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Liu S.,Huazhong University of Science and Technology | Cai M.,Huazhong University of Science and Technology | Deng R.,Huazhong University of Science and Technology | Wang J.,Huazhong University of Science and Technology | And 3 more authors.
Korea Australia Rheology Journal

A facile and versatile route to prepare porous polymer microparticles with tunable pore size and density through the combination of phase separation and emulsion-solvent evaporation method is demonstrated. When volatile organic solvent (e.g., chloroform) diffuses through the aqueous phase containing poly(vinyl alcohol) (PVA) and evaporates, n-hexadecane (HD) and polystyrene (PS) in oil-in-water emulsion droplets occur to phase separate due to the incompatibility between PS and HD, ultimately yielding microparticles with porous structures. Interestingly, density of the pores (pore number) on the shell of microparticles can be tailored from one to hundreds by simply varying the HD concentration and/ or the rate of solvent evaporation. Moreover, this versatile approach for preparing porous microparticles with tunable pore size and density can be applied to other types of hydrophobic polymers, organic solvents, and alkanes, which will find potential applications in the fields of pharmaceutical, catalyst carrier, separation, and diagnostics. © 2014 The Korean Society of Rheology and Springer. Source

Liang R.,Hubei Key Laboratory Of Materials Chemistry And Service Failure | Dong L.,Tongji Medical College | Deng R.,Hubei Key Laboratory Of Materials Chemistry And Service Failure | Wang J.,Tongji Medical College | And 7 more authors.
European Polymer Journal

Surfactant-free biodegradable polymeric nanoparticles (NPs) with uniform sizes were prepared by self-organized precipitation (SORP) method. Size and size distribution of the NPs can be easily tuned by varying the preparation conditions. More importantly, we demonstrate that hydrophobic species, semiconductor nanocrystals, and magnetic NPs can be encapsulated into the polymeric NPs effectively and quantitatively to generate multifunctional hybrid NPs. No surfactant is employed during the preparation process, which is crucial for the formed polymeric NPs to be used in bio-related applications. To evaluate the influence of surfactants on cellular behavior, cellular uptake and cytotoxicity of surfactant-free NPs and surfactant-coated NPs were performed. Our results indicated that surfactant-free NPs could be more promptly and effectively phagocytized by cells in vitro compared to residual surfactant-coated NPs prepared from the emulsion-solvent evaporation method, providing a proof that the surfactant-free NPs have more advantages in cellular uptake and more safety in drug delivery and bio-imaging. Moreover, surfactant-coated NPs inhibited cellular uptake of NPs, and had selective toxicity to melanoma A875 cells rather than human umbilical vein endothelial cells (EVC-304), especially for surfactant polyoxyethylene octyl phenyl ether (Triton X-100) due to the generation of intracellular reactive oxygen species (ROS). The surfactant-free uniform NPs prepared from SORP, combining desirable characteristics of hydrophobic drugs and functional materials, may prove advantageous in simultaneous drug delivery, imaging and magnetic field manipulation applications. © 2014 Elsevier Ltd. All rights reserved. Source

Dong L.,Huazhong University of Science and Technology | Li M.,National Engineering Center for Nanomedicine | Zhang S.,Huazhong University of Science and Technology | Li J.,Huazhong University of Science and Technology | And 4 more authors.

Gold nanoclusters (Au NCs) are one of the most promising fluorescent nanomaterials for bioimaging, targeting, and cancer therapy due to their tunable optical properties, yet their biocompatibility still remains unclear. Herein, the cytotoxicity of bovine serum albumin (BSA)-stabilized Au NCs is studied by using three tumor cell lines and two normal cell lines. The results indicate that Au NCs induce the decline of cell viabilities of different cell lines to varying degrees in a dose- and time-dependent manner, and umbilical vein endothelial cells which had a higher intake of Au NCs than melanoma cells show more toxicity. Addition of free BSA to BSA-Au NCs solutions can relieve the cytotoxicity, implying that BSA can prevent cell damage. Moreover, Au NCs increase intracellular reactive oxygen species (ROS) production, further causing cell apoptosis. Furthermore, N-acetylcysteine, a ROS scavenger, partially reverses Au NCs-induced cell apoptosis and cytotoxicity, indicating that ROS might be one of the primary reasons for the toxicity of BSA-Au NCs. Surprisingly, Au NCs with concentrations of 5 and 20 nM significantly inhibit tumor growth in the xenograft mice model of human liver cancer, which might provide a new avenue for the design of anti-cancer drug delivery vehicles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Liang R.,Hubei Key Laboratory Of Materials Chemistry And Service Failure | Wang J.,Tongji Medical College | Wang J.,Affiliated Hospital of Binzhou Medical College | Dong L.,Tongji Medical College | And 9 more authors.

We present a simple, yet versatile strategy for the fabrication of uniform biodegradable polymer nanoparticles (NPs) with controllable sizes by a hand-driven membrane-extrusion emulsification approach. The size and size distribution of the NPs can be easily tuned by varying the experimental parameters, including initial polymer concentration, surfactant concentration, number of extrusion passes, membrane pore size, and polymer molecular weight. Moreover, hydrophobic drugs (e.g., paclitaxel (PTX)) and inorganic NPs (e.g., quantum dots (QDs) and magnetic NPs (MNPs)) can be effectively and simultaneously encapsulated into the polymer NPs to form the multifunctional hybrid NPs through this facile route. These PTX-loaded NPs exhibit high encapsulation efficiency and drug loading density as well as excellent drug sustained release performance. As a proof of concept, the A875 cell (melanoma cell line) experiment in vitro, including cellular uptake analysis by fluorescence microscope, cytotoxicity analysis of NPs, and magnetic resonance imaging (MRI) studies, indicates that the PTX-loaded hybrid NPs produced by this technique could be potentially applied as a multifunctional delivery system for drug delivery, bio-imaging, and tumor therapy, including malignant melanoma therapy. © 2013 IOP Publishing Ltd. Source

Yu X.,Hubei Key Laboratory Of Materials Chemistry And Service Failure | Yu X.,National Engineering Center for Nanomedicine | Zhao Z.,CAS Changchun Institute of Applied Chemistry | Nie W.,CAS Changchun Institute of Applied Chemistry | And 9 more authors.

A detailed study on the direct synthesis of biocompatible polyesters (e.g., PLA, PLGA or PCL) microcapsules and multifunctional microcapsules, which does not require any template and core removal, is presented. The technique is based on the modified self-emulsification process within the emulsion droplets by simply adding sodium dioctyl sulfosuccinate (Aerosol OT or AOT) as a cosurfactant to the initial polymer solution, followed by double emulsion formation due to the coalescence of the internal water droplets. Microcapsules with tunable sizes (ranging from hundreds of nanometers to tens of micrometers) and morphologies were then obtained through solidification of droplet shell of the double emulsion via solvent removal. In this report, we have systematically investigated the effect of experimental parameters, such as polymer and AOT concentration, polymer molecular weight on the double emulsion formation process, and the final morphologies of the microcapsules. We demonstrate that the capsules can encapsulate either hydrophobic or hydrophilic dyes during solvent evaporation. Dye-release studies show a correlation between shell thickness, capsules size, and diffusive release rate, providing insights into the shell formation and shell thickness processing. Moreover, hydrophobic nanoparticles, such as oleic-acid coated Fe 3O 4 nanoparticles and quantum dots, can also be incorporated into the walls of the microcapsules. Such functional microcapsules might find applications in the fields of controlled release, bioimaging, diagnostics, and targeting. © 2011 American Chemical Society. Source

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