Preparation of PVP hydrogel nanoparticles using lecithin vesicles

Abstract

Recebido em 21/6/10; aceito em 20/8/10; publicado na web em 15/10/10 Hydrogels micro, sub-micro and nanoparticles are of great interest for drug encapsulation and delivery or as embolotherapic agents. In this work it is described the preparation of nano and sub-microparticles of pre-formed, high molecular weight and monomer free poly(N-vinyl-2-pyrrolidone) encapsulated inside the core of lecithin vesicles. The hydrogel particles are formed with a very narrow diameter distribution, of about 800 nm, and a moderate swelling ratio, of approximately 10.

Functionalization of Flat Sheet and Hollow Fiber Microfiltration Membranes for Water Applications

“…For small particle characterization, most analyses are performed in solution using common methods such as DLS, transmission electron microscopy (TEM), atomic force microscopy (AFM), BET surface analysis or SEM picture analysis, − including works related to Fe, Fe/Ni and Fe/Pd NPs. ,,, For solid materials, SEM/TEM pictures are taken, calculating the mean particle size by visual measuring, even with an image analysis software . Recent works have shown the potential of image analysis (2D metrics) for small particles, mostly TEM images in liquid phase. − This work applies this concept on the SEM pictures from the membrane/particle nanocomposite to quantify the shape descriptors of the Fe NPs in 2D.…”

The assembly of dialkyldimethylammonium bromide cationic lipids as vesicles or monolayers in presence of poly(ethylene glycol)

“…the cooling thermograms, point to the formation of vesicles and lamellae in the viscous media of PEG, with similar structure to those formed in water [11]. Such vesicles in PEG gel solution may find application in controlled drug delivery [19]. Table 6 summarizes the figures on the effect of PEG on the D n DAB vesicle properties, lipid complete solubilization and vesicle stability induced by PEG.…”

“…The assembly of lipids into vesicles or monolayers in aqueous environments may find useful applications in nanomedicine as the assembled structures themselves display detached functions in drug delivery, and the aqueous moiety in which such structures are embedded, may function stabilizer for the colloidal complexes. Therefore, vesicle in polymer environments can be useful in preparation of nanostructures for controlled drug delivery [19].…”