Polysaccharides nanospheres

Biologicals Lipids, peptides, nucleic acids, polysaccharides, viruses Vesicles, nanotubes, rings, nanoparticles, nanocapsules, nanospheres... 

To make nanoparticles able to escape complement activation, Passirani et alJ" proposed to coat nanospheres with heparin. This compound, which is a polysaccharide, is a physiological inhibitor of complement activation in vivo. Heparin-coated poly(methylmetha-crylate) nanoparticles were prepared by emulsion polymerization. In the method, the radical polymerization of methylmethacrylate was initiated by heparin according to an original method involving cerium ions and allowing heparin to covalently attach to poly(methyl-methacrylate). 

Pallado P, Benedetti PL, Callegaro L. Nanospheres comprising a biocompatible polysaccharide. US patent 6 214 384, 2001. 

Ohya Y, Shiratani M, Kobayashi H, Ouchi T Release behavior of 5-fluorouradl from chito-san-gel nanospheres immobilizing 5-fluorour-acil coated with polysaccharides and their cell speciflc cytotoxicity. Pure Appl Chem 1994, A31, 629-642. 

In the forementioned laboratories, we started with a new strategy based on phase separation in order to prepare natural particles. Simple or complex coacervation methods involving proteins or protein and polysaccharide mixtures3 were used to create new matrices dedicated to controlled release applications. The colloidal carriers produced were in the micrometre or nanometre size range depending on the substrates or the methods used. Wheat proteins, gliadins, were implicated in simple coacervation to produce nanospheres. Controlled release experiments with model compounds were conducted in order to evaluate... 

Recently, the ability of fi-CyD to form particles without polymers or phosphohpids has been studied. Indeed, by employing a reticulation of -CyD during the preparation process, it is possible to directly obtain microparticles (spheres and capsules) [10, 15]. On the other hand, reticulation of -CyD can also be performed to synthesize a -CD polymer, capable of forming nanospheres mixed with modified polysaccharide spontaneously [46]. 

Ohya, Y, Shiratani, M., Kobayashi, H., and Ouchi, T. (1994). Release behavior of 5-fluorouracil from chitosan-gel nanospheres immobilizing 5-fluorouracil coated with polysaccharides and their cell specific (ytotoxicily, PureAppl. Chem., A31,629-642. 

Natural polysaccharides such as chitosan and alginate are promising materials for their applications, particularly in drug delivery, due to their favorable biocompatibility, biodegradability, pH sensitivity, and mucoadhesive properties [157, 158]. Covalently crossUnked polysaccharide-based nanospheres are quite stable compared with other several other t5q)es of polysaccharide-based nanospheres. The conventional methods for preparation of covalently crosslinked polysaccharide-based nanospheres include emulsion crosslinking, solvent evaporation, spray... 

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