title: Iron(III)-doped, silica nanoshells: a biodegradable form of silica.
abstract: Silica nanoparticles are being investigated for a number of medical applications; however, their use in vivo has been questioned because of the potential for bioaccumulation. To obviate this problem, silica nanoshells were tested for enhanced biodegradability by doping iron(III) into the nanoshells. Exposure of the doped silica to small molecule chelators and mammalian serum was explored to test whether the removal of iron(III) from the silica nanoshell structure would facilitate its degradation. Iron chelators, such as EDTA, desferrioxamine, and deferiprone, were found to cause the nanoshells to degrade on the removal of iron(III) within several days at 80 °C. When the iron(III)-doped, silica nanoshells were submerged in fetal bovine and human serums at physiological temperature, they also degrade via removal of the iron by serum proteins, such as transferrin, over a period of several weeks.
authors.affiliation: Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Kristina K
authors.initials: KK
authors.lastname: Pohaku Mitchell
authors.forename: Alexander
authors.initials: A
authors.lastname: Liberman
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Kummel
authors.forename: William C
authors.initials: WC
authors.lastname: Trogler
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism; D002417:Cattle; D000077543:Deferiprone; D003676:Deferoxamine / Q000378:metabolism; D004492:Edetic Acid / Q000378:metabolism; D005290:Ferric Compounds / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007502:Iron Chelating Agents / Q000378:metabolism; D057145:Nanoshells / Q000737:chemistry* / Q000648:ultrastructure; D011728:Pyridones / Q000378:metabolism; D044967:Serum / Q000378:metabolism; D012822:Silicon Dioxide / Q000737:chemistry* / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D005290:Ferric Compounds; D007502:Iron Chelating Agents; D011728:Pyridones; D014168:Transferrin; D000077543:Deferiprone; D012822:Silicon Dioxide; D004492:Edetic Acid; D003676:Deferoxamine