The objective of this work was to investigate the mechanism of release of active pharmaceutical ingredients (APIs) both small molecules (ketoprofen, indomethacin, coumarin-6) and macromolecules ...(human serum albumin, ovalbumin), from PLGA (50:50) nanoparticulates (400–700
nm), having drug loadings less than 10%. The nanoparticulates were prepared by emulsification/solvent evaporation methods and release determined in phosphate buffer pH 7.4 at 37
°C. The release profiles exhibited an initial burst release phase, a slower lag phase and a second increased release rate phase. The profiles were consistent with a model in which the first phase of the release reflects diffusion controlled dissolution of drug accessible to the solid/dissolution medium interface and the second phase reflects release of drug entrapped in the polymer, the release of which was dependent on the bulk degradation of the polymer. The burst phase tended to increase with increase in API loading and solubility. The polymer erosion related parameters also indicated that increased drug loading accelerated this phase of API release. Small acidic hydrophobic actives such as ketoprofen and indomethacin had a much greater effect on these parameters than the larger hydrophilic more neutral proteins, HSA and ovalbumin.
Desde los años 1970, la superpoblación ha vuelto al debate sociopolítico, asociado a las preocupaciones medioambientales. Es una cuestión muy compleja, reconocen los especialistas y, podríamos ...añadir, difícil de explicar a los más jóvenes. No obstante, a partir del análisis de un álbum y de una novela corta, veremos que no es imposible, siendo de gran ayuda para lograrlo, la brevedad de estos dos géneros literarios.
This work provides a new understanding of critical process parameters involved in the production of inhalation aerosol particles by ultrasonic spray freeze drying to enable precise control over ...particle size and aerodynamic properties. A series of highly porous mannitol, lysozyme, and bovine serum albumin (BSA) particles were produced, varying only the solute concentration in the liquid feed, cs, from 1 to 5wt%. The particle sizes of mannitol, BSA, and lysozyme powders were independent of solute concentration, and depend only on the drop size produced by atomization. Both mannitol and lysozyme formulations showed a linear relationship between the computed Fine Particle Fraction (FPF) and the square root of cs, which is proportional to the particle density, ρ, given a constant particle size dg. The FPF decreased with increasing cs from 57.0% to 16.6% for mannitol and 44.5% to 17.2% for lysozyme. Due to cohesion, the BSA powder FPF measured by cascade impaction was less than 10% and independent of cs. Ultrasonic spray freeze drying enables separate control over particle size, dg, and aerodynamic size, da which has allowed us to make the first experimental demonstration of the widely accepted rule da=dg(ρ/ρo)1/2 with particles of constant dg, but variable density, ρ (ρo is unit density).
To identify determinants of early progressive renal decline in type 2 diabetes a range of markers was studied in 1032 patients enrolled into the 2nd Joslin Kidney Study. eGFR slopes estimated from ...serial measurements of serum creatinine during 5-12 years of follow-up were used to define early renal decline. At enrollment, all patients had normal eGFR, 58% had normoalbuminuria and 42% had albuminuria. Early renal decline developed in 6% and in 18% patients, respectively. As determinants, we examined baseline values of clinical characteristics, circulating markers: TNFR1, KIM-1, and FGF23, and urinary markers: albumin, KIM-1, NGAL, MCP-1, EGF (all normalized to urinary creatinine) and the ratio of EGF to MCP-1. In univariate analysis, all plasma and urinary markers were significantly associated with risk of early renal decline. When analyzed together, systolic blood pressure, TNFR1, KIM-1, the albumin to creatinine ratio, and the EGF/MCP-1 ratio remained significant with the latter having the strongest effect. Integration of these markers into a multi-marker prognostic test resulted in a significant improvement of discriminatory performance of risk prediction of early renal decline, compared with the albumin to creatinine ratio and systolic blood pressure alone. However, the positive predictive value was only 50% in albuminuric patients. Thus, markers in plasma and urine indicate that the early progressive renal decline in Type 2 diabetes has multiple determinants with strong evidence for involvement of tubular damage. However, new, more informative markers are needed to develop a better prognostic test for such decline that can be used in a clinical setting.
Mammalian cells have been shown to internalize oligonucleotide-functionalized gold nanoparticles (DNA-Au NPs or siRNA-Au NPs) without the aid of auxiliary transfection agents and use them to initiate ...an antisense or RNAi response. Previous studies have shown that the dense monolayer of oligonucleotides on the nanoparticle leads to the adsorption of serum proteins and facilitates cellular uptake. Here, we show that serum proteins generally act to inhibit cellular uptake of DNA-Au NPs. We identify the pathway for DNA-Au NP entry in HeLa cells. Biochemical analyses indicate that DNA-Au NPs are taken up by a process involving receptor-mediated endocytosis. Evidence shows that DNA-Au NP entry is primarily mediated by scavenger receptors, a class of pattern-recognition receptors. This uptake mechanism appears to be conserved across species, as blocking the same receptors in mouse cells also disrupted DNA-Au NP entry. Polyvalent nanoparticles functionalized with siRNA are shown to enter through the same pathway. Thus, scavenger receptors are required for cellular uptake of polyvalent oligonucleotide functionalized nanoparticles.
O-Phosphoethanolamine (PEA) is an endogenous substance that is attracting interest as a biomarker for depression, and thus there is a need to develop a simple analytical method that specifically ...measures PEA. Therefore, this study aimed to develop a simple and specific enzyme-linked immunosorbent assay (ELISA) for PEA.
Anti-PEA antibody was obtained by immunizing mice with an antigen conjugated with mercaptosuccinyl bovine serum albumin using m-maleimidobenzoyl-N-hydroxysulfosuccinimide ester (MBS). In this assay, the PEA to be quantified is chemically modified by benzoyl chloride that is allowed to compete with a PEA-MBS-HRP conjugate for binding to a limited amount of an anti-PEA antibody, which was used to coat the wells of a microtiter plate. This ELISA shows a linear range of detection of 0.11–27 μM, and a limit of quantification of 0.144 μM. The anti-PEA antibody showed high affinity for benzoyl PEA. No detectable cross-reactivity was found with benzoyl 2-aminoethanol, O-phospho-l-tyrosine or benzoyl sphingosine-1-phosphate. The values of plasma PEA levels measured by this ELISA were comparable to those measured by HPLC, and a strong correlation was observed between the values determined by the two methods. The developed ELISA should provide a valuable new tool for the quantification of PEA in human plasma.
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•We developed an ELISA for PEA, a biomarker of depression.•This is the first ELISA that exhibits specificity for PEA.•The limit of quantification is 0.144 μM for PEA.•This method is useful for the quantification of PEA in human plasma.
È ormai noto come la produzione digitale abbia quasi del tutto soppiantato le tradizionali pratiche del disegno nel processo architettonico. Se da un lato l’uso della rappresentazione digitale ha ...interrotto la produzione grafica tradizionale, dall’altro essa rende possibile una sempre più efficace e immersiva disseminazione e divulgazione di progetti architettonici antichi non sufficientemente conosciuti, se non inediti o, ancora, immaginati. In questo senso, il presente contributo vuole indagare e sviluppare la digitalizzazione di uno dei più importanti progetti in ambito costiero posto in essere da parte del Ministero dei Lavori Pubblici e concretizzato mediante la redazione dell’Album dei fari illustrato dalle notizie intorno ai loro caratteri e posizione, al fine di rendere fruibili tutti quei progetti in tutto o in parte realizzati per la crescita delle nostre coste. Il progetto proposto nel 1873, all’indomani dell’Unità d’Italia, prevede la progettazione e la realizzazione di quattrocentosessantadue segnalamenti marittimi per gli ottomila chilometri di costa italiana. La digitalizzazione dell’Album dei fari, ovvero un caposaldo per la storia della costruzione di queste architetture costiere, si configura dunque come l’azione fondamentale per intraprendere un percorso di conoscenza e comparazione di tipo digitale delle strutture costiere passate e presenti, secondo i dettami dell’interdisciplinarietà Albisinni, De Carlo 2011.
Multiple rodent models have been used to study diabetic kidney disease (DKD). The purpose of the present study was to compare models of diabetes and obesity-induced metabolic syndrome and determine ...differences in renal outcomes. C57BL/6 male mice were fed either normal chow or high fat diet (HFD). At postnatal week 8, chow-fed mice were randomly assigned to low-dose streptozotocin (STZ, 55 mg/kg/day, five consecutive days) or vehicle control, whereas HFD-fed mice were given either one high-dose of STZ (100 mg/kg) or vehicle control. Intraperitoneal glucose tolerance tests were performed at Week 14, 20 and 30. Urinary albumin to creatinine ratio (ACR) and serum creatinine were measured, and renal structure was assessed using Periodic Acid Schiff (PAS) staining at Week 32. Results showed that chow-fed mice exposed to five doses of STZ resembled type 1 diabetes mellitus with a lean phenotype, hyperglycaemia, microalbuminuria and increased serum creatinine levels. Their kidneys demonstrated moderate tubular injury with evidence of tubular dilatation and glycogenated nuclear inclusion bodies. HFD-fed mice resembled metabolic syndrome as they were obese with dyslipidaemia, insulin resistance, and significantly impaired glucose tolerance. One dose STZ, in addition to HFD, did not worsen metabolic features (including fasting glucose, non esterified fatty acid, and triglyceride levels). There were significant increases in urinary ACR and serum creatinine levels, and renal structural changes were predominantly related to interstitial vacuolation and tubular dilatation in HFD-fed mice.
The adsorption characteristics of bovine serum albumin (BSA) onto the supermacroporous poly(hydroxyethylmethacrylate)-Reactive Green 19 p(HEMA)-RG cryogel disks have been investigated in this paper. ...p(HEMA) cryogel disks were prepared by radical polymerization initiated by N,N,N′,N′-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. Reactive Green (RG) 19 was covalently attached to the p(HEMA) cryogel disks. These disks were used in BSA adsorption studies to interrogate the effects of pH, initial protein concentration, ionic strength, and temperature. BSA adsorption capacity of the p(HEMA)-RG cryogel disk was significantly improved after the incorporation of RG. Adsorption capacity reached a plateau value at about 0.8 mg/mL at pH 4.0. The amount of adsorbed BSA decreased from 37.7 to 13.9 mg/g with increasing NaCl concentration. The enthalpy of BSA adsorption onto the p(HEMA)-RG cryogel disk was calculated as −58.4 kJ/mol. The adsorption equilibrium isotherm was fitted well by the Freundlich model. BSA was desorbed from cryogel disks (over 90 %) using 0.5 M NaSCN, and the purity of desorbed BSA was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The experimental results showed that the p(HEMA)-RG cryogel disks have potential for the quick protein separation and purification process.
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