 mg/dL.

Biosensing Techniques↗

PubMedDate not supplied

Effects of dextranation on the pharmacokinetics of short peptides. A PET study on mEGF.

The effects of dextranation on the biodistribution of mouse epidermal growth factor (mEGF, 6 kDa) were assessed. By reductive amination, mEGF was coupled to 13 and 46 kDa dextran. The two dextranated conjugates and free mEGF were labeled with the positron-emitting nuclide (76)Br (T(1/2) = 16 h). After intravenous administration to Sprague Dawley rats, the radioactivity biodistribution was evaluated by positron emission tomography (PET) and by measurements of dissected tissues. The dextranation prolonged the retention time in blood, especially when the dextran chain was long. [(76)Br]mEGF-dextran conjugates were shown to have significantly, more than 5 times, lower kidney accumulation than the nonconjugated [(76)Br]mEGF. In conclusion, dextranation affects the biodistribution of mEGF in vivo giving a prolonged circulation time, a decreased uptake in kidney, and an increased spleen accumulation.

Animals↗

PubMedDate not supplied

Optimization and characterization of dextran membranes prepared by electrospinning.

Dextran is soluble in both water and organic solvents, so it could be a versatile biomacromolecule for preparing nanofibrous electrospun membranes by blending with either water-soluble bioactive agents or hydrophobic biodegradable polymers for biomedical applications. We have formulated electrospun dextran membranes, and the effects of various processing parameters on the membrane properties were investigated. It was found that uniform nanofibrous dextran membranes could be formed by using water, DMSO/water, and DMSO/DMF mixtures as solvents through adjusting the processing conditions (solution concentration, voltage, and the distance between the electrode and the collecting plate). When water was used as a solvent, up to 10% (w/w) of bovine serum albumin (BSA) or lysozyme could be directly incorporated into the dextran electrospun membrane without compromising its morphology. No significant effect of the electrospinning process on lysozyme activity was observed. The composite electrospun membranes consisting of poly(D,L-lactide-co-glycolide) (PLGA) and dextran were obtained using DMSO/DMF (50/50, volume ratio) mixture as solvents. For cross-linking the electrospun membrane, dextran was modified by substitution of methacrylate groups at the hydroxyl sites. It was found that the electrospun membranes prepared from methacrylated dextran can be cured by UV irradiation in the presence of 1% of 2,2-dimethoxy-2-phenylacetophenone (DMPA) as a photoinitiator.

Animals↗