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Esposito R, Cavasso D, Niccoli M, D’Errico G. Phase Inversion and Interfacial Layer Microstructure in Emulsions Stabilized by Glycosurfactant Mixtures. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:331. [PMID: 33513926 PMCID: PMC7911527 DOI: 10.3390/nano11020331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 02/05/2023]
Abstract
Identification of strategies to prolong emulsion kinetic stability is a fundamental challenge for many scientists and technologists. We investigated the relationship between the emulsion stability and the surfactant supramolecular organization at the oil-water interface. The pseudo-phase diagrams of emulsions formed by water and, alternatively, a linear or a branched oil, stabilized by mixtures of two sugar-based surfactants, Span80 and Tween80, are presented. The surfactant ordering and dynamics were analyzed by electron paramagnetic resonance (EPR) spectroscopy. In Oil-in-Water (O/W) emulsions, which are stable for more than four days, disordered surfactant tails formed a compact and viscous layer. In Water-in-Oil (W/O) emulsions, whose stability is much lower, surfactants formed an ordered layer of extended tails pointing toward the continuous apolar medium. If linear oil was used, a narrow range of surfactant mixture composition existed, in which emulsions did not demix in the whole range of water/oil ratio, thus making it possible to study the phase inversion from O/W to W/O structures. While conductometry showed an abrupt inversion occurring at a well-defined water/oil ratio, the surfactant layer microstructure changed gradually between the two limiting situations. Overall, our results demonstrate the interconnection between the emulsion stability and the surfactant layer microstructuring, thus indicating directions for their rational design.
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Affiliation(s)
- Rodolfo Esposito
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 4, Complesso Universitario di Monte Sant’Angelo, I-80126 Naples, Italy; (R.E.); (D.C.); (M.N.)
| | - Domenico Cavasso
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 4, Complesso Universitario di Monte Sant’Angelo, I-80126 Naples, Italy; (R.E.); (D.C.); (M.N.)
| | - Marcella Niccoli
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 4, Complesso Universitario di Monte Sant’Angelo, I-80126 Naples, Italy; (R.E.); (D.C.); (M.N.)
| | - Gerardino D’Errico
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 4, Complesso Universitario di Monte Sant’Angelo, I-80126 Naples, Italy; (R.E.); (D.C.); (M.N.)
- Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase (CSGI), Via della Lastruccia 3, I-50019 Florence, Italy
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Abramov E, Ottaviani MF, Shames AI, Fattori A, Garti N. Structural Characterization of Reconstituted Bioactive-Loaded Nanodomains after Embedding in Films Using Electron Paramagnetic Resonance and Self-Diffusion Nuclear Magnetic Resonance Techniques. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7879-7886. [PMID: 31120758 DOI: 10.1021/acs.langmuir.9b00578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pharmaceutical applications of microemulsions (MEs) as drug delivery vehicles are recently gaining scientific and practical interests. Most MEs are able to solubilize bioactive molecules, but, at present, they cannot guarantee either controlled release of the drugs or significant advantage in the bioavailability of the bioactives. This study proposes to incorporate the modified ME structures, or nanodomains, into a natural polymeric film, to be used as a stable and capacious reservoir of drug-loaded nanodomains. These nanodomain-loaded films may release the nanodroplets along with the drug molecules in a slow and controlled way. Gellan gum, an anionic polysaccharide, was used in aqueous solution as the film former, and curcumin, hydrophobic polyphenol, served as the guest molecule in the loaded systems. Films were prepared by using empty and curcumin-loaded MEs. It is imperative to verify the persistence of the ME structure upon the dissolution of the film mimicking its behavior when in contact with a human physiological aqueous environment via reaching the cell membranes. For this purpose, the films were dissolved, and the reconstituted ME structure was compared with the ME structure before film formation. Characterization of these structures, before and after dissolution, was achieved using electron paramagnetic resonance (EPR) and self-diffusion nuclear magnetic resonance (SD-NMR) techniques. Specific spin probes were inserted in the system, and a computer-aided analysis of the EPR spectra was performed to provide information on nanodomain microstructure assemblies. In addition, the SD-NMR profile of each component was analyzed to extract information on the diffusivity of the ME components before film formation and after ME reconstitution. The EPR and SD-NMR results were in good agreement to each other. The most important finding was that, after film dissolution, the ME nanodomains were reversibly and spontaneously reformed. It was also found that the film did not perturb the ME-nanodomain structure embedded in it. The film remained transparent and the bioactive curcumin was easily solubilized into the ME-droplet/water interface even after film dissolution. The combined techniques confirmed that the film constituted by bioactive-loaded MEs can serve as novel drug delivery vehicles.
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Affiliation(s)
- Eva Abramov
- The Ratner Chair of Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry , The Hebrew University of Jerusalem , Edmond J. Safra Campus , Givat Ram, Jerusalem 91904 , Israel
| | - Maria Francesca Ottaviani
- Department of Pure and Applied Sciences (DiSPeA) , University of Urbino , Via Ca' le Suore 2/4 , Urbino 61029 , Italy
| | - Alexander I Shames
- Department of Physics , Ben-Gurion University of the Negev , P.O. Box 653, Beer-Sheva 8410501 , Israel
| | - Alberto Fattori
- Department of Pure and Applied Sciences (DiSPeA) , University of Urbino , Via Ca' le Suore 2/4 , Urbino 61029 , Italy
| | - Nissim Garti
- The Ratner Chair of Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry , The Hebrew University of Jerusalem , Edmond J. Safra Campus , Givat Ram, Jerusalem 91904 , Israel
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Ballesteros A, Bornscheuer U, Capewell A, Combes D, Condoret JS, Koenig K, Kolisis FN, Marty A, Menge U, Scheper T, Stamatis H, Xenakis A. Review Article Enzymes in Non-Conventional Phases. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242429509040103] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kogan A, Rozner S, Mehta S, Somasundaran P, Aserin A, Garti N, Ottaviani MF. Characterization of the Nonionic Microemulsions by EPR. I. Effect of Solubilized Drug on Nanostructure. J Phys Chem B 2008; 113:691-9. [DOI: 10.1021/jp807161g] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Anna Kogan
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
| | - Shoshana Rozner
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
| | - Somil Mehta
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
| | - Ponisseril Somasundaran
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
| | - Abraham Aserin
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
| | - Nissim Garti
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
| | - Maria Francesca Ottaviani
- Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, NSF IUCR Center for Advanced Studies in Novel Surfactants, Columbia University, New York, New York 10027, and Institute of Chemical Sciences, University of Urbino, Piazza Rinascimento 6, 61029 Urbino, Italy
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