季铵化聚乙烯亚胺/SiO_2微粒的制备及其抗菌性能

Preparation and bactericidal activity of SiO_2 microparticles grafted with quaternized polyethylenimines

通过4-溴丁酰氯的媒介,将水溶性聚乙烯亚胺(PEI)接枝在纳米SiO2表面,分别用1-溴己烷和碘甲烷对接枝的PEI进行N-烷基化修饰,使PEI中的部分氨基转变成季铵盐,得到水不溶性季铵化聚乙烯亚胺(QPEI)/SiO2微粒,其中PEI接枝量质量分数为14.8%,季铵化的氨基质量分数22.8%。红外光谱分析证实PEI接枝在纳米SiO2表面,随后成功地被卤代烷N-烷基化修饰。透射电镜观察发现QPEI/SiO2的形态不规则,大多数颗粒团聚成200—300 nm的微粒。抗菌检测结果表明,QPEI/SiO2微粒对金黄色葡萄球菌(S.aureu)和大肠杆菌(E.coli)的最小抑菌质量浓度(MIC)分别为80μg/mL和1 200μg/mL。QPEI/SiO2微粒破坏了细胞的完整性,最终将整个细胞分解成碎片。

Water-soluble polyethylenimine （PEI） was grafted intermedium effect of 4-bromobutyryl chloride, and quaternized polyethylenimines （ QPEI/SiO2 ） was 1-bromohexane and idomethane, respectively. The onto the surface of nano-SiO2 particles the water-insoluble antimicrobial SiO2 particles through the grafted with prepared followed by the N-alkylation of coated PEI with grafted mass fraction of PEI on the composite of QPEI/SiO2 is 14.8%, and the mass fraction of the quaternized amino groups in PEI is 22.8%. The results of IR analysis testify that the macromolecular PEI is successfully immobilized on the surface of SiO2 nanoparticles. The morphology of QPEI/SiO2 observed with transmission electron microscope （TEM） shows that the shape of SiO2 nanoparticles grafted with PEI is irregular, compared with blank SiO2 nanoparticles, and most of them aggregate to form many microparticles with 200-300 nm in size. The minimum inhibitory mass concentrations （MIC） of QPEI/SiO2 against Gram-positive bacterium, Staphylococcus aureus and Gram-negative bacterium, Escherichia coli are 80 μg/mL and 1 200μg/mL, respectively. QPEI/SiO2 damaged the integrity of cell structure and decomposed the bacterial cells during the biocidal process.