Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Langmuir. 2011 Jan 4;27(1):420-9. doi: 10.1021/la1039909. Epub 2010 Dec 7.
Bactericidal paramagnetic particles were obtained either through the attachment of a conjugate of poly(ethyleneimine) (PEI) and poly(hexamethylene biguanide) (PHMBG) to the surface of magnetite (Fe(3)O(4)) particles, or via the sol-gel encapsulation of magnetite particles with a functional silane (3-glycidoxypropyl trimethoxysilane) and subsequent binding of the polysiloxane shell by the amine/imine groups of PHMBG. The encapsulated core-shell particles possess a high saturation magnetization, which is preserved for more than 10 months while in contact with air in aqueous suspensions. The minimum inhibitory concentration (MIC) of the encapsulated particles for eight types of bacteria was size-dependent, with polydisperse submillimeter particles possessing a several-fold higher MIC than analogous particles sized below 250 nm. The encapsulated particles are biocompatible and nontoxic to mammalian cells such as mouse fibroblasts. The particles efficiently bind both glycopeptide components mimicking the gram-positive bacteria membranes and whole bacteria, and possess broad-range bactericidal activity. The cell-particle complexes can be captured, manipulated, and removed by means of a magnet.
杀菌磁性颗粒可以通过将聚（亚乙基亚胺）（PEI）和聚（六亚甲基双胍）（PHMBG）的缀合物附着在磁铁矿（Fe3O4）颗粒的表面上，或者通过用功能化硅烷（3-缩水甘油丙基三甲氧基硅烷）对磁铁矿颗粒进行溶胶-凝胶包封，随后通过 PHMBG 的胺/亚胺基团结合聚硅氧烷壳来获得。包封的核壳颗粒具有高的饱和磁化强度，在与水悬浮液中的空气接触超过 10 个月后仍保持不变。包封颗粒对八种类型细菌的最小抑菌浓度（MIC）取决于尺寸，多分散亚毫米级颗粒的 MIC 比类似的小于 250nm 的颗粒高几倍。包封的颗粒对哺乳动物细胞如小鼠成纤维细胞具有生物相容性和低毒性。颗粒能够有效地结合模拟革兰氏阳性细菌膜和整个细菌的糖肽成分，并具有广谱杀菌活性。细胞-颗粒复合物可以通过磁体捕获、操作和去除。
