Liuchun Zheng

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Name: 郑柳春
Organization: Institute of Chemistry, Chinese Academy of Sciences , China
Department:
Title: Associate Researcher/Associate Professor(PhD)

TOPICS

Co-reporter:Shaohua Wu;Wen Zhou;Chuncheng Li;Yaonan Xiao;Wenxiang Zhu
Journal of Polymer Science Part A: Polymer Chemistry 2016 Volume 54( Issue 9) pp:1259-1267
Publication Date(Web):
DOI:10.1002/pola.27968

ABSTRACT

Novel carboxyl- and amino-functionalized copolyesters, based on poly(ε-caprolactone)-block-poly(butylene fumarate)-block-poly(ε-caprolactone), were efficiently synthesized via Michael-type thiol-ene click chemistry. The resulting amphiphilic copolyesters with controllable molecular weights and abundant positively or negatively charged groups could spontaneously form pH-sensitive micelles in aqueous solutions, as confirmed by transmission electron microscopy, dynamic light scattering, fluorescence probing technique, and zeta potential analyses. Importantly, charge-reversal hybrid micelles can be obtained by co-assembly of carboxyl- and amino-functionalized copolyesters. The surface charges of hybrid micelles reversed rapidly from negative to positive at isoelectric point via protonation of surface carboxyl and amino groups. Interestingly, the hybrid micelles showed apparent pH-triggered Nile red-release behavior in acidic condition resembling tumor intracellular environment, which is fairly desirable for drug delivery. Our work indicates that co-assembly is a facile but efficient way to prepare charge-reversal micelles, which have great potential to be used as intelligent drug delivery systems for cancer therapy. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1259–1267

Co-reporter:Shaohua Wu, Liuchun Zheng, Chuncheng Li, Shuaidong Huo, Yaonan Xiao, Guohu Guan and Wenxiang Zhu  
Polymer Chemistry 2015 vol. 6(Issue 9) pp:1495-1501
Publication Date(Web):04 Dec 2014
DOI:10.1039/C4PY01305K
A series of amphiphilic and anionic copolyesters of sulfonated poly(butylene succinate) (SPBS) with sulfonate groups distributed randomly along the biodegradable backbone were synthesized via addition of sodium hydrogen sulphite to carbon–carbon double bonds on the backbone of poly(butylene succinate-co-butylene fumarate) (PBSF). The content of hydrophilic sulfonate groups can be facilely regulated by changing the initial feed ratio. The structures of PBSF and SPBS were systematically characterized by NMR and GPC. The negatively charged micelles self-assembled from SPBS were prepared by the dialysis method and characterized by NMR, DLS and TEM. In vitro cytotoxicity assay indicates that the SPBS micelles possess excellent biocompatibility. The biocompatibility of SPBS micelles increases with increasing content of sulfonate groups. This work provides a broad new method to facilely synthesize novel anionic copolyesters with high efficiency and controllable anion content. These copolyesters are highly promising as drug delivery carriers for cancer therapy.
Co-reporter:Zhaodong Wang, Liuchun Zheng, Chuncheng Li, Dong Zhang, Yaonan Xiao, Guohu Guan, Wenxiang Zhu
Carbohydrate Polymers 2013 Volume 94(Issue 1) pp:505-510
Publication Date(Web):15 April 2013
DOI:10.1016/j.carbpol.2013.01.090
An ionic liquid, 1-ethyl-3-methylimidazolium acetate (EMIMAc), was synthesized and employed as a homogeneous and green reaction media to prepare chitosan-graft-polycaprolactone (CS-g-PCL) via ring-opening polymerization, using stannous octoate (Sn(Oct)2) as a catalyst. The structures and compositions of copolymers could be facilely controlled by the reaction conditions and feed ratios. The grafting content of polycaprolactone (PCL) could reach as high as 630%. The chemical structures of the copolymers were systematically characterized by 1H NMR, Fourier transform infrared spectroscopy (FTIR) and wide-angle X-ray diffraction (WAXD), while thermal properties were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal stability and glass transition temperature (Tg) of the graft copolymers vary regularly with the change of PCL grafting content.Highlights► The chitosan-graft-polycaprolactone was synthesized through a convenient, green and efficient method. ► The grafting content of polycaprolactone (PCL) of the copolymer could reach as high as 630%. ► The obtained graft copolymers are expected to have the advantageous properties of two polymers.