Oselys Rodriguez Justo

Incorporation of antibiotics in liposomes designed for tuberculosis therapy by inhalation.

Liposomal encapsulation of tuberculostatic drugs can potentially increase their therapeutic index. The incorporation of isoniazid, pyrazinamide, rifampicin, ethionamide, and streptomycin in extruded distearoylphosphatidylcholine/cholesterol liposomes designed for administration through inhalation was evaluated. Ethionamide and rifampicin were incorporated during lipid film formation, whereas solutions of the remaining drugs were used to hydrate preformed lipid bilayers. Final drug to lipid ratios around 0.3 were achieved for isoniazid and pyrazinamide, and mean vesicle diameters varied from 286 to 329 nm. No expressive drug leakage or mean vesicle diameter changes occurred during 3 weeks. No significant incorporation was achieved for streptomycin, ethionamide, and rifampicin.

Growth of Escherichia coli under extremely low-frequency electromagnetic fields.

The inflence of extremely low-frequency (ELF) electromagnetic fields on Escherichia coli cultures in submerse fermentation was studied. The fermentation processes were carried out recycling the culture medium externally through a stainless steel tube inserted in a magnetic field generator (solenoid). The exposure time and electromagnetic induction were varied in a range of 1 to 12 h and 0.010 to 0.10 T, respectively, according to a Box-Wilson Central Composite Designs of face centered with five central points. Growth of E. coli could be altered (stimulated or inhibited) under magnetic fieldinduced effects. E. coli culturesexposed at 0.1 T during 6.5 h exhibited changes in its viability compared to unexposed cells, which was 100 times higher than the control. The magnetic field generator associated with the cellular suspension recycle is a new way of magnetic treatment in fermentation processes and could be appropriate to industrial scale up.The influence of extremely low-frequency (ELF) electromagnetic fields on Escherichia coli cultures in submerse fermentation was studied. The fermentation processes were carried out recycling the culture medium externally through a stainless steel tube inserted in a magnetic field generator (solenoid). The exposure time and electromagnetic induction were varied in a range of 1 to 12 h and 0.010 to 0.10 T, respectively, according to a Box-Wilson Central Composite Designs of face centered with five central points. Growth of E. coli could be altered (stimulated or inhibited) under magnetic fieldinduced effects. E. coli cultures exposed at 0.1 T during 6.5 h exhibited changes in its viability compared to unexposed cells, which was 100 times higher than the control. The magnetic field generator associated with the cellular suspension recycle is a new way of magnetic treatment in fermentation processes and could be appropriate to industrial scale up.

Kanamycin incorporation in lipid vesicles prepared by ethanol injection designed for tuberculosis treatment

The primary goal of this study was the production of liposomes encapsulating kanamycin for drug administration by inhalation. The selected drug is indicated for multiresistant tuberculosis, and administration through inhalation allows both local delivery of the drug to the lungs and systemic therapy. The ethanol injection method used for the liposome production is easily scaled up and is characterized by simplicity and low cost. Vesicles were prepared using different lipid compositions, including hydrogenated soybean phosphatidylcholine and cholesterol (SPC/Chol), egg phosphatidylcholine and cholesterol (EPC/Chol), distearoyl phosphatidylcholine and cholesterol (DSPC/Chol), distearoyl phosphatidylcholine, dimyristoyl phosphatidylethanolamine and cholesterol (DSPC/DMPE/Chol), dipalmitoyl phosphatidylcholine and cholesterol (DPPC/Chol) and dipalmitoyl phosphatidylcholine, dipalmitoyl phosphatidylglycerol and cholesterol (DPPC/DPPG/Chol). The effects of different operational conditions for vesicle production and drug encapsulation were evaluated, aiming at a compromise between final process cost and suitable vesicle characteristics. The best performance concerning drug incorporation was achieved with the DSPC/Chol system, although its production cost was considerably larger than that of the natural lipids formulations. Encapsulation efficiencies up to 63% and final drug to lipid molar ratios up to 0.1 were obtained for SPC/Chol vesicles presenting mean diameters of 132 nm incubated at 60°C with the drug for 60 min at an initial drug‐to‐lipid molar ratio of 0.16.

Bioreactor coupled with electromagnetic field generator : Effects of extremely low frequency electromagnetic fields on ethanol production by Saccharomyces cerevisiae

The effect of extremely low frequency (ELF) magnetic fields on ethanol production by Saccharomyces cerevisiae using sugar cane molasses was studied during batch fermentation. The cellular suspension from the fermentor was externally recycled through a stainless steel tube inserted in two magnetic field generators, and consequently, the ethanol production was intensified. Two magnetic field generators were coupled to the bioreactor, which were operated conveniently in simple or combined ways. Therefore, the recycle velocity and intensity of the magnetic field varied in a range of 0.6–1.4 m s−1 and 5–20 mT, respectively. However, under the best conditions with the magnetic field treatment (0.9–1.2 m s−1 and 20 mT plus solenoid), the overall volumetric ethanol productivity was approximately 17% higher than in the control experiment. These results made it possible to verify the effectiveness of the dynamic magnetic treatment since the fermentations with magnetic treatment reached their final stage in less time, i.e., approximately 2 h earlier, when compared with the control experiment.

Evaluation of in vitro anti-inflammatory effects of crude ginger and rosemary extracts obtained through supercritical CO2 extraction on macrophage and tumor cell line: the influence of vehicle type.

BackgroundNumerous plants from have been investigated due to their anti-inflammatory activity and, among then, extracts or components of ginger (Zingiber officinale Roscoe) and rosemary (Rosmarinus officinalis L.), sources of polyphenolic compounds. 6-gingerol from ginger rhizome and carnosic acid and carnosol from rosemary leaves present anti-tumor, anti-inflammatory and antioxidant activities. However, the evaluation of the mechanisms of action of these and other plant extracts is limited due to their high hydrophobicity. Dimethylsulfoxide (DMSO) is commonly used as a vehicle of liposoluble materials to mammalian cells in vitro, presenting enhanced cell penetration. Liposomes are also able to efficiently deliver agents to mammalian cells, being capable to incorporate in their structure not only hydrophobic molecules, but also hydrophilic and amphiphilic compounds. Another strategy is based on the use of Pluronic F-68, a biocompatible low-foaming, non-ionic surfactant, to disperse hydrophobic components. Here, these three delivery approaches were compared to analyze their influence on the in vitro anti-inflammatory effects of ginger and rosemary extracts, at different concentrations, on primary mammalian cells and on a tumor cell line.MethodsGinger and rosemary extracts free of organic solvents were obtained by supercritical fluid extraction and dispersed in DMSO, Pluronic F-68 or liposomes, in variable concentrations. Cell viability, production of inflammatory mediators and nitric oxide (NO) release were measured in vitro on J774 cell line and murine macrophages primary culture stimulated with bacterial lipopolysaccharide and interferon-γ after being exposed or not to these extracts.ResultsGinger and rosemary extracts obtained by supercritical CO2 extraction inhibited the production of pro-inflammatory cytokines and the release of NO by peritoneal macrophages and J774 cells. The delivery vehicles influenced the anti-inflammatory effects. Comparatively, the ginger extract showed the highest anti-inflammatory activity on the tumor cell line. Controversially, rosemary extract dispersed on DMSO induced a more significant IL-1 and TNF-α reduction than ginger extract in primary macrophages.ConclusionsAmongst the tested delivery vehicles, DMSO was the most suitable, presenting reduced cytotoxicity, followed by Pluronic F-68 and liposomes, provably due to differences in their form of absorption, distribution and cellular metabolism. Co-administration of liposomes and plant extracts may cause death of macrophages cells and induction of NO production. It can be concluded that some of the beneficial effects attributed to extracts of ginger and rosemary may be associated with the inhibition of inflammatory mediators due to their high antioxidant activity. However, these effects were influenced by the type of delivery vehicle.

Screening of Metarhizium spp. strains for anticancer indolizidine alkaloid production and its rapid detection by MS analysis

Six fungi strains (M. anisopliae 3935, 4516, 4819, PL57, PL43 and M. flavoviride CG291) were studied regarding their ability to produce an anticancer indolizidine alkaloid. The culture process was carried out in Shaken flask at 26oC and 200 rpm using three different culture medium containing oat meal extract supplemented with glucose and DL-lysine or Czapek culture medium. The mycelial extracts produced by Metarhizium spp. cultures were directly submitted to electrospray ionization mass spectrometry (ESI-MS) analysis and the highest alkaloid concentration (approximately, 6 mg.L-1) was reached when M. anisopliae 3935 was tested.

Efeito da adição de precursores na produção de alcaloide anticancerígeno usando a técnica de planejamento experimental

The effect of precursors on the anticancer alkaloid production by submerged fermentation using M. anisopliae 3935 was studied, according to complete experimental design 22 with three central points. The results showed that lysine was the most important variable, however, when both lysine and glucose were added to the fermentation medium, the alkaloid production reached, approximately, 17 mg L-1 after 120 hours of fermentation. Then, the scale-up of the process was carried out and these results were confirmed. Finally, 35 mg L-1 of alkaloid at 192 h were attained after increment of added aminoacid lysine.