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Modulation of Silica Nanoparticle Uptake into Human Osteoblast Cells by Variation of the Ratio of Amino and Sulfonate Surface Groups: Effects of Serum.

Shahabi S, Treccani L, Dringen R, Rezwan K - ACS Appl Mater Interfaces (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: †Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.

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.

No MeSH data available.


Related in: MedlinePlus

Fluorescence microscopy micrographs of HOB cells incubatedwithout (a–j) or with (k–t) FCS for 0.5 or 6 h at 37°C with 100 μg/mL FFSNPs, revealing cellular uptake andintracellular localization of the particles. In all images, green,blue, and red fluorescence indicates the actin cytoskeleton, the nuclei,and FFSNPs, respectively. Scale bars: 50 μm.
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fig3: Fluorescence microscopy micrographs of HOB cells incubatedwithout (a–j) or with (k–t) FCS for 0.5 or 6 h at 37°C with 100 μg/mL FFSNPs, revealing cellular uptake andintracellular localization of the particles. In all images, green,blue, and red fluorescence indicates the actin cytoskeleton, the nuclei,and FFSNPs, respectively. Scale bars: 50 μm.

Mentions: The uptake of FFSNPs with varioussurface charges into HOB cells was studied in the absence and presenceof serum. Particle internalization in HOBs was characterized by fluorescencemicroscopy. Results obtained after 0.5 or 6 h of exposure to the FFSNPsat the final concentration of 100 μg/mL are presented in Figure 3. In all fluorescence microscopy micrographs, actincytoskeletons (green) and nuclei (blue) were stained with AF 488 andDAPI, respectively. RBITC labeled FFSNPs are visible with their typicalred fluorescence. Particle uptake into HOBs was observed for bothserum-free and serum-containing incubation media for all types ofFFSNPs investigated (Figure 3). Fluorescencemicroscopic inspection of the treated cultures revealed that for allconditions investigated more than 90% of the cells contained FFSNPs(data not shown).


Modulation of Silica Nanoparticle Uptake into Human Osteoblast Cells by Variation of the Ratio of Amino and Sulfonate Surface Groups: Effects of Serum.

Shahabi S, Treccani L, Dringen R, Rezwan K - ACS Appl Mater Interfaces (2015)

Fluorescence microscopy micrographs of HOB cells incubatedwithout (a–j) or with (k–t) FCS for 0.5 or 6 h at 37°C with 100 μg/mL FFSNPs, revealing cellular uptake andintracellular localization of the particles. In all images, green,blue, and red fluorescence indicates the actin cytoskeleton, the nuclei,and FFSNPs, respectively. Scale bars: 50 μm.
© Copyright Policy - editor-choice
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490775&req=5

fig3: Fluorescence microscopy micrographs of HOB cells incubatedwithout (a–j) or with (k–t) FCS for 0.5 or 6 h at 37°C with 100 μg/mL FFSNPs, revealing cellular uptake andintracellular localization of the particles. In all images, green,blue, and red fluorescence indicates the actin cytoskeleton, the nuclei,and FFSNPs, respectively. Scale bars: 50 μm.
Mentions: The uptake of FFSNPs with varioussurface charges into HOB cells was studied in the absence and presenceof serum. Particle internalization in HOBs was characterized by fluorescencemicroscopy. Results obtained after 0.5 or 6 h of exposure to the FFSNPsat the final concentration of 100 μg/mL are presented in Figure 3. In all fluorescence microscopy micrographs, actincytoskeletons (green) and nuclei (blue) were stained with AF 488 andDAPI, respectively. RBITC labeled FFSNPs are visible with their typicalred fluorescence. Particle uptake into HOBs was observed for bothserum-free and serum-containing incubation media for all types ofFFSNPs investigated (Figure 3). Fluorescencemicroscopic inspection of the treated cultures revealed that for allconditions investigated more than 90% of the cells contained FFSNPs(data not shown).

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: †Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.

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.

No MeSH data available.


Related in: MedlinePlus