纸质出版日期:2019-5,
网络出版日期:2019-4-11,
收稿日期:2019-1-25,
修回日期:2019-3-14
扫 描 看 全 文
引用本文
阅读全文PDF
设计合成了一类含苯硼酸和氨基结构的聚环氧乙烷(PEO)大分子交联剂,利用其与含聚乙烯醇(PVA)的三嵌段共聚物PVA-b-PEO-b-PVA之间的动态共价作用,构筑得到一类在生理pH下稳定,且对葡萄糖有响应的动态共价凝胶;详细研究了交联剂用量、PVA链段长度对凝胶化过程及凝胶稳定性的影响,证明PVA链段越长、交联剂用量越高,凝胶的稳定性越高,同时这类凝胶的屈服力较高,性质上更接近固体. 凝胶在pH = 7.4,37 °C保持其结构稳定性. 进一步发现这类动态共价凝胶具有较强的结构修复能力以及对糖的响应能力,凝胶可包载蛋白质FITC-BSA,加入葡萄糖后,其释放显著加快.
Boronic acid can form dynamic covalent boronic ester bonds with 1,2-diol or 1,3-diol moieties. This property has been used to prepare malleable and self-healing covalent polymer networks as well as glucose-responsive hydrogels. It remains a challenge to fabricate strong hydrogels with fast glucose-responsivity. Glucose-responsive dynamic covalent hydrogels were prepared by crosslinking poly(vinyl alcohol) (PVA) containing triblock copolymer and poly(ethylene oxide) (PEO) containing phenylboric acid. Specifically, we synthesized a new type ofα,ω-phenylboronic acid substituted PEO crosslinker. The feature of the crosslinker is that amino-groups are introduced to the neighboring position of boronic acid, which will accelerate the boronic ester exchange. The gelation of this crosslinker with three PVA-b-PEO-b-PVA triblock copolymers at physiological pH was examined. Time-dependent dynamic storage and loss modulus of the hydrogels were monitored by rheological measurements. Formation of hydrogels turned out be very fast after mixing the crosslinker and triblock copolymer solutions. Stable dynamic covalent hydrogels were obtained after incubating the hydrogels for 12 h. The copolymer composition, PVA chain length, and content of crosslinker were found to greatly affect the hydrogel properties. Higher polymer concentration, longer PVA chains, and more PEO crosslinker endowed hydrogels with higher modulus. Gels with high yield stress were obtained by utilizing block copolymer with longer PVA segments or adding more crosslinker. Both pH and temperature affected the hydrogel properties. The formed hydrogels displayed higher modulus at pH = 7.4 than those at pH = 6.0, and the stability of the hydrogel could still be maintained at 37 °C. In addition, the hydrogels exhibited good structural recovery ability due to the covalent dynamic crosslinking. Finally, the hydrogels could load FITC-BSA, and the release profile of FITC-BSA was accelerated in the presence of glucose.
A new type of glucose-responsive dynamic covalent hydrogel was prepared by mixing a triblock copolymer PVA-b-PEO-b-PVA with α,ω-phenylboronic acid substituted PEO. The hydrogel could load FITC-BSA, the release of which was accelerated in the presence of glucose due to the disassembly of the hydrogel caused by the competitive interaction of glucose with the phenylboronic acid moieties.
刺激响应性水凝胶是一类在外界刺激(温度、pH、光、还原条件以及生物分子等)响应下能发生溶胶-凝胶转变或凝胶解离的动态凝胶,在生物医用领域得到重要应用[
Fig 1 (a) Dynamic covalent complex between PVA and PBA and the glucose-triggered dissociation of the complex; (b) Glucose-responsive dynamic covalent hydrogel from PVA-b-PEO-b-PVA and PEO crosslinker
我们前期的工作中利用含聚乙烯醇的嵌段共聚物、环糊精以及含苯硼酸的交联剂复合构筑得到葡萄糖响应性水凝胶[
3-氨基苯硼酸(97%,北京普瑞东方试剂公司). 叠氮化钠(98%,浙江东阳市凯明特种试剂公司). 三苯基膦(99%,Acros). N,N-二异丙基-N-乙基胺 (DIPEA,98%,Sigma-Aldrich). D-果糖(98%,国药集团化学试剂有限公司). 异硫氰酸荧光素(FITC, 95%,Alfa Aesar),牛血清白蛋白(BSA,Sigma-Aldrich). 氯仿(分析纯,北京化工厂),加入氢化钙回流8 h后蒸出. 三乙胺(分析纯,北京化工厂),加入乙酸酐回流8 h后蒸出,加入氢化钙干燥过夜,氮气保护下蒸出. 对甲苯磺酰氯(北京化工厂),石油醚中重结晶. 聚乙二醇(PEO,Mn = 1000,Fluka),溶于二氯甲烷,加入硫酸镁干燥,过滤除去硫酸镁,旋转蒸发除去二氯甲烷后,45 °C下真空干燥24 h. 丙烯酰氯由丙烯酸与苯甲酰氯反应后蒸出,再次蒸馏收集72 ~ 76 °C馏分. 3-丙烯酰胺基苯硼酸(APBA)按照文献方法合成[
1.2.1 核磁共振(NMR)测试
400 MHz 1H-NMR用Bruker ARX-400核磁共振仪进行测定;300 MHz 1H-NMR用Varian-300核磁共振仪进行测定,以四甲基硅烷(TMS)为内标.
1.2.2 紫外-可见分光光度计测试
使用Shimadzu公司UV-2101PC紫外-可见分光光度计,测试温度为25 °C.
1.2.3 流变性质测试
使用Physica MCR 301(Anton Paar)应力控制流变仪进行动态流变实验. 使用CP25-2锥板测量系统以及PP25平行板测量系统,CP25-2 圆板直径为25 mm,倾斜锥面与圆板之间的角度为2°;PP25圆板直径为25 mm,测试时平行板与样品台的间距为0.5 mm. 上样后,小心移除测量模具边缘溢出的样品,用低黏度油覆盖样品边缘以防止测试过程中水分挥发. 对于锥板所测样品,在3 Pa的应力和0.1 Hz的振荡频率下稳定,监测凝胶化过程. 对于平行板所测样品,测试前样品在3 Pa的应力和0.1 Hz的振荡频率下稳定10 min. 在2种模具下,振荡频率扫描在0.5%的应变下进行,扫描范围为100 ~ 0.1 rad/s. 应变扫描在1 Hz(6.28 rad/s)下进行,扫描范围为0.01% ~ 1000%. 变温测试在1 Hz下进行,升温速率为1 °C/min. 凝胶结构恢复能力的测试在20 rad/s的角频率下进行,经10 min稳定后(3 Pa的应力下),向样品施加104 Pa的应力,持续时间为90 s,将大应力撤去,代以15 Pa的小应力,观察样品的恢复行为. 若无特殊说明,流变性质测试均在25 °C下进行.
PEO交联剂的合成路线如
Fig 2 Synthetic route of PEO crosslinker: (a) tosyl chloride, triethylamine, r.t., 12 h; (b) NaN3, DMF, 80 °C, 14 h; (c) triphenylphosphine, THF, H2O, r.t., 12 h; (d) 3-(acrylamino)phenylboronic acid, DIPEA, MeOH, 50 °C, 72 h
1.3.1 化合物1的合成
将双羟基PEO (Mn=1000,n = 22,30 g,30 mmol)和三乙胺(9.5 g,93.9 mmol)溶于200 mL二氯甲烷中,冰浴中冷却,将100 mL对甲苯磺酰氯(18 g,94.4 mmol)的二氯甲烷溶液缓慢滴加至上述溶液中,滴加完毕后室温搅拌12 h. 过滤除去生成的三乙胺盐酸盐,旋转蒸发除去溶剂,将粗产物溶于500 mL去离子水中,用乙醚(3 × 100 mL)洗涤除去剩余的对甲苯磺酰氯,用二氯甲烷(3 × 150 mL)萃取产物,萃取有机相合并后用无水硫酸镁干燥过夜,除去干燥剂和溶剂后得到淡黄色液体(36.5 g,收率为93%).
1H-NMR (300 MHz, CDCl3, δ): 2.46 (s, 6H, CH_
1.3.2 化合物2的合成
将化合物1 (36.5 g,27.9 mmol)和叠氮化钠(5.85 g,90 mmol) 溶于350 mL DMF中,在80 °C下反应14 h,过滤除去未溶解的叠氮化钠,旋转蒸发除去大部分DMF后,将粗产物溶于400 mL去离子水中,用氯仿萃取产品(3 × 200 mL),萃取有机相合并后用无水硫酸镁干燥过夜,除去干燥剂和溶剂后得到淡黄色液体(25.5 g,收率为91%).
1H-NMR (300 MHz, CDCl3, δ): 3.37 (t, 4H, N3CH_
1.3.3 化合物3的合成
将化合物2 (25.5 g,25.5 mmol),三苯基膦(19 g,72 mmol)和去离子水(1 mL)溶于300 mL THF中,室温下敞开体系中反应14 h,旋蒸除去大部分溶剂后,向粗产物中加入100 mL去离子水,用盐酸(1 mol/L)将溶液调至pH = 1,过滤除去白色固体,并用50 mL 4%盐酸洗涤固体,洗涤液与滤液合并. 用乙酸乙酯洗涤上述水溶液(3 × 50 mL),向水相中加入氢氧化钠固体至油层出现,用二氯甲烷萃取产品(3 × 150 mL),萃取有机相合并后用氢氧化钠和无水硫酸钠干燥过夜,除去干燥剂和溶剂后得到白色固体(22.0 g,收率为78%).
1H-NMR (400 MHz, CDCl3, δ): 2.89 (t, 4H, ―CH_
1.3.4 PEO交联剂的合成
将化合物3 (4.0 g,4.0 mmol),3-丙烯酰胺基苯硼酸(2.29 g,12 mmol)以及二异丙基乙基胺(1.55 g,12 mmol)溶于30 mL甲醇中,溶液经2次冷冻—抽真空—解冻循环后,在真空下封管,在50 °C下反应72 h. 反应液浓缩后在0 °C乙醚中沉淀3次,收集固体并真空干燥后得到黄色固体产物(4.52 g,收率为82%).
1H-NMR (400 MHz, D2O, NaOD, δ): 2.72 ~ 2.75 (m, 5.4H, ―CH2CH_
本文使用的3种三嵌段共聚物PVA230-b-PEO90-b-PVA230, PVA450-b-PEO90-b-PVA450和PVA770-b-PEO90-b-PVA770分别简写为T1、T2和T3,两嵌段共聚物PEO45-b-PVA450简写为D. 通过调节嵌段共聚物的分子量、结构、浓度以及PEO交联剂的浓度等因素制备得到了一系列水凝胶,凝胶的组成及性质总结在
Copolymer | Hydrogel a | cc b (mg/mL) | G′ c (Pa) | tanδ c | Yield stress d (Pa) |
---|---|---|---|---|---|
PVA230-b-PEO90-b-PVA230 (T1) | T1-1 | 35.5 | 4680 | 0.27 | 980 |
T1-2 | 17.8 | 82 | 0.44 | 40 | |
PVA450-b-PEO90-b-PVA450 (T2) | T2-1 | 35.5 | 7900 | 0.30 | 1650 |
T2-2 | 17.8 | 515 | 0.42 | 170 | |
PVA770-b-PEO90-b-PVA770 (T3) | T3-1 | 35.5 | 9820 | 0.33 | 2380 |
T3-2 | 17.8 | 863 | 0.35 | 230 |
a Copolymer concentration: 25 mg/mL; b Concentration of PEO crosslinker; c Data obtained at 68.7 rad/s; d Maximum measured stress just before the G′ and G′′ intersection
将87.5 mg BSA溶于7 mL乙酸钠溶液(pH = 9,0.1 mol/L),然后将溶有10 mg FITC的1 mL DMSO溶液加入到上述溶液中,4 °C下避光反应12 h. 反应结束后避光在PBS溶液中透析96 h,冷冻干燥得到橙色松软固体. 配置不同浓度的FITC-BSA溶液(pH = 7.4,50 mmol磷酸盐缓冲液),测定溶液的紫外吸收光谱,利用495与580 nm处吸光度的差值对浓度做图,得到工作曲线.
将20 mg FITC-BSA溶于0.6 mL PEO交联剂水溶液中,待溶解完全,取0.5 mL上述溶液与0.5 mL聚合物T2溶液等体积同时滴加混合,FITC-BSA的最终浓度为16.7 mg/mL. 静置12 h,将凝胶取出,分为质量相等的3份,分别置于不含糖、含10 g/L葡萄糖和含30 g/L葡萄糖的10 mL磷酸盐缓冲液中,在指定的时间点,分别从3个体系中取出1 mL溶液用于紫外吸收光谱测定,测量完毕将该溶液重新加入到释放体系中,利用495与580 nm处的吸光度的差值计算FITC-BSA的相对释放量. 实验结束向释放体系中加入果糖彻底破坏凝胶,此溶液的吸光度定为100%.
从PEO(n = 22)出发,经过4步反应得到了两端均为苯硼酸结构的PEO交联剂(
Fig 1 1H-NMR sepctrum of α,ω-phenylboronic terminated PEO crosslinker in D2O
Fig 2 Time-dependent dynamic storage modulus and loss modulus for (a) T1-1, (b) T2-1 and (c) T3-1 hydrogels;(d) Time-dependent tanδ for T2-1 hydrogel (f = 0.1 Hz, σ = 3 Pa)
采用3种三嵌段共聚物和1种两嵌段共聚物分别与上述PEO交联剂混合制备水凝胶. 共聚物的组成、简写以及凝胶的组成与编号总结于
2.2.1 凝胶化过程
在流变仪的样品台上制备凝胶,在较小的应力和频率下原位监测凝胶化过程. 详细考察了嵌段共聚物组成、交联剂用量对凝胶流变性质的影响. 将共聚物与交联剂溶液混合后,体系黏度迅速增加,样品平衡过程中模量随时间的变化如
2.2.2 凝胶平衡时间对于流变性质的影响
在凝胶制备过程中,将共聚物溶液和交联剂溶液于样品瓶中混合,稍经振荡,即有类似固体的凝胶形成,而由于凝胶化速率过快,不易得到均匀的凝胶,会产生部分黏稠可流动的混合液. 通过将2种溶液等体积同时加入的方式,可以将流动部分显著降低,进一步经过充分的静置(12 h),整个体系可以倒置不发生流动.
Fig 3 (a) Dynamic storage modulus and loss modulus as a function of angular frequency (γ = 0.5%); (b) Strain (f = 1 Hz) of T2-1 hydrogels after being incubated for 1 and 12 h, respectively
2.2.3 PVA链段长度及交联剂用量对凝胶流变性质的影响
PVA链段长度对凝胶流变性质的影响如
Fig 4 Dynamic storage modulus and loss modulus as a function of angular frequency of T1-1, T2-1 and T3-1 hydrogels (γ = 0.5%)
Fig 5 Strain sweep curves of T1-1, T2-1 and T3-1 hydrogels (f = 1 Hz)
作为对照,我们还测量了两嵌段共聚物凝胶D1的角频率扫描(电子支持信息图S4),凝胶T2-1的模量显著高于D1的模量,表明与两嵌段共聚物相比,三嵌段共聚物更能有效形成凝胶交联网络.
2.2.4 pH及温度对凝胶性质的影响
苯硼酸与二醇的结合常数具有显著的pH依赖性,通常情况下,pH较高,结合常数较大[
Fig 6 Dynamic storage modulus and loss modulus as a function of angular frequency of (a) T2-1′, pH = 6 and (b) T2-1, pH = 7.4 (γ = 0.5%)
对以上结果的解释如下,交联剂结构中的氨基可以稳定苯硼酸与PVA之间的动态共价复合物,提高了二者的结合常数,使凝胶在pH = 7.4时具有较高的模量和持续的弹性响应. 当pH值降低到6左右时,苯硼酸与PVA的结合常数降低,产生2种效果:(1)体系中的动态共价复合物的数量减少,交联密度降低;(2)动态共价复合物之间苯硼酸和二醇的交换速率提高,交联点的寿命变短. 2种效果表现为在低pH下,凝胶模量降低和松弛时间缩短.
Fig 7 (a) Temperature-dependent storage modulus and loss modulus of T2-1 hydrogel (f = 1 Hz, γ = 0.5%); (b) Dynamic storage modulus and loss modulus of T2-1 hydrogel as a function of angular frequency (γ = 0.5%) at 25 and 37 °C, respectively
2.2.5 凝胶的结构恢复能力
利用凝胶T2-1进行结构恢复能力测试. 首先对凝胶施加104 Pa的应力(104 Pa为仪器设定值,由于凝胶结构被破坏,实测应力为3000 ~ 4000 Pa)破坏凝胶结构,然后将大应力撤去,在15 Pa的较小应力下观察凝胶模量的恢复情况,结果如
Fig 8 (a) Time-dependent storage modulus and loss modulus and (b) shear stress of T2-1 hydrogel
在第2个恢复周期内(400 s),G′的恢复百分比由75.85%增大到91.2%;在第3个恢复周期内(200 s),G′的恢复百分比由71.2%增大到93.3%. 经过3个屈服-恢复循环,凝胶仍保持了很强的结构恢复能力,在第3个恢复周期结束,G′与平台模量相比仅仅下降了7%. 凝胶持续的结构恢复能力是因为凝胶的动态共价交联作用,虽然大的应力可以破坏凝胶的内部结构,但由于PVA与交联剂的结合是可逆的,在大应力撤去后,凝胶内部会重新进行组织和整合,逐渐恢复其起始结构,这一实验结果与文献中关于动态共价凝胶的报道是一致的[
利用与制备凝胶T2-1相同的条件来包载FITC-BSA并考察FITC-BSA的释放行为.与未包载FITC-BSA的凝胶相比,包载有FITC-BSA的凝胶中可流动部分的体积较大,静置12 h后,无显著改观;推测这是由于FITC-BSA的尺寸较大,产生了较大的空间阻碍作用,导致部分PVA与PEO交联剂的无法充分交联. 但该体系中仍有一部分以形状固定的凝胶形式存在,如
Fig 9 (a) Photo image of T2-1 hydrogel loaded with BSA-FITC; (b) release profiles of BSA-FITC from T2-1 hydrogel at 25 °C in 50 mmol phosphate buffer (pH = 7.4) containing 0, 10, and 30 g/L of glucose, respectively
设计合成了一类新结构的含苯硼酸和氨基结构的PEO交联剂,利用PVA-b-PEO-b-PVA三嵌段共聚物中PVA与该交联剂中苯硼酸之间的动态共价作用,构筑得到一类在生理pH下稳定的动态共价凝胶;PVA链段越长,交联剂用量越高,凝胶的稳定性越高,同时这类凝胶的屈服力较高,并表现出较强的结构修复能力. 凝胶可包载FITC-BSA,其释放行为具有葡萄糖响应性.
Xue K, Liow S S, Karim A A, Li Z B, Loh X J . Chem Rec , 2018 . 18 1517 - 1529 . DOI:10.1002/tcr.v18.10 . [百度学术]
Ferreira N N, Ferreira L M B, Cardoso V M O, Boni F I, Souza A L R, Gremiao M P D . Eur Polym J , 2018 . 99 117 - 133 . DOI:10.1016/j.eurpolymj.2017.12.004 . [百度学术]
Li J Y, Mooney D J . Nat Rev Mater , 2016 . 1 16701 . [百度学术]
Amaral A J R, Pasparakis G . Polym Chem , 2017 . 8 6464 - 6484 . DOI:10.1039/C7PY01386H . [百度学术]
Wang H Y, Heilshorn S C . Adv Mater , 2015 . 27 3717 - 3736 . DOI:10.1002/adma.v27.25 . [百度学术]
Brooks W L A, Sumerlin B S . Chem Rev , 2016 . 116 1375 - 1397 . DOI:10.1021/acs.chemrev.5b00300 . [百度学术]
Elshaarani T, Yu H J, Wang L, Zain A, Ullah R S, Haroon M, Khan R U, Fahad S, Khan A, Nazir A, Usman M, Naveed K U R . J Mater Chem B , 2018 . 6 3831 - 3854 . DOI:10.1039/C7TB03332J . [百度学术]
Yesilyurt V, Webber M J, Appel E A, Godwin C, Langer R, Anderson D G . Adv Mater , 2016 . 28 86 - 91 . DOI:10.1002/adma.201502902 . [百度学术]
Guo R W, Su Q, Zhang J W, Dong A J, Lin C G, Zhang J H . Biomacromolecules , 2017 . 18 1356 - 1364 . DOI:10.1021/acs.biomac.7b00089 . [百度学术]
Bao C Y, Jiang Y J, Zhang HY, Lu X Y, Sun J Q . Adv Funct Mater , 2018 . 28 1800560 DOI:10.1002/adfm.v28.23 . [百度学术]
Zhang M, Song C C, Du F S, Li Z C . ACS Appl Mater Interfaces , 2017 . 9 25905 - 25914. [百度学术]
Tang S C, Ma H, Tu H C, Wang H R, Lin P C, Anseth K S . Adv Sci , 2018 . 5 1800638 DOI:10.1002/advs.201800638 . [百度学术]
Huang Z J, Delparastan P, Burch P, Cheng J, Cao Y, Messersmith P B . Biomater Sci , 2018 . 6 2487 - 2495 . DOI:10.1039/C8BM00453F . [百度学术]
Mukherjee S, Hill M R, Sumerlin B S . Soft Matter , 2015 . 11 6152 - 6161 . DOI:10.1039/C5SM00865D . [百度学术]
Kataoka K, Miyazaki H, Bunya M, Okano T, Sakurai, Y . J Am Chem Soc , 1998 . 120 12694 - 12695 . DOI:10.1021/ja982975d . [百度学术]
Zhang Y, Guan Y, Zhou S . Biomacromolecules , 2007 . 8 3842 - 3847 . DOI:10.1021/bm700802p . [百度学术]
Lapeyre V, Gosse I, Chevreux S, Ravaine V . Biomacromolecules , 2006 . 7 3356 - 3363 . DOI:10.1021/bm060588n . [百度学术]
Hoare T, Pelton R . Biomacromolecules , 2008 . 9 733 - 740 . DOI:10.1021/bm701203r . [百度学术]
Wu W, Mitra N, Yan E C Y, Zhou S . ACS Nano , 2010 . 4 4831 - 4839 . DOI:10.1021/nn1008319 . [百度学术]
Hassan C, Peppas N . Adv Polym Sci , 2000 . 153 37 - 65 . DOI:10.1007/3-540-46414-X . [百度学术]
Lorand J P, Edwards J O . J Org Chem , 1959 . 24 769 - 774 . DOI:10.1021/jo01088a011 . [百度学术]
Brooks W L A, Deng C C, Sumerlin B S . ACS Omega , 2018 . 3 17863 - 17870 . DOI:10.1021/acsomega.8b02999 . [百度学术]
Carretti E, Grassi S, Cossalter M, Natali I, Caminati G, Weiss R G, Baglioni P, Dei L G . Langmuir , 2009 . 25 8656 - 8662 . DOI:10.1021/la804306w . [百度学术]
Robb I, Smeulders J T . Polymer , 1997 . 38 2165 - 2169 . DOI:10.1016/S0032-3861(96)00755-0 . [百度学术]
Kitano S, Kataoka K, Koyama Y, Okano T, Sakurai Y . Makromol Chem, Rapid Commun , 1991 . 12 227 - 233 . DOI:10.1002/marc.1991.030120405 . [百度学术]
Hisamitsu I, Kataoka K, Okano T, Sakurai Y . Pharm Res , 1997 . 14 289 - 293 . DOI:10.1023/A:1012033718302 . [百度学术]
Ivanov A E, Larsson H, Galaev I Y, Mattiasson B . Polymer , 2004 . 45 2495 - 2505 . DOI:10.1016/j.polymer.2004.02.022 . [百度学术]
Duncan T T, Weiss R G . Colloid Polym Sci , 2018 . 296 1047 - 1056 . DOI:10.1007/s00396-018-4326-7 . [百度学术]
Nurpeissova Z A, Alimkhanova S G, Mangazbayeva R A, Shaikhutdinov Y M, Mun G A, Khutoryanskiy V V . Eur Polym J , 2015 . 69 132 - 139 . DOI:10.1016/j.eurpolymj.2015.06.003 . [百度学术]
Peters G M, Chi X D, Brockman C, Sessler J L . Chem Commun , 2018 . 54 5407 - 5409 . DOI:10.1039/C8CC02610F . [百度学术]
Lee J, Ko J H, Mansfield K M, Nauka P C, Bat E, Maynard H D . Macromol Biosci , 2018 . 18 1700372 DOI:10.1002/mabi.v18.5 . [百度学术]
Yang T, Ji R, Deng X X, Du F S, Li Z C . Soft Matter , 2014 . 10 2671 - 2678 . DOI:10.1039/c3sm53059k . [百度学术]
Yang Ting(杨挺), Deng Xinxing(邓鑫星), Du Fusheng(杜福胜), Li Zichen(李子臣) . 高分子学报 , Acta Polymerica Sinica , 2014 . 1553 - 1560. [百度学术]
Tong Y Y, Dong Y Q, Du F S, Li Z C . J Polym Sci, Part A: Polym Chem , 2009 . 47 1901 - 1910 . DOI:10.1002/pola.23288 . [百度学术]
Li J, Loh S . Adv Drug Delivery Rev , 2008 . 60 1000 - 1017 . DOI:10.1016/j.addr.2008.02.011 . [百度学术]
Liu F Y, Li F Y, Deng G H, Chen Y M, Zhang B Q, Zhang J, Liu C Y . Macromolecules , 2010 . 45 1636 - 1645. [百度学术]
Roberts M C, Hanson M C, Massey A P, Karren E A, Kiser P F . Adv Mater , 2007 . 19 2503 - 2507 . DOI:10.1002/(ISSN)1521-4095 . [百度学术]
322
浏览量
50
下载量
2
CSCD
相关文章
相关作者
相关机构