Application Of Novel Nanogel Synthesized By Photochemistry Method In An Emulsion-free Aqueous Solution

Novel nanogels with size below 120 nm in diameter were prepared by usingprepolymers and nontoxic metal ion in an emulsion-free aqueous solution viaphotocross-linking method.The results are summarized as follows:The water-soluble polyethylenimine(PEI)nanogels with narrow particles sizedistributions were prepared from PEI prepolymers via ferrous ion-induced self-assemblymethod at room temperature.The chelation of PEI with some metal ions(Cu²⁺,Fe²⁺,Fe³⁺,Zn²⁺)was studied by Dynamic Light Scattering(DLS).The results indicated that the PEIwas totally chelated with ferrous.The nanogel sizes can be controlled from 30 nm to 80nm in diameter by adjusting the molar ratios of prepolymers to ferrous ions,the nanogelexhibited a good stability in aqueous media.The influencing factors of preparing PEInanogels were also studied,such as prepolymer concentration,reaction temperature,reaction time and different anions.The structure and shapes of nanogels were charactedby DLS,AFM,SEM and XPS.The nanogels showed high zeta potentials,and could form nanosized complexeswith plasmid DNA.Compared with PEI25K,nanogels exhibited good transfectionefficiencies and significantly low cytotoxicity.Above results clearly demonstrated theadvantages of the PEI nanogels over PEI(25K),and their potential use as gene carriers.Because the structure of nanogels was relatively unstable,the high stable nanogelswere prepared by photocross-linking method.At last,the high stable nanogels withnarrow distributions were obtained by selecting proper radiation source,radiationintensity,and radiation time and so on.In general,the PEI nanogel prepared byphotocross-linking method were used as nanogel studying modle,we extended that thecomposite design of the nanogel was from styrene- maleic anhydride(SMA)prepolymer,which the structure was confimed by ¹HNMR,IR spectrum.