title: Nanomagnetic activation as a way to control the efficacy of nucleic acid delivery.
abstract: OBJECTIVE
  To explore the potential of magnetofection in delivering pDNA to primary mouse embryonic fibroblasts (PMEFs) and porcine fetal fibroblasts (PFFs) and investigate an effect of magnetic cell labeling on transfection efficacy.
  
  
  METHODS
  The formulation and a dose of the magnetic vector were optimized. The efficacy of the procedure was quantified by vector internalization, transgene expression and cell iron loading upon specific labeling with Ab-conjugated magnetic beads or non-specific labeling with MNPs.
  
  
  RESULTS
  Up to sixty percent of PMEF and PFF cells were transfected at low pDNA doses of 4-16 pg pDNA/cell. Specific labeling of the PMEFs with MNPs, resulted in a 3- and 2-fold increase in pDNA internalization upon magnetofection and lipofection, respectively, that yielded a 2-4-fold increase in percent of transgene-expressing cells. Non-specific cell labeling had no effect on the efficacy of the reporter expression, despite the acquisition of similar magnetic moments per cell. In PFFs, specific magnetic labeling of the cell surface receptors inhibited internalization and transfection efficacy.
  
  
  CONCLUSIONS
  Magnetic labeling of cell-surface receptors combined with the application of an inhomogenous magnetic field (nanomagnetic activation) can affect the receptor-mediated internalization of delivery vectors and be used to control nucleic acid delivery to cells.
authors.affiliation: Institute of Experimental Oncology and Therapy Research, KLinikum rechts der Isar der Technischen Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Bartosz F
authors.initials: BF
authors.lastname: Grześkowiak
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Sánchez-Antequera
authors.forename: Edelburga
authors.initials: E
authors.lastname: Hammerschmid
authors.forename: Markus
authors.initials: M
authors.lastname: Döblinger
authors.forename: Dietmar
authors.initials: D
authors.lastname: Eberbeck
authors.forename: Anna
authors.initials: A
authors.lastname: Woźniak
authors.forename: Ryszard
authors.initials: R
authors.lastname: Słomski
authors.forename: Christian
authors.initials: C
authors.lastname: Plank
authors.forename: Olga
authors.initials: O
authors.lastname: Mykhaylyk
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000008:administration & dosage* / Q000235:genetics; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry; D005347:Fibroblasts / Q000378:metabolism*; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D051379:Mice; D046529:Microscopy, Electron, Transmission; D010957:Plasmids; D061251:Primary Cell Culture; D013194:Staining and Labeling; D013499:Surface Properties; D013552:Swine; D014162:Transfection / Q000379:methods*
chemical_list: D004337:Drug Carriers; D058185:Magnetite Nanoparticles; D004247:DNA