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Jiang S.,Max Planck Institute for Polymer Research | Jiang S.,Shanxi Institute of Coal CAS Chemistry | Jiang S.,University of Chinese Academy of Sciences | Lv L.-P.,Max Planck Institute for Polymer Research | And 4 more authors.
RSC Advances | Year: 2016

Materials capable of controlling the release of functional agents are promising for drug delivery and corrosion protection. A dual-responsive multicompartment nanostructure is designed by embedding redox-responsive nanocapsules in pH-responsive nanofibers by colloid-electrospinning. This combination allows an enhanced control over the release of payloads directed by properties of nanocontainers and nanofibers. © The Royal Society of Chemistry 2016.


Jiang S.,Max Planck Institute for Polymer Research | Jiang S.,Shanxi Institute of Coal CAS Chemistry | Jiang S.,University of Chinese Academy of Sciences | Lv L.,Max Planck Institute for Polymer Research | And 6 more authors.
Nanoscale | Year: 2016

We demonstrate here that the control over the release rate of payloads and on the selectivity of the release can be achieved by designing nanomaterials with a hierarchical structure. Redox-responsive silica nanocapsules are first synthesized to allow for an accelerated release of the corrosion inhibitor 2-mercaptobenzothiazole as a payload upon chemical reduction and retarded release upon oxidation. In a second step, we embedded the nanocapsules into nanofibers by colloid-electrospinning, yielding a hierarchical composite structure. Remarkably, the encapsulation of the nanocapsules in the fibers provides two decisive advantages that are a higher selectivity of the release and a higher control over the release rate of payloads. © 2016 The Royal Society of Chemistry.


Estupinan D.,Max Planck Institute for Polymer Research | Bannwarth M.B.,Max Planck Institute for Polymer Research | Mylon S.E.,Lafayette College | Landfester K.,Max Planck Institute for Polymer Research | And 4 more authors.
Nanoscale | Year: 2016

Silica nanoparticles are versatile materials whose physicochemical surface properties can be precisely adjusted. Because it is possible to combine several functionalities in a single carrier, silica-based materials are excellent candidates for biomedical applications. However, the functionality of the nanoparticles can get lost upon exposure to biological media due to uncontrolled biomolecule adsorption. Therefore, it is important to develop strategies that reduce non-specific protein-particle interactions without losing the introduced surface functionality. Herein, organosilane chemistry is employed to produce magnetic silica nanoparticles bearing differing amounts of amino and alkene functional groups on their surface as orthogonally addressable chemical functionalities. Simultaneously, a short-chain zwitterion is added to decrease the non-specific adsorption of biomolecules on the nanoparticles surface. The multifunctional particles display reduced protein adsorption after incubation in undiluted fetal bovine serum as well as in single protein solutions (serum albumin and lysozyme). Besides, the particles retain their capacity to selectively react with biomolecules. Thus, they can be covalently bio-functionalized with an antibody by means of orthogonal click reactions. These features make the described multifunctional silica nanoparticles a promising system for the study of surface interactions with biomolecules, targeting, and bio-sensing. © 2016 The Royal Society of Chemistry.


Corrales T.P.,Max Planck Institute for Polymer Research | Corrales T.P.,University of Tarapacá | Friedemann K.,Max Planck Institute for Polymer Research | Fuchs R.,Max Planck Institute for Polymer Research | And 5 more authors.
Langmuir | Year: 2016

Nanofibers composed of silica nanoparticles, used as structural building blocks, and polystyrene nanoparticles introduced as sacrificial material are fabricated by bicolloidal electrospinning. During fiber calcination, sacrificial particles are combusted leaving voids with controlled average sizes. The mechanical properties of the sintered silica fibers with voids are investigated by suspending the nanofiber over a gap and performing three-point bending experiments with atomic force microscopy. We investigate three different cases: fibers without voids and with 60 or 260 nm voids. For each case, we study how the introduction of the voids can be used to control the mechanical stiffness and fracture properties of the fibers. Fibers with no voids break in their majority at a single fracture point (70% of cases), segmenting the fiber into two pieces, while the remaining cases (30%) fracture at multiple points, leaving a gap in the suspended fiber. On the other hand, fibers with 60 nm voids fracture in only 25% of the cases at a single point, breaking predominantly at multiple points (75%). Finally, fibers with 260 nm voids fracture roughly in equal proportions leaving two and multiple pieces (46% vs 54%, respectively). The present study is a prerequisite for processes involving the controlled sectioning of nanofibers to yield anisometric particles. © 2016 American Chemical Society.


Fickert J.,Max Planck Institute for Polymer Research | Landfester K.,Max Planck Institute for Polymer Research | Crespy D.,Max Planck Institute for Polymer Research | Crespy D.,Vidyasirimedhi Institute of Science and Technology VISTEC
Polymer Chemistry | Year: 2016

We introduce here a concept allowing the synthesis of smart nanocapsules without a surfactant. Copolymers with masked carboxylic acid groups are desilylated during the nanocapsule preparation and this leads to pH-responsive and self-stabilized nanocontainers encapsulating a large amount of hydrophobic substances. The nanocapsules can be either disrupted for release applications or reversibly aggregated by lowering the pH of the dispersion. The concentration of the nanocapsules in water can be increased by more than 6 times by isolating the nanocontainers at low pH and re-dispersing them at high pH values. © 2016 The Royal Society of Chemistry.


Wald S.,Max Planck Institute for Polymer Research | Wurm F.R.,Max Planck Institute for Polymer Research | Landfester K.,Max Planck Institute for Polymer Research | Crespy D.,Max Planck Institute for Polymer Research | Crespy D.,Vidyasirimedhi Institute of Science and Technology VISTEC
Polymers | Year: 2016

Inverse (water-in-oil) miniemulsions are an important method to encapsulate hydrophilic payloads such as oligonucleotides or peptides. However, the stabilization of inverse miniemulsions usually requires block copolymers that are difficult to synthesize and/or cannot be easily removed after transfer from a hydrophobic continuous phase to an aqueous continuous phase. We describe here a new strategy for the synthesis of a surfactant for inverse miniemulsions by radical addition-fragmentation chain transfer (RAFT) polymerization, which consists in a homopolymer with triisopropylsilyl protecting groups. The protecting groups ensure the efficient stabilization of the inverse (water-in-oil, w/o) miniemulsions. Nanocapsules can be formed and the protecting group can be subsequently cleaved for the re-dispersion of nanocapsules in an aqueous medium with a minimal amount of additional surfactant. © 2016 by the authors.


Dohler D.,Martin Luther University of Halle Wittenberg | Rana S.,Martin Luther University of Halle Wittenberg | Rupp H.,Martin Luther University of Halle Wittenberg | Bergmann H.,Martin Luther University of Halle Wittenberg | And 4 more authors.
Chemical Communications | Year: 2016

A simple and unique damage-sensing tool mediated by a Cu(i)-catalyzed [3+2] cycloaddition reaction is reported, where a fluorogenic "click"-reaction highlights physical damage by a strong fluorescence increase accompanied by in situ monitoring of localized self-healing. © The Royal Society of Chemistry.


Duanglaor P.,Chulalongkorn University | Thiampanya P.,Chulalongkorn University | Sudyoadsuk T.,Vidyasirimedhi Institute of Science and Technology VISTEC | Promarak V.,Vidyasirimedhi Institute of Science and Technology VISTEC | Pulpoka B.,Chulalongkorn University
Journal of Energy Chemistry | Year: 2015

Bipyridylporphyrin derivatives possessing a porphyrin moiety as the electron donor and bipyridyl moiety as the electron-acceptor were designed and synthesized for dye-sensitized solar cells (DSSCs). The photophysical and electrochemical properties were investigated by absorption spectrometry and cyclic voltammetry. Density functional theory (DFT) was employed to study electron distribution. From the photovoltaic performance measurements, a maximum conversion efficiency (η) of 0.38% was achieved based on the bipyridylporphyrin ruthenium dye A7 (JSC = 1.33 mA/cm2, VOC = 0.45 V, FF = 0.64) under 1.5 irradiation (100 mW/cm2). © 2015 Science Press and Dalian Institute of Chemical Physics.


PubMed | Inha University and Vidyasirimedhi Institute of Science and Technology VISTEC
Type: Journal Article | Journal: ACS applied materials & interfaces | Year: 2016

In this study, we demonstrated that the MT1-MMP-responsive peptide (sequence: GPLPLRSWGLK) and doxorubicin-conjugated poly(lactic-co-glycolic acid/poly(styrene-alt-maleic anhydride) core/shell microparticles (PLGA/pSMA MPs) can be applied for intrahepatic arterial injection for hepatocellular carcinoma (HCC). PLGA/pSMA MPs were prepared with a capillary-focused microfluidic device. The particle size, observed by scanning electron microscopy (SEM), was around 22 3 m. MT1-MMP-responsive peptide and doxorubicin (DOX) were chemically conjugated with pSMA segments on the shell of MPs to form a PLGA/pSMA-peptide-DOX complex, resulting in high encapsulation efficiency (91.1%) and loading content (2.9%). DOX was released from PLGA/pSMA-peptide-DOX MPs in a pH-dependent manner (25% at pH 5.4 and 8% at pH 7.4) and accumulated significantly in an MT1-MMP-overexpressing Hep3B cell line. An in vivo intrahepatic injection study showed localization of MPs on the hepatic vessels and hepatic lobes up to 24 h after the injection without any shunting to the lung. Moreover, MPs efficiently inhibited tumor growth of Hep3B hepatic tumor xenografted mouse models. We expect that PLGA/pSMA-peptide-DOX MPs can be utilized as an effective intrahepatic drug delivery system for the treatment of HCC.


Hayakawa T.,Hojun Co. | Minase M.,Hojun Co. | Fujita K.-I.,Hojun Co. | Ogawa M.,Vidyasirimedhi Institute of Science and Technology VISTEC
Clays and Clay Minerals | Year: 2016

A modified procedure for bentonite purification and a new method for the quantitative characterization of bentonite using smectite content are reported. Bentonite found in a drill core of Tsunagi Mine, Niigata, Japan was evaluated by the new method to demonstrate the substantial increase in smectite content from 40% in the original bentonite to 75% after purification using a new procedure. Powder samples were prepared by putting blocks of bentonite into acetone to remove water without mechanical crushing. The powdered, acetone-dried bentonite was purified by a dispersion-sedimentation method in water after cation exchange of the interlayer Ca2+ ion with Na+ ion by the reaction of raw bentonite with aqueous NaCl. The purification was evaluated using X-ray diffraction and thermogravimetric analyses (TG). The raw bentonite contained feldspar, quartz, and cristobalite, and feldspar and quartz were removed by the new purification procedure. The purification was evaluated quantitatively by comparing the TG data before and after the purification. The purified bentonite swelled in water to give a stable aqueous suspension and 3 g of purified bentonite dispersed in 60 mL of water was stable for several days. The replacement of interlayer sodium with dibehenyldimethylammonium gave an organophilic clay, which swelled in toluene. The bentonite has potential practical uses as a purified bentonite and an organophilic bentonite. © 2016, Clay Minerals Society. All rights reserved.

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