Synthesis And Properties Of Amphiphilic Nanotechnology Based Drug Delivery Systems

Traditional anti-tumor drugs have many defects in the treatment of cancer. Forexample, normal tissues would be damaged and the toxic side effects are serious; drugrelease rate can’t be controlled and repeated administration is needed; tumor cells canalso easily become simultaneously resistant to different drugs. Solving these problemsby delivering anti-tumor drugs in nanotechnology based drug delivery systems is afeasible method. Recent years, owing to severe shortage of donor blood, it is urgent toconstruct an effective blood substitutes. In order to reduce the dissociation of Oxygenduring transportation and improve the Oxygen content in hypoxic tissue, it is feasibleto deliver Oxygen by hemoglobin (Hb)-based drug delivery system. Polymeric drugdelivery system is widely used in delivering drugs, especially when it is based onamphiphilic polymers due to their satisfactory properties. In this paper, I mainly didthree aspects of research.Firstly, Mitoxantrone loaded chitosan-poly(lactide)-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (Cs-co--PLA-DPPE) particles were synthesized bydouble emulsion and nanoprecipitation method. The morphology, stability and drugcontrolled release ability of the prepared drug delivery system were also studied byTransmission electron microscopy (TEM), Dynamic Light Scattering (DLS) andUV-visible spectroscopy (UV-Vis) in this paper. The results showed that MTO-loadednanoparticles were uniform spheres with narrow size distribution. Diameter ofnanoparticles prepared by double emulsion and nanoprecipitation methods isrespectively about200nm and150nm. The encapsulation efficiency of MTO-loadednanoparticles prepared by double emulsion method is higher than that prepared bynanoprecipitation method. Drugs could release from nanoparticles in a slow rate andthe release rate was pH dependable.Secondly, Fluorescently labeled amphiphilic polymer palmiticacid-Polyethyleneimine (PA-PEI) is successfully synthesized. Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) were used to confirm the structureof the polymer. Using this polymer as drug carrier, bortezomib and paclitaxel wereincorporated into nanoparticles by emulsion solvent evaporation method. Themorphology, encapsulation and controlled release profile of the prepared drugdelivery system were studied by TEM, DLS and High performance liquidchromatography (HPLC). The results demonstrated that drugs-loaded nanoparticleswere uniform spheres with satisfactory size distribution. Size of the preparednanoparticles was about200nm. Drugs could release from nanoparticles in acontrollable rate. Bortezomib is more easily encapsulated into nanparticles thanpaclitaxel. The release rate of bortezomib is higher than paclitaxel.Thirdly, using Polyethylene glycol-(poly(lactic-co-glycolic acid)(PEG-PLGA)as drug carrier, hemoglobin was incorporated into drug delivery system by doubleemulsion method. To study its Oxygen carrying capacity. The morphology,encapsulation efficiency of the prepared drug delivery system and the structure ofhemoglobin structure were confirmed by TEM, DLS and UV-Vis. The results showedthat the morphology of hemoglobin-loaded nanoparticles were uniform spheres. Thestructure of hemoglobin in nanoparticles is unbroken and Oxygen could Dissociatedfrom hemoglobin in nanoparticles under low Oxygen pressure.