Preparation Of Biocompatible Nanocarriers And Application In Controlled Drug Release

Drug delivery systems (DDS) have been widely used in biomedical fields due to that they can solubilize potent chemotherapeutic drugs with poor solubility and uneven distribution thus improve their bioavailability, hence enhancing their therapeutic effect and overcome side effects. Biocompatible drug delivery systems could elongate circulation time in vivo and accumulate in tumor tissue. A variety of nanocarriers have been reported in order to improve the load capacity, realize the targeted delivery of anti-cancer drugs, increase the uptake of drugs in cancer cells, enhance their therapeutic effect. Multi stimuli-responsive such as pH, temperature, redox, light, magnetic field, ultrasound have been introduced in nanocarriers, which realized the targeting delivery and controlled release of anticancer drugs.Biocompatible drug delivery systems were prepared to investigate the load capacity and drug controlled release behavior. The results showed the obtained drug carriers had potential in targeting delivery. In order to achieve the target, the FA-PEG-OA micelles were prepared in contrast with mPEG-OA micelles. The micelles had advantage on targeted delivery, small particle size, high stability, high load capacity, pH-induced controlled release. The drug-loading capacity and efficiency of the micelles for the five model drugs revealed the micelles had higher load capacity of DOX. The controlled release performance showed pH-induced controlled release due to the pKa value of DOX.In order to improve the stability and realize the pH-responsive of the drug carriers, novel core cross-linked (CCL) micelles with pH-responsive PDEA cores and biocompatible PEG coronas were prepared by ATRP. The CCL micelles were more stable than mPEG-DEA micelles fabricated by self-assembly. The results demonstrated that the pH-responsive CCL micelles had a potential application in fields such as drug delivery and smart release.In order to achieve better drug controlled release, multi-stimuli responsive Fe3O4@PMAA@PNIPAM polymeric nanoparticles with core-shell architecture were prepared. In this system, magnetism made the nanoparticles easy to separate and achieve targeted drug release. The drug carriers could be biodegradable and release drug-loaded more quickly by the cleavage disulfide linkages. Further, nanoparticles with pH/temperature sensitive characteristics had great advantage on controlled drug release and realized more effective therapeutic effect. Controlled drug release experiment demonstrated the polymeric nanoparticles could realize reduction/pH/ temperature controlled release in response to the environment.