Presenter：Prof. Hsing-WenSung (宋信文)，台湾新竹清华大学
Title: Bubble-Generating Carrier Systems forLocalized Controlled Release
Time: 09:00 AM, Sept. 27th
Location: 909B
Abstract
In this work, two bubble-generating agents, ammonium bicarbonate(ABC) and sodium bicarbonate (SBC) that can generate CO2 bubbles, areseparately encapsulated in carrier systems for actively triggering drug releaselocally. Widely recognized for their ability to increase intratumoralaccumulation, PEGylated liposomes are employed as stable vehicles for carryingdoxorubicin (DOX; Doxil®). However, the slow and passive drug release from theDoxil® formulation significantly inhibits its antitumor efficacy. To resolvethis problem, our group develops a thermoresponsive liposomal formulation. Asthe key component of this liposomal formulation, its encapsulated ABC createsthe transmembrane gradient needed for a highly efficient DOX encapsulation.Moreover, at a high temperature of roughly 42°C, ABC decomposition generatesCO2 bubbles, subsequently creating permeable defects in the lipid bilayer andultimately inducing a rapid DOX release to instantly increase the drugconcentration locally. The feasibility of using this thermoresponsivebubble-generating liposomal system for tumor-specific chemotherapy under mildhyperthermia is investigated. The in vitro drug-release profiles are quantifiedfrom test liposomes under mild hyperthermia conditions. Their in vivo biodistribution,pharmacokinetics, drug accumulation, and antitumor activity against locallyheated tumors are examined as well. We also develop hollow microspheres (HMs)that can deliver anticancer drug into tumor cells and quickly release the drugin an acidic organelle such as lysosome. The HMs are fabricated from PLGA usinga double-emulsion method, with the aqueous core contai ning DOX and SBC. In acidic environments, SBC reacts with theacid to quickly generate CO2 bubbles, triggering the shell of the HMs todisrupt, thereby quickly releasing DOX locally and causing the cells to die.These highly stimuli-responsive carrier systems contribute to efforts toestablish effective tumor-selective chemotherapy.
Biography
Hsing-Wen Sung is a Tsing Hua DistinguishedChair Professor, Department of Chemical Engineering and the Director ofInstitute of Biomedical Engineering, National Tsing Hua University. He receivedhis PhD degree from Biomedical Engineering Program, Georgia Institute ofTechnology in May 1988. His research interests are biomaterials, tissueengineering, and drug/gene delivery. Professor Sung has received numerousawards such as, Fellow of American Institute for Medical and BiologicalEngineering, Fellow of International Union of Societies for BiomaterialsScience and Engineering, Academician of Asia Pacific Academy of Materials, HoChin Tui Outstanding Research Award, National Science Council OutstandingResearch Award, Professor Tsai-The Lai Award, Elsevier 2015 Biomaterials Best PaperAward, and 2016 TERMIS-AP Outstanding Scientist Award. He has been on theEditorial Boards of Journal of Controlled Release, Tissue Engineering, andAdvanced Healthcare Materials; also, he has been serving as a Handling Editorfor Biomaterials. Professor Sung has published 250 scientific papers andreceived 110 international patents.
Contact: Zhuang Liu
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