15 research outputs found
Microfluidic preparation of monodisperse microcapsules of silica glass with controlled morphological and optical characteristics
Les nanosciences reprĂ©sentent, actuellement, un domaine de recherche en pleine expansion grĂące aux nombreuses applications auxquelles elles peuvent ĂȘtre associĂ©es, et en particulier Ă la course Ă la miniaturisation des systĂšmes. De plus, il a rapidement Ă©tĂ© montrĂ© que les propriĂ©tĂ©s physico-chimiques des matĂ©riaux Ă lâĂ©chelle nanomĂ©trique sont modifiĂ©es parfois de maniĂšre drastique, Ă cause par exemple des effets quantiques apparaissant Ă des tailles aussi petites, mais aussi en raison des effets de confinement. Le confinement de molĂ©cules ou de particules Ă lâĂ©chelle nanoscopique nĂ©cessite donc la fabrication de matĂ©riaux hĂŽtes possĂ©dant ce quâil convient dâappeler des sites de confinement, câest-Ă -dire des sites possĂ©dant une taille voisine de celle du systĂšme Ă insĂ©rer. Ce type de matĂ©riau est dĂ©sormais relativement connu, et deux familles monopolisent lâintĂ©rĂȘt, Ă savoir la silice mĂ©soporeuse, aussi et rĂ©cemment utilisĂ©, les verres bioactifs Ă base de silice ayant des caractĂ©ristiques contrĂŽlĂ©es qui constituent des matĂ©riaux hĂŽtes de confinement qui peuvent ĂȘtre immergĂ©s dans des fluides complexes tel que le plasma sanguin synthĂ©tique. Pour rĂ©aliser ces travaux on a besoins dâappliquer plusieurs techniques de caractĂ©risations telles que la diffusion des Rayons X et des Neutrons, la Microscopie Electronique Ă Balayage et Ă Transmission, la spectroscopie Infrarouge Ă TransformĂ© de Fourier etc...De plus, ces derniĂšres annĂ©es, des systĂšmes microfluidiques ont Ă©tĂ© utilisĂ©s pour Ă©laborer des Ă©mulsions doubles, des microcapsules ou des microparticules, avec la particularitĂ© dâobtenir des populations trĂšs monodisperses par rapport Ă celles obtenues avec des techniques plus traditionnelles et de morphologie contrĂŽlĂ©e. Dans le domaine pharmaceutique, ces capacitĂ©s sont particuliĂšrement intĂ©ressantes pour la synthĂšse de mĂ©dicaments Ă libĂ©ration contrĂŽlĂ©e. Elles permettent dâobtenir des particules monodisperses de polymĂšre encapsulantes pour lesquelles lâeffet de relargage brutal est diminuĂ© et qui possĂšdent des vitesses de relargage plus lentes que celles observĂ©es avec des procĂ©dĂ©s de fabrication conventionnels.Nanoscience currently represent a growing area of research through the many applications for which they may be associated, particularly in the race for miniaturization of systems. In addition, it was quickly demonstrated that the physico-chemical properties of nanoscale materials are sometimes changed drastically, for example because of quantum effects occurring at sizes as small, but also because of confinement effects .Confinement of molecules or particles at the nanoscale therefore requires the manufacture of host materials with what to call containment sites, that is to say, sites with a size close to that of the system insert. This type of material is now relatively well known, and two families monopolize the interest, ie the mesoporous silica, and also recently used bioactive glasses based on silica having controlled characteristics that are host materials containment can be immersed in complex fluids such as synthetic blood plasma.To do this work several characterization techniques we need to apply, including the spread of X-rays and neutrons, the Scanning Electron Microscopy and Transmission, Infrared spectroscopy Transformed Fourier etc ...Moreover, in recent years, microfluidic systems were used to prepare double emulsions, microcapsules or microparticles, with the particularity to obtain highly monodisperse populations compared to those obtained with more traditional and controlled morphology techniques. In the pharmaceutical field, these capabilities are particularly interesting for the synthesis of controlled release to drugs. They enable polymer monodisperse particles encapsulating why the sudden release effect is decreased and have slower release rates than those observed with conventional manufacturing processe
Elaboration par voie microfluidique de microcapsules monodisperses de verre de silice à caractéristiques morphologiques et optiques contrÎlées
Nanoscience currently represent a growing area of research through the many applications for which they may be associated, particularly in the race for miniaturization of systems. In addition, it was quickly demonstrated that the physico-chemical properties of nanoscale materials are sometimes changed drastically, for example because of quantum effects occurring at sizes as small, but also because of confinement effects .Confinement of molecules or particles at the nanoscale therefore requires the manufacture of host materials with what to call containment sites, that is to say, sites with a size close to that of the system insert. This type of material is now relatively well known, and two families monopolize the interest, ie the mesoporous silica, and also recently used bioactive glasses based on silica having controlled characteristics that are host materials containment can be immersed in complex fluids such as synthetic blood plasma.To do this work several characterization techniques we need to apply, including the spread of X-rays and neutrons, the Scanning Electron Microscopy and Transmission, Infrared spectroscopy Transformed Fourier etc ...Moreover, in recent years, microfluidic systems were used to prepare double emulsions, microcapsules or microparticles, with the particularity to obtain highly monodisperse populations compared to those obtained with more traditional and controlled morphology techniques. In the pharmaceutical field, these capabilities are particularly interesting for the synthesis of controlled release to drugs. They enable polymer monodisperse particles encapsulating why the sudden release effect is decreased and have slower release rates than those observed with conventional manufacturing processesLes nanosciences reprĂ©sentent, actuellement, un domaine de recherche en pleine expansion grĂące aux nombreuses applications auxquelles elles peuvent ĂȘtre associĂ©es, et en particulier Ă la course Ă la miniaturisation des systĂšmes. De plus, il a rapidement Ă©tĂ© montrĂ© que les propriĂ©tĂ©s physico-chimiques des matĂ©riaux Ă lâĂ©chelle nanomĂ©trique sont modifiĂ©es parfois de maniĂšre drastique, Ă cause par exemple des effets quantiques apparaissant Ă des tailles aussi petites, mais aussi en raison des effets de confinement. Le confinement de molĂ©cules ou de particules Ă lâĂ©chelle nanoscopique nĂ©cessite donc la fabrication de matĂ©riaux hĂŽtes possĂ©dant ce quâil convient dâappeler des sites de confinement, câest-Ă -dire des sites possĂ©dant une taille voisine de celle du systĂšme Ă insĂ©rer. Ce type de matĂ©riau est dĂ©sormais relativement connu, et deux familles monopolisent lâintĂ©rĂȘt, Ă savoir la silice mĂ©soporeuse, aussi et rĂ©cemment utilisĂ©, les verres bioactifs Ă base de silice ayant des caractĂ©ristiques contrĂŽlĂ©es qui constituent des matĂ©riaux hĂŽtes de confinement qui peuvent ĂȘtre immergĂ©s dans des fluides complexes tel que le plasma sanguin synthĂ©tique. Pour rĂ©aliser ces travaux on a besoins dâappliquer plusieurs techniques de caractĂ©risations telles que la diffusion des Rayons X et des Neutrons, la Microscopie Electronique Ă Balayage et Ă Transmission, la spectroscopie Infrarouge Ă TransformĂ© de Fourier etc...De plus, ces derniĂšres annĂ©es, des systĂšmes microfluidiques ont Ă©tĂ© utilisĂ©s pour Ă©laborer des Ă©mulsions doubles, des microcapsules ou des microparticules, avec la particularitĂ© dâobtenir des populations trĂšs monodisperses par rapport Ă celles obtenues avec des techniques plus traditionnelles et de morphologie contrĂŽlĂ©e. Dans le domaine pharmaceutique, ces capacitĂ©s sont particuliĂšrement intĂ©ressantes pour la synthĂšse de mĂ©dicaments Ă libĂ©ration contrĂŽlĂ©e. Elles permettent dâobtenir des particules monodisperses de polymĂšre encapsulantes pour lesquelles lâeffet de relargage brutal est diminuĂ© et qui possĂšdent des vitesses de relargage plus lentes que celles observĂ©es avec des procĂ©dĂ©s de fabrication conventionnels
Synthesis of mesoporous silica hollow microspheres with controlled structural and optical properties using droplet-based microfluidics
<div>Thisstudyfocusesonthedevelopmentofanoriginaltemplate-freemethodforthesynthesisandcharacterizationofhighlymonodisperseandmesoporoushollowsilicamicrospherescontaininghighlyorderednanometer-scaleporesofcontrollablesize.</div><div>Fabricationofsuchmicrosystemsisofafundamentalandpracticalinterest,sincetheycanbeusedforcontrolleddrugdelivery,cellsencapsulationandculture,catalysis,biosensors,bio-materialsandtissue-engineering,etc.</div
Synthesis and functionalization of 92S bioactive glasses for drug delivery system
<p>A new glass formulation,
with the molar composition 92% SiO<sub>2</sub>â 6 % CaO â 2% P<sub>2</sub>O<sub>5</sub>
was synthesized using the sol-gel process, for applications as biomaterial in
orthopaedic or maxillo facial surgery. Pellets, made of glass powder, were
uniaxially compacted and soaked in
Simulated Body Fluid (SBF) for up to 7 days at 37°C to evaluate glass
bioactivity. Ionic exchanges at the
interface glass-SBF were evaluated by studying evolutions of calcium,
phosphorus and silicon concentrations in
SBF using ICP-OES. Changes in glass surface, and the formation of crystalline
phases were analyzed using XRD, SEM, EDS and FTIR methods. In the
pharmaceutical field, these materials are particularly interesting for the
synthesis of drugs for controlled release. </p
Preparation of Mesoporous and monodisperse microdrops of bioglass through microfluidic chip
<p>The sol-gel method, with use of specific
surfactants, is a preferred approach to generating a controlled porosity
material of high specific surface. The development of microfluidics and the
development of new manufacturing technologies for miniaturized devices can
perform complex operations (synthesis, mixing, analysis ...) across the
nanolitre.</p
Evaluation de la bioactivitĂ© dâun verre synthĂ©tisĂ© par voie sol-gel
<p>Dâun point de vue structural, on peut
définir un verre comme
« un solide non cristallin ». </p>
<p>Certains verres se comportent comme des
matĂ©riaux totalement inertes, dâautres sont biodĂ©gradables et dâautres enfin
ont présentés une adaptation osseuse trÚs satisfaisante. Ce dernier type
particulier de verre; contenant de la silice, du calcium et des phosphates est
appelĂ© bioverre ou verre bioactif : il a la propriĂ©tĂ© de se lier intimement Ă
lâos et de mieux sâadapter aux tissus que les biomatĂ©riaux habituellement
utilisés.</p><p><br></p
Microfluidic-assisted Formation of Highly Monodisperse and Mesoporous Silica Soft Microcapsules
<div>The fabrication of mesoporous silica microcapsules with a highly controlled particle size ranging in the micrometer size presents a major challenge in many academic and industrial research areas, such as for the developement of smart drug delivery systems with a well controlled loading and release of bioactive molecules...</div
Role and effect of meso-structuring surfactants on properties and formation mechanism of microfluidic-enabled mesoporous silica microspheres
202306 bcwwVersion of RecordSelf-fundedPublishe
Microfluidic-assisted Formation of Highly Monodisperse and Mesoporous Silica Soft Microcapsules
Abstract The fabrication of mesoporous silica microcapsules with a highly controlled particle size ranging in the micrometer size presents a major challenge in many academic and industrial research areas, such as for the developement of smart drug delivery systems with a well controlled loading and release of (bio)active molecules. Many studies based on the solvent evaporation or solvent diffusion methods have been developed during the last two decades in order to control the particle size, which is often found to range at a sub-micrometer scale. Droplet-based microfluidics proved during the last decade a powerful tool to produce highly monodisperse and mesoporous silica solid microspheres with a controllable size in the micrometer range. We show in the present study, in contrast with previous microfluidic-assisted approaches, that a better control of the diffusion of the silica precursor sol in a surrounding perfluorinated oil phase during the silica formation process allows for the formation of highly monodisperse mesoporous silica microcapsules with a diameter ranging in the 10 micrometer range. We show also, using optical, scanning and transmission electron microscopies, small angle x-ray diffraction and BET measurements, that the synthesized mesoporous silica microcapsules exhibit a soft-like thin shell with a thickness of about 1âÎŒm, across which 5.9ânm sized mesopores form a well-ordered hexagonal 2D network. We suggest and validate experimentally a model where the formation of such microcapsules is controlled by the solvent evaporation process at the droplet-air interface