title: Understanding magnetic nanoparticle osteoblast receptor-mediated endocytosis using experiments and modeling.
abstract: Iron oxide nanoparticles are promising candidates for controlling drug delivery through an external magnetic force to treat a wide range of diseases, including osteoporosis. Previous studies have demonstrated that in the presence of hydroxyapatite coated magnetite (Fe3O4) nanoparticles, osteoblast (or bone forming cell) proliferation and long-term functions (such as calcium deposition) were significantly enhanced. Hydroxyapatite is the major inorganic component of bone. As a further attempt to understand why, in the current study, the uptake of such nanoparticles into osteoblasts was experimentally investigated and mathematically modeled. Magnetite nanoparticles were synthesized using a co-precipitation method and were coated with hydroxyapatite. A cellular uptake experiment at low temperatures indicated that receptor-mediated endocytosis contributed to the internalization of the magnetic nanoparticles into osteoblasts. A model was further developed to explain the uptake of magnetic nanoparticles into osteoblasts using receptor-mediated endocytosis. This model may explain the internalization of hydroxyapatite into osteoblasts to elevate intracellular calcium levels necessary to promote osteoblast functions to treat a wide range of orthopedic problems, including osteoporosis.
authors.affiliation: Department of Physics, Brown University, Providence, RI 02912, USA.
authors.forename: Nhiem
authors.initials: N
authors.lastname: Tran
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Webster
mesh_terms: D020099:Coated Materials, Biocompatible / Q000494:pharmacology; D017886:Durapatite / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008954:Models, Biological; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
chemical_list: D020099:Coated Materials, Biocompatible; D058185:Magnetite Nanoparticles; D011956:Receptors, Cell Surface; D017886:Durapatite