Preparation And Characterization Of Starch Nanoparticles In Ionic Liquid Microemulsions With1-hexadecyl-3-methylimidazolium Bromide As Surfactant

As a kind of natural polymers, starch was not used as drug-carriers for its poorsolubility and global forming tendency in the early stage. Starch or its derivatives waspreparaed as microspheres, which could slow the release of drug, prolong the actingtime of drug and enhance the drug bioavailability. Moreover, if starch microsphereswere preparaed in nano-scale, it could be widely used in drug delivery system as drugcarrier due to the huge specific surface area, high colloid stability and good adsorptionperformance of starch nanoparticles. In order to find an environmental and effectivemethod for the synthesis of starch nanoparticles, broadening the application of starchnanoparticles in biomedical field, this manuscript have systematically studied thepreparation and characterizes of starch nanoparticles from several aspects: thepreparation and properties of IL microemulsions, the preparation and characterizationof starch nanoparticles based on IL microemulsions system and the drug loading andreleasing properties of starch nanoparticles.C16mim Br/butan-1-ol/cyclohexane/water([Omim]Ac) microemulsions systemswere prepared, respectively, and characterized by dilution experiment, dynamic lightscattering(DLS), pseudo-ternary phase diagram and conductivity measurements. Theformation of W/O microemulsions and IL/O microemulsions were proved.Starch nanoparticles were prepared using W/O microemulsions and IL/Omicroemulsions as recation system, respectively, and characterized by scanningelectron microscope(SEM), dynamic light scanning(DLS), X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR). The results of SEM showed thatstarch nanoparticles were spherical particles with small size. DLS showed that starchnanoparticles possessed small size and narrow size distribution. XRD spectrogramdemonstrated that the crystal structure of starch lost, presenting the amorphousstructure. FTIR data proved the formation of crosslinking bonds in starch molecules.At last, the drug loading property of starch nanoparticles was investigated withMethylene Blue and Mitoxantrone Hydrochloride as model drugs, respectively.Then,the effect of loading time, loading temperature and drug concentration on drugloading amount and encapsulation efficiency was stuied. It was found that the drugloading amount was significantly affected by loading time, loading temperature anddrug concentration. With the prolong of loading time, the drug loading amount andencapsulation efficiency increased firstly, then reduced gradually after reaching themaxmium. With the rise of loading temperature, the drug loading amount andencapsulation efficiency also increased firstly, then reduced gradually after reachingthe peak. The increase of drug concentration led to the rising of drug loading amountbut the encapsulation efficiency increased firstly and then decreased with the rise ofdrug concentration. The release process of drug-loaded starch nanoparticles containedtwo phases: the initial burst release phase and the slow release phase, starchnanoparticles showed slow-relaese properities to some extent.