Cellophane Membrane Research Articles

Development of Novel Lyophilized Mixed Micelle Amphotericin B Formulation for Treatment of Systemic Fungal Infection

The purpose of the study was to develop a stable, controlled release Amphotericin B (Amph B) lyophilized mixed micelle (MM) formulation using hydrogenated soya phosphatidylcholine (HSPC) and bile salts in monomeric form and evaluate it for therapeutic performance and side effects. The MM formulations of Amph B were prepared using sodium deoxycholate (NDC)/sodium taurocholate (NTC)/sodium cholate (NC), and HSPC. The optimization of bile salt: HSPC ratio in the MM formulation was done using 2(4) factorial designs. MM formulations were lyophilized using sucrose as a cryoprotectant and analyzed for per cent micelle yield, per cent drug loading and per cent entrapment efficiency. Comparative in vitro diffusion studies, hemolytic activity, and minimum inhibitory concentration (MIC) of developed MM formulations and marketed formulation (Fungizone) were evaluated using cellophane membrane, human red blood cells and Candida albicans respectively. In vivo studies of MM formulations were also carried out on Candida albicans infected white albino rats and compared with Fungizone. The optimized molar ratio of bile salt: HSPC was found to be 8:11. Among all MM formulations prepared, NDC/ HSPC formulation found to have maximum per cent drug loading (4.96+/-0.8%), per cent entrapment efficiency (93.2+/-1.5%) and per cent micelle yield (96.4+/-1.4%). The in vitro drug diffusion studies of developed MM formulations show close to zero-order diffusion kinetics. All MM formulations show improved therapeutic index and reduced side effects compared to reference formulation Fungizone. The NDC/HSPC MM formulation was found to have least hemolytic activity, MIC and mortality rate at all dosage levels. Improved antifungal activity and reduced toxicity of Amph B solubilized in MM may be due to higher cellular uptake of the drug by fungal cells of infected tissues from MM formulations. Hence, Amph B MM formulation could be a safe and effective viable alternative in the treatment of systemic fungal infections.

Enhancement of the release of azelaic acid through the synthetic membranes by inclusion complex formation with hydroxypropyl-β-cyclodextrin

The aim of this study was to investigate the release rates of azelaic acid and azelaic acid-hydroxypropyl-β-cyclodextrin (HPβCD) inclusion complex through three types of synthetic membranes, namely cellophane, silicone and elastomer membranes. Solid inclusion complexes of azelaic acid-HPβCD at the molar ratio of 1:1 were prepared by coevaporation and freeze-drying methods, subsequently characterized by differential scanning calorimetry, X-ray diffractometry and dissolution studies. Solid inclusion complex obtained by coevaporation method which exhibited the inclusion of azelaic acid in the HPβCD cavity and gave the highest dissolution rate of azelaic acid was selected for the release study. Release studies of azelaic acid and this complex through the synthetic membranes were conducted using vertical Franz diffusion cells at 30 °C for 6 days. The release rates of azelaic acid through the synthetic membranes were enhanced by the formation of inclusion complex with HPβCD at the molar ratio of 1:1, with the increasing fluxes of about 41, 81 and 28 times of the uncomplexed system in cellophane, silicone and elastomer membranes, respectively. The result from this study can be applied for the development of azelaic acid for topical use.

Synthesis and Antimicrobial Activity of Oxacillin Polyesters

Water-soluble polymeric esters (polyesters) of oxacillin, based on linear poly(N-2-hydroxypropyl methacrylamide) poly(HPMA) and branched biodegradable poly(HPMA) containing interchain labile urethane bonds, have been synthesized and characterized with respect to composition, homogeneity, molecular weight (MW), and antimicrobial activity. The hydrolysis kinetics of oxacillin polyester, based on branched poly(HPMA) with MW = 71000 at 37°C, was studied in a physiological solution at pH 7.0 and in a buffer at pH 2.0 using the method of dialysis through a cellophane membrane. Under these conditions, oxacillin polyester is hydrolyzed at a high rate (especially in an acid medium), which provides for a prolonged antimicrobial activity of oxacillin. All oxacillin polyesters exhibit considerable antimicrobial activity with respect to St. aureus.

Solid Lipid Nanoparticles Bearing Flurbiprofen for Transdermal Delivery

Topical application of the drugs at the pathological sites offer potential advantages of delivering the drug directly to the site of action and thus producing high tissue concentrations of the drug. The solid lipid nanoparticles (SLN) bearing flurbiprofen were prepared by microemulsion method by dispersing o/w microemulsion in a cold aqueous surfactant medium under mechanical stirring. The SLN gel was prepared by adding SLN dispersion to polyacrylamide gel prepared by using polyacrylamide (0.5%), glycerol (10%), and water (69.5%). Shape and surface morphology was determined by scanning electron microscopy that revealed fairly spherical shape of the formulation. Percent drug entrapment was higher in SLN dispersion in comparison to SLN gel formulations. In vitro drug release, determined using cellophane membrane, showed that SLN dispersion exhibited higher drug release compared with SLN gel formulations. Both the SLN dispersion and SLN-gel formulation possessed a sustained drug release over a 24-hr period, but this sustained effect was more pronounced with SLN-gel formulations. The percent inhibition of edema after 8 hr was 55.51 ± 0.26% in case of SLN-T4-gel, whereas flurbiprofen and SLN-T4 dispersion exhibited 28.81 ± 0.46 and 31.89 ± 0.82 inhibition of edema. The SLN-T4-gel not only decreased the inflammation to larger magnitude, but also sustained its effect.

広範囲周波数の交流通電によるリドカインのセロハン膜透過

This study examined whether lidocaine molecules can be transported through an artificial membrane by the application of AC. A cellophane membrane was placed between donor and receptor compartments. The donor compartment was filled with lidocaine hydrochloride (40 and 60 mmol/l) and the receptor compartment with pure water. A sine wave at 5 voltage levels and 5 frequencies was applied between the parallel plate electrodes. The impedance of the solution in the receptor compartment was measured to determine the concentration of the lidocaine. The transportation efficiency in the condition of high concentration was markedly enhanced with the application of 15 and 20 V at every frequency. Although no frequency dependence was observed in the 500 Hz to 100 kHz range, the transportation efficiency was markedly enhanced at 1 MHz. It is considered that lidocaine ions are transported by vibration or rotation energy induced by AC. The formation of electrode polarization is decreased in the high-frequency range resulting in attenuation of the voltage drop in the solution and increase of the transportation efficiency with the passage of AC.

Utility of a cultural method for identification of the ericoid mycobiont Oidiodendron maius confirmed by ITS sequence analysis

A simple cultural method was investigated for its reliability in distinguishing the ericoid mycobiont Oidiodendron maius from selected other species of Oidiodendron. Forty three isolates were grouped by morphology after 28 d growth on cereal agar overlaid with a cellophane membrane. All isolates of O. maius and its close relative O. citrinum expressed characteristic colonial morphologies allowing recognition regardless of sporulation. Isolates grouped by colonial features correlated with strongly supported groupings obtained by analysis of nuclear ribosomal internal transcribed spacer (ITS) region sequences, including O. maius with O. citrinum, O. griseum with O. flavum, and O. truncatum as an independent group. Isolates of O. tenuissimum, including the ex-type of the purported synonym O. fuscum, demonstrated cultural variation and were dispersed among several different groups in the ITS analysis. O. fuscum is here regarded as a distinct taxon.

The Relation Between Swelling Properties and Cross-Linking of Hydrogels Designed for Colon-Specific Drug Delivery

Copolymers of 2-hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA)-based hydrogels containing 5% and 10% of a cross-linking agent were studied as drug delivery systems. Terephthalic acid was covalently linked with HEMA, abbreviated as CA (cross-linking agent). Free radical cross-linking copolymerization of HEMA and methacrylic acid (MAA) in three different molar ratios, mixed with a particulate 3, 3-azobis (6-hydroxy benzoic acid) (ABHB) as an azo derivative of 5-aminosalicylic acid with the various ratios CA as cross-linking agent were carried out with using 2, 2, Azobisisobutyronitrile as initiator at the temperature range 60–70°C. The compositions of the cross-linked three-dimensional polymers were determined by FTIR spectroscopy. Glass transition temperature of the network polymers was determined calorimetrically. The hydrolysis of drug-polymer conjugates was carried out in cellophane membrane dialysis bags containing an aqueous buffer solution (pH 7.4 and pH 1) at 37°C. The drug-release profiles indicate that the amount of drug release depends on its degree of swelling and cross-linking.

Solubility Enhancement of Indomethacin with Poly(amidoamine) Dendrimers and Targeting to Inflammatory Regions of Arthritic Rats

This work includes investigation on solubility enhancement of indomethacin (IND) in the presence of poly(amidoamine) (PAMAM) dendrimers and passive targeting of the PAMAM/IND complex so formed to the inflamed regions in an animal model. The complex formation was confirmed by infrared and 1H nuclear magnetic resonance spectroscopy methods. Solubility of IND in aqueous G4-PAMAM followed Higuchi's AN curve depending on pH of the solubilizing medium. The solubility was decreased upon addition of dendrimer to the IND saturated solution at various pH, indicating aggregation behavior of the PAMAM/IND complex and conforming to the Higuchi's AN solubility profile. The in vitro release of IND from the PAMAM/IND complex through a cellophane membrane, from a Franz diffusion cell, showed 79±3.2% drug release in 24 h. The drug release was further retarded in the presence of human serum albumin (HSA) suggesting the significance of complex HSA binding in altering in vivo behavior of the complex. Intravenous administration of the PAMAM/IND complex formulation in rats showed a two-compartment pharmacokinetic profile. Enhanced effective IND concentrations in the inflamed regions were obtained for the prolonged time period with the PAMAM/IND complex compared to the free drug in arthritic rats indicating preferred accumulation of IND to the inflamed region. The targeting efficiency of PAMAM/IND complex was 2.29 times higher compared to free drug. In contrast to the previous investigations, two interesting findings reported here are: (a) solubility behavior of IND in G4-PAMAM dendrimer deviates from linearity with increasing concentrations of dendrimer at acidic to neutral pH values and (b) inspite of lymphatic drainage, retention of PAMAM/IND complexes occurs at the inflammatory site.

Independent genetic mechanisms mediate turgor generation and penetration peg formation during plant infection in the rice blast fungus.

The first barrier to infection encountered by foliar pathogens is the host cuticle. To traverse this obstacle, many fungi produce specialized infection cells called appressoria. MST12 is essential for appressorium-mediated penetration and infectious growth by the rice pathogen Magnaporthe grisea. In this study, we have characterized in detail the penetration defects of an mst12 deletion mutant. Appressoria formed by the mst12 mutant developed normal turgor pressure and ultrastructure but failed to form penetration pegs either on cellophane membranes or on plant epidermal cells. Deletion and site-directed mutagenesis analyses indicated that both the homeodomain and zinc finger domains, but not the middle region, of MST12 are essential for appressorial penetration and plant infection. The mst12 mutant appeared to be defective in microtubule reorganization associated with penetration peg formation. In mature appressoria, the mutant lacked vertical microtubules observed in the wild type. The mst12 mutant also failed to elicit localized host defence responses, including papilla formation and autofluorescence. Our data indicate that generation of appressorium turgor pressure and formation of the penetration peg are two independent processes. MST12 may play important roles in regulating penetration peg formation and directing the physical forces exerted by the appressorium turgor in mature appressoria.

Effect of radiation and thermal treatment on structural and transport parameters for cellulose regenerated membranes

Modifications caused by different types of ionizing radiation and thermal treatment on transport, chemical and structural parameters of polymeric (regenerated cellulose) membranes have been studied. Particularly, the effect of different types of radiation (ultraviolet light (UV) and ionising radiation (Ir) with different doses) and heating at 60°C on transport and electrical parameters for a cellophane membrane has been considered by determining salt permeability and electrical resistance for the different samples. These parameters were obtained from salt diffusion and impedance spectroscopy (IS) measurements with the membranes in contact with NaCl solutions at different concentrations. Chemical surface and structural modifications of the polymer matrix due to the treatments have also been determined by X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (ATR mode).Results obtained from infrared spectroscopy seem to indicate that ionising radiation modifies the proportion of OH links, which is related to the dose of irradiation. XPS analysis only shows small differences in the atomic concentration and shape of the C 1s spectra. On the other hand, an increase of salt permeability for heated and UV-treated membranes was obtained, while this parameter decreases in the case of irradiated membranes. This result could be related to a change in the packing of the polymer chains, which results in an increase of the fractional void volume in the case of heat- and UV-treated membranes and the opposite effect for the irradiated ones; for these latter, a correlation between the irradiation dose and the decrease in permeability values was also obtained. IS results show a decrease in the electrical resistance of all treated samples. This fact can be due to the most open structure of heated and UV-treated samples, previously indicated; however, due to the closer structure assumed for the irradiated sample, this point might be related to the presence of free radicals in agreement with ATR results.

Vehicle effects on in vitro release of tiaprofenic acid from different topical formulations

The aim of the present study was to investigate the in vitro release properties of tiaprofenic acid (TA) from different topical vehicles. Carbopol ® 940 gel, chitosan gel, two types of emulsion-based ointment formulations (o/w and w/o) and hydrophilic petrolatum USP were prepared with 2% drug content. Drug release from all vehicles through a standard cellophane membrane was evaluated by using Franz-type diffusion cells. In vitro release study results showed that the diffusion coefficients of the drug from vehicles rank according to the following order: Carbopol ® 940 gel ( D = 3.11 × 10 –7 ± 0.54 cm 2/s) > chitosan gel ( D = 0.27 × 10 –7 ± 0.08 cm 2/s) > emulsion-based ointment (o/w) ( D = 0.18 × 10 –7 ± 0.05 cm 2/s) > emulsion-based ointment (w/o) ( D = 0.13 × 10 –7 ± 0.02 cm 2/s) > hydrophilic petrolatum USP ( D = 0.02 × 10 –7 ± 0.01 cm 2/s). Carbopol ® 940 gel base showed significantly higher drug release than other vehicles ( P < 0.001). These results indicated that Carbopol ® 940 gel base is a good candidate for the topical delivery of TA, giving significantly higher drug release than the other vehicles.

Controlled Release of Biomolecules from pH-sensitive Network Polymers Prepared by Radiation Polymerization

Copolymers of 2-hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA) based hydrogels containing 5 and 10% of a cross-linking agent were studied as drug delivery systems. Terephthalic acid was covalently linked with HEMA, abbreviated as CA. Radiation copolymerization of HEMA and MAA, mixed with a particulate glibenclamide with the various ratios CA as crosslinking agent were carried out at the room temperature. The structure of the CA was confirmed by FTIR, 1H NMR and 13C NMR spectroscopy. The compositions of the cross-linked three-dimensional polymers were determined by FTIR spectroscopy. Glass transition temperature (Tg) of the network polymers was determined calorimetrically. The hydrolysis of drug-polymer conjugates was carried out in cellophane membrane dialysis bags containing an aqueous buffer solution (pH 7.4 and pH 1) at 37°C. The drug-release profiles indicate that amount drug release depends on their degree of swelling and cross-linking.

Determination of trace elements in serum samples by isotope dilution inductively coupled plasma mass spectrometry using on-line dialysis

An on-line dialysis flow system coupled to inductively coupled plasma mass spectrometry to determine trace elements in serum samples by isotope dilution is presented. Isotope dilution was performed on samples incubated with enriched 65Cu, 66Zn, 77Se and 206Pb for 24 h at 36 °C prior to dialysis to quantified total element concentrations. The sample and acceptor solutions flowed through the dialysis unit with cellophane membrane placed in between the compartments. The serum sample (1 mL) was left to recycle in a closed path while the acceptor solution was continuously pumped along the dialyzer channel and through a cationic AG50W X-8 resin column. After 10 min, around 70% of Na, K and Cl migrate from the sample. Three replicate injections of 0.1 mL were performed for the clean sample after each separation step. The on-line coupling of the dialyzer to ICP-MS allowed isotope dilution for total element determination either in the cleaned sample or by eluting the cations retained in the resin to be carried out. Results demonstrated no matrix effects from alkaline elements or spectral interference from ArNa+ on 63Cu, ArCl+ on 77Se and 34SO2+ on 66Zn. The precision of isotope ratio measurements for Cu and Zn was around 1% and for Se and Pb was around 2.5%. The values found for the reference serum sample IMEP-17 were in good agreement with the certified values for Cu, Zn and Se.

Visual characterization of the extracellular matrix of Cochliobolus heterostrophus and a mutant strain with a modified matrix

Two layers of extracellular matrix (ECM) and a film secreted outside the layers were visualized on germlings of Cochliobolus heterostrophus Drechsler grown on glass slides, cellophane membranes, and the surface of maize leaves. A mutant of C. heterostrophus, less virulent than the wild type, possessed the inner layer of ECM and the film, but not the outer layer. Using cytochemical and morphological methods, we explored the hypothesis that the reduced virulence of the mutant in leaves was due to the absence of the outer layer of the ECM. All ECMs were characterized using ruthenium red fixation, cryopreservation, immunocytochemistry, and colloidal gold labeling, before being examined with light and electron microscopy. With immunocytochemistry, antigens were localized in islands stained with ruthenium red within the scaffolding of the outer layer of the wild-type ECM on leaf surfaces and within the leaf. In the mutant, antigens were localized in the film on leaf surfaces. Comparisons between leaves infected by the two strains showed hyphae to be enclosed within material interpreted to be host response within intercellular spaces of leaves infected by the mutant, but not the wild type.Key words: Cochliobolus, cytochemistry, extracellular matrix, microscopy, mutant, virulence.

Linear Type Azo-Containing Polyurethanes for Colon-Specific Drug Delivery

New biodegradable polyurethanes containing azo-linked polymeric prodrugs of 5-aminosalicylic acid (5-ASA) in the main chain were prepared by reacting 1,6-Hexamethylenediisocyanate (HDI) with 3,30-azobis(6-hydroxy benzoic acid) (ABHB) and 5-[4-(hydroxyl phenyl) azo] salicylic acid (HPAS) as azo derivatives of 5-ASA. The polymers were characterized by FTIR and 1H-NMR spectroscopy. The hydrolysis of polyurethane containing azoderivatives of 5-ASA was carried out in cellophane membrane dialysis bags containing aqueous buffer solution (pH 1/4 8.5 and pH 1/4 1) at 37 C. Detection of the hydrolysis product by UV spectroscopy showed that ABHB and HPAS were released by the hydrolysis of the urethane bond in the polymer chain.

Controlled‐release of drugs from cross‐linked polymers containing cubane as a crosslinking agent

AbstractTwo anti‐inflammatory drugs, indomethacin and aspirin together with cubane‐1, 4‐dicarboxylic acid (CDA) were covalently linked with 2‐hydroxyethyl methacrylate (HEMA). The drug‐linked HEMA (indomethacin‐linked HEMA) is abbreviated as HI, aspirin‐linked HEMA as HA and cubane‐1, 4‐dicarboxylic acid (CDA) linked to two HEMA group is the cross‐linking agent (CA). A difunctional spacer group was introduced between the drugs and acrylic moiety of the monomer through a hydrolyzable ester linkage. Free radical cross‐linking polymerization of the monomers with drug effect was carried out in dioxane solution at various CA ratios, using AIBN as initiator in the temperature range 60‐70°C. The compositions of the cross‐linked three‐dimensional polymers were determined by FT‐IR spectroscopy. The glass transition temperature (Tg) of the network polymers was determined calorimetrically. The hydrolysis of drug‐polymer conjugates was carried out in cellophane membrane dialysis bags containing an aqueous buffer solution (pH 8 and pH 1) at 37°C. Detection of the hydrolysis product by UV spectroscopy shows that the drugs were released by hydrolysis of the ester bond located between the drug and spacer group.

Physiology of a colony of Pleurotus pulmonarius grown on medium overlaid with a Cellophane membrane.

The physiology of a colony of Pleurotus pulmonarius grown on potato dextrose agar overlaid with a Cellophane membrane (PDA-WC) was studied. On PDA-WC, the colony presented higher biomass density and productivity of fruit body formation (4.84+/-0.23 mg mycelial biomass/cm2 and 23.7+/-3.12 microg ml(-1) h(-1), respectively) than that which developed on potato dextrose agar without Cellophane (PDA-OC; 0.26+/-0.01 mg mycelial biomass/cm2 and 10.8+/-1.57 microg ml(-1) h(-1), respectively). In cultures developed on PDA-WC, intracellular laccases and beta-1,3-glucanases activities were lower [12+/-0.9 arbitrary units (AU)/g mycelial biomass and 1.33+/-0.1 international units (IU)/g mycelial biomass, respectively] than those observed on PDA-OC (20.65+/-1.0 AU/g mycelial biomass and 3.67+/-0.2 IU/g mycelial biomass, respectively). In cultures developed on PDA-WC, intracellular protein and glycogen concentrations were lower (1.9+/-0.9 and 117+/-3.5 mg/g mycelial biomass, respectively) than those observed on PDA-OC (14.3+/-1.1 and 347+/-2.9 mg/g mycelial biomass, respectively). The radial growth rate and the content of glucans in the cell wall were not significantly different between cultures developed on PDA-WC and PDA-OC. These results show that the use of the Cellophane as a tool to study in vitro fungal physiology might affect the interpretation of experimental results, since the physiology under otherwise similar conditions was different on medium with and without Cellophane.

A study of temperature effect on chemical, structural and transport parameters determined for two different regenerated cellulose membranes

Chemical, structural and electrochemical characterizations of two cellophane membranes depending on both cellulose content (20 and 25 kg/m 2) and thermal treatment (60 °C during 4 h), have being carried out. Different transport parameters were determined by measuring water and salt fluxes, membrane potential and impedance spectroscopy using NaCl solutions at different concentrations. Chemical degradation of the membrane surfaces due to membrane heating was obtained from XPS spectra. Electrochemical results shown that treated and untreated samples behave as weak cation-exchangers, but small differences in their electrical parameters (membrane fixed charge concentration, cation transport number and electrical resistance) due to both the thermal treatment and the amount of cellulose were obtained. Results also indicate a more open structure for the membrane with higher content of cellulose. The influence of concentration/polarization layers on salt permeation was also studied by measuring salt diffusion at different stirring rates. Moreover, variation of water permeability with temperature for untreated samples seems indicate changes in the membrane structure around 40 °C, which was confirmed by differential scanning calorimetry (DSC) thermograms.

Preparation of new biodegradable polyurethanes as a therapeutic agent

Cubylamines and cubylmethylamines are of interest as antiviral agents. New biodegradable polyurethanes and polyetherurethanes having hydrolytically labile morphine groups as a therapeutic agent were prepared by reacting 1,4-diisocyanatocubane (DICC) with morphine. The polyetherurethanes containing morphine were prepared by reacting poly(ethylene glycol) with an excess of DICC to obtain a prepolymer which was reacted with morphine, which contains two hydroxyl groups. The structure of the polymers was confirmed by FTIR and 1H NMR spectroscopy. The hydrolysis of drug-polymer conjugates was carried out in cellophane membrane dialysis bags containing aqueous buffer solution (pH 8) at 37 °C. UV spectroscopy was used to show that both 1,4-diaminocubane (DAC) and morphine were released by hydrolysis of the polyurethane segments. The polyurethane drug conjugates have longer duration of activity, due to slow release of DAC and morphine.

The CBEL glycoprotein of Phytophthora parasitica var-nicotianae is involved in cell wall deposition and adhesion to cellulosic substrates.

The cell wall of the oomycete plant pathogen Phytophthora parasitica var. nicotianae contains a protein called CBEL that shows cellulose-binding (CB), elicitor (E) of defense in plants and lectin-like (L) activities. The biological role of this molecule in Phytophthora was investigated by generating transgenic strains suppressed in CBEL expression. Phenotypic characterization of these strains showed that they were severely impaired in adhesion to a cellophane membrane, differentiation of lobed structures in contact with cellophane, and formation of branched aggregating hyphae on cellophane and on flax cellulose fibres. Infection assays revealed that the strains suppressed in CBEL expression were not greatly affected in pathogenicity and formed branched aggregating hyphae in contact with the roots of the host plant, thereby indicating that CBEL is involved in the perception of cellulose rather than in the morphogenesis of hyphal aggregates. Interestingly, the absence of CBEL was correlated with abnormal formation of papillae-like cell wall thickenings in vitro, suggesting that CBEL is involved in cell wall deposition in Phytophthora. Reverse genetics in oomycetes has long been hampered by their diploid nature and difficulties in transformation and regeneration. The gene inactivation approach reported in this work provides the first direct evidence for intrinsic functions of an elicitor and cell wall protein in oomycetes.