Poloxamer-based binary hydrogels for delivering tramadol hydrochloride: sol-gel transition studies, dissolution-release kinetics, in vitro toxicity, and pharmacological evaluation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Pharmacology of the glucagon-like peptide-1 analog exenatide extended-release in healthy cats

Exenatide extended-release (ER) is a microencapsulated formulation of the glucagon-like peptide 1-receptor agonist exenatide: It has a protracted pharmacokinetic profile that allows a once-weekly injection with comparable efficacy to insulin with an improved safety profile in type II diabetic people. Here, we studied the pharmacology of exenatide ER in 6 healthy cats. A single subcutaneous injection of exenatide ER (0.13 mg/kg) was administered on day 0. Exenatide concentrations were measured for 12 wk. A hyperglycemic clamp (target = 225 mg/dL) was performed on days 7 (clamp I) and 21 (clamp II) with measurements of insulin and glucagon concentrations. Glucose tolerance was defined as the amount of glucose required to maintain hyperglycemia during the clamp. Continuous glucose monitoring was performed on weeks 0, 2, and 6 after injection. Plasma concentrations of exenatide peaked at 1 h and 4 wk after injection. Comparing clamp I with clamp II, fasting blood glucose decreased (mean standard deviation = 11 8 mg/dL, P = 0.02), glucose tolerance improved (median [range] +33% 14%-138%], P = 0.04), insulin concentrations increased (+36.5% [-9.9% to 274.1%], P = 0.02), and glucagon concentrations decreased (-4.7% [0%-12.1%], P = 0.005). Compared with preinjection values on continuous glucose monitoring, glucose concentrations decreased and the frequency of readings <50 mg/dL increased at 2 and 6 wk after injection of exenatide ER. This did not correspond to clinical hypoglycemia. No other side effects were observed throughout the study. Exenatide ER was safe and effective in improving glucose tolerance 3 wk after a single injection. Further evaluation is needed to determine its safety, efficacy, and duration of action in diabetic cats. (C) 2015 Elsevier Inc. All rights reserved.

Evaluation of sodium diclofenac release using natural rubber latex as carrier

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of recasting procedure upon corrosion behavior and metallic ion release of Co-Cr-Mo dental alloy in physiological

Recasting process influence upon corrosion behavior of Co-Cr-Mo dental alloy in simulated physiological serum has been investigated using chemical and electrochemical techniques. Recast Co-Cr-Mo alloy by induction (IND) or by blowtorch (FLAME) has exhibited similar dendritic structures. Both IND and FLAME alloys have presented good corrosion resistance in physiological serum. Passivation process provides this corrosion resistance. Codissolution makes this process difficult. Passive films, formed on these alloys, have been analyzed as a dual layer consisting of an inner barrier and an outer porous layer. Passive film protective characteristics are higher in FLAME than in IND alloy. On this last alloy, the passive film is more porous due to a higher Codissolution. ©Carl Hanser Verlag, München.

Purification and characterization of a unique pectin lyase from aspergillus giganteus able to release unsaturated monogalacturonate during pectin degradation

A pectin lyase, named PLIII, was purified to homogeneity from the culture filtrate of Aspergillus giganteus grown in submerged culture containing orange peel waste as carbon source. PLIII was able to digest apple pectin and citrus pectins with different degrees of methyl esterification. Interestingly, the PLIII activity was stimulated in the presence of some divalent cations including Pb(2+) and was not significantly affected by Hg(2+). Like other pectin lyases, PLIII is stimulated by but is not dependent on Ca(2+). The main soluble product released during the degradation of pectic substances promoted by the PLIII is compatible with an unsaturated monogalacturonate. PLIII is a unique enzyme able to release unsaturated monogalacturonate as the only soluble product during the degradation of pectic substances; therefore, PLIII was classified as an exo-pectin lyase. To our knowledge, this is the first characterization of an exo-pectin lyase. The PLIII described in this work is potentially useful for ethanol production from pectin-rich biomass, besides other common applications for alkaline pectinases like preparation of textile fibers, coffee and tea fermentation, vegetable oil extraction, and the treatment of pulp in papermaking.

Anthocyanin incorporated dental copolymer: bacterial growth inhibition, mechanical properties, and compound release rates and stability by (1)h NMR

Objective. To evaluate bacterial growth inhibition, mechanical properties, and compound release rate and stability of copolymers incorporated with anthocyanin (ACY; Vaccinium macrocarpon). Methods. Resin samples were prepared (Bis-GMA/TEGDMA at 70/30 mol%) and incorporated with 2 w/w% of either ACY or chlorhexidine (CHX), except for the control group. Samples were individually immersed in a bacterial culture (Streptococcus mutans) for 24 h. Cell viability (n = 3) was assessed by counting the number of colony forming units on replica agar plates. Flexural strength (FS) and elastic modulus (E) were tested on a universal testing machine (n = 8). Compound release and chemical stability were evaluated by UV spectrophotometry and (1)H NMR (n = 3). Data were analyzed by one-way ANOVA and Tukey's test ( α = 0.05). Results. Both compounds inhibited S. mutans growth, with CHX being most effective (P < 0.05). Control resin had the lowest FS and E values, followed by ACY and CHX, with statistical difference between control and CHX groups for both mechanical properties (P < 0.05). The 24 h compound release rates were ACY: 1.33 μg/mL and CHX: 1.92 μg/mL. (1)H NMR spectra suggests that both compounds remained stable after being released in water. Conclusion. The present findings indicate that anthocyanins might be used as a natural antibacterial agent in resin based materials.

Polymeric and solid lipid nanoparticles for sustained release of carbendazim and tebuconazole in agricultural applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Trypanosoma cruzi and Its soluble antigens induce NET release by stimulating toll-like receptors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Participation of dectin-1 receptor on NETs release against Paracoccidioides brasiliensis: role on extracellular killing

Paracoccidioides brasiliensis is a dimorphic fungus from the Paracoccidioides genus, which is the causative agent of paracoccidioidomycosis, a chronic, subacute or acute mycosis, with visceral and cutaneous involvement. This disease that is acquired through inhalation primarily attacks the lungs but, can spread to other organs. Phagocytic cells as neutrophils play an important role during innate immune response against this fungus, but studies on antifungal activities of these cells are scarce. In addition to their ability to eliminate pathogens by phagocytosis and antimicrobial secretions, neutrophils can trap and kill microorganisms by release of extracellular structures composed by DNA and antimicrobial proteins, called neutrophil extracellular traps (NETs). Here, we provide evidence that P. brasiliensis virulent strain (P. brasiliensis 18) induces NETs release. These structures were well evidenced by scanning electron microscopy, and specific NETs compounds such as histone, elastase and DNA were shown by confocal microscopy. In addition, we have shown that dectin-1 receptor is the main PRR to which fungus binds to induce NETS release. Fungi were ensnared by NETs, denoting the role of these structures in confining the fungus, avoiding dissemination. NETs were also shown to be involved in fungus killing, since fungicidal activity detected before and mainly after neutrophils activation with TNF-α, IFN-γ and GM-CSF was significantly inhibited by cocultures treatment with DNAse.

Controlled swollen and drug release from urea-cross-linked polyether/siloxane hybrids

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Insights into the swelling process and drug release mechanisms from cross-linked pectin/high amylose starch matrices

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)