title: Osteogenic differentiation of mesenchymal stem cells using PAMAM dendrimers as gene delivery vectors.
abstract: This paper reports the use of different generations of polyamidoamine (PAMAM) dendrimers for the in vitro transfection of mesenchymal stem cells (MSCs). A systematic study was carried out on the transfection efficiency achieved by the PAMAM dendrimers using a beta-galactosidase reporter gene system. Transfection results were shown to be dependent upon the generation of dendrimers, the amine to phosphate group ratio and the cell passage number. In all cases, the transfection efficiency was very low. Nevertheless, it was hypothesized that a low transfection level could be sufficient to promote the in vitro differentiation of MSCs towards the osteoblastic lineage. To address this possibility, dendrimers carrying the human bone morphogenetic protein-2 (hBMP-2) gene-containing plasmid were used. All quantitative (alkaline phosphatase activity, osteocalcin secretion and calcium deposition) and qualitative (von Kossa staining) osteogenic markers were significantly stronger in transfected cells when compared to non-transfected ones. This study not only clearly demonstrates that a low transfection level can be sufficient for inducing in vitro differentiation of MSCs to the osteoblast phenotype but also highlights the importance of focusing research on the development of gene delivery vectors in the concrete application.
authors.affiliation: Centro de Química da Madeira, Departamento de Química, Universidade da Madeira, Campus Universitário da Penteada, Funchal, Portugal.
authors.forename: José Luís
authors.initials: JL
authors.lastname: Santos
authors.forename: Elena
authors.initials: E
authors.lastname: Oramas
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Pêgo
authors.forename: Pedro Lopes
authors.initials: PL
authors.lastname: Granja
authors.forename: Helena
authors.initials: H
authors.lastname: Tomás
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D002470:Cell Survival; D002478:Cells, Cultured; D050091:Dendrimers; D015870:Gene Expression; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000196:embryology; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D010012:Osteogenesis; D010957:Plasmids / Q000008:administration & dosage* / Q000235:genetics / Q000633:toxicity; D011073:Polyamines / Q000008:administration & dosage* / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D050091:Dendrimers; C104700:PAMAM Starburst; D011073:Polyamines; D001616:beta-Galactosidase