title: Different patterns of nuclear and mitochondrial penetration by the G3 PAMAM dendrimer and its biotin-pyridoxal bioconjugate BC-PAMAM in normal and cancer cells in vitro.
abstract: The intracellular localization and colocalization of a fluorescently labeled G3 amine-terminated cationic polyamidoamine (PAMAM) dendrimer and its biotin-pyridoxal (BC-PAMAM) bioconjugate were investigated in a concentration-dependent manner in normal human fibroblast (BJ) and squamous epithelial carcinoma (SCC-15) cell lines. After 24 hours treatment, both cell lines revealed different patterns of intracellular dendrimer accumulation depending on their cytotoxic effects. Cancer cells exhibited much higher (20-fold) tolerance for native PAMAM treatment than fibroblasts, whereas BC-PAMAM was significantly toxic only for fibroblasts at 50 µM concentration. Fibroblasts accumulated the native and bioconjugated dendrimers in a concentration-dependent manner at nontoxic range of concentration, with significantly lower bioconjugate loading. After reaching the cytotoxicity level, fluorescein isothiocyanate-PAMAM accumulation remains at high, comparable level. In cancer cells, native PAMAM loading at higher, but not cytotoxic concentrations, was kept at constant level with a sharp increase at toxic concentration. Mander's coefficient calculated for fibroblasts and cancer cells confirmed more efficient native PAMAM penetration as compared to BC-PAMAM. Significant differences in nuclear dendrimer penetration were observed for both cell lines. In cancer cells, PAMAM signals amounted to ~25%-35% of the total nuclei area at all investigated concentrations, with lower level (15%-25%) observed for BC-PAMAM. In fibroblasts, the dendrimer nuclear signal amounted to 15% at nontoxic and up to 70% at toxic concentrations, whereas BC-PAMAM remained at a lower concentration-dependent level (0.3%-20%). Mitochondrial localization of PAMAM and BC-PAMAM revealed similar patterns in both cell lines, depending on the extracellular dendrimer concentration, and presented significantly lower signals from BC-PAMAM, which correlated well with the cytotoxicity.
authors.affiliation: Bioorganic Chemistry Laboratory, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Uram
authors.affiliation: Bioorganic Chemistry Laboratory, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Szuster
authors.affiliation: Cosmetology Department, University of Information Technology and Management in Rzeszow, Rzeszow, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Filipowicz
authors.affiliation: Institute of Nursery and Health Sciences, Faculty of Medicine, University of Rzeszow, Rzeszow, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Gargasz
authors.affiliation: Institute of Nursery and Health Sciences, Faculty of Medicine, University of Rzeszow, Rzeszow, Poland.
authors.forename: Stanisław
authors.initials: S
authors.lastname: Wołowiec
authors.affiliation: Department of Drug Technology and Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Wałajtys-Rode
mesh_terms: D001710:Biotin / Q000737:chemistry* / Q000494:pharmacology; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D050091:Dendrimers / Q000737:chemistry* / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D011730:Pyridoxal / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D050091:Dendrimers; C104700:PAMAM Starburst; D011730:Pyridoxal; D001710:Biotin
keywords: PAMAM G3 dendrimer; bioconjugate; colocalization; confocal microscopy; mitochondria; normal and cancer cells; nuclei