Hao Zhao

Shanghai Jiao Tong University, Shanghai, Shanghai Shi, China

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Publications (3)6.26 Total impact

  • Tiantian Ren · Weien Yuan · Hao Zhao · Tuo Jin
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    ABSTRACT: Protein-loaded dextran nanoparticles were prepared by the method of freezing-induced phase separation. The average diameter of protein-loaded dextran nanoparticles prepared using this method was between 100 and 300 nm. The protein-loaded dextran nanoparticles were then microencapsulated into polylactide-co-glycolide acid (PLGA) microspheres by the solid-in-oil-in-water (S O W) multiple emulsion technique. The release behaviour of the microspheres showed that the method might improve the release profile and bioactivity in vitro , and also reduce initial burst and aggregation. The method will be potentially developed to solve protein-controlled release problems.
    No preview · Article · Mar 2011 · Micro & Nano Letters
  • Weien Yuan · Tiantian Ren · Fei Wu · Hao Zhao · Tuo Jin
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    ABSTRACT: Biodegradable material poly(D, L-lactic-co-glycolic) acid (PLGA) plays an important role in drug-sustained release systems. Here, we describe a glycerol modified solid-in-oil-in-water (m-S/O/W) emulsion method for PLGA microspheres, in order to encapsulate proteins in PLGA by utilizing dextran glassy particles to protect the proteins from denaturing, unfolding, and aggregation during preparation and new external water phase to prevent the inner dextran glassy particles from leaking into the external water phase. External water phase containing 20, 40, 60, 80% glycerol showed that proteins released faster and more completely with increased glycerol content. According to their varied release profiles, microspheres of different formulations could be used to encapsulate vaccines or for delivering proteins over long-term. Copyright © 2009 John Wiley & Sons, Ltd.
    No preview · Article · May 2009 · Polymers for Advanced Technologies
  • Weien Yuan · Yan Geng · Fei Wu · Yajun Liu · Meiyan Guo · Hao Zhao · Tuo Jin
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    ABSTRACT: This study investigates a method of preparing hazard-resistant protein-loaded polysaccharide glassy microparticles using freezing-induced phase separation method without exposure to water/oil, water/air interface and cross-linking reagents. Model protein (such as bovine serum albumin, myoglobin and beta-galactosidase (beta-Gal)) was dissolved in water together with dextran and polyethylene glycol (PEG), followed by a freezing process to form a temperature-stabilized aqueous-aqueous emulsion wherein dextran separated out as the dispersed phase with protein partitioned in preferentially. The frozen sample was freeze-dried and washed with dichloromethane (DCM) to remove the PEG continuous phase, after which protein-loaded polysaccharide particles, 1-4 microm in diameter, were harvested. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) patterns showed that the particles were in glassy state. These glassy polysaccharide microparticles can well protect the delicate structure of proteins and preserve their bioactivities under deleterious environment interacting with organic solvents, vortex and centrifugation processes that often involve during the formulation processes leading to polymer-based sustained-release systems. Therefore, this freezing-induced phase separation method is a mild and effective way to encapsulate protein into hazard-resistant polysaccharide glassy particles, which ensure its stability in subsequent formulating processes that leads to polymer-based sustained-release system.
    No preview · Article · Oct 2008 · International Journal of Pharmaceutics