The Research Of Polysarcosine Modified Gold Nanopar-ticles And Their Biological Properties

Inorganic nanoparticles(NPs)were widely used in biological and biomedical area because of their stability and antifouling ability in complex biological conditions.Polysarcosine(PS)is a kind of poly-peptides,which has good biocompatibility and promising future in biomedical field.In this study,gold nanoparticles with good stability were modified with PS in order to study the stability,biocompatibility and blood circulation properties in vitro and in vivo.Firstly,AuNPs@PEG,AuNPs@PS1,AuNPs@PS2 and AuNPs@PS3 were prepared using PEG-SH(Mw:2 kD),PS1(Mw:1.8 kD),PS2(Mw:2.6 kD),PS3(Mw:6.8 kD),respectively.The stability and resistance capacity towards protein adsorption of the four kinds of gold nanoparticles were studied under different conditions,i.e.PBS solution,PBS buffer solution(containing 10%FBS)and water solution with a wide pH range.AuNPs@PS2 showed the best stability and the lowest protein adsorption capacity.Therefore,AuNPs@PEG and AuNPs@PS2 were chosen in the further animal experiments.It is found that AuNPs@PS2 had a significantly longer blood cycle time and a lower reticuloendothelial system capture amount,indicating that PS modified gold nanoparticles have a better biocompatibility.Based on the previous study,we chose PS(with single-chain molecular weight of 2.6 kD)and PEG(with single-chain molecular weight of 2 kD)to modify the gold nanorods,expecting to take advantage of its photothermal effect to treat cancer.Then,AuNRs@PEG and AuNRs@PS were prepared and superior stability and resistance capacity towards protein adsorption under different conditions(PBS solution,PBS water solution(containing 10%FBS)and buffer solution with a wide pH range)were observed.For the further animal experiments,results showed that AuNRs@PS has a longer circulation time in vivo and a higher accumulation amount in the tumor tissue,and therefore achieved a better photothermal effect in cancer treating process.