title: Intracellular protein delivery by hollow mesoporous silica capsules with a large surface hole.
abstract: We prepared cell membrane-permeable hollow mesoporous silica capsules (HMSCs) by a simple new method. CTAB micellar assembly in cholesterol emulsion gave rise to a novel capsular morphology of the HMSC particles. The HMSCs consisted of mesostructured silica walls with a large surface hole (25-50 nm) and the average particle dimension was 100-300 nm. They exhibited high surface areas of up to 719.3 m(2) g(-1) and a mesoporous range of pores of 2.4-2.7 nm. The surface-functionalized HMSCs could also be prepared by a similar co-condensation method using tetraethoxysilane with various organoalkoxysilane precursors in the presence of cholesterol. These organically modified HMSCs could be further modified on demand. For example, a carboxy-functionalized HMSC could be surface-functionalized by a green fluorescent 5-aminofluorescein (AFL) through an amidation reaction to afford a fluorescent AFL-HMSC. The hollow capsular morphology of the HMSCs with a large surface hole enabled us to develop very efficient intracellular delivery systems for membrane-impermeable ions, molecules, and various functional proteins. Non-covalent sequestration and delivery of proteins as well as covalent linkage of fluorescent molecules on the silica surface are effective for this system. The highly negatively charged green fluorescent probe mag-fluo-4 could be intracellularly delivered into HeLa cells by HMSC without any difficulty. The HMSCs could also effectively transport large functional proteins such as antibodies into HeLa cells. The efficiency of protein delivery by HMSC seems to be 3-22-fold higher than that of mesoporous silica nanospheres (MSNs) based on confocal laser scanning microscopy (CLSM) analysis.
authors.affiliation: Department of Chemistry and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies, Yongin, Korea.
authors.forename: Ji-Sun
authors.initials: JS
authors.lastname: Lim
authors.forename: Kiwon
authors.initials: K
authors.lastname: Lee
authors.forename: Jong-Nam
authors.initials: JN
authors.lastname: Choi
authors.forename: Yong-Kyung
authors.initials: YK
authors.lastname: Hwang
authors.forename: Mi-Yeon
authors.initials: MY
authors.lastname: Yun
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Yong Sun
authors.initials: YS
authors.lastname: Won
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Hyockman
authors.initials: H
authors.lastname: Kwon
authors.forename: Seong
authors.initials: S
authors.lastname: Huh
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry*; D004058:Diffusion; D006367:HeLa Cells; D006801:Humans; D008422:Materials Testing; D053769:Nanocapsules / Q000008:administration & dosage / Q000737:chemistry* / Q000648:ultrastructure; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D000911:Antibodies, Monoclonal; D053769:Nanocapsules; D012822:Silicon Dioxide