Search results for "encapsulation"
showing 10 items of 92 documents
Boosting the in situ encapsulation of proteins with MIL-100(Fe): the role of strong Lewis acid centers
2021
Encapsulation of biomolecules using Metal-Organic Frameworks (MOFs) to form stable biocomposites has been demonstrated a valuable strategy for their preservation and controlled release, which has been however restricted to specific electrostatic surface conditions. We present a general in situ strategy that promotes the spontaneous MOF growth onto a broad variety of proteins, for the first time, regardless of their surface nature. We demonstrate that MOFs based on cations exhibiting considerable inherent acidity such as MIL-100(Fe) enable biomolecule encapsulation, including alkaline proteins previously inaccesible by the welldeveloped in situ encapsulation with azolate-based MOFs. In parti…
Spectroscopic markers of the T-R quaternary transition in human hemoglobin
2004
n questo lavoro, usiamo un protocollo sol-gel per intrappolare e confrontare gli stati quaternari R e T di entrambi i deossigenati (deossiHb) ederivati di ossido di carbonio (HbCO) dell'emoglobina umana. La banda di assorbimento ottico del vicino infrarosso III e lo stretching di CO a infrarossibanda sono utilizzati per rilevare l'effetto della struttura quaternaria sulle proprietà spettrali di deoxyHb e HbCO; confronto con mioglobinaconsente una valutazione dei contributi terziari e quaternari ai turni di banda misurati. La RXLa transizione T è indicata per causare un bluspostamento della banda III di ~ 35 cm?1per deoxyHb e uno spostamento rosso della banda di allungamento CO di soli ~ 0…
Selective encapsulation of a chloride anion in a 1H-pyrazole Cu2+ metallocage
2021
A self-assembled metallobox from copper(ii) and two macrocycles containing 1H-pyrazole ligands has been prepared. The internal cavity of the box is able to selectively encapsulate a single chloride anion over any other halide anion.
Physico-chemical state influences in vitro release profile of curcumin from pectin beads
2014
International audience; Curcumin is a polyphenolic compound with diverse effects interesting to develop health benefit products but its formulation in functional foods or in food supplement is hampered by its poor water solubility and susceptibility to alkaline conditions, light, oxidation and heat. Encapsulation of curcumin could be a mean to overcome these difficulties. In this paper, curcumin was encapsulated by ionotropic gelation method in low methoxyl pectin beads associated with different surfactants: Solutol®, Transcutol® and sodium caseinate. After encapsulation, physico-chemical properties of encapsulated curcumin such as its solubility, physical state, tautomeric forms and encaps…
Influence of temperature and NaCl on the release in aqueous liquid media of aroma compounds encapsulated in edible films
2012
This work analyses the release of n-hexanal and D-limonene from edible films, previously encapsulated in the iota-carrageenan matrix (with and without lipid). Both volatile compounds have different physicochemical properties. The effect of temperature (25 degrees C and 37 degrees C) and dissolution medium (water and 0.9% NaCl) on the release and retention of aroma compounds were studied. Hydrophobicity and wettability properties of active iota-carrageenan films were also studied and they were related with the internal and surface microstructure of films. Results highlight that D-limonene is encapsulated in the lipid phase of the films decreasing the release in the salt medium. D-limonene, t…
Encapsulació i estructura informativa en el debat parlamentari. Una anàlisi contrastiva (català – espanyol – anglès)
2016
Parliamentary debate (PD) as a specific genre of parliamentary discourse exhibits a hybrid nature: part oral and part written discourse. It is performed orally, but planned ahead and formal. From the point of view of lexical cohesion, encapsulation by means of abstract and unspecific nouns (e.g. factor reason) is an indicator of the informative density and the underlying written natureof PD.With the tools provided by Discourse Analysis and Cognitive Linguistics, this paper aims at describing and characterizing cross-linguistically lexical encapsulation’s potential to define the information struc-ture of PD. In this regard, encapsulation is analyzed in relation to the notions of topic and fo…
Préparation de liposomes fonctionnels pour l’encapsulation de composés bioactifs ou de sondes moléculaires fluorescentes pour l’imagerie cellulaire
2016
At ICMUB Institute, SUV liposomes have been used to achieve fluorophore encapsulation (subphtalocyanine) for cellular imaging [1] and have been bioconjugated to a peptide (bombesin) to achieve site-specificity, thanks to the structural modification of cholesterol, a component of the liposome, upon introduction of a reactive function. Hence, such liposomes fonctionnalised on the outer face may react with the terminal function of the peptide. Upon purification of the liposome by FPLC a 15 % encapsulation rate was measured by UV/Vis and attempted by ICP. The (outer) diameter of the liposomes (dDLS and dMET) ranged between 20 and 60 nm depending on the type of function or substituents on the ou…
Luminescent supramolecular heterometallic macrocycles and their encapsulation on cholate gels
2018
The metal complex formed by coordination of Zn(II) to 1,7-bis(4-methylpyridine)-4-(2- naphthylmethyl)-1,4,7-triazaheptane (ZnL2+) was reacted in aqueous solution with [Pd(NO3)2(en)] and [Pt(NO3)2(en)] salts to form the self-assembled heterometallic macrocycles [Zn2L2Pd2(en)2]8+ and [Zn2L2Pt2(en)2]8+, respectively. Pd(II) and Pt(II)- coordination modulates the original emission of ZnL2+ arising from the presence of the naphthalene chromophore and the formation of the macrocycles can be monitored due to the PET process occurring with coordination of Pd(II) and Pt(II) to the pyridine units of ZnL2+. Additionally, several studies reveal that these heteromacrocycles can be encapsulated in Zn(II)…
In situ crosslinkable hyaluronan hydrogels for tissue engineering
2003
We describe the development of an injectable, cell-containing hydrogel that supports cell proliferation and growth to permit in vivo engineering of new tissues. Two thiolated hyaluronan (HA) derivatives were coupled to four alpha,beta-unsaturated ester and amide derivatives of poly(ethylene glycol) (PEG) 3400. The relative chemical reactivity with cysteine decreased in the order PEG-diacrylate (PEGDA)>>PEG-dimethacrylate>PEG-diacrylamide>PEG-dimethacrylamide. The 3-thiopropanoyl hydrazide derivative (HA-DTPH) was more reactive than the 4-thiobutanoyl hydrazide, HA-DTBH. The crosslinking of HA-DTPH with PEGDA in a molar ratio of 2:1 occurred in approximately 9 min, suitable for an in situ cr…
Microfluidic Fabrication of Physically Assembled Nanogels and Micrometric Fibers by Using a Hyaluronic Acid Derivative
2017
The employ of a hyaluronic acid (HA) derivative, bearing octadecyl (C18) and ethylenediamine (EDA) groups, for microfluidic fabrication of nanogels and microfibers is reported in this study. Two HA-EDA-C18 derivatives (125 and 320 kDa) having ionic strength sensitive properties are synthesized and characterized. The control of the rheological properties of HA-EDA-C18 aqueous dispersions by formation of inclusion complexes with hydroxypropyl-β-cyclodextrins (HPCD) is described. Reversibility of C18/HPCD complexation and physical crosslinking is detected in media with different ionic strength through oscillation frequency tests. HA-EDA-C18 125 kDa is employed for nanogel fabrication. Control …