Preparation And Characterization Of The PH Sensitive Carriers For Drug And Gene Delivery

As the development of biological and material science, the Gene Cure method and the Target Drug Cure method were proposed in order to treat the diseases that were hard to cure by using the traditional methods. The carriers were the most important factor to realize this aim. In this paper, the aminopropyltriethoxysilane(APTES) was used to synthesize the carriers by using two kinds of different materials.In order to take advantage of the biocompability and biodegradability of calcium carbonate, a simple method was introduced to synthesize calcium carbonate microparticles with different morphologies, for example the hollow microspheres(H-Calcium), the follower-like microspheres(P-Calcium) and the peanut-like microparticles(P-Calcium). The possible formation mechanisms of these kinds of calcium carbonate microparticles were discussed in this paper. And the rod-like calcium carbonate microparticles(r CCMP) with homogeneous size distribution was used to load the anticancer drug(doxorubicin(DOX)). The drug loaded and releasing properties, the cytotoxicity, the inhibition of tumor cells were evaluated. The drug loaded rate was up to 90%. The results of drug releasing tests showed that the r CCMP had a high drug-loaded ability and the drug releasing speed was dependent on the p H value of microenvironments. And the DOX loaded rod-like calcium carbonate(DOX-r CCMP) exhibited a strong inhibition of tumor cells. And the calcium carbonate microspheres(CCMP) was used as the gene(Osterix gene) carriers. The results showed that this kind of microspheres possessed the ability to realize the transfection rate, but lower. More researches were needed to realize this aim.The PCL-Asp/PNH microspheres was synthesized by using the self-assembly method between PCL-Asp and PNH molecules. The mean diameter of PCL-Asp/PNH microspheres was about 300 nm with narrow size distribution. The PCL-Asp/PNH microspheres possessed good biocompatiablty with low cytotoxicity. This kind of material was used to load the DOX. The loaded rate was up to 77.7% in the DOX solution. The drug releasing property was evaluated by using PBS solution with different p H value. The results showed that the releasing rate was up to 77.16% in the acid environment, and lower than 20% in the neutral environment. This result means that its drug releasing property was dependent on the p H value of environment.