Study On Preparation And Characterization Of Starch Nanoparticle In Ionic Liquid Based Microemulsions

Starch nanoparticles, the particle size ranging from1to1000nm, possess huge specificsurface area, high colloid stability and adsorption performance. Therefore, the starchnanoparticles as a drug carrier have been widely used in drug delivery system. Thismanuscript mainly investigated several aspects: the solubility of native corn starch in ionicliquids(ILs), the preparation and properties of IL microemulsions containing starch, thepreparation and characterization of starch nanoparticles in IL microemulsions system and thedrug loading and releasing properties of starch nanoparticles. We studied the preparation andproperties of starch nanoparticles through IL microemulsions in order for finding theenvironmentally friendly and effective method for the synthesis of starch nanoparticles,providing a theoretical underpinning for the application of starch nanoparticles in biomedicalfield and expanding the application of starch.The methods based on the turbidity and polarization cross were used to investigate thesolubility of native corn starch in [Amim]Cl,[Bmim]Cl,[Bmim]Ac and [Omim]Ac and theeffect of temperature, starch concentration and water content on the solubility of starch in ILs.The results showed that high temperature leads to increase of dissolution time of starch in ILs.With the increase of starch concentration, the dissolution time shows a little longer in somedegree. The more water content leads to the worse stability of starch solution.Two kinds of IL microemulsions were prepared using [Omim]Ac as polar phase and[Bmim]PF6as non-polar phase, respectively, and characterized by phase diagram,conductivity measurements, UV–Vis spectrophotometry and dynamic light scattering(DLS).The formation of IL/O microemulsions and W/IL microemulsions were demonstrated.Starch nanoparticles were prepared through IL/O microemulsions and W/ILmicroemulsions, respectively, and characterized by fourier transform infrared spectroscopy(FTIR), scanning electron microscope(SEM), X-ray diffraction(XRD) and DLS. FTIR datademonstrated the formation of crosslinking bonds in starch molecules. The results of SEMrevealed that starch nanoparticles were spherical particles and showed aggregation or clusterformation. XRD data showed that the crystal structure of starch had been changed aftercrosslinking reaction. DLS showed that starch nanoparticles possessed small size and narrow size distribution.In addition, drug loading property of starch nanoparticles was investigated withMitoxantrone Hydrochloride as the drugs as function of changes in the adsorption conditions,such as loading time, loading temperature, particle size and drug concentration. It was foundthat the drug loading was significantly influenced by loading time, loading temperature anddrug concentration. With the increase of loading time, the drug loading and encapsulationefficiency increased firstly, then reduced gradually after reaching a peak value. The higherloading temperature could lead to the decrease of drug loading and encapsulation efficiency.The increase of drug concentration caused rising of drug loading but the decline inencapsulation efficiency. The release curve of drug-loaded starch nanoparticles contained twophases: an initial burst release phase and a sustained release phase depending on the particlesize and degradation of starch nanoparticles.