title: Modulation of Silica Nanoparticle Uptake into Human Osteoblast Cells by Variation of the Ratio of Amino and Sulfonate Surface Groups: Effects of Serum.
abstract: To study the importance of the surface charge for cellular uptake of silica nanoparticles (NPs), we synthesized five different single- or multifunctionalized fluorescent silica NPs (FFSNPs) by introducing various ratios of amino and sulfonate groups into their surface. The zeta potential values of these FFSNPs were customized from highly positive to highly negative, while other physicochemical properties remained almost constant. Irrespective of the original surface charge, serum proteins adsorbed onto the surface, neutralized the zeta potential values, and prevented the aggregation of the tailor-made FFSNPs. Depending on the surface charge and on the absence or presence of serum, two opposite trends were found concerning the cellular uptake of FFSNPs. In the absence of serum, positively charged NPs were more strongly accumulated by human osteoblast (HOB) cells than negatively charged NPs. In contrast, in serum-containing medium, anionic FFSNPs were internalized by HOB cells more strongly, despite the similar size and surface charge of all types of protein-covered FFSNPs. Thus, at physiological condition, when the presence of proteins is inevitable, sulfonate-functionalized silica NPs are the favorite choice to achieve a desired high rate of NP internalization.
authors.affiliation: †Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
authors.forename: Shakiba
authors.initials: S
authors.lastname: Shahabi
authors.affiliation: †Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Treccani
authors.affiliation: ‡Centre for Biomolecular Interactions Bremen and Centre for Environmental Research and Sustainable Technology, Faculty 2 (Biology/Chemistry), University of Bremen, Leobener Strasse, NW2, 28359 Bremen, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Dringen
authors.affiliation: †Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
authors.forename: Kurosch
authors.initials: K
authors.lastname: Rezwan
mesh_terms: D002478:Cells, Cultured; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism*; D010006:Osteoblasts / Q000378:metabolism*; D012822:Silicon Dioxide / Q000737:chemistry / Q000493:pharmacokinetics*; D013451:Sulfonic Acids / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D005456:Fluorescent Dyes; D013451:Sulfonic Acids; D012822:Silicon Dioxide
keywords: cellular uptake; functionalization; osteoblast; protein corona; silica nanoparticle; surface charge