Preparation Of Biodegradable Drug-loaded Nanoparticles And Their In Vitro Release Behaviors

In recent years, polymeric nanoparticles with certain functional properties and morphology become one of the hot topics because of its application in medcine, especially in the drug delivery systems.The technique for preparing polymeric nanoparticles includes solvent evaporation/extraction, emulsion polymerization, interfacial polycondensation and spray drying. In this paper, the drug-loading nanoparticles were prepared via the facile heterogenous coprecipitation technique. Then the nanoparticles have been coated with polyelectrolytes via layer-by-layer self-assembly. The drug release conditions of the microspheres before and after coating with polyelectrolytes have been studied to discuss the application of layer-by-layer self-assembly in drug controlled release.1. Preparation of magnetic drug-loading nanoparticles and their in vitro release behaviorsIn this part, a facile method has been used to prepare drug-loading nanoparticles. Briefly, the near monodispersed ibuprofen-loaded superparamagnetic alginate nanoparticles were prepared as follows:The model drug ibuprofen (IBU), sodium alginate (SAL) and the superparamagnetic Fe3O4 nanoparticles have been dissolved in deionized water, then coprecipitated in acidic condition accompanied by ultrasonic. Sodium alginate used to fabricate the microspheres has excellent biocompatibility and biodegradability, and the degradation products are harmless to human body health. Compared to the traditional methods, the method lodged in this part could avoid the harm to the human body without the using of any emulsifier. Hopefully, the microspheres can be used in drug targeted release due to the Fe3O4 in it.2. Stimuli-responsive multilayer chitosan hollow microspheres via layer-by-layer assemblyNovel stimuli-responsive multilayer chitosan hollow microspheres with the single component chitosan have been prepared by the sequential layer-by-layer electrostatic self-assembly technique on the surface of the sacrificial templates (polystyrene sulfonate, PSS) with chitosan (CS) as the polycation and carboxymethyl chitosan (CMCS) as the polyanion, respectively. Furthermore, the pH and ionic strength dual-responsive of the multilayer chitosan microcapsules were studied via the DLS analysis. With the single component chitosan used for fabrication being biocompatible, the multilayer chitosan microcapsules are expected to be used in the controlled release of drug.3. Preparation of biodegradable drug-loading nanoparticles via layer-by-layer self-assembly and their in vitro release behaviorsBased on the previous two parts, the chitosan multilayers were self-assembled onto the drug-loaded superparamagnetic alginate nanoparticles to produce the novel magnetic-targeted controlled release drug delivery system, with chitosan as the polycation (CS) and the carboxymehtyl chitosan (CMCS) as the polyanion. To study the effect of the hollow microspheres prepared in the second part in drug controlled release. The drug release conditions of the microspheres before and after coating with polyelectrolytes have been studied to discuss the application of layer-by-layer self-assembly in drug controlled release.