title: Modification of human BMSC with nanoparticles of polymeric biomaterials and plasmid DNA for BMP-2 secretion.
abstract: BACKGROUND
  Genetic modification of human bone marrow stem cells (hBMSCs) before administration to a patient is emerging as a viable approach to creating tailored cells that perform effectively in a clinical setting. To this end, safe delivery systems are needed that can package therapeutic genes into nanoparticles for cellular delivery.
  
  
  METHODS
  We evaluated different plasmids on gene expression and compared the effective plasmids directly in hBMSCs. Then, we evaluated the transfection efficiencies of the polymeric carriers linoleic acid-substituted polyethylenimine (PEI-LA), polyethylenimine (PEI)-25, and PEI-2 using flow cytometry. We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide to compare the toxicity of PEI-LA and PEI-25 on hBMSCs. We further assessed bone morphogenetic protein-2 (BMP-2) secretion and the osteogenic activity of hBMSCs transfected with the polymeric (PEI-LA and PEI-25) gWIZ-BMP-2 complex.
  
  
  RESULTS
  Unlike the transformed cells that gave robust (>50%) transfection, only a few percent (<10%) of hBMSCs was transfected by the developed nanoparticles in culture. The plasmid DNA design was critical for expression of the transgene product, with the choice of the right promoter clearly enhancing the efficiency of transgene expression. Using the in-house designed PEI-LA, hBMSCs secreted BMP-2 in culture (~4 ng BMP-2/10(6) cells/d), which indicates the feasibility of using PEI-LA as a delivery system. Furthermore, we demonstrated an increased osteogenic activity in vitro for hBMSCs transfected with the PEI-LA containing the BMP-2 expression system.
  
  
  CONCLUSIONS
  These results provide encouraging evidence for the potential use of a low toxic PEI-LA to genetically modify hBMSC.
authors.affiliation: Department of Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Yufu
authors.initials: Y
authors.lastname: Wang
authors.forename: Nesrine Z
authors.initials: NZ
authors.lastname: Mostafa
authors.forename: Charlie Y M
authors.initials: CY
authors.lastname: Hsu
authors.forename: Laura
authors.initials: L
authors.lastname: Rose
authors.forename: Cezary
authors.initials: C
authors.lastname: Kucharki
authors.forename: Jinglong
authors.initials: J
authors.lastname: Yan
authors.forename: Hongxing
authors.initials: H
authors.lastname: Jiang
authors.forename: Hasan
authors.initials: H
authors.lastname: Uludağ
mesh_terms: D000293:Adolescent; D000328:Adult; D001854:Bone Marrow Cells / Q000187:drug effects*; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D018014:Gene Transfer Techniques; D057809:HEK293 Cells; D006801:Humans; D008875:Middle Aged; D053758:Nanoparticles / Q000627:therapeutic use*; D010012:Osteogenesis; D010957:Plasmids; D011094:Polyethyleneimine / Q000008:administration & dosage*; D033581:Stem Cell Transplantation; D019076:Transgenes; D055815:Young Adult
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D011094:Polyethyleneimine