title: Porous-wall hollow glass microspheres as novel potential nanocarriers for biomedical applications.
abstract: Porous-wall hollow glass microspheres (PW-HGMs) are a novel form of glass material consisting of a 10- to 100-microm-diameter hollow central cavity surrounded by a 1-microm-thick silica shell. A tortuous network of nanometer-scale channels completely penetrates the shell. We show here that these channels promote size-dependent uptake and controlled release of biological molecules in the 3- to 8-nm range, including antibodies and a modified single-chain antibody variable fragment. In addition, a 6-nm (70-kDa) dextran can be used to gate the porous walls, facilitating controlled release of an internalized short interfering RNA. PW-HGMs remained in place after mouse intratumoral injection, suggesting a possible application for the delivery of anticancer drugs. The combination of a hollow central cavity that can carry soluble therapeutic agents with mesoporous walls for controlled release is a unique characteristic that distinguishes PW-HGMs from other glass materials for biomedical applications.
  
  
  BACKGROUND
  Porous-wall hollow glass microspheres (PW-HGMs) are a novel form of glass microparticles with a tortuous network of nanometer-scale channels. These channels allow size-dependent uptake and controlled release of biological molecules including antibodies and single-chain antibody fragments. PW-HGMs remained in place after mouse intratumoral injection, suggesting a possible application for the delivery of anti-cancer drugs.
authors.affiliation: Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA. sli@mcg.edu
authors.forename: Shuyi
authors.initials: S
authors.lastname: Li
authors.forename: Lynsa
authors.initials: L
authors.lastname: Nguyen
authors.forename: Hairong
authors.initials: H
authors.lastname: Xiong
authors.forename: Meiyao
authors.initials: M
authors.lastname: Wang
authors.forename: Tom C-C
authors.initials: TC
authors.lastname: Hu
authors.forename: Jin-Xiong
authors.initials: JX
authors.lastname: She
authors.forename: Steven M
authors.initials: SM
authors.lastname: Serkiz
authors.forename: George G
authors.initials: GG
authors.lastname: Wicks
authors.forename: William S
authors.initials: WS
authors.lastname: Dynan
mesh_terms: D000818:Animals; D003911:Dextrans / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005453:Fluorescence; D005898:Glass / Q000737:chemistry*; D006801:Humans; D007267:Injections; D051379:Mice; D008819:Mice, Nude; D008863:Microspheres; D008970:Molecular Weight; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D009369:Neoplasms / Q000378:metabolism; D009696:Nucleic Acids / Q000378:metabolism; D010316:Particle Size; D016062:Porosity; D011506:Proteins / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D003911:Dextrans; D004337:Drug Carriers; D009696:Nucleic Acids; D011506:Proteins; D016650:Fluorescein-5-isothiocyanate