| It is believed that the nanoparticles can effectively enhance the selectivity and bioavailability of the drugs,thus to improve the efficacy of cancer therapy.ln recent years,Peptide polymers have been widely used in drug delivery system due to their excellent biocompatibility and biodegradability.In the second part of this dissertation,we synthesised our tri-block polypeptide by the ring opening polymerization of ZLLys-NCA and ZCys-NCA in two steps.And then we got our desire production by removal of benzy protecting groups from the polypeptide.The structure and composition of resulting polymer were demonstrated by 1H-NMR,GPC and Elemental Analysis.we use G-SH to reduce disulfide bonds and then dialyzed in water,disulfide-cross-linked nanogel will formed after 48h.The tri-block polypeptide was much less cytotoxic and has a better siRNA binding capability when compared with branchedpoly(ethylenimine)with Mw of 25 kDaCellulose is one of the most abundant and most widely distributed polysaccharides in nature,which is an important renewable energy.We can get commonly used chemicals such as glucose or water-soluble oligosaccharides by hydrolyzing cellulose.After a further chemical conversion we would get 5-HMF,a kind of higher value-added chemicals.In conventional solvent,hydrolysis of cellulose usually needs high reaction temperature and long reaction time and the hydrolysis is offen imcomplete becouse the poor solubility of the cellulose.In the third part of this dissertation,zinc chloride hydrated salt with 2mol/L hydrochloric acid conditions were chosed to dissolve cellulose.We use rice straw as a source of cellulose,at atmospheric pressure and 95?,The depolymerization of cellulose was finished in 8 min and the yeild of glucose is 24.35%.Next,Adding 40ml DMSO in the reactor and the Reaction was continued for 2 hours at 150?,the yeild of 5-HMF is 15.2%.We studied the affect of reaction temperature,reaction time and feeding model on saccharification reaction. |
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