Synthesis And Performance Of Chitosan-Mesoporous Silica Drug-loading Nanoparticles

Targeted drug systems have important implications for the high incidence of breast cancer prevention. Environmental responsive micro/nano drug carriers wrapping antitumor drug system represents one of the best targeted drug system for its unique advantages. It not only can be used as an effective carrier to protect drug molecules from degradation, but also can release drugs in cancer cells, increase the drug curative effect and reduce the side effects. It has a good application prospect in drug controlled release.Chitosan is a p H-sensitive natural polymer, it can be used as drug carrier with good biocompatibility, biodegradability, nontoxic, etc. Meanwhile, mesoporous silica nanoparticles(MSN) is a kind of inorganic nano drug carrier with good biocompatibility, thermal stability, larger specific surface area, and non-toxic. In this work, a series of p H sensitive chitosan- mesoporous silica drug-loading nanoparticles were prepared to exploit the advantages of natural polymer and inorganic nanoparticles. Chitosan and mesoporous silica nanoparticles were chosen as the drug carriers. The structure, morphology and drug release properties of the drug-loading nanoparticles were studied. The main contents and conclusions are shown as follows:(1) Mesoporous silica nanoparticles were prepared by sol-gel and dual template method with tetraethyl orthosilicate as the silica source. Morphology was studied by transmission election microscopy. The structure of MSN were studied by the nitrogen stripping absorption experiment. MSN nanoparticles presented spherical or ellipsoidal shape with uniform particle size distribution. The particle size of MSN nanoparticles increased with the increase amount of surfactant cetyl trimethyl ammonium bromide(CTAB). The Brunauer- Emmett- Teller(BET) specific surface area and pore volume analysis showed that MSN nanoparticles with specific surface area and pore volume was more suitable as drug carrier when CTAB concentration was 5.7 m M.(2) MSN/IBU(Ibuprofen) was prepared via desorption-diffusion method with IBU as the model drug. PH-responsive CS/MSN/IBU was obtained through self-assembly of hydrogen bonding. The structures of drug-loading nanoparticles were investigated by FTIR. The morphology and particles size were characterized by scanning electron microscopy and transmission electron microscopy. Drug loading properties were analyzed by ultraviolet spectrophotometer. Furthermore, the influence of chitosan mass fraction on drug loading efficiency was also studied. Drug-loading nanoparticles also presentated relatively spherical shape with uniform particle size distribution. The BET surface area of drug-loading nanoparticles decreased greatly comparing with MSN, which proved that drug-loading nanoparticles was successfully achieved. Drug loading efficiency of IBU loading into MSN was 52.8%. When the mass fraction of chitosan was 0.2%, 0.4%, 0.6%, drug-loading efficiency of IBU into CS/MSN/IBU were 22.2%, 28.9% and 38.4%, respectively.(3) The release properties and release kinetics of drug-loading nanoparticles were studied. In simulated body temperature environment and normal tissue fluid(p H 7.4), the release amount of MSN/IBU was slightly higher than the cancer cells. The release of IBU did not have p H-responsive property and the drug release mode was non-Fickian diffusion and typical Fickian diffusion, respectively.