title: Iron-Loaded Magnetic Nanocapsules for pH-Triggered Drug Release and MRI Imaging.
abstract: Magnetic nanocapsules were synthesized for controlled drug release, magnetically assisted delivery, and MRI imaging. These magnetic nanocapsules, consisting of a stable iron nanocore and a mesoporous silica shell, were synthesized by controlled encapsulation of ellipsoidal hematite in silica, partial etching of the hematite core in acid, and reduction of the core by hydrogen. The iron core provided a high saturation magnetization and was stable against oxidation for at least 6 months in air and 1 month in aqueous solution. The hollow space between the iron core and mesoporous silica shell was used to load anticancer drug and a T1-weighted MRI contrast agent (Gd-DTPA). These multifunctional monodispersed magnetic "nanoeyes" were coated by multiple polyelectrolyte layers of biocompatible poly-l-lysine and sodium alginate to control the drug release as a function of pH. We studied pH-controlled release, magnetic hysteresis curves, and T1/T2MRI contrast of the magnetic nanoeyes. They also served as MRI contrast agents with relaxivities of 8.6 mM-1s-1(r1) and 285 mM-1s-1(r2).
authors.affiliation: Department of Chemistry, Center for Optical Materials Science and Engineering (COMSET), and Environmental Toxicology Program, Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Center for Optical Materials Science and Engineering (COMSET), and Environmental Toxicology Program, Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Dino
authors.initials: D
authors.lastname: Sulejmanovic
authors.affiliation: Department of Bioengineering, Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Moore
authors.affiliation: Vanderbilt University Medical Center, Vanderbilt University , Nashville, Tennessee 37232, United States.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Colvin
authors.affiliation: Department of Materials Science and Engineering and Center for Optical Materials Science and Engineering (COMSET), Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Bin
authors.initials: B
authors.lastname: Qi
authors.affiliation: Department of Materials Science and Engineering and Center for Optical Materials Science and Engineering (COMSET), Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: O Thompson
authors.initials: OT
authors.lastname: Mefford
authors.affiliation: Vanderbilt University Medical Center, Vanderbilt University , Nashville, Tennessee 37232, United States.
authors.forename: John C
authors.initials: JC
authors.lastname: Gore
authors.affiliation: Department of Bioengineering, Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Frank
authors.initials: F
authors.lastname: Alexis
authors.affiliation: Department of Chemistry, Center for Optical Materials Science and Engineering (COMSET), and Environmental Toxicology Program, Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Shiou-Jyh
authors.initials: SJ
authors.lastname: Hwu
authors.affiliation: Department of Chemistry, Center for Optical Materials Science and Engineering (COMSET), and Environmental Toxicology Program, Clemson University , Clemson, South Carolina 29634, United States.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Anker
references.citation: Eur Radiol. 2001;11(11):2319-31
references.pmid: 11702180
references.citation: J Colloid Interface Sci. 1969 Feb;29(2):187-93
references.pmid: 5776564
references.citation: J Mater Chem. 2012 Jul 7;22(25):12802-12809
references.pmid: 24520183
references.citation: ChemMedChem. 2008 Sep;3(9):1311-5
references.pmid: 18613203
references.citation: Adv Drug Deliv Rev. 2006 Dec 30;58(15):1655-70
references.pmid: 17125884
references.citation: J Am Chem Soc. 2010 Jan 20;132(2):552-7
references.pmid: 20017538
references.citation: ACS Nano. 2011 Jul 26;5(7):5390-9
references.pmid: 21634407
references.citation: Angew Chem Int Ed Engl. 2008;47(29):5362-5
references.pmid: 18551493
references.citation: ACS Nano. 2013 Feb 26;7(2):1178-87
references.pmid: 23281651
references.citation: Langmuir. 2009 Dec 15;25(24):14079-85
references.pmid: 20560555
references.citation: Proc Natl Acad Sci U S A. 2006 Mar 28;103(13):4930-4
references.pmid: 16549762
references.citation: ACS Nano. 2010 Jan 26;4(1):529-39
references.pmid: 20041633
references.citation: Int J Pharm. 2008 Apr 16;354(1-2):217-26
references.pmid: 18191350
references.citation: Science. 1998 Nov 6;282(5391):1111-4
references.pmid: 9804547
references.citation: Pharm Res. 2009 Jan;26(1):235-43
references.pmid: 18712584
references.citation: Clin Pharmacokinet. 2003;42(5):419-36
references.pmid: 12739982
references.citation: Mol Pharm. 2014 Jan 6;11(1):24-39
references.pmid: 24215280
references.citation: Handb Exp Pharmacol. 2010;(197):55-86
references.pmid: 20217526
references.citation: J Am Chem Soc. 2006 Aug 23;128(33):10676-7
references.pmid: 16910651
references.citation: Langmuir. 2007 Apr 10;23(8):4554-62
references.pmid: 17338557
references.citation: Langmuir. 2008 Oct 21;24(20):11811-8
references.pmid: 18808160
references.citation: Mol Pharm. 2008 Jul-Aug;5(4):505-15
references.pmid: 18672949
references.citation: Ther Deliv. 2014 Feb;5(2):97-100
references.pmid: 24483186
references.citation: Langmuir. 2009 Sep 1;25(17):9728-33
references.pmid: 19507842
references.citation: Chem Soc Rev. 2007 Apr;36(4):636-49
references.pmid: 17387411
references.citation: Angew Chem Int Ed Engl. 2001 Dec 3;40(23):4447-4449
references.pmid: 12404441
references.citation: Small. 2008 Nov;4(11):1925-9
references.pmid: 18752211
references.citation: Mol Pharm. 2012 Jan 1;9(1):91-101
references.pmid: 22098247
references.citation: Biomacromolecules. 2003 Nov-Dec;4(6):1773-83
references.pmid: 14606908
references.citation: J Am Chem Soc. 2005 Apr 27;127(16):5732-3
references.pmid: 15839639
references.citation: Int J Hyperthermia. 2005 Nov;21(7):637-47
references.pmid: 16304715
references.citation: Bioconjug Chem. 1999 Mar-Apr;10(2):186-91
references.pmid: 10077466
references.citation: Biomaterials. 2006 Jul;27(20):3691-700
references.pmid: 16574222
references.citation: Ann Intern Med. 1979 Nov;91(5):710-7
references.pmid: 496103
references.citation: Chem Commun (Camb). 2011 Mar 7;47(9):2631-3
references.pmid: 21234477
references.citation: Cancer Res. 1996 May 1;56(9):2082-5
references.pmid: 8616854