Hybrid silica nanoparticles with hyperbranched polymer and polyelectrolyte shells

Mori, Hideharu; Chan‐Seng, Delphine; Zhang, M.; Müller, Axel H. E.

doi:10.1007/b94006

Cited by 4 publications

(3 citation statements)

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“…However, as a result, poor control over the amount of the captured NPs and, consequently, a significant increase of the micellar core size was obtained. − Covering the NPs with a thin silica shell is a smart and effective route. Several ways for encapsulating small particles with a silica shell exist. − A reverse microemulsion approach was developed for encapsulating single NPs while controlling simultaneously the thickness of the silica layer. − Further advantages of this approach are the biocompatibility of silica and the well investigated methods for its surface modification, which in turn offers stable chemical bonds between the core and the attached molecules. − …”

Section: Introductionmentioning

confidence: 99%

PDMAEMA-Grafted Core–Shell–Corona Particles for Nonviral Gene Delivery and Magnetic Cell Separation

et al. 2013

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Monodisperse, magnetic nanoparticles as vectors for gene delivery were successfully synthesized via the grafting-from approach. First, oleic acid stabilized maghemite nanoparticles (γ-Fe2O3) were encapsulated with silica utilizing a reverse microemulsion process with simultaneous functionalization with initiating sites for atom transfer radical polymerization (ATRP). Polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) from the core-shell nanoparticles led to core-shell-corona hybrid nanoparticles (γ-Fe2O3@silica@PDMAEMA) with an average grafting density of 91 polymer chains of DP(n) = 540 (PDMAEMA540) per particle. The permanent attachment of the arms was verified by field-flow fractionation. The dual-responsive behavior (pH and temperature) was confirmed by dynamic light scattering (DLS) and turbidity measurements. The interaction of the hybrid nanoparticles with plasmid DNA at various N/P ratios (polymer nitrogen/DNA phosphorus) was investigated by DLS and zeta-potential measurements, indicating that for N/P ≥ 7.5 the complexes bear a positive net charge and do not undergo secondary aggregation. The hybrids were tested as transfection agents under standard conditions in CHO-K1 and L929 cells, revealing transfection efficiencies >50% and low cytotoxicity at N/P ratios of 10 and 15, respectively. Due to the magnetic properties of the hybrid gene vector, it is possible to collect most of the cells that have incorporated a sufficient amount of magnetic material by using a magnetic activated cell sorting system (MACS). Afterward, cells were further cultivated and displayed a transfection efficiency of ca. 60% together with a high viability.

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Section: Introductionmentioning

confidence: 99%

PDMAEMA-Grafted Core–Shell–Corona Particles for Nonviral Gene Delivery and Magnetic Cell Separation

et al. 2013

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“…The incorporation of Ce‐Zr mixed oxide nanoparticles into the polymer matrix leads to the formation of a crack‐free film which in turn enhances the mechanical and corrosion resistance properties 24. The highly branched amphiphilic polyethyleneimine‐silver,25 hyperbranched polymer–silica,26 epoxy–zirconia and methyl modified silica,27–28 Ceria/Zirconia nanoparticle with silica29 have also been reported and used for different hybrid coating applications. However as per our information there is no report available on the use Ce‐Zr mixed oxide nanoparticle in combination with HBPUs.…”

Section: Introductionmentioning

confidence: 99%

Effect of NCO/OH ratio and Ce‐Zr nanoparticles on the thermo‐mechanical properties of hyperbranched polyurethane urea coatings

Mishra

Allauddin

Radhika

et al. 2011

Polymers for Advanced Techs

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The present study describes the effect of NCO/OH ratio and addition of Cerium (Ce)‐Zirconium (Zr) mixed oxide nanoparticles on the properties of Hyperbranched Polyurethane Urea (HBPUU) Coatings. Initially a hydroxyl terminated hyperbranched polymer (HTBP) was synthesized through A3 + CB2 approach. The HTBP and Ce‐Zr nanopowder dispersed HTBP, both were reacted with hexamethylene diisocyanate (HDI) separately; at various NCO/OH eq. ratios to get different NCO terminated HBPU and HBPU/Ce‐Zr hybrid prepolymers. These prepolymers were used for the preparation of HBPUU and HBPUU/Ce‐Zr hybrid coating films through moisture curing. The techniques such as 1H NMR, 13C NMR, FT‐IR, and XRD have been used for structural information while Dynamic mechanical and thermal analyzer (DMTA), Thermogravimetric analysis (TGA) and Universal testing machine (UTM) have been used for evaluation of thermo‐mechanical properties. The combined spectroscopic investigations results indicate the formation of HBPUU network with a degree of branching of 76% while FT‐IR deconvolution results indicates the formation of more hydrogen bonded structure with increasing NCO/OH ratio. The XRD and FT‐IR studies confirm the presence of Ce‐Zr mixed nanoparticles in the HBPUU hybrids. As per TGA and DMTA analysis the thermal stability, char residue, storage modulus (E', material stiffness) and glass transition temperature (Tg), increases with increasing NCO/OH ratio and Ce‐Zr nanoparticle loading in HBPUU coatings. In general, UTM data suggest that the tensile strength increases and per cent elongation at break decreases with increasing the NCO/OH ratio and addition level of nanoparticles in HBPUU coatings. Copyright © 2009 John Wiley & Sons, Ltd.

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“…[8][9][10] Moreover, only in some of these the HBP has been employed as the main organic phase and not only as an additive in combination with other linear polymers. [11][12][13][14] HBPs belong to a group of macromolecules known as dendritic polymers.…”

Section: Introductionmentioning

confidence: 99%

Hyperbranched Polymer/TiO₂ Hybrid Nanoparticles Synthesized via an In Situ Sol‐Gel Process

Gianni

Trabelsi

Rizza

et al. 2007

Macro Chemistry & Physics

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Two different kinds of HBPs were used in the preparation of nanocomposite materials based on TiO 2 nanoparticles. One of the HBPs was characterized by the presence of free OH end groups in its structure, while the other one was obtained via a partial modification reaction which allowed to introduce some alkoxysilane functional groups. The TiO 2 particles were prepared in situ in the polymer solution by means of a sol-gel process starting from Ti(iOPr) 4 as precursor. The polymer/TiO 2 mixture, subsequently coated and cured in the presence of diisocyanate, gave rise to a hard coating. TiO 2 was found to be dispersed on nanometer scale inside the final coatings obtained from both the polymers, and the TiO 2 nanocomposite coatings were also characterized by improved thermal and hardness properties compared to TiO 2 free systems. Still the two different kinds of HBPs showed a different interaction with the TiO 2 particles, and it has been evidenced that the modification is required to achieve a better dispersion of the particles in the matrix and better properties for the final coating. Thus, by applying the modified HBP, TiO 2 could be dispersed and stabilized in the polymer matrix as individual nanoparticles of only 6 nm in diameter.

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Hybrid silica nanoparticles with hyperbranched polymer and polyelectrolyte shells

Cited by 4 publications

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PDMAEMA-Grafted Core–Shell–Corona Particles for Nonviral Gene Delivery and Magnetic Cell Separation

PDMAEMA-Grafted Core–Shell–Corona Particles for Nonviral Gene Delivery and Magnetic Cell Separation

Effect of NCO/OH ratio and Ce‐Zr nanoparticles on the thermo‐mechanical properties of hyperbranched polyurethane urea coatings

Hyperbranched Polymer/TiO₂ Hybrid Nanoparticles Synthesized via an In Situ Sol‐Gel Process

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Hybrid silica nanoparticles with hyperbranched polymer and polyelectrolyte shells

Cited by 4 publications

References 0 publications

PDMAEMA-Grafted Core–Shell–Corona Particles for Nonviral Gene Delivery and Magnetic Cell Separation

PDMAEMA-Grafted Core–Shell–Corona Particles for Nonviral Gene Delivery and Magnetic Cell Separation

Effect of NCO/OH ratio and Ce‐Zr nanoparticles on the thermo‐mechanical properties of hyperbranched polyurethane urea coatings

Hyperbranched Polymer/TiO2 Hybrid Nanoparticles Synthesized via an In Situ Sol‐Gel Process

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Hyperbranched Polymer/TiO₂ Hybrid Nanoparticles Synthesized via an In Situ Sol‐Gel Process