张先正
个性化签名
- 姓名:张先正
- 目前身份:
- 担任导师情况:
- 学位:
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学术头衔:
博士生导师, 教育部“新世纪优秀人才支持计划”入选者
- 职称:-
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学科领域:
高分子化学
- 研究兴趣:
张先正,1971年8月出生,1994年7月于武汉大学化学系获学士学位,2000年6月于武汉大学化学系获博士学位。2000年9月至2001年8月新加坡国家材料研究所(IMRE)助理研究员(Research Associate)。2001年9月至2004年9月美国康耐尔大学(Cornell University)博士后及美国National Textile Center (NTC)基金项目M01-B01和M01-CR01研究员(Investigator)。2004年9月回国到武汉大学化学与分子科学学院生物医用高分子材料教育部重点实验室。已在相关领域发表论文近50篇,其中包括第一作者SCI源刊文章33篇,第一作者论文被他人引用上百次。向美国专利局申报有关生物材料的专利两项以及译作两章。
学术兼职:国家科学技术奖评审专家、生物医用高分子材料教育部重点实验室副主任、化学与分子科学学院学术委员会委员、国际期刊Medical Science Monitor (MSM) 编委会委员。
近期承担或参与的主要基金:主持国家自然科学基金面上项目:新型生物降解温度敏感水凝胶的制备及应用。主持湖北省杰出人才基金:环境敏感水凝胶的制备及应用。以研究骨干身份参与国家重点基础研究发展计划(973计划): 装载基因材料的分子设计及组织诱导作用和机理。
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1912
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830
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成果数
20
张先正, Xian-Zheng Zhang, Da-Qing Wu, Chih-Chang Chu*
Biomaterials 25(2004)3793-3805,-0001,():
-1年11月30日
A method was developed to prepare thermosensitive poly (N-isopropylacrylamide) (PNIPAAm) hydrogels with an interpenetrating polymer network (IPN) structure for the purpose of improving its mechanical properties, response rate to temperature and sustained release of drugs. Although the differential scanning calorimetry data exhibited similarly lower critical solution temperature (LCST) between IPN-and non-IPN-PNIPAAm hydrogels, an increase in the glass transition temperature (Tg) ofthe IPNs relative to the normal PNIPAAm hydrogel was observed. In addition, the mechanical properties ofthe IPNs were greatly improved when compared with the normal PNIPAAm hydrogel. The interior morphology ofthe IPN-PNIPAAm hydrogels was revealed by scanning electron microscopy (SEM); the IPN hydrogels showed a fibrillar-like porous network structure that normal PNIPAAm did not have. Furthermore, by measuring the temperature dependence ofthe swelling ratio and deswelling kinetics, these IPN hydrogels also exhibited improved intelligent characteristics (e.g., controllable faster response rate) that depended on the composition ratio of the two network components. From the applications viewpoint, the effects of a shrinking-reswelling cycle around the LCST on the properties ofthe IPN hydrogels were examined to determine ifthese properties would be stable for potential applications. Bovine serum albumin was chosen as the model protein for examining its release from the IPNs at different temperatures. The release data suggested that an improved controlled release could be achieved by the IPN-PNIPAAm hydrogels without losing their intelligent properties.
N-isopropylacrylamide, Interpenetrating polymer network, Hydrogel, Controlled drug release, Albumin
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张先正, Xian-Zheng Zhang and Chih-Chang Chu*
J. Mater. Chem., 2003, 13, 2457-2464,-0001,():
-1年11月30日
We have demonstrated a new strategy for preparing poly (N-isopropylacrylamide) (PNIPAAm) gel with significantly improved properties by polymerization-crosslinking in organic solvent (dimethyl sulfoxide, DMSO) and at low temperatures (0.5 and -22℃, below the melting point of DMSO). The effects of different synthesis conditions, including monomer concentration and polymerization temperature, on the formation of the PNIPAAm gels in DMSO were investigated. The properties of the resulting cryo-PNIPAAm gels were characterized by scanning electron microscopy (SEM) to reveal their interior morphology as well as the temperature dependence of the equilibrium swelling ratio, shrinking and swelling kinetics in water and their oscillatory shrinking-swelling kinetics over 3 min temperature cycles between 26 and 37℃. The SEM micrographs reveal that the interior microstructures of the cryo-PNIPAAm gels are very different from conventional PNIPAAm gels, and are much more regular and oriented than the conventional gels. This unique interior morphology of the cryo-PNIPAAm gels is believed to be responsible for the improved swelling and deswelling kinetics and excellent dynamic response without loss of water retention upon temperature cycling.
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【期刊论文】Thermosensitive PNIPAAm cryogel with superfast and stable oscillatory properties
张先正, Xian-Zheng Zhang and Chih-Chang Chu*
CHEM. COMMUN., 2003, 1446-1447,-0001,():
-1年11月30日
Through copolymerization/crosslinking in dimethyl sulfoxide (DMSO) at temperature below the melting point of DMSO, we demonstrated a novel poly (N-isopropylacrylamide) (PNIPAAm) hydrogel with regularly oriented micromatrix; the superfast/stable oscillatory hydration-dehydration character of this hydrogel would find wide applications in biomedical field.
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张先正, Xian-Zheng Zhang a, b, *, Jian-Tao Zhang a, Ren-Xi Zhuo a, Chih-Chang Chu b
Polymer 43(2002)4823-4827,-0001,():
-1年11月30日
A crown ether derivative (4′-allyldibenzo-18-crown-6, CE) was covalently incorporated into the network of temperature sensitive poly (Nisopropylacrylamide) (PNIPA) hydrogels by copolymerization in a mixed solvent of water and tetrahydrofuran (H2O/THF). The poly(Nisopropylacrylamide-co-4′-allyldibenzo-18-crown-6) (poly(NIPA-co-CE)) hydrogels exhibited dramatically faster deswelling rates than normal PNIPA hydrogels at a temperature (50℃) above their lower critical solution temperatures. The effect of the solvent component ratio in the mixed solvent during the copolymerization on the swelling properties of the poly (NIPA-co-CE) hydrogel was investigated. The thermosensitive poly (NIPA-co-CE) hydrogels have potential applications in the extraction of cations and separation of chiral drugs.
N-isopropylacrylamide, Crown ether, Temperature sensitive hydrogel
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【期刊论文】Cellulose acetate membranes for transdermal delivery of scopolamine base
张先正, Fang-Jing Wang a, Yi-Yan Yang a, *, Xian-Zheng Zhang a, Xiao Zhu b, Tai-shung Chung a, c, Shabbir Moochhala b
Materials Science and Engineering C 20(2002)93-100,-0001,():
-1年11月30日
Transdermal delivery is one of the most convenient drug administration routes. In this study, the cellulose acetate membranes were cast with acetone as a solvent at 22 and 40℃. Polyethylene glycol (PEG, MW 600) was used as a pore-forming agent. The in vitro release rates of scopolamine base as a model drug through the membranes were evaluated in phosphate buffer solution (PBS, pH 7.4) at 32℃. The membranes were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal mechanical analysis (TMA) and thermogravimetric analysis (TGA). It was observed that the drug permeation through the cellulose acetate membranes was obviously affected by the incorporated PEG content and formed membrane morphology. There was no drug flux from the cellulose acetate membranes prepared without PEG. An increased PEG content resulted in a faster scopolamine release due to a more porous structure created. Both the membrane fabrication temperature and the PEG content can affect the thermal, mechanical and morphological properties of the resultant membranes. With the optimized fabrication conditions, linear in vitro release profiles of scopolamine over 3 days were achieved. The membranes developed would be useful for transdermal delivery of drugs.
Cellulose acetate membranes, Polyethylene glycol (, PEG), , Transdermal delivery, Scopolamine
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张先正, Xian-Zheng Zhang†, Yi-Yan Yang*, †, Fan-Jing Wang†, and Tai-Shung Chung†, ‡
Langmuir 2002, 18, 2013-2018,-0001,():
-1年11月30日
In this paper, a P (NIPAAm-co-AAc) hydrogel with rapid temperature sensitivity and improved oscillatory properties over small temperature cycles around the physiologic temperature of 37℃ was synthesized in an alkaline solution (Tris/HCl solution, pH 8.8 and I=0.5M). SEM micrographs revealed that the unique properties achieved can be attributed to the expanded network structure generated in the alkaline solution during the copolymerization reaction. As a result of the dissociation of the carboxyl groups (-COOH) of AAc to carboxylate anions (-COO-), the electrostatic repulsion between carboxylate anions was strong and led to the expanded conformations of polymer chains. Therefore, the network of the hydrogels thus obtained was extremely expanded and exhibited fast temperature sensitivity and improved oscillating swelling-deswelling properties.
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【期刊论文】A novel thermo-responsive drug delivery system with positive controlled release
张先正, Xian-Zheng Zhang a, b, *, Ren-Xi Zhuo a, Jing-Zhou Cui a, Jiao-Tao Zhang a
International Journal of Pharmaceutics 235(2002)43-50,-0001,():
-1年11月30日
The model drug, 5-fluorouracil (5-FU) was loaded into the poly (N-isopropylacrylamide) (PNIPA) hydrogel at 25℃, then the drug-loaded, swollen hydrogel sample was carefully enveloped in the dialysis bag to form a novel thermo-responsive drug delivery system (DDS). The concentration of released 5-FU was monitored at 266 nm on the UV spectrophotometer. We found that this novel DDS provides a positive drug release pattern and the drug, 5-FU, was released faster at the increased temperature (37℃, 25℃) than the one at the decreased temperature (10℃<25℃). This was attributed to the double control of the thermo-sensitivity of the hydrogel matrix and the dialysis membrane. By employing the fast response PNIPA hydrogel instead of the conventional hydrogel in this novel DDS, we can further control the drug release rate and/or drug release amount etc., without changing the positive, thermo-responsive drug release pattern.
Thermo-responsive, Poly(, N-isopropylacrylamide), , Hydrogel, Controlled release, Drug delivery system
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张先正, Xian-Zheng Zhang*, Yi-Yan Yang*, and Tai-Shung Chung*, †
Journal of Colloid and Interface Science 246, 105-111(2002),-0001,():
-1年11月30日
Poly (N-isopropylacrylamide) (PNIPAAm) hydrogel exhibits a response to external temperature variation and shrinks in volume abruptly as the temperature is increased above its lower critical solution temperature. It has great potential applications in biomedical fields. A rapid response rate is essential, especially when this material is designed as an on-off switch for targeted drug delivery. However, due to the appearance of a thick, dense skin layer on the hydrogel surface during the shrinking process, the deswelling rate of conventional PNIPAAm gels is low. In this article, a novel method is proposed to modify the surface morphology of PNIPAAm gel, in which the swollen gels are frozen at low temperature (-20℃). The scanning electron micrographs revealed that a fishnet-like skin layer appeared on the surfaces of the cold-treated gels. Dramatically rapid deswelling was achieved with the cold-treated gels since the fishnet-like structure with numerous small pores prevented the formation of a dense, thick skin layer during the deswelling process, which commonly occurs in normal PNIPAAm hydrogels. Prolonging the cold treatment from 1 day to 10 days resulted in a slightly higher deswelling rate. Rearrangement of the hydrogel matrix structure during the freezing process might contribute to the formation of the fishnet-like skin layer. The water uptake of the hydrogels increased nearly in proportion to the square root of time, indicating that the reswelling rate of hydrogels was controlled predominantly by water diffusion into the network. However, there were no significant differences in the equilibrated swelling ratio and reswelling kinetics at room temperature (22℃) between normal gels and coldtreated gels, which implied that cold treatment did not change bulk porosity and gel tortuosity much.
temperature-sensitive, hydrogel, poly (, N-isopropylacrylamide), , fast response, cold treatment
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张先正, Xian-Zheng Zhang, Ren-Xi Zhuo*
Materials Letters 52(2002)5-9,-0001,():
-1年11月30日
Poly (N-isopropylacrylamide-co-methyl methacrylate.) (P(NIPA-co-MMA)) hydrogel was synthesized by making use of the phase separation technique in the mixed solvent (distilled water/glacial acetic acid). This hydrogel responds to external temperature changes very quickly owing to its macroporous network structure formed during the copolymerization/crosslinking process. In this paper, the on-off switch behavior of the P (NIPA-co-MMA) hydrogel with different content of hydrophobic component (MMA) was further investigated and proved to be more sensitive. This fast responsive hydrogel with hydrophobic component and improved sensitivity of its on-off switch behavior would have potential applications in the field of drug-controlled release.
Thermosensitive, Hydrogel, Phase separation, Rapid response, On-off switch
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张先正, Xianzheng Zhang, Renxi Zhuo
Journal of Colloid and Interface Science 223, 311-313(2000),-0001,():
-1年11月30日
A new PNIPA hydrogel was synthesized by carrying out the polymerization in the gelated corn starch aqueous solution. This PNIPA hydrogel has an improved surface property and does not form the disadvantageous bubbles during the shrinking process. This change is due to the hydrogen bonds between the corn starch and the hydrophilic side groups of the PNIPA chains, which let the starch act as the long graft-like chains of the PNIPA hydrogel. During the reswelling process, this PNIPA hydrogel exhibits a sigmoidal swelling pattern. This hydrogel with improved surface property may be very useful for the potential applications of the temperature-sensitive hydrogel.
temperature-sensitive, PNIPA, hydrogel, surface property
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