Generic Delivery of Payload of Nanoparticles Intracellularly via Hybrid Polymer Capsules for Bioimaging Applications

Towards the goal of development of a generic nanomaterial delivery system and delivery of the ‘as prepared’ nanoparticles without ‘further surface modification’ in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb3+ was observed after internalization of LaF3:Tb3+(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification

Edible bio-based nanostructures: delivery, absorption and potential toxicity

The development of bio-based nanostructures as nanocarriers of bioactive compounds to specific body sites has been presented as a hot topic in food, pharmaceutical and nanotechnology fields. Food and pharmaceutical industries seek to explore the huge potential of these nanostructures, once they can be entirely composed of biocompatible and non-toxic materials. At the same time, they allow the incorporation of lipophilic and hydrophilic bioactive compounds protecting them against degradation, maintaining its active and functional performance. Nevertheless, the physicochemical properties of such structures (e.g., size and charge) could change significantly their behavior in the gastrointestinal (GI) tract. The main challenges in the development of these nanostructures are the proper characterization and understanding of the processes occurring at their surface, when in contact with living systems. This is crucial to understand their delivery and absorption behavior as well as to recognize potential toxicological effects. This review will provide an insight into the recent innovations and challenges in the field of delivery via GI tract using bio-based nanostructures. Also, an overview of the approaches followed to ensure an effective deliver (e.g., avoiding physiological barriers) and to enhance stability and absorptive intestinal uptake of bioactive compounds will be provided. Information about nanostructures potential toxicity and a concise description of the in vitro and in vivo toxicity studies will also be given.Joana T. Martins, Oscar L. Ramos, Ana C. Pinheiro, Ana I. Bourbon, Helder D. Silva and Miguel A. Cerqueira (SFRH/BPD/89992/2012, SFRH/BPD/80766/2011, SFRH/BPD/101181/2014, SFRH/BD/73178/2010, SFRH/BD/81288/2011, and SFRH/BPD/72753/2010, respectively) are the recipients of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE, Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes," REF.NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. We also thank to the European Commission: BIOCAPS (316265, FP7/REGPOT-2012-2013.1) and Xunta de Galicia: Agrupamento INBIOMED (2012/273) and Grupo con potencial de crecimiento. The support of EU Cost Action FA1001 is gratefully acknowledged

Acoustic near- to far-field characteristics of nozzle radiation through plug flow jets

This paper reports a theoretical and numerical study of the radiation of sound through jet exhausts. It focuses on the transition from near field to far field by considering the features of the near field solution and how these features translate to the far field. The main finding of this work is the importance (in some cases) of lateral waves radiating from the jet. While the presence of lateral waves has long been recognized, there has been no systematic investigation of the practical consequences of these waves in the prediction of sound propagation through jet mixing layers. The physical mechanisms involved in the generation of these waves are presented as well as the conditions under which they become significant. This paper also discusses the validity of the far-field approximation when lateral waves are present. It is shown that the standard far-field asymptotic can be improved by adding a correction term which accounts for the presence of the lateral waves

New Simple Procedure To Determine The Threshold Voltage Of Mosfets

A new alternative technique is proposed to extract the threshold voltage from the subthreshold-to-strong inversion transition region of MOSFETs. It uses an auxiliary operator that involves integration of the drain current as a function of gate voltage. Tests show that the procedure produces results comparable to conventional methods

Tipicit\ue0 e atipicit\ue0 nei contratti pubblici

Gli scritti pubblicati in questo volume costituiscono la trasposizione delle relazioni, opportunamente rivisitate e per lo pi\uf9 arricchite di ogni necessario riferimento dottrinale e giurisprudenziale, tenute nell\u2019ambito del Convegno organizzato il 6 febbraio 2006 dal Centro Ricerca e Formazione sugli Appalti Pubblici della Spisa. Il tema della tipicit\ue0-atipicit\ue0 dei contratti pubblici costituisce da sempre uno dei nodi essenziali da sciogliere, se si vuole predicare una effettiva autonomia negoziale della Pubblica Amministrazione; in mancanza di ci\uf2 la pur conclamata capacit\ue0 di diritto privato risulterebbe lettera morta e uno dei tanti proclami diretti a soddisfare la politica del momento, ma non ad identificare strumenti dell\u2019azione idonei a valorizzarla in termini di efficienza, efficacia ed economicit\ue0. Ne \ue8 derivata, grazie alle qualit\ue0 scientifiche e professionali dei relatori, una riflessione approfondita, che si segnala, anche per la sistematicit\ue0 degli argomenti trattati, all\u2019attenzione degli studiosi

RENAL HEMODYNAMICS, PLASMA AMINO-ACIDS AND HORMONES AFTER A MEAT MEAL IN PROGRESSIVE NEPHRON LOSS

Ten patients with chronic renal failure (GFR 29-97 ml/min), on free diets providing 1 g/kg B.W. of proteins, ingested an oral protein load (meat meal, 2 g/kg B.W.). GFR and RPF increased significantly over baseline with no change in filtration fraction. Within 30 min of the meal and for the next 3 h a statistically significant increase was observed in the plasma concentrations of the following amino acid groups: essential, non-essential, total, branched-chain, ketogenic, glycogenic, glycogenic and ketogenic, basic, acid, polar and non-polar. At 30 min the smallest increase was seen in acid and polar amino acids (6.7% and 7.6%, respectively). At 180 min the largest increase (78.8%) was seen for glycogenic and ketogenic amino acids and total plasma amino acids were 1.58 times baseline. After the meat meal plasma glucagon and insulin rose significantly, while growth hormone, plasma renin activity and aldosterone did not vary

Tubular function by lithium clearance, plasma amino acids and hormones following a meat meal in childhood

Tubular function was measured by lithium clearance (CLi) and by its derived formulae before and after the transient increase (lasting 90min) in glomerular filtration rate (GFR) following a meat meal (2g protein/kg body weight) in 12 normal children. Three baseline and 4 clearances after the meal were obtained, each lasting 30min. The mean baseline Cu was 23.1 ± 1.64ml/min/1.73m2. At peak GFR response (60min from starting the meal), CLi averaged 27.6±2.4ml/min/1.73m2 (p2, p<0.01 vs. baseline) 120min after starting the meal, while GFR returned to baseline values. Fractional lithium excretion averaged 0.23±0.04 at baseline and increased continuously after the meat meal and. at completion of the study, it averaged 0.38±0.07 (p<0.025vs. baseline). The distal absolute and fractional sodium reabsorption increased throughout the studies following the meal and peaked at 120min. The functional changes were associated with a statistically significant increase in the plasma concentration of insulin, glucagon, and total amino acids after the meal. The latter at the end of the study was almost doubled (5,600 ±780 versus 3,200μM at baseline, p<0.01). The data indicate that the tubulo glomerular feedback mechanism operates normally after a meat meal. The finding on increased distal sodium reabsorption might point to the existence of an insulin-dependent mechanism. © 1991 S. Karger AG, Basel