title: Targeted cell uptake of a noninternalizing antibody through conjugation to iron oxide nanoparticles in primary central nervous system lymphoma.
abstract: BACKGROUND
  At present there is no standard of care for patients with primary central nervous system lymphoma (PCNSL) because of the difficulty in delivering therapeutically effective doses of drugs to the intracellular site of the target PCNSL. Here we report the use of an iron oxide nanoparticle to promote the internalization of a PCNSL targeting antibody by target cells.
  
  
  METHODS
  Iron oxide nanoparticles coated with a copolymer of chitosan-grafted polyethylene glycol (NPs) were conjugated with an anti-CD20 single-chain variable fragment-streptavidin fusion protein (FP), and optically activated with Oregon Green 488. The ability of NP-FP to target PCNSL cells was assessed using flow cytometry and the ferrozine assay. Cell internalization of NP-FP was examined by confocal fluorescence microscopy.
  
  
  RESULTS
  The antibody-conjugated NPs had a near-neutral zeta potential and remained stable in biological media for more than 1 week, which may minimizes nonspecific cell uptake. The diameter of the NPs was about 70 nm, which is in an optimal range for maximizing cell uptake. The selective binding of these NPs was demonstrated with binding to PCNSL cells 3- to 4-fold higher than binding to control cells. Z-stack imaging by confocal microscopy revealed the NPs were internalized by PCNSL cells.
  
  
  CONCLUSIONS
  The high-degree specific binding and cell uptake of NP-FP in PCNSL suggests this NP formulation can be further developed to improve therapy of PCNSL.
authors.affiliation: Department of Neurosurgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning, People's Republic of China.
authors.forename: Tingzhong
authors.initials: T
authors.lastname: Wang
authors.forename: Forrest M
authors.initials: FM
authors.lastname: Kievit
authors.forename: Omid
authors.initials: O
authors.lastname: Veiseh
authors.forename: Hamed
authors.initials: H
authors.lastname: Arami
authors.forename: Zachary R
authors.initials: ZR
authors.lastname: Stephen
authors.forename: Chen
authors.initials: C
authors.lastname: Fang
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Liu
authors.forename: Richard G
authors.initials: RG
authors.lastname: Ellenbogen
authors.forename: Miqin
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000906:Antibodies / Q000008:administration & dosage / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000276:immunology*; D002264:Carboxylic Acids; D045744:Cell Line, Tumor; D016543:Central Nervous System Neoplasms / Q000188:drug therapy*; D048271:Chitosan / Q000737:chemistry; D004396:Coloring Agents; D004337:Drug Carriers; D005290:Ferric Compounds / Q000008:administration & dosage*; D005297:Ferrozine; D005434:Flow Cytometry; D006801:Humans; D007502:Iron Chelating Agents; D016393:Lymphoma, B-Cell / Q000628:therapy*; D018613:Microscopy, Confocal; D053758:Nanoparticles; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000627:therapeutic use*; D019809:Streptavidin / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000906:Antibodies; D018951:Antigens, CD20; D002264:Carboxylic Acids; D004396:Coloring Agents; D004337:Drug Carriers; D005290:Ferric Compounds; D007502:Iron Chelating Agents; C436864:Oregon Green 488 carboxylic acid; D011993:Recombinant Fusion Proteins; C000499:ferric oxide; D005297:Ferrozine; D011092:Polyethylene Glycols; D048271:Chitosan; D019809:Streptavidin
keywords: CD20; CP; Cell targeting; Chitosan-grafted PEG; Control NP; FBS; FP; Fetal bovine serum; Fusion protein; HFF; Human foreskin fibroblast; MRI; Magnetic resonance imaging; NP; NP-control; Nanomedicine; Nanoparticle; OG488; Oregon Green 488; PBS; PCNSL; PEG; Phosphate-buffered saline; Polyethylene glycol; Primary central nervous system lymphoma; Theranostic