title: Nanodisco balls: control over surface versus core loading of diagnostically active nanocrystals into polymer nanoparticles.
abstract: Nanoparticles of complex architectures can have unique properties. Self-assembly of spherical nanocrystals is a high yielding route to such systems. In this study, we report the self-assembly of a polymer and nanocrystals into aggregates, where the location of the nanocrystals can be controlled to be either at the surface or in the core. These nanospheres, when surface decorated with nanocrystals, resemble disco balls, thus the term nanodisco balls. We studied the mechanism of this surface loading phenomenon and found it to be Ca(2+) dependent. We also investigated whether excess phospholipids could prevent nanocrystal adherence. We found surface loading to occur with a variety of nanocrystal types including iron oxide nanoparticles, quantum dots, and nanophosphors, as well as sizes (10-30 nm) and shapes. Additionally, surface loading occurred over a range of polymer molecular weights (∼30-3000 kDa) and phospholipid carbon tail length. We also show that nanocrystals remain diagnostically active after loading onto the polymer nanospheres, i.e., providing contrast in the case of magnetic resonance imaging for iron oxide nanoparticles and fluorescence for quantum dots. Last, we demonstrated that a fluorescently labeled protein model drug can be delivered by surface loaded nanospheres. We present a platform for contrast media delivery, with the unusual feature that the payload can be controllably localized to the core or the surface.
authors.affiliation: Departments of Radiology, ‡Bioengineering, §Biochemistry and Biophysics, ⊥Cardiology, ∥Chemistry, and #Materials Science and Engineering, University of Pennsylvania , 3400 Spruce Street, 1 Silverstein, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Chhour
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gallo
authors.forename: Rabee
authors.initials: R
authors.lastname: Cheheltani
authors.forename: Dewight
authors.initials: D
authors.lastname: Williams
authors.forename: Ajlan
authors.initials: A
authors.lastname: Al-Zaki
authors.forename: Taejong
authors.initials: T
authors.lastname: Paik
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Nichol
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Tian
authors.forename: Pratap C
authors.initials: PC
authors.lastname: Naha
authors.forename: Walter R
authors.initials: WR
authors.lastname: Witschey
authors.forename: Harry R
authors.initials: HR
authors.lastname: Allcock
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Murray
authors.forename: Andrew
authors.initials: A
authors.lastname: Tsourkas
authors.forename: David P
authors.initials: DP
authors.lastname: Cormode
mesh_terms: D000268:Adhesiveness; D000818:Animals; D002122:Calcium Chloride / Q000737:chemistry; D002460:Cell Line; D003287:Contrast Media / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003287:Contrast Media; D004337:Drug Carriers; D005290:Ferric Compounds; D010743:Phospholipids; D011108:Polymers; C045869:polybis(carbophenoxypropane); C000499:ferric oxide; D002122:Calcium Chloride
keywords: MRI; directed assembly; multimodal; nanoparticles; polyphosphazene; theranostic