用户名: 密码: 验证码:
降解型可注射水凝胶的合成及其用于药物缓释和细胞培养的研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
近年来,可注射水凝胶作为一种新型的生物医用高分子材料成为生物医学领域的研究热点之一。其中,可降解的多糖基可注射水凝胶由于其良好的生物相容性和生物降解性引起了人们的广泛关注。然而,该类水凝胶应用于临床尚存在一些亟待解决的问题,如源自动物体的多糖存在病原传递和批次稳定性的问题,无法大规模应用,需要寻找类似的多糖来取代;水凝胶的凝胶浓度较高,不利于实际操作;在多糖中引入非生物降解的合成高分子时,会带来一定的毒副作用;用于药物释放时,药物的理化性质和药物/水凝胶的相互作用未纳入考察的范围等。本论文工作针对上述问题展开了多糖基降解型可注射水凝胶的合成、表征及其作为药物缓释载体和细胞培养支架的应用等研究。
     我们合成了一系列多糖基降解型可注射水凝胶,采用傅立叶变换红外光谱(FTIR)和核磁共振光谱(H NMR)对其结构进行了表征,采用扫描电子显微镜(SEM)观察了水凝胶的内部形貌,通过倒置法和紫外透光率测定了凝胶化时间,通过称重法考察了水凝胶在磷酸盐缓冲液(PBS)中的溶胀行为及降解行为,采用四甲基偶氮唑盐微量酶反应比色法(MTT法)初步评价了水凝胶的生物相容性,研究了可注射水凝胶作为药物释放载体和细胞培养支架的可行性。具体研究内容如下:
     1.制备了氧化羧甲基纤维素/N-琥珀酰基壳聚糖(OCMC/NSC)可注射水凝胶,用FTIR表征了其结构,考察了OCMC的氧化度对可注射水凝胶的凝胶化时间、溶胀行为及降解行为的影响。采用MTT法考察了水凝胶的生物相容性。以牛血清蛋白(BSA)为模型药物考察了OCMC/NSC可注射水凝胶的释药行为,并通过荧光光谱法考察了释放后的BSA的构象变化。研究发现,OCMC的氧化度越大,水凝胶的凝胶化时间越短,溶胀比越低,降解速率越慢。OCMC/NSC可注射水凝胶无明显细胞毒性。水凝胶对BSA有一定的缓释作用,且释放后的BSA的构象未发生变化。该研究表明,基于席夫碱交联反应的可注射水凝胶在形成过程中不需要引入其他引发剂或交联剂,可避免该类物质的毒副作用。
     2.采用硫酸软骨素(ChS)和壳聚糖(CS)制备了可生物降解的可注射水凝胶,重点考察了大分子上醛基和氨基的比例对可注射水凝胶的性能的影响,如凝胶化时间、交联密度、交联点间平均分子量、机械性能、溶胀行为及降解行为。体外细胞毒性实验表明,制备的水凝胶具有较好的生物相容性。将模型药物氨茶碱、吲哚美辛和溶菌酶通过简单的混合的方式负载到水凝胶内部。药物释放行为表明,药物的理化性质及药物/聚合物相互作用对药物的释放行为有重要影响。该研究将为新的药物递送体系的开发与应用提供思路。
     3.将温敏性聚合物聚N-异丙基丙烯酰胺(PNIPAAm)接枝到羧甲基纤维素(CMC)的分子链上,制备了一种具有较低凝胶浓度、可降解的可注射水凝胶(CMC-g-PNIPAAm)。该凝胶的凝胶浓度为2 wt%,低于文献报道的其他PNIPAAm基水凝胶的凝胶浓度。该凝胶对HEK 293T细胞显示出良好的生物相容性。以溶菌酶为模型蛋白质药物,考察了CMC-g-PNIPAAm水凝胶对溶菌酶的体外释放行为,结果显示,接枝率较大的水凝胶对溶菌酶有一定的缓释作用。圆二色谱及荧光光谱表明,释放后溶菌酶的二级结构和三级结构没有发生变化。以溶壁微球菌(Micrococcus lysodeikticus)为底物,测定了释放后溶菌酶的活力,结果表明释放后溶菌酶的活力未受影响。以上研究结果表明该温敏型可注射水凝胶在蛋白质药物的缓控释方面有广阔的应用前景。
     4.在硫酸软骨素(ChS)分子中引入了低分子量的PNIPAAm,合成了一种可生物降解的可注射水凝胶。PNIPAAm的合成采用可逆-加成断裂链转移(RAFT)聚合,以使其降解后可通过肾脏排出体外。测定了水凝胶的相转变行为及凝胶化时间,结果显示,水凝胶的相转变温度在室温与37℃之间,凝胶化时间在70 s到90 s范围内,便于实际操作。体外降解实验表明,水凝胶在37℃的透明质酸酶溶液(酶浓度为100 U/m1)中降解4周后,失重率大于40%。二维细胞培养和三维细胞培养结果显示,水凝胶具有良好的生物相容性,能保持细胞的存活及增殖能力。细胞在水凝胶内部分层分布。研究结果表明该可注射水凝胶有望用于细胞的三维培养载体。
As novel biomedical materials, injectable hydrogels show bright application perspective. Especially, degradable polysaccharide-based injectable hydrogels have been extensively studied due to their biodegradability and biocompatibility. However, several challenges still remain for clinical applications. For example, the polysaccharide derived from animal sources present the risk of batch-to-batch variations and the possibility of immune responses upon injection; critical gelation concentration at which gelation occurs is high; incorporating synthetic polymers into the backbone of polysaccharide may increase the cytotoxicity of the hydrogel when they are non-biodegradable and not readily cleared away from the body under physiological conditions; the physico-chemical properties of the drugs and drug-polymer interaction are not considered. In view of these problems, we synthesized a series of novel degradable polysaccharide-based injectable hydrogels and investigated their potential applications in drug delivery and cell culture.
     A series of degradable polysaccharide-based injectable hydrogels were developed, and were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H NMR. Scanning electron microscopy (SEM) was employed to investigate the porous structure of the hydrogels. Hydrogel gelation time was measured by the vial inversion method and UV/vis spectroscopy. The swelling and degradation behavior of the hydrogels in PBS were determined by weighing method. Cytotoxicity evaluation of the hydrogels were performed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The potential applications of the injectable hydrogels in drug delivery and cell culture were inveatigated. The detailed research contents are as follows:
     1. Injectable hydrogels derived from oxidized carboxymethylcellulose (OCMC) and N-succinyl-chitosan (NSC) were prepared by Schiff base reaction. The gelation readily took place at physiological pH and temperature. Several parameters, such as matrix gelation time, equilibrium swelling ratio, matrix degradation rate and drug release profile, were investigated. The in vitro cytotoxicity studies showed that the OCMC/NSC hydrogels were non-cytotoxic. The controlled release profile of BSA was obtained. Importantly, activity of released BSA was retained. This newly described OCMC/NSC hydrogels formed without requiring additional initiators, crosslinkers or light sources, eliminating the toxicity associated with such agents.
     2. Injectable and biodegradable hydrogels based on oxidized chondroitin sulfate (OChS) and N-succinyl-chitosan (NSC) were developed. We focused on the physical characteristics of the hydrogels (e.g. crosslinking density, molecular weight between crosslinks and mechanical strength) and the effects of physico-chemical properties of the drugs and drug-polymer interaction on drug release behaviors. The model drugs aminophylline, indomethacin and lysozyme were easily incorporated into the hydrogels by mixing with the gel precursors. Release studies showed that the physico-chemical properties of the drugs and drug-polymer interaction play an important role in drug release behaviors. The study provided necessary information for the design and development of novel drug delivery systems.
     3. CMC-g-PNIPAAm copolymers were developed by decorating the backbone of carboxymethylcellulose (CMC) with linear chains of poly(N-isopropylacrylamide) (PNIPAAm), with the ultimate aim of synthesizing a biodegradable and injectable hydrogel that also possesses a low gelation concentration. Their aqueous solutions were found to undergo a reversible subphysiological phase transition at the concentration of 2 wt%. The value is much lower than that reported for many PNIPAAm-based copolymers. The phase transition behavior, gelation time, injectability, viscosity, swelling, degradation and cytocompatibility were explored. Lysozyme was used as the model drug. In vitro release of lysozyme from the injectable hydrogel was studied. Secondary and tertiary structure analysis and biological assays of the released protein showed that encapsulation and release did not affect the protein conformation and functionality. These results indicate that this biocompatible and injectable hydrogel system may be useful as a potential vehicle for therapeutic proteins for sustained release applications.
     4. Biohybrid injectable hydrogels based on chondroitin sulfate (ChS) and poly(N-isopropylacrylamide) (PNIPAAm) were developed. PNIPAAm was synthesized at various molecular weights by RAFT polymerization. The molecular weight range suitable for renal clearance was an important factor in the experimental design. The phase transition temperature was between room temperature and 37℃and the gelation time was 70-90 s, indicating their possibility for further clinical application. Hydrogel degradation was determined in PBS with 100 U/ml of hyaluronidase at 37℃and the results revealed that the hydrogels lost above 40% of their weight after 4 weeks. In vitro two-dimensional (2-D) and three-dimensional (3-D) cell cultures were performed. Cells demonstrated excellent viability when cultured with the hydrogel. In addition, the arrangement of multiple cell layers in the hydrogel was achieved. These results indicate the injectable hydrogels may be expected to have wide potential applications as a vehicle for the delivery of therapeutic cells.
引文
[1]刘锋,卓仁禧水凝胶的制备及应用[J].高分子通报.1995,4:205-216.
    [2]Yu, L., Ding, J.D. Injectable hydrogels as unique biomedical materials[J]. Chem. Soc. Rev.2008,37:1473-1481.
    [3]Li, Y., Rodrigues, J., Tomas, H. Injectable and biodegradable hydrogels:gelation, biodegradation and biomedical applications [J]. Chem. Soc. Rev.2012,41: 2193-2221.
    [4]魏宏亮,王连才,张爱英,朱凯强,冯增国可注射水凝胶的制备与应用[J].化学进展.2004,6:1008-1016.
    [5]Klouda, L., Mikos, A. Thermoresponsive hydrogels in biomedical applications [J]. Eur. J. Pharm. Biopharm.2008,68:34-45.
    [6]Ruel-Gariepy, E., Leroux, J.-C. In situ-forming hydrogels--review of temperature-sensitive systems[J]. Eur. J. Pharm. Biopharm.2004,58:409-426.
    [7]Mourya, V.K., Inamdar, N.N. Chitosan-modifications and applications: Opportunities galore[J]. React. Funct. Polym.2008,68:1013-1051.
    [8]Kim, S., Nishimoto, S.K., Bumgardner, J.D., Haggard, W.O., Gaber, M.W., Yang, Y. A chitosan/β-glycerophosphate thermo-sensitive gel for the delivery of ellagic acid for the treatment of brain cancer[J]. Biomaterials.2010,31:4157-4166.
    [9]Chenite, A., Chaput, C., Wang, D., Combes, C., Buschmann, M.D., Hoemann, C.D., Leroux, J.C., Atkinson, B.L., Binette, F., Selmani, A. Novel injectable neutral solutions of chitosan form biodegradable gels in situ[J]. Biomaterials. 2000,21:2155-2161.
    [10]王东武,杨柳,段小军,李忠体外构建可注射性组织工程软骨的初步研究[J].第三军医大学学报.2006,11:1145-1147.
    [11]Ruel-Gariepy, E., Shive, M., Bichara, A., Berrada, M., Le Garrec, D., Chenite, A., Leroux, J.-C. A thermosensitive chitosan-based hydrogel for the local delivery of paclitaxel[J]. Eur. J. Pharm. Biopharm.2004,57:53-63.
    [12]Richardson, S.M., Hughes, N., Hunt, J.A., Freemont, A.J., Hoyland, J.A. Human mesenchymal stem cell differentiation to NP-like cells in chitosan-glycerophosphate hydrogels[J]. Biomaterials.2008,29:85-93.
    [13]Chenite, A., Buschmann, M., Wang, D., Chaput, C, Kandani, N. Rheological characterisation of thermogelling chitosan/glycerol-phosphate solutions[J]. Carbohydr. Polym.2001,46:39-47.
    [14]Tang, Y.F., Du, Y.M., Hu, X.W., Shi, X.W., Kennedy, J.F. Rheological characterisation of a novel thermosensitive chitosan/poly(vinyl alcohol) blend hydrogel[J]. Carbohydr. Polym.2007,67:491-499.
    [15]Tang, Y.F., Du, Y.M., Li, Y, Wang, X.Y., Hu, X.W. A thermosensitive chitosan/poly(vinyl alcohol) hydrogel containing hydroxyapatite for protein delivery[J]. J. Biomed. Mater. Res. A.2009,91 A:953-963.
    [16]Bain, M.K., Bhowmik, M., Ghosh, S.N., Chattopadhyay, D. In situ fast gelling formulation of methyl cellulose for in vitro ophthalmic controlled delivery of ketorolac tromethamine[J]. J. Appl. Polym. Sci.2009,113:1241-1246.
    [17]Liang, H.F., Hong, M.H., Ho, R.M., Chung, C.K., Lin, Y.H., Chen, C.H., Sung, H. W. Novel method using a temperature-sensitive polymer (methylcellulose) to thermally gel aqueous alginate as a pH-sensitive hydrogel[J]. Biomacromolecules. 2004,5:1917-1925.
    [18]Tang, Y.F., Wang, X.Y., Li, Y, Lei, M., Du, Y.M., Kennedy, J.F., Knill, C.J. Production and characterisation of novel injectable chitosan/methylcellulose/salt blend hydrogels with potential application as tissue engineering scaffolds [J]. Carbohydr. Polym.2010,82:833-841.
    [19]Trojani, C, Weiss, P., Michiels, J.F., Vinatier, C., Guicheux, J., Daculsi, G, Gaudray, P., Carle, G.F., Rochet, N. Three-dimensional culture and differentiation of human osteogenic cells in an injectable hydroxypropylmethylcellulose hydrogel[J]. Biomaterials.2005,26:5509-5517.
    [20]Vinatier, C., Gauthier, O., Fatimi, A., Merceron, C., Masson, M., Moreau, A., Moreau, F., Fellah, B., Weiss, P., Guicheux, J. An injectable cellulose-based hydrogel for the transfer of autologous nasal chondrocytes in articular cartilage defects[J]. Biotechnol. Bioeng.2009,102:1259-1267.
    [21]Weiss, P., Gauthier, O., Bouler, J.M., Grimandi, G, Daculsi, G. Injectable bone substitute using ahydrophilic polymer[J]. Bone.1999,25:67S-70S.
    [22]Iooss, P., Le Ray, A.M., Grimandi, G., Daculsi, G, Merle, C. A new injectable bone substitute combining poly(s-caprolactone) microparticles with biphasic calcium phosphate granules[J]. Biomaterials.2001,22:2785-2794.
    [23]Trojani, C, Boukhechba, F., Scimeca, J.C., Vandenbos, F., Michiels, J.F., Daculsi, G, Boileau, P., Weiss, P., Carle, G.F., Rochet, N. Ectopic bone formation using an injectable biphasic calcium phosphate/Si-HPMC hydrogel composite loaded with undifferentiated bone marrow stromal cells[J]. Biomaterials.2006,27:3256-3264.
    [24]Ding, C.X., Zhao, L.L., Liu, F.Y., Cheng, J., Gu, J.X., Dan, S., Liu, C.Y., Qu, X.Z., Yang, Z.Z. Dually responsive injectable hydrogel prepared by in situ cross-linking of glycol chitosan and benzaldehyde-capped PEO-PPO-PEO[J]. Biomacromolecules.2010,11:1043-1051.
    [25]Fults, K.A., Johnston, T.P. Sustained-release of urease from a Poloxamer gel matrix[J]. PDA J. Pharm. Sci. Technol.1990,44:58-65.
    [26]Mayol, L., Quaglia, F., Borzacchiello, A., Ambrosio, L., Rotonda, M. A novel poloxamers/hyaluronic acid in situ forming hydrogel for drug delivery: Rheological, mucoadhesive and in vitro release properties [J]. Eur. J. Pharm. Biopharm.2008,70:199-206.
    [27]Pisal, S.S., Paradkar, A.R., Mahadik, K.R., Kadam, S.S. Pluronic gels for nasal delivery of Vitamin B12. Part I:Preformulation study [J]. Int. J. Pharm.2004,270: 37-45.
    [28]Pillai, O., Panchagnula, R. Transdermal delivery of insulin from poloxamer gel: ex vivo and in vivo skin permeation studies in rat using iontophoresis and chemical enhancers[J]. J. Controlled Release.2003,89:127-140.
    [29]Lee, S.H., Lee, J.E., Baek, W.Y., Lim, J.O. Regional delivery of vancomycin using pluronic F-127 to inhibit methicillin resistant Staphylococcus aureus (MRSA) growth in chronic otitis media in vitro and in vivo[J]. J. Controlled Release.2004,96:1-7.
    [30]Johnston, T.P., Punjabi, M.A., Froelich, C.J. Sustained delivery of interleukin-2 from a Poloxamer 407 gel matrix following intraperitoneal injection in mice[J]. Pharm. Res.1992,9:425-434.
    [31]Wang, P.L., Johnston, T.P. Sustained-release interleukin-2 following intramuscular injection in rats[J]. Int. J. Pharm.1995,113:73-81.
    [32]Pec, E.A., Wout, Z.G., Johnston, T.P. Biological activity of urease formulated in poloxamer 407 after intraperitoneal injection in the rat[J]. J. Pharm. Sci.1992,81: 626-630.
    [33]Morishita, M., Barichello, J.M., Takayama, K., Chiba, Y., Tokiwa, S., Nagai, T. Pluronic(?) F-127 gels incorporating highly purified unsaturated fatty acids for buccal delivery of insulin[J]. Int. J. Pharm.2001,212:289-293.
    [34]Liaw, J., Lin, Y.C. Evaluation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) gels as a release vehicle for percutaneous fentanyl[J]. J. Controlled Release.2000,68:273-282.
    [35]Miyazaki, S., Tobiyama, T., Takada, M., Attwood, D. Percutaneous absorption of indomethacin from Pluronic F127 gels in rats[J]. J. Pharm. Pharmacol.1995,47: 455-457.
    [36]Miyazaki, S., Takeuchi, S., Yokouchi, C., Takada, M. Pluronic F-127 gels as a vehicle for topical administration of anticancer agents[J]. Chem. Pharm. Bull. (Tokyo).1984,32:4205-4208.
    [37]Katakam, M., Ravis, W.R., Banga, A.K. Controlled release of human growth hormone in rats following parenteral administration of poloxamer gels[J]. J. Controlled Release.1997,49:21-26.
    [38]Dibiase, M.D., Rhodes, C.T. Formulation and evaluation of epidermal growth factor in Pluronic F-127 gel[J]. Drug Dev. Ind. Pharm.1996,22:823-831.
    [39]Park, K.M., Lee, S.Y., Joung, Y.K., Na, J.S., Lee, M.C., Park, K.D. Thermosensitive chitosan-Pluronic hydrogel as an injectable cell delivery carrier for cartilage regeneration[J]. Acta Biomater.2009,5:1956-1965.
    [40]杨维东,陈富林,毛天球,顾晓明,李石保,陶凯,陈书军以合成水凝胶为载体建造可注射性软骨[J].实用口腔医学杂志.1999,5:378-380.
    [41]Jung, H.H., Park, K., Han, D.K. Preparation of TGF-β1-conjugated biodegradable pluronic F127 hydro gel and its application with adipose-derived stem cells[J]. J. Controlled Release.2010,147:84-91.
    [42]Rzaev, Z.M.O., Dincer, S., Piskin, E. Functional copolymers of N-isopropylacrylamide for bioengineering applications [J]. Prog. Polym. Sci.2007, 32:534-595.
    [43]Chen, J.P., Cheng, T.H. Thermo-responsive chitosan-graft-poly (N-isopropylacrylamide) injectable hydrogel for cultivation of chondrocytes and meniscus cells[J]. Macromol. Biosci.2006,6:1026-1039.
    [44]Ibusuki, S., Iwamoto, Y., Matsuda, T. System-engineered cartilage using poly(N-isopropylacrylamide)-grafted gelatin as in situ-formable scaffold:in vivo performance[J]. Tissue Eng.2003,9:1133-1142.
    [45]Fitzpatrick, S.D., Jafar Mazumder, M.A., Lasowski, F., Fitzpatrick, L.E., Sheardown, H. PNIPAAm-grafted-collagen as an injectable, in situ gelling, bioactive cell delivery scaffold[J]. Biomacromolecules.2010,11:2261-2267.
    [46]Cao, Y.X., Zhang, C., Shen, W.B., Cheng, Z.H., Yu, L.L., Ping, Q.N. Poly(N-isopropylacrylamide)-chitosan as thermosensitive in situ gel-forming system for ocular drug delivery [J]. J. Controlled Release.2007,120:186-194.
    [47]Chen, J.P., Cheng, T.H. Preparation and evaluation of thermo-reversible copolymer hydrogels containing chitosan and hyaluronic acid as injectable cell carriers[J]. Polymer.2009,50:107-116.
    [48]Comolli, N., Neuhuber, B., Fischer, I., Lowman, A. In vitro analysis of PNIPAAm-PEG, a novel, injectable scaffold for spinal cord repair[J]. Acta Biomater.2009,5:1046-1055.
    [49]Zentner, G.M., Rathi, R., Shih, C., McRea, J.C., Seo, M.H., Oh, H., Rhee, B.G., Mestecky, J., Moldoveanu, Z., Morgan, M., Weitman, S. Biodegradable block copolymers for delivery of proteins and water-insoluble drugs[J]. J. Controlled Release.2001,72:203-215.
    [50]Lee, D.S., Shim, M.S., Kim, S.W., Lee, H., Park, I., Chang, T. Novel thermoreversible gelation of biodegradable PLGA-block-PEO-block-PLGA triblock copolymers in aqueous solution[J]. Macromol. Rapid Commun.2001,22: 587-592.
    [51]Shim, M.S., Lee, H.T., Shim, W.S., Park, I., Lee, H., Chang, T., Kim, S.W., Lee, D.S. Poly(D,L-lactic acid-co-glycolic acid)-b-poly(ethylene glycol)-b-poly (D,L-lactic acid-co-glycolic acid) triblock copolymer and thermoreversible phase transition in water[J]. J. Biomed. Mater. Res.2002,61:188-196.
    [52]林浩,田华雨,孙敬茹,庄秀丽,陈学思,李悦生,景遐斌温度敏感的PLGA-PEG-PLGA水凝胶的合成、表征和药物释放[J].高等学校化学学报.2006,27:1385-1388.
    [53]Jeong, B., Bae, Y.H., Kim, S.W. Thermoreversible gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions [J]. Macromolecules.1999,32:7064-7069.
    [54]Jeong, B., Bae, Y.H., Kim, S.W. Biodegradable thermosensitive micelles of PEG-PLGA-PEG triblock copolymers [J]. Colloids Surf. B. Biointerfaces.1999, 16:185-193.
    [55]Jeong, B., Kibbey, M.R., Birnbaum, J.C., Won, Y.Y., Gutowska, A. Thermogelling biodegradable polymers with hydrophilic backbones: PEG-g-PLGA[J]. Macromolecules.2000,33:8317-8322.
    [56]Jeong, B., Wang, L.Q., Gutowska, A. Biodegradable thermoreversible gelling PLGA-g-PEG copolymers[J]. Chem. Commun.2001,1516-1517.
    [57]Chung, Y.M., Simmons, K.L., Gutowska, A., Jeong, B. Sol-gel transition temperature of PLGA-g-PEG aqueous solutions[J]. Biomacromolecules.2002,3: 511-516.
    [58]Lu, D.D., Yuan, J.C., Li, H., Lei, Z.Q. Synthesis and characterization of a series of biodegradable and biocompatible PEG-supported poly(lactic-ran-glycolic acid) amphiphilic barbell-like copolymers [J]. J. Polym. Sci., Part A:Polym. Chem. 2008,46:3802-3812.
    [59]Gil, E.S., Hudson, S.M. Stimuli-reponsive polymers and their bioconjugates[J]. Prog. Polym. Sci.2004,29:1173-1222.
    [60]Jeong, B., Bae, Y.H., Lee, D.S., Kim, S.W. Biodegradable block copolymers as injectable drug-delivery systems[J]. Nature.1997,388:860-862.
    [61]Jeong, B., Bae, Y.H., Kim, S.W. Drug release from biodegradable injectable thermosensitive hydrogel of PEG-PLGA-PEG triblock copolymers[J]. J. Controlled Release.2000,63:155-163.
    [62]Qiao, M.X., Chen, D.W., Hao, T.N., Zhao, X.L., Hu, H.Y., Ma, X.C. Effect of bee venom peptide-copolymer interactions on thermosensitive hydrogel delivery systems[J]. Int. J. Pharm.2007,345:116-124.
    [63]Hvidt, S., Joergensen, E.B., Brown, W., Schillen, K. Micellization and gelation of aqueous solutions of a triblock copolymer studied by rheological techniques and scanning calorimetry[J]. The Journal of Physical Chemistry.1994,98: 12320-12328.
    [64]Madbouly, S.A., Otaigbe, J.U., Nanda, A.K., Wicks, D.A. Thermal-induced simultaneous liquid-liquid phase separation and liquid-solid transition in aqueous polyurethane dispersions[J]. Polymer.2005,46:10897-10907.
    [65]Bae, S.J., Suh, J.M., Sohn, Y.S., Bae, Y.H., Kim, S.W., Jeong, B. Thermogelling Poly(caprolactone-b-ethylene glycol-b-caprolactone) aqueous solutions[J]. Macromolecules.2005,38:5260-5265.
    [66]Santoro, M., Marchetti, P., Rossi, F., Perale, G, Castiglione, F., Mele, A., Masi, M. Smart approach to evaluate drug diffusivity in injectable agar-carbomer hydrogels for drug delivery[J]. J. Phys. Chem. B.2011,115:2503-2510.
    [67]Srividya, B., Cardoza, R.M., Amin, P.D. Sustained ophthalmic delivery of ofloxacin from a pH triggered in situ gelling system[J]. J. Controlled Release. 2001,73:205-211.
    [68]Perale, G, Veglianese, P., Rossi, F., Peviani, M., Santoro, M., Llupi, D., Micotti, E., Forloni, G., Masi, M. In situ agar-carbomer hydrogel poly condensation:A chemical approach to regenerative medicine[J]. Mater. Lett.2011,65:1688-1692.
    [69]Chiu, Y.L., Chen, S.C., Su, C.J., Hsiao, C.W., Chen, Y.M., Chen, H.L., Sung, H.W. pH-triggered injectable hydrogels prepared from aqueous N-palmitoyl chitosan:In vitro characteristics and in vivo biocompatibility[J]. Biomaterials. 2009,30:4877-4888.
    [70]Nguyen, K.T., West, J.L. Photopolymerizable hydrogels for tissue engineering applications[J]. Biomaterials.2002,23:4307-4314.
    [71]Bryant, S.J., Nuttelman, C.R., Anseth, K.S. Cytocompatibility of UV and visible light photoinitiating systems on cultured NIH/3T3 fibroblasts in vitro[J]. J. Biomater. Sci. Polym. Ed.2000,11:439-457.
    [72]Cruise, G.M., Scharp, D.S., Hubbell, J.A. Characterization of permeability and network structure of interfacially photopolymerized poly(ethylene glycol) diacrylate hydrogels[J]. Biomaterials.1998,19:1287-1294.
    [73]Park, Y.D., Tirelli, N., Hubbell, J.A. Photopolymerized hyaluronic acid-based hydrogels and interpenetrating networks[J]. Biomaterials.2003,24:893-900.
    [74]Elisseeff, J., McIntosh, W., Anseth, K., Riley, S., Ragan, P., Langer, R. Photoencapsulation of chondrocytes in poly(ethylene oxide)-based semi-interpenetrating networks[J]. J. Biomed. Mater. Res.2000,51:164-171.
    [75]Lee, F., Chung, J.E., Kurisawa, M. An injectable hyaluronic acid-tyramine hydrogel system for protein delivery[J]. J. Controlled Release.2009,134: 186-193.
    [76]Wang, L.S., Chung, J.E., Pui-Yik Chan, P., Kurisawa, M. Injectable biodegradable hydrogels with tunable mechanical properties for the stimulation of neurogenesic differentiation of human mesenchymal stem cells in 3D culture[J]. Biomaterials.2010,31:1148-1157.
    [77]Wennink, J.W.H., Niederer, K., Bochynska, A.I., Moreira Teixeira, L.S., Karperien, M., Feijen, J., Dijkstra, P.J. Injectable hydrogels by enzymatic co-crosslinking of dextran and hyaluronic acid tyramine conjugates [J]. Macromol. Symp.2011,309-310:213-221.
    [78]Kobayashi, S., Uyama, H., Kimura, S. Enzymatic polymerization[J]. Chem. Rev. 2001,101:3793-3818.
    [79]Jin, R., Moreira Teixeira, L.S., Dijkstra, P.J., Karperien, M., van Blitterswijk, C.A., Zhong, Z.Y., Feijen, J. Injectable chitosan-based hydrogels for cartilage tissue engineering [J]. Biomaterials.2009,30:2544-2551.
    [80]Tran, N.Q., Joung, Y.K., Lih, E., Park, K.D. In situ forming and rutin-releasing chitosan hydrogels as injectable dressings for dermal wound healing[J]. Biomacromolecules.2011,12:2872-2880.
    [81]Jin, R., Moreira Teixeira, L.S., Dijkstra, P.J., van Blitterswijk, C.A., Karperien, M., Feijen, J. Enzymatically-crosslinked injectable hydrogels based on biomimetic dextran-hyaluronic acid conjugates for cartilage tissue engineering[J]. Biomaterials.2010,31:3103-3113.
    [82]Tan, H., Chu, C.R., Payne, K.A., Marra, K.G. Injectable in situ forming biodegradable chitosan-hyaluronic acid based hydrogels for cartilage tissue engineering[J]. Biomaterials.2009,30:2499-2506.
    [83]Weng, L., Chen, X., Chen, W. Rheological characterization of in situ crosslinkable hydrogels formulated from oxidized dextran and N-carboxyethyl chitosan[J]. Biomacromolecules.2007,8:1109-1115.
    [84]Weng, L., Romanov, A., Rooney, J., Chen, W. Non-cytotoxic, in situ gelable hydrogels composed of N-carboxyethyl chitosan and oxidized dextran[J]. Biomaterials.2008,29:3905-3913.
    [85]Su, W.Y., Chen, Y.C., Lin, F.H. Injectable oxidized hyaluronic acid/adipic acid dihydrazide hydrogel for nucleus pulposus regeneration[J]. Acta Biomater.2010, 6:3044-3055.
    [86]Hahn, S., Oh, E., Miyamoto, H., Shimobouji, T. Sustained release formulation of erythropoietin using hyaluronic acid hydrogels crosslinked by Michael addition[J]. Int. J. Pharm.2006,322:44-51.
    [87]Hiemstra, C, van der Aa, L.J., Zhong, Z., Dijkstra, P.J., Feijen, J. Novel in situ forming, degradable dextran hydrogels by Michael addition chemistry:synthesis, rheology, and degradation[J]. Macromolecules.2007,40:1165-1173.
    [88]Hiemstra, C, van der Aa, L.J., Zhong, Z., Dijkstra, P.J., Feijen, J. Rapidly in situ-forming degradable hydrogels from dextran thiols through Michael addition[J]. Biomacromolecules.2007,8:1548-1556.
    [89]Jin, R., Moreira Teixeira, L.S., Krouwels, A., Dijkstra, P.J., van Blitterswijk, C.A., Karperien, M., Feijen, J. Synthesis and characterization of hyaluronic acid-poly(ethylene glycol) hydrogels via Michael addition:An injectable biomaterial for cartilage repair[J]. Acta Biomater.2010,6:1968-1977.
    [90]侯丹丹,郝彤,叶霖,张爱英,王常勇,冯增国通过麦克加成反应形成的三臂聚乙二醇丙烯酸酯可注射水凝胶的制备与表征[J].高分子学报.2008,4:388-393.
    [91]Elbert, D.L., Pratt, A.B., Lutolf, M.P., Halstenberg, S., Hubbell, J.A. Protein delivery from materials formed by self-selective conjugate addition reactions[J]. J. Controlled Release.2001,76:11-25.
    [92]Kang, H.A., Jeon, G.J., Lee, M.Y., Yang, J.W. Effectiveness test of alginate-derived polymeric surfactants [J]. J Chem Technol Biotechnol.2002,77: 205-210.
    [93]Rowley, J.A., Madlambayan, G, Mooney, D.J. Alginate hydrogels as synthetic extracellular matrix materials[J], Biomaterials.1999,20:45-53.
    [94]Wang, L., Shelton, R.M., Cooper, P.R., Lawson, M., Triffitt, J.T., Barralet, J.E. Evaluation of sodium alginate for bone marrow cell tissue engineering [J]. Biomaterials.2003,24:3475-3481.
    [95]羊书勇,杨维东,雷德林,陈富林,唐立辉,陈希哲,杨连甲,毛天球可注射性组织工程骨的初步研究[J].实用口腔医学杂志.2001,4:271-273.
    [96]Paige K.T., Cima L.G., Yaremchuk M.J., Vacanti J.P., Vacanti C.A. Injectable cartilage[J]. Plast. Reconstr. Surg.1995,96:1390-1398.
    [97]Stevens, M.M., Qanadilo, H.F., Langer, R., Prasad Shastri, V. A rapid-curing alginate gel system:utility in periosteum-derived cartilage tissue engineering [J]. Biomaterials.2004,25:887-894.
    [98]LeRoux, M.A., Guilak, F., Setton, L.A. Compressive and shear properties of alginate gel:Effects of sodium ions and alginate concentration[J]. J. Biomed. Mater. Res.1999,47:46-53.
    [99]Zhao, L., Weir, M.D., Xu, H.H.K. An injectable calcium phosphate-alginate hydrogel-umbilical cord mesenchymal stem cell paste for bone tissue engineering[J]. Biomaterials.2010,31:6502-6510.
    [100]Marsich, E., Borgogna, M., Donati, I., Mozetic, P., Strand, B.L., Salvador, S.G., Vittur, F., Paoletti, S. Alginate/lactose-modified chitosan hydrogels:A bioactive biomaterial for chondrocyte encapsulation[J]. J. Biomed. Mater. Res. A.2008, 84A:364-376.
    [101]Freeman, I., Kedem, A., Cohen, S. The effect of sulfation of alginate hydrogels on the specific binding and controlled release of heparin-binding proteins [J]. Biomaterials.2008,29:3260-3268.
    [102]Loebsack, A., Greene, K., Wyatt, S., Culberson, C, Austin, C, Beiler, R., Roland, W., Eiselt, P., Rowley, J., Burg, K., Mooney, D., Holder, W., Halberstadt, C. In vivo characterization of a porous hydrogel material for use as a tissue bulking agent[J]. J. Biomed. Mater. Res.2001,57:575-581.
    [103]Bidarra, S.J., Barrias, C.C., Fonseca, K.B., Barbosa, M.A., Soares, R.A., Granja, P.L. Injectable in situ crosslinkable RGD-modified alginate matrix for endothelial cells delivery[J]. Biomaterials.2011,32:7897-7904.
    [104]Cohen, S., Lobel, E., Trevgoda, A., Peled, Y. A novel in situ-forming ophthalmic drug delivery system from alginates undergoing gelation in the eye[J]. J. Controlled Release.1997,44:201-208.
    [1]Hoffman, A.S. Hydrogels for biomedical applications[J]. Adv. Drug Del. Rev. 2002,54:3-12.
    [2]Bhattarai, N., Ramay, H.R., Gunn, J., Matsen, F.A., Zhang, M. PEG-grafted chitosan as an injectable thermosensitive hydrogel for sustained protein release [J]. J. Controlled Release.2005,103:609-624.
    [3]Leach, J.B., Schmidt, C.E. Characterization of protein release from photocrosslinkable hyaluronic acid-polyethylene glycol hydrogel tissue engineering scaffolds[J]. Biomaterials.2005,26:125-135.
    [4]Wu, D.Q., Qiu, F., Wang, T., Jiang, X.J., Zhang, X.Z., Zhuo, R.X. Toward the development of partially biodegradable and injectable thermoresponsive hydrogels for potential biomedical applications [J]. ACS Appl. Mater. Interfaces.2009,1: 319-327.
    [5]Bae, Y.H., Kim, S.W. Hydrogel delivery systems based on polymer blends, block co-polymers or interpenetrating networks[J]. Adv. Drug Del. Rev.1993,11: 109-135.
    [6]Lee, K.Y., Mooney, D.J. Hydrogels for tissue engineering [J]. Chem. Rev.2001, 101:1869-1880.
    [7]Bezemer, J.M., Radersma, R., Grijpma, D.W., Dijkstra, P.J., Feijen, J., van Blitterswijk, C.A. Zero-order release of lysozyme from poly(ethylene glycol)/poly(butylene terephthalate) matrices[J]. J. Controlled Release.2000,64: 179-192.
    [8]Park, T.G., Lu, W., Crotts, G. Importance of in vitro experimental conditions on protein release kinetics, stability and polymer degradation in protein encapsulated poly (D,L-lactic acid-co-glycolic acid) microspheres[J]. J. Controlled Release. 1995,33:211-222.
    [9]Ruel-Gariepy, E., Leroux, J.C. In situ-forming hydrogels--review of temperature-sensitive systems[J]. Eur. J. Pharm. Biopharm.2004,58:409-426.
    [10]Chiu, Y.L., Chen, S.C., Su, C.J., Hsiao, C.W., Chen, Y.M., Chen, H.L., Sung, H.W. pH-triggered injectable hydrogels prepared from aqueous N-palmitoyl chitosan:In vitro characteristics and in vivo biocompatibility[J]. Biomaterials. 2009,30:4877-4888.
    [11]Park, K.M., Lee, S.Y., Joung, Y.K., Na, J.S., Lee, M.C., Park, K.D. Thermosensitive chitosan-Pluronic hydrogel as an injectable cell delivery carrier for cartilage regeneration [J]. Acta Biomater.2009,5:1956-1965.
    [12]Rozier, A., Mazuel, C., Grove, J., Plazonnet, B. Gelrite(?):A novel, ion-activated, in-situ gelling polymer for ophthalmic vehicles. Effect on bioavailability of timolol[J]. Int. J. Pharm.1989,57:163-168.
    [13]Shu, X. Z., Liu, Y.C., Palumbo, F.S., Luo, Y., Prestwich, G.D. In situ crosslinkable hyaluronan hydrogels for tissue engineering [J]. Biomaterials.2004, 25:1339-1348.
    [14]Lee, F., Chung, J.E., Kurisawa, M. An injectable hyaluronic acid-tyramine hydrogel system for protein delivery[J]. J. Controlled Release.2009,134: 186-193.
    [15]Lee, K.Y., Yuk, S.H. Polymeric protein delivery systems[J]. Prog. Polym. Sci. 2007,32:669-697.
    [16]Jeong, B., Bae, Y.H., Lee, D.S., Kim, S.W. Biodegradable block copolymers as injectable drug-delivery systems[J]. Nature.1997,388:860-862.
    [17]Ito, T., Yeo, Y., Highley, C.B., Bellas, E., Kohane, D.S. Dextran-based in situ cross-linked injectable hydrogels to prevent peritoneal adhesions[J]. Biomaterials. 2007,28:3418-3426.
    [18]Bhattarai, N., Gunn, J., Zhang, M. Chitosan-based hydrogels for controlled, localized drug delivery[J]. Adv. Drug Del. Rev.2010,62:83-99.
    [19]Tan, H., Chu, C.R., Payne, K.A., Marra, K.G. Injectable in situ forming biodegradable chitosan-hyaluronic acid based hydrogels for cartilage tissue engineering[J]. Biomaterials.2009,30:2499-2506.
    [20]Kato, Y., Onishi, H., Machida, Y. Biological characteristics of lactosaminated N-succinyl-chitosan as a liver-specific drug carrier in mice[J]. J. Controlled Release.2001,70:295-307.
    [21]Falabella, C.A., Melendez, M.M., Weng, L., Chen, W. Novel macromolecular crosslinking hydrogel to reduce intra-abdominal adhesions[J]. J. Surg. Res.2010, 159:772-778.
    [22]袁金芳,郭保林,张晓丽,高青雨pH、离子强度敏感性壳聚糖水凝胶的合成及其对辅酶A的控制释放[J].功能材料.2007,1:36-39.
    [23]Weng, L., Chen, X., Chen, W. Rheological characterization of in situ crosslinkable hydrogels formulated from oxidized dextran and N-carboxyethyl chitosan[J]. Biomacromolecules.2007,8:1109-1115.
    [24]Ito, T., Yeo, Y., Highley, C.B., Bellas, E., Benitez, C.A., Kohane, D.S. The prevention of peritoneal adhesions by in situ cross-linking hydrogels of hyaluronic acid and cellulose derivatives[J]. Biomaterials.2007,28:975-983.
    [25]Brazel, C.S., Peppas, N.A. Mechanisms of solute and drug transport in relaxing, swellable, hydrophilic glassy polymers[J]. Polymer.1999,40:3383-3398.
    [26]Hennink, W.E., van Nostrum, C.F. Novel crosslinking methods to design hydrogels[J]. Adv. Drug Del. Rev.2002,54:13-36.
    [27]Balakrishnan, B., Jayakrishnan, A. Self-cross-linking biopolymers as injectable in situ forming biodegradable scaffolds[J]. Biomaterials.2005,26:3941-3951.
    [28]Prochazkova, S., Varum, K.M., Ostgaard, K. Quantitative determination of chitosans by ninhydrin[J]. Carbohydr. Polym.1999,38:115-122.
    [29]Kang, H.A., Jeon, G.J., Lee, M.Y., Yang, J.W. Effectiveness test of alginate-derived polymeric surfactants [J]. J. Chem. Technol. Biotechnol.2002, 77:205-210.
    [30]Zhu, A., Chen, T., Yuan, L., Wu, H., Lu, P. Synthesis and characterization of N-succinyl-chitosan and its self-assembly of nanospheres[J]. Carbohydr, Polym. 2006,66:274-279.
    [31]Sui, W., Wang, Y., Dong, S., Chen, Y. Preparation and properties of an amphiphilic derivative of succinyl-chitosan[J]. Colloids Surf. Physicochem. Eng. Aspects.2008,316:171-175.
    [32]Kelner, A., Schacht, E.H. Tailor-made polymers for local drug delivery:release of macromolecular model drugs from biodegradable hydrogels based on poly(ethylene oxide)[J]. J. Controlled Release.2005,101:13-20.
    [33]Bezemer, J.M., Grijpma, D.W., Dijkstra, P.J., van Blitterswijk, C.A., Feijen, J. A controlled release system for proteins based on poly(ether ester) block-copolymers:polymer network characterization[J]. J. Controlled Release. 1999,62:393-405.
    [34]Johnson, R.E., Lanaski, L.A., Gupta, V., Griffin, M.J., Gaud, H.T., Needham, T.E., Zia, H. Stability of atriopeptin III in poly(D, L-lactide-co-glycolide) microspheres[J]. J. Controlled Release.1991,17:61-67.
    [35]Wang, N., Ye, L., Yan, F., Xu, R. Spectroscopic studies on the interaction of azelnidipine with bovine serum albumin[J]. Int. J. Pharm.2008,351:55-60.
    [36]Zheng, Y., Lu, J., Liu, L., Zhao, D., Ni, J. Fluorescence analysis of aldolase dissociation from the N-terminal of the cytoplasmic domain of band 3 induced by lanthanide[J]. Biochem. Biophys. Res. Commun.2003,303:433-439.
    [37]Gumiisderelioglu, M., Kesgin, D. Release kinetics of bovine serum albumin from pH-sensitive poly(vinyl ether) based hydrogels[J]. Int. J. Pharm.2005,288: 273-279.
    [1]Hoare, T.R., Kohane, D.S. Hydrogels in drug delivery:Progress and challenges[J]. Polymer.2008,49:1993-2007.
    [2]Lee, K.Y., Mooney, D.J. Hydrogels for tissue engineering[J]. Chem. Rev.2001, 101:1869-1880.
    [3]Jeong, B., Lee, K.M., Gutowska, A., An, Y.H. Thermogelling biodegradable copolymer aqueous solutions for injectable protein delivery and tissue engineering [J]. Biomacromolecules.2002,3:865-868.
    [4]Weng, L., Chen, X., Chen, W. Rheological characterization of in situ crosslinkable hydrogels formulated from oxidized dextran and N-carboxyethyl chitosan[J]. Biomacromolecules.2007,8:1109-1115.
    [5]Lee, F., Chung, J.E., Kurisawa, M. An injectable hyaluronic acid-tyramine hydrogel system for protein delivery[J]. J. Controlled Release.2009,134: 186-193.
    [6]Cai, S., Liu, Y., Shu, X.Z., Prestwich, G.D. Injectable glycosaminoglycan hydrogels for controlled release of human basic fibroblast growth factor[J]. Biomaterials.2005,26:6054-6067.
    [7]Wu, D.Q., Qiu, F., Wang, T., Jiang, X.J., Zhang, X.Z., Zhuo, R.X. Toward the development of partially biodegradable and injectable thermoresponsive hydrogels for potential biomedical applications[J]. ACS Appl. Mater. Interfaces.2008,1: 319-327.
    [8]Chen, Y.L., Lee, H.P., Chan, H.Y., Sung, L.Y., Chen, H.C., Hu, Y.C. Composite chondroitin-6-sulfate/dermatan sulfate/chitosan scaffolds for cartilage tissue engineering[J]. Biomaterials.2007,28:2294-2305.
    [9]Kuijpers, A.J., van Wachem, P.B., van Luyn, M.J.A., Brouwer, L.A., Engbers, G.H.M., Krijgsveld, J., Zaat, S.A.J., Dankert, J., Feijen, J. In vitro and in vivo evaluation of gelatin-chondroitin sulphate hydrogels for controlled release of antibacterial proteins[J]. Biomaterials.2000,21:1763-1772.
    [10]Nunthanid, J., Luangtana-anan, M., Sriamornsak, P., Limmatvapirat, S., Huanbutta, K., Puttipipatkhachorn, S. Use of spray-dried chitosan acetate and ethylcellulose as compression coats for colonic drug delivery:Effect of swelling on triggering in vitro drug release[J]. Eur. J. Pharm. Biopharm.2009,71: 356-361.
    [11]Siepmann, J., Faisant, N., Akiki, J., Richard, J., Benoit, J.P. Effect of the size of biodegradable microparticles on drug release:experiment and theory[J]. J. Controlled Release.2004,96:123-134.
    [12]Coughlan, D.C., Quilty, F.P., Corrigan, O.I. Effect of drug physicochemical properties on swelling/deswelling kinetics and pulsatile drug release from thermoresponsive poly(N-isopropylacrylamide) hydrogels[J]. J. Controlled Release.2004,98:97-114.
    [13]Fundueanu, G., Constantin, M., Ascenzi, P. Poly(N-isopropylacrylamide-co-acrylamide) cross-linked thermoresponsive microspheres obtained from preformed polymers:Influence of the physico-chemical characteristics of drugs on their release profiles[J]. Acta Biomater.2009,5:363-373.
    [14]Jeong, B., Bae, Y.H., Kim, S.W. Drug release from biodegradable injectable thermosensitive hydrogel of PEG-PLGA-PEG triblock copolymers[J]. J. Controlled Release.2000,63:155-163.
    [15]Dawlee, S., Sugandhi, A., Balakrishnan, B., Labarre, D., Jayakrishnan, A. Oxidized chondroitin sulfate-cross-linked gelatin matrixes:a new class of hydrogels[J]. Biomacromolecules.2005,6:2040-2048.
    [16]Prochazkova, S., Varum, K.M., Ostgaard, K. Quantitative determination of chitosans by ninhydrin[J]. Carbohydr. Polym.1999,38:115-122.
    [17]Ito, T., Yeo, Y., Highley, C.B., Bellas, E., Benitez, C.A., Kohane, D.S. The prevention of peritoneal adhesions by in situ cross-linking hydrogels of hyaluronic acid and cellulose derivatives [J]. Biomaterials.2007,28:975-983.
    [18]Flory, P.J., Rehner, J.J. Statistical mechanics of cross-linked polymer networksⅡ. swelling[J]. J. Chem. Phys.1943,11:521-526.
    [19]Lee, K.Y., Bouhadir, K.H., Mooney, D.J. Degradation behavior of covalently cross-linked poly (aldehyde guluronate) hydrogels[J]. Macromolecules.2000,33: 97-101.
    [20]Liu, H.L., Liu, M.Z., Zhang, L.J., Ma, L.W., Chen, J., Wang, Y.J. Dual-stimuli sensitive composites based on multi-walled carbon nanotubes and poly(N,N-diethylacrylamide-co-acrylic acid) hydrogels[J]. React. Funct. Polym. 2010,70:294-300.
    [21]Jaiswal, M, Dinda, A.K., Gupta, A., Koul, V. Polycaprolactone diacrylate crosslinked biodegradable semi-interpenetrating networks of polyacrylamide and gelatin for controlled drug delivery[J]. Biomed. Mater.2010,5:065014.
    [22]Lin, C.C., Metters, A.T. Hydrogels in controlled release formulations:Network design and mathematical modeling[J]. Adv. Drug Del. Rev.2006,58: 1379-1408.
    [23]Ayres, J.L., Osborne, J.L., Hopfenberg, H.B., Koros, W.J. Effect of variable storage times on the calculation of diffusion coefficients characterizing small molecule migration in polymers[J]. Ind. Eng. Chem. Prod. Res. Dev.1983,22: 86-89.
    [24]Painter, T., Larsen, B. Formation of hemiacetals between neighbouring hexuronic acid residues during the periodate oxidation of alginate[J]. Acta Chem. Scand. 1970,24:813-833.
    [25]Gomez, C.G., Rinaudo, M., Villar, M.A. Oxidation of sodium alginate and characterization of the oxidized derivatives [J]. Carbohydr. Polym.2007,67: 296-304.
    [26]Kang, H.A., Jeon, G.J., Lee, M.Y., Yang, J.W. Effectiveness test of alginate-derived polymeric surfactants [J]. J Chem Technol Biotechnol.2002,77: 205-210.
    [27]Del Arco, M., Cebadera, E., Gutierrez, S., Martin, C, Montero, M., Rives, V., Rocha, J., Sevilla, M. Mg,Al layered double hydroxides with intercalated indomethacin:Synthesis, characterization, and pharmacological study [J]. J. Pharm. Sci.2004,93:1649-1658.
    [28]Ni, B.L., Liu, M.Z., Lu, S.Y., Xie, L.H., Zhang, X., Wang, Y.F. Novel slow-release multielement compound fertilizer with hydroscopicity and moisture preservation[J]. Ind. Eng. Chem. Res.2010,49:4546-4552.
    [29]Ding, S.D., Zheng, G.C., Zeng, J.B., Zhang, L., Li, Y.D., Wang, Y.Z. Preparation, characterization and hydrolytic degradation of poly[p-dioxanone-(butylene succinate)] multiblockcopolymer[J]. Eur. Polym. J.2009,45:3043-3057.
    [30]Lee, S.Y., Tae, G. Formulation and in vitro characterization of an in situ gelable, photo-polymerizable Pluronic hydrogel suitable for injection[J]. J. Controlled Release.2007,119:313-319.
    [31]Balakrishnan, B., Jayakrishnan, A. Self-cross-linking biopolymers as injectable in situ forming biodegradable scaffolds[J]. Biomaterials.2005,26:3941-3951.
    [32]Brazel, C.S., Peppas, N.A. Mechanisms of solute and drug transport in relaxing, swellable, hydrophilic glassy polymers[J]. Polymer.1999,40:3383-3398.
    [33]Pan, D., Zhang, H., Zhang, T., Duan, X. A novel organic-inorganic microhybrids containing anticancer agent doxifluridine and layered double hydroxides: Structure and controlled release properties [J]. Chem. Eng. Sci.2010,65: 3762-3771.
    [34]Bezemer, J.M., Radersma, R., Grijpma, D.W., Dijkstra, P.J., Feijen, J., van Blitterswijk, C.A. Zero-order release of lysozyme from poly(ethylene glycol)/poly(butylene terephthalate) matrices[J]. J. Controlled Release.2000,64: 179-192.
    [35]Hiemstra, C, Zhong, Z., van Steenbergen, M.J., Hennink, W.E., Feijen, J. Release of model proteins and basic fibroblast growth factor from in situ forming degradable dextran hydrogels[J]. J. Controlled Release.2007,122:71-78.
    [1]Brown, L.R. Commercial challenges of protein drug delivery[J]. Expert Opin. Drug Deliv.2005,2:29-42.
    [2]Lee, F., Chung, J.E., Kurisawa, M. An injectable hyaluronic acid-tyramine hydrogel system for protein delivery[J]. J. Controlled Release.2009,134: 186-193.
    [3]Hahn, S.K., Kim, J.S., Shimobouji, T. Injectable hyaluronic acid microhydrogels for controlled release formulation of erythropoietin[J]. J. Biomed. Mater. Res. A. 2007,80A:916-924.
    [4]Hoare, T.R., Kohane, D.S. Hydrogels in drug delivery:Progress and challenges[J]. Polymer.2008,49:1993-2007.
    [5]Park, K.M., Lee, S.Y., Joung, Y.K., Na, J.S., Lee, M.C., Park, K.D. Thermosensitive chitosan-Pluronic hydrogel as an injectable cell delivery carrier for cartilage regeneration [J]. Acta Biomater.2009,5:1956-1965.
    [6]Tsitsilianis, C. Responsive reversible hydrogels from associative "smart" macromolecules[J]. Soft Matter.2010,6:2372-2388.
    [7]Rozier, A., Mazuel, C, Grove, J., Plazonnet, B. Gelrite(?):A novel, ion-activated, in-situ gelling polymer for ophthalmic vehicles. Effect on bioavailability of timolol[J]. Int. J. Pharm.1989,57:163-168.
    [8]Gao, X., Zhou, Y, Ma, G, Shi, S., Yang, D., Lu, F., Nie, J. A water-soluble photocrosslinkable chitosan derivative prepared by Michael-addition reaction as a precursor for injectable hydrogel[J]. Carbohydr. Polym.2010,79:507-512.
    [9]Chiu, Y.L., Chen, S.C., Su, C.J., Hsiao, C.W., Chen, Y.M., Chen, H.L., Sung, H.W. pH-triggered injectable hydrogels prepared from aqueous N-palmitoyl chitosan:In vitro characteristics and in vivo biocompatibility[J]. Biomaterials.2009,30: 4877-4888.
    [10]Lee, Y, Chung, H.J., Yeo, S., Ahn, C.-H., Lee, H., Messersmith, P.B., Park, T.G. Thermo-sensitive, injectable, and tissue adhesive sol-gel transition hyaluronic acid/pluronic composite hydrogels prepared from bio-inspired catechol-thiol reaction[J]. Soft Matter.2010,6:977.
    [11]Van Tomme, S.R., Storm, G, Hennink, W.E. In situ gelling hydrogels for pharmaceutical and biomedical applications[J]. Int. J. Pharm.2008,355:1-18.
    [12]Nguyen, M.K., Huynh, C.T., Gao, G.H., Kim, J.H., Huynh, D.P., Chae, S.Y., Lee, K.C., Lee, D.S. Biodegradable oligo(amidoamine/β-amino ester) hydrogels for controlled insulin delivery [J]. Soft Matter.2011,7:2994-3001.
    [13]Ibusuki, S., Iwamoto, Y., Matsuda, T. System-engineered cartilage using poly(N-isopropylacrylamide)-grafted gelatin as in situ-formable scaffold:in vivo performance [J]. Tissue Eng.2003,9:1133-1142.
    [14]Gan, T., Guan, Y., Zhang, Y. Thermogelable PNIPAM microgel dispersion as 3D cell scaffold:effect of syneresis[J]. J. Mater. Chem.2010,20:5937-5944.
    [15]Klouda, L., Mikos, A.G Thermoresponsive hydrogels in biomedical applications[J]. Eur. J. Pharm. Biopharm.2008,68:34-45.
    [16]Tan, H., Ramirez, C.M., Miljkovic, N., Li, H., Rubin, J.P., Marra, K.G. Thermosensitive injectable hyaluronic acid hydrogel for adipose tissue engineering [J]. Biomaterials.2009,30:6844-6853.
    [17]Chen, J., Cheng, T. Preparation and evaluation of thermo-reversible copolymer hydrogels containing chitosan and hyaluronic acid as injectable cell carriers[J]. Polymer.2009,50:107-116.
    [18]Reza, A.T., Nicoll, S.B. Characterization of novel photocrosslinked carboxymethylcellulose hydrogels for encapsulation of nucleus pulposus cells[J]. Acta Biomater.2010,6:179-186.
    [19]Lu, S.Y., Liu, M.Z., Ni, B.L., Gao, C.M. A novel pH-and thermo-sensitive PVP/CMC semi-IPN hydrogel:Swelling, phase behavior, and drug release study[J]. J. Polym. Sci., Part B:Polym. Phys.2010,48:1749-1756.
    [20]Vasile, C, Bumbu, G.G., Petronela Dumitriu, R., Staikos, G Comparative study of the behavior of carboxymethyl cellulose-g-poly(N-isopropylacrylamide) copolymers and their equivalent physical blends[J]. Eur. Polym. J.2004,40: 1209-1215.
    [21]Pollock, J.F., Healy, K.E. Mechanical and swelling characterization of poly(N-isopropyl acrylamide-co-methoxy poly(ethylene glycol) methacrylate) sol-gels[J]. Acta Biomater.2010,6:1307-1318.
    [22]Talukdar, M.M., Vinckier, I., Moldenaers, P., Kinget, R. Rheological characterization of xanthan gum and hydroxypropylmethyl cellulose with respect to controlled-release drug delivery[J]. J. Pharm. Sci.1996,85:537-540.
    [23]Li, C., Tang, Y, Armes, S.P., Morris, C.J., Rose, S.F., Lloyd, A.W., Lewis, A.L. Synthesis and characterization of biocompatible thermo-responsive gelators based on ABA triblock copolymers [J]. Biomacromolecules.2005,6:994-999.
    [24]Bokias, G, Mylonas, Y, Staikos, G, Bumbu, G.G., Vasile, C. Synthesis and aqueous solution properties of novel thermoresponsive graft copolymers based on a carboxymethylcellulose backbone[J]. Macromolecules.2001,34: 4958-4964.
    [25]Shugar, D. The measurement of lysozyme activity and the ultra-violet inactivation of lysozyme [J]. Biochim. Biophys. Acta.1952,8:302-309.
    [26]Durand, A., Hourdet, D. Synthesis and thermoassociative properties in aqueous solution of graft copolymers containing poly(N-isopropylacrylamide) side chains[J]. Polymer.1999,40:4941-4951.
    [27]Schild, H.G., Tirrell, D.A. Interaction of poly(N-isopropylacrylamide) with sodium n-alkyl sulfates in aqueous solution[J]. Langmuir.1991,7:665-671.
    [28]Robb, S.A., Lee, B.H., McLemore, R., Vernon, B.L. Simultaneously physically and chemically gelling polymer system utilizing a poly(NIPAAm-co-cysteamine)-based copolymer[J]. Biomacromolecules.2007,8:2294-2300.
    [29]Fujimoto, K.L., Ma, Z., Nelson, D.M., Hashizume, R., Guan, J., Tobita, K. Wagner, W.R. Synthesis, characterization and therapeutic efficacy of a biodegradable, thermoresponsive hydrogel designed for application in chronic infarcted myocardium[J]. Biomaterials.2009,30:4357-4368.
    [30]Fundueanu, G, Constantin, M., Ascenzi, P. Poly(N-isopropylacrylamide-co-acrylamide) cross-linked thermoresponsive microspheres obtained from preformed polymers:Influence of the physico-chemical characteristics of drugs on their release profiles[J]. Acta Biomater.2009,5:363-373.
    [31]Lee, F., Chung, J.E., Kurisawa, M. An injectable hyaluronic acid-tyramine hydrogel system for protein delivery[J]. J. Controlled Release.2009,134: 186-193.
    [32]Chen, J.P., Cheng, T.H. Preparation and evaluation of thermo-reversible copolymer hydrogels containing chitosan and hyaluronic acid as injectable cell carriers[J]. Polymer.2009,50:107-116.
    [33]Principi, T., Goh, C.C.E., Liu, R.C.W., Winnik, F.M. Solution properties of hydrophobically modified copolymers of N-isopropylacrylamide and N-glycine acrylamide:a study by microcalorimetry and fluorescence spectroscopy[J]. Macromolecules.2000,33:2958-2966.
    [34]Kalyanasundaram, K., Thomas, J.K. Environmental effects on vibronic band intensities in pyrene monomer fluorescence and their application in studies of micellar systems[J]. J. Am. Chem. Soc.1977,99:2039-2044.
    [35]Lii, S.Y., Liu, M.Z., Ni, B.L. An injectable oxidized carboxymethylcellulose /N-succinyl-chitosan hydrogel system for protein delivery [J]. Chem. Eng. J.2010, 160:779-787.
    [36]Censi, R., Vermonden, T., van Steenbergen, M.J., Deschout, H., Braeckmans, K., De Smedt, S.C., van Nostrum, C.F., di Martino, P., Hennink, W.E. Photopolymerized thermosensitive hydrogels for tailorable diffusion-controlled protein delivery [J]. J. Controlled Release.2009,140:230-236.
    [37]Knubovets, T., Osterhout, J.J., Connolly, P.J., Klibanov, A.M. Structure, thermostability, and conformational flexibility of hen egg-white lysozyme dissolved in glycerol[J]. Proc. Natl. Acad. Sci. USA.1999,96:1262-1267.
    [38]Fang, J. Temperature-sensitive hydrogels composed of chitosan and hyaluronic acid as injectable carriers for drug delivery [J]. Eur. J. Pharm. Biopharm.2008,68: 626-636.
    [39]Koutsopoulos, S., Unsworth, L.D., Nagai, Y., Zhang, S. Controlled release of functional proteins through designer self-assembling peptide nanofiber hydrogel scaffold[J]. Proc. Natl. Acad. Sci. USA.2009,106:4623-4628.
    [40]Wang, N., Ye, L., Yan, F., Xu, R. Spectroscopic studies on the interaction of azelnidipine with bovine serum albumin[J]. Int. J. Pharm.2008,351:55-60.
    [41]Zheng, Y, Lu, J., Liu, L., Zhao, D., Ni, J. Fluorescence analysis of aldolase dissociation from the N-terminal of the cytoplasmic domain of band 3 induced by lanthanide[J]. Biochem. Biophys. Res. Commun.2003,303:433-439.
    [1]Hernandez, R.M., Orive, G., Murua, A., Pedraz, J.L. Microcapsules and microcarriers for in situ cell delivery[J]. Adv. Drug Del. Rev.2010,62:711-730.
    [2]Wang, F., Li, Z., Khan, M., Tamama, K., Kuppusamy, P., Wagner, W.R., Sen, C.K., Guan, J. Injectable, rapid gelling and highly flexible hydrogel composites as growth factor and cell carriers[J]. Acta Biomater.2010,6:1978-1991.
    [3]Li, Z., Guo, X., Matsushita, S., Guan, J. Differentiation of cardiosphere-derived cells into a mature cardiac lineage using biodegradable poly(N-isopropylacrylamide) hydrogels[J]. Biomaterials.2011,32:3220-3232.
    [4]Sa-Lima, H., Caridade, S.G., Mano, J.F., Reis, R.L. Stimuli-responsive chitosan-starch injectable hydrogels combined with encapsulated adipose-derived stromal cells for articular cartilage regeneration[J]. Soft Matter.2010,6: 5184-5195.
    [5]Liu, K.L., Zhu, J.L., Li, J. Elucidating rheological property enhancements in supramolecular hydrogels of short poly[(R,S)-3-hydroxybutyrate]-based amphiphilic triblock copolymer and a-cyclodextrin for injectable hydrogel applications [J]. Soft Matter.2010,6:2300-2311.
    [6]Li, J., Li, X., Ni, X., Wang, X., Li, H., Leong, K.W. Self-assembled supramolecular hydrogels formed by biodegradable PEO-PHB-PEO triblock copolymers and a-cyclodextrin for controlled drug delivery [J]. Biomaterials.2006, 27:4132-4140.
    [7]Lee, Y., Chung, H.J., Yeo, S., Ahn, C.H., Lee, H., Messersmith, P.B., Park, T.G. Thermo-sensitive, injectable, and tissue adhesive sol-gel transition hyaluronic acid/pluronic composite hydrogels prepared from bio-inspired catechol-thiol reaction[J]. Soft Matter.2010,6:977.
    [8]Mano, J.F. Stimuli-responsive polymeric systems for biomedical applications [J]. Adv. Eng. Mater.2008,10:515-527.
    [9]Pollock, J.F., Healy, K.E. Mechanical and swelling characterization of poly(N-isopropyl acrylamide-co-methoxy poly(ethylene glycol) methacrylate) sol-gels[J]. Acta Biomater.2010,6:1307-1318.
    [10]Mortisen, D., Peroglio, M., Alini, M., Eglin, D. Tailoring thermoreversible hyaluronan hydrogels by "click" chemistry and RAFT polymerization for cell and drug therapy[J]. Biomacromolecules.2010,11:1261-1272.
    [11]Guan, J., Hong, Y., Ma, Z., Wagner, W.R. Protein-reactive, thermoresponsive copolymers with high flexibility and biodegradability[J]. Biomacromolecules. 2008,9:1283-1292.
    [12]Healy, J.M., Lewis, S.D., Kurz, M., Boomer, R.M., Thompson, K.M., Wilson, C., McCauley, T.G. Pharmacokinetics and biodistribution of novel aptamer compositions[J]. Pharm. Res.2004,21:2234-2246.
    [13]Smith, A.E., Xu, X., McCormick, C.L. Stimuli-responsive amphiphilic (co)polymers via RAFT polymerization[J]. Prog. Polym. Sci.35:45-93.
    [14]Ganachaud, F., Monteiro, M.J., Gilbert, R.G., Dourges, M.A., Thang, S.H., Rizzardo, E. Molecular weight characterization of poly(N-isopropylacrylamide) prepared by living free-radical polymerization[J]. Macromolecules.2000,33: 6738-6745.
    [15]Convertine, A.J., Ayres, N., Scales, C.W., Lowe, A.B., McCormick, C.L. Facile, controlled, room-temperature RAFT polymerization of N-isopropylacrylamide[J]. Biomacromolecules.2004,5:1177-1180.
    [16]Tan, H., Ramirez, C.M., Miljkovic, N., Li, H., Rubin, J.P., Marra, K.G. Thermosensitive injectable hyaluronic acid hydrogel for adipose tissue engineering [J]. Biomaterials.2009,30:6844-6853.
    [17]Chen, J., Cheng, T. Preparation and evaluation of thermo-reversible copolymer hydrogels containing chitosan and hyaluronic acid as injectable cell carriers[J]. Polymer.2009,50:107-116.
    [18]Chen, Y.L., Lee, H.P., Chan, H.Y., Sung, L.Y., Chen, H.C., Hu, Y.C. Composite chondroitin-6-sulfate/dermatan sulfate/chitosan scaffolds for cartilage tissue engineering[J]. Biomaterials.2007,28:2294-2305.
    [19]Liu, Y., Cai, S., Shu, X.Z., Shelby,J., Prestwich, G.D. Release of basic fibroblast growth factor from a crosslinked glycosaminoglycan hydrogel promotes wound healing[J]. Wound Repair Regen.2007,15:245-251.
    [20]Kuijpers, A.J., van Wachem, P.B., van Luyn, M.J.A., Brouwer, L.A., Engbers, G.H.M., Krijgsveld, J., Zaat, S.A.J., Dankert, J., Feijen, J. In vitro and in vivo evaluation of gelatin-chondroitin sulphate hydrogels for controlled release of antibacterial proteins[J]. Biomaterials.2000,21:1763-1772.
    [21]Neradovic, D., Soga, O., Van Nostrum, C.F., Hennink, W.E. The effect of the processing and formulation parameters on the size of nanoparticles based on block copolymers of poly(ethylene glycol) and poly(N-isopropylacrylamide) with and without hydrolytically sensitive groups[J]. Biomaterials.2004,25: 2409-2418.
    [22]Lai, J.T., Filla, D., Shea, R. Functional polymers from novel carboxyl-terminated trithiocarbonates as highly efficient RAFT agents[J]. Macromolecules.2002,35: 6754-6756.
    [23]Wei, H.L., Yang, Z., Chu, H.J., Zhu, J., Li, Z.C., Cui, J.S. Facile preparation of poly(N-isopropylacrylamide)-based hydrogels via aqueous Diels-Alder click reaction[J]. Polymer.2010,51:1694-1702.
    [24]Fitzpatrick, S.D., Jafar Mazumder, M.A., Lasowski, F., Fitzpatrick, L.E., Sheardown, H. PNIPAAm-grafted-collagen as an injectable, in situ gelling, bioactive cell delivery scaffold[J]. Biomacromolecules.2010,11:2261-2267.
    [25]Jiang, X., Lok, M.C., Hennink, W.E. Degradable-brushed pHEMA-pDMAEMA synthesized via ATRP and click chemistry for gene delivery [J]. Bioconj. Chem. 2007,18:2077-2084.
    [26]Garbern, J.C., Hoffman, A.S., Stayton, P.S. Injectable pH-and temperature-responsive poly(N-isopropylacrylamide-co-propylacrylic acid) copolymers for delivery of angiogenic growth factors[J]. Biomacromolecules. 2010,11:1833-1839.
    [27]Hahn, S.K., Kim, J.S., Shimobouji, T. Injectable hyaluronic acid microhydrogels for controlled release formulation of erythropoietin[J]. J. Biomed. Mater. Res. A. 2007,80A:916-924.
    [28]Kujawa, P., Segui, F., Shaban, S., Diab, C., Okada, Y., Tanaka, F., Winnik, F.M. Impact of end-group association and main-chain hydration on the thermosensitive properties of hydrophobically modified telechelic poly(N-isopropylacrylamides) in water[J]. Macromolecules.2006,39:341-348.
    [29]Xia, Y., Burke, N.A.D., Stover, H.D.H. End group effect on the thermal response of narrow-disperse poly(N-isopropylacrylamide) prepared by atom transfer radical polymerization[J]. Macromolecules.2006,39:2275-2283.
    [30]Strehin, I., Nahas, Z., Arora, K., Nguyen, T., Elisseeff, J. A versatile pH sensitive chondroitin sulfate-PEG tissue adhesive and hydrogel[J]. Biomaterials.2010,31: 2788-2797.
    [31]Im, S.J., Choi, Y.M., Subramanyam, E., Huh, K.M. Synthesis and characterization of biodegradable elastic hydrogels based on poly(ethylene glycol) and poly(s-caprolactone) blocks[J]. Macromol. Res.2007,15:363-369.
    [32]Censi, R., Vermonden, T., van Steenbergen, M.J., Deschout, H., Braeckmans, K., De Smedt, S.C., van Nostrum, C.F., di Martino, P., Hennink, W.E. Photopolymerized thermosensitive hydrogels for tailorable diffusion-controlled protein delivery[J]. J. Controlled Release.2009,140:230-236.
    [33]Csoka, A.B., Frost, G.I., Stern, R. The six hyaluronidase-like genes in the human and mouse genomes[J]. Matrix Biol.2001,20:499-508.
    [34]Jedrzejas, M.J., Stern, R. Structures of vertebrate hyaluronidases and their unique enzymatic mechanism of hydrolysis[J]. Proteins.2005,61:227-238.
    [35]Bhadriraju, K., Chen, C.S. Engineering cellular microenvironments to improve cell-based drug testing[J]. Drug Discov. Today.2002,7:612-620.
    [36]Trojani, C, Weiss, P., Michiels, J.F., Vinatier, C, Guicheux, J., Daculsi, G., Gaudray, P., Carle, G.F., Rochet, N. Three-dimensional culture and differentiation of human osteogenic cells in an injectable hydroxypropylmethylcellulose hydrogel[J], Biomaterials.2005,26:5509-5517.
    [37]Ouyang, A., Ng, R., Yang, S.T. Long-term culturing of undifferentiated embryonic stem cells in conditioned media and three-dimensional fibrous matrices without extracellular matrix coating[J]. Stem Cells.2007,25:447-454.
    [38]吴国平,周燕,谭文松人皮肤成纤维细胞在二维和三维培养系统中的生长代谢特性[J].中国组织工程研究与临床康复.2007,11:74-77.
    [39]Gan, T., Zhang, Y., Guan, Y. In situ gelation of P(NIPAM-HEMA) microgel dispersion and its applications as injectable 3D cell scaffold[J]. Biomacromolecules.2009,10:1410-1415.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700