Synthesis, characterization and fine-tuning of bimodal poly(organosiloxane) nanoparticles

Scherer, Christian; Utech, Stefanie; Scholz, S.; Noskov, Sergey; Kindervater, Petra; Graf, Robert; Thünemann, Andreas F.; Maskos, Michael

doi:10.1016/j.polymer.2010.09.065

Cited by 8 publications

(4 citation statements)

References 26 publications

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“…The synthesis of carboxy-modified rhodamine B-labeled poly(organosiloxane) core–shell nanoparticles was performed as described previously in an aqueous emulsion with dodecylbenzenesulfonic acid as the surfactant using a slightly modified procedure (Scheme S2 in Supporting Information). , The composition of monomers for the core was 7 g of trimethoxymethylsilane (T), 5 g of diethoxydimethylsilane (D), 3 g of ( p -chloromethyl)phenyltrimethoxysilane, and 0.5 g of rhodamine B-( p -trimethoxysilyl)benzylester. For the subsequent polycondensation of they carboxy-modified shell, 2 g of T, 3 g of D, and 5 g of 3-(triethoxysilyl)propylsuccinic anhydride were used.…”

Section: Experimental Sectionmentioning

confidence: 99%

Temperature-Triggered Protein Adsorption on Polymer-Coated Nanoparticles in Serum

et al. 2015

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The protein corona, which forms on the nanoparticle's surface in most biological media, determines the nanoparticle's physicochemical characteristics. The formation of the protein corona has a significant impact on the biodistribution and clearance of nanoparticles in vivo. Therefore, the ability to influence the formation of the protein corona is essential to most biomedical applications, including drug delivery and imaging. In this study, we investigate the protein adsorption on nanoparticles with a hydrodynamic radius of 30 nm and a coating of thermoresponsive poly(2-isopropyl-2-oxazoline) in serum. Using multiangle dynamic light scattering (DLS) we demonstrate that heating of the nanoparticles above their phase separation temperature induces the formation of agglomerates, with a hydrodynamic radius of 1 μm. In serum, noticeably stronger agglomeration occurs at lower temperatures compared to serum-free conditions. Cryogenic transmission electron microscopy (cryo-TEM) revealed a high packing density of agglomerates when serum was not present. In contrast, in the presence of serum, agglomerated nanoparticles were loosely packed, indicating that proteins are intercalated between them. Moreover, an increase in protein content is observed upon heating, confirming that protein adsorption is induced by the alteration of the surface during phase separation. After cooling and switching the surface back, most of the agglomerates were dissolved and the main fraction returned to the original size of approximately 30 nm as shown by asymmetrical flow-field flow fractionation (AF-FFF) and DLS. Furthermore, the amounts of adsorbed proteins are similar before and after heating the nanoparticles to above their phase-separation temperature. Overall, our results demonstrate that the thermoresponsivity of the polymer coating enables turning the corona formation on nanoparticles on and off in situ. As the local heating of body areas can be easily done in vivo, the thermoresponsive coating could potentially be used to induce the agglomeration of nanoparticles and proteins and the accumulation of nanoparticles in a targeted body region.

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Section: Experimental Sectionmentioning

confidence: 99%

Temperature-Triggered Protein Adsorption on Polymer-Coated Nanoparticles in Serum

et al. 2015

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“…Poly(organosiloxane) NPs were synthesized by condensation of di-and trialkoxysilanes as described previously (31)(32)(33). Briefly, the synthesis of 12 nm core-shell NPs (R ¼ 6.2 5 1.3 nm (TEM)) was carried out under alkaline conditions using benzethonium chloride as surfactant at a fleet ratio of 0.3.…”

Section: Sample Preparationmentioning

confidence: 99%

Size Influences the Effect of Hydrophobic Nanoparticles on Lung Surfactant Model Systems

Dwivedi

Harishchandra

Koshkina

et al. 2014

Biophysical Journal

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The alveolar lung surfactant (LS) is a complex lipid protein mixture that forms an interfacial monolayer reducing the surface tension to near zero values and thus preventing the lungs from collapse. Due to the expanding field of nanotechnology and the corresponding unavoidable exposure of human beings from the air, it is crucial to study the potential effects of nanoparticles (NPs) on the structural organization of the lung surfactant system. In the present study, we investigated both, the domain structure in pure DPPC monolayers as well as in lung surfactant model systems. In the pure lipid system we found that two different sized hydrophobic polymeric nanoparticles with diameter of ~12 nm and ~136 nm have contrasting effect on the functional and structural behavior. The small nanoparticles inserted into fluid domains at the LE-LC phase transition are not visibly disturbing the phase transition but disrupting the domain morphology of the LE phase. The large nanoparticles led to an expanded isotherm and to a significant decrease in the line tension and thus to a drastic disruption of the domain structures at a much lower number of nanoparticles with respect to the lipid. The surface activity of the model LS films again showed drastic variations due to presence of different sized NPs illustrated by the film balance isotherms and the atomic force microscopy. AFM revealed laterally profuse multilayer protrusion formation on compression but only in the presence of 136 nm sized nanoparticles. Moreover we investigated the vesicle insertion process into a preformed monolayer. A severe inhibition was observed only in the presence of ~136 nm NPs compared to minor effects in the presence of ~12 nm NPs. Our study clearly shows that the size of the nanoparticles made of the same material determines the interaction with biological membranes.

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“…By sequential addition of mixtures with different ratios of bi- to tri-functional monomers, different crosslinking densities can be realized and the formation of systems with core–shell architecture is possible. By introducing monomers with functional groups, each of the structural elements (core, shell or one of multiple shells) can be functionalized independently [ 66 – 68 ]. The addition of a chloromethylphenyl co-monomer for instance allows for selective fluorescence labeling of the core [ 69 – 70 ].…”

Section: Introductionmentioning

confidence: 99%

“…The preparation of the poly(organosiloxane) particles that we report on is based on previously described syntheses by our group [ 66 , 69 ]. These procedures were extended as follows [ 75 ]: First, core–shell particles with a dye-labelled core were synthesized by using the basic synthesis route.…”

Section: Introductionmentioning

confidence: 99%

The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions

Bantz¹,

Koshkina²,

Lang³

et al. 2014

Beilstein J. Nanotechnol.

129

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SummaryDue to the recent widespread application of nanomaterials to biological systems, a careful consideration of their physiological impact is required. This demands an understanding of the complex processes at the bio–nano interface. Therefore, a comprehensive and accurate characterization of the material under physiological conditions is crucial to correlate the observed biological impact with defined colloidal properties. As promising candidates for biomedical applications, two SiO2-based nanomaterial systems were chosen for extensive size characterization to investigate the agglomeration behavior under physiological conditions. To combine the benefits of different characterization techniques and to compensate for their respective drawbacks, transmission electron microscopy, dynamic light scattering and asymmetric flow field-flow fractionation were applied. The investigated particle systems were (i) negatively charged silica particles and (ii) poly(organosiloxane) particles offering variable surface modification opportunities (positively charged, polymer coated). It is shown that the surface properties primarily determine the agglomeration state of the particles and therefore their effective size, especially under physiological conditions. Thus, the biological identity of a nanomaterial is clearly influenced by differentiating surface properties.

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Synthesis, characterization and fine-tuning of bimodal poly(organosiloxane) nanoparticles

Cited by 8 publications

References 26 publications

Temperature-Triggered Protein Adsorption on Polymer-Coated Nanoparticles in Serum

Temperature-Triggered Protein Adsorption on Polymer-Coated Nanoparticles in Serum

Size Influences the Effect of Hydrophobic Nanoparticles on Lung Surfactant Model Systems

The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions

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