title: Fe3O4-PEI-RITC magnetic nanoparticles with imaging and gene transfer capability: development of a tool for neural cell transplantation therapies.
abstract: OBJECTIVE
  To develop Fe(3)O(4)-PEI-RITC magnetic nanoparticles with multimodal MRI-fluorescence imaging and transfection capability, for use in neural cell replacement therapies.
  
  
  METHODS
  The Fe(3)O(4)-PEI-RITC MNPs were synthesised through a multi-step chemical grafting procedure: (i) Silanisation of MNPs with 3-iodopropyltrimethoxysilane; (ii) PEI coupling with iodopropyl groups on the MNP surface; and (iii) RITC binding onto the PEI coating. The cell labelling and transfection capabilities of these particles were evaluated in astrocytes derived from primary cultures.
  
  
  RESULTS
  Fe(3)O(4)-PEI-RITC MNPs did not exert acute toxic effects in astrocytes (at ≤ 6 days). Cells showed rapid and extensive particle uptake with up to 100% cellular labelling observed by 24 h. MRI and microscopy studies demonstrate that the particles have potential for use in bimodal MR-fluorescence imaging. Additionally, the particles were capable of delivering plasmids encoding reporter protein (approximately 4 kb) to astrocytes, albeit with low efficiencies.
  
  
  CONCLUSIONS
  Multifunctional Fe(3)O(4)-PEI-RITC MNPs were successfully prepared using a multi-step synthetic pathway, with the PEI and RITC chemically bound onto the MNP surface. Their combined MR-fluorescence imaging capabilities with additional potential for transfection applications can provide a powerful tool, after further development, for non-invasive cell tracking and gene transfer to neural transplant populations.
authors: Chemical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors: Humphrey H P
authors: HH
authors: Yiu
authors: Mark R
authors: MR
authors: Pickard
authors: Cristina I
authors: CI
authors: Olariu
authors: Stephen R
authors: SR
authors: Williams
authors: Divya M
authors: DM
authors: Chari
authors: Matthew J
authors: MJ
authors: Rosseinsky
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000637:transplantation; D017690:Cell Transplantation; D002478:Cells, Cultured; D005290:Ferric Compounds / Q000737:chemistry*; D018014:Gene Transfer Techniques; D007097:Imines / Q000737:chemistry*; D007150:Immunohistochemistry; D008280:Magnetics; D008856:Microscopy, Fluorescence; D053758:Nanoparticles; D011095:Polyethylenes / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; D007097:Imines; D011095:Polyethylenes; C505405:poly(ethylene imine); C000499:ferric oxide