西咪替丁水凝胶贴剂的研制及性能研究

以聚丙烯酸钠及聚乙烯吡咯烷酮为凝胶基质,以维生素E为透皮吸收促进剂制备标题化合物。采用紫外分光光度法测定西咪替丁含量;以剥离强度和黏着力为检测指标,通过单因素和正交实验优选标题化合物的最优处方;而后对其进行体外性能研究。标题化合物较优处方(质量百分比)为:5.5%聚丙烯酸钠、0.15%聚乙烯吡咯烷酮、1.4%氢氧化铝、1.2%羧甲基纤维素钠、1.5%酒石酸、30%甘油、1%维生素E和1.5%西咪替丁;固化温度为50℃,固化时间为2 h。此时其24 h的药物累积释放率为23.65%,26 h药物累积透皮渗透量达1 010.22μg/cm2。结果表明,以聚丙烯酸钠/聚乙烯吡咯烷酮基为高分子骨架的水凝胶基质易于涂布,涂布后有足够的强度,适合用作贴剂的水凝胶基质;含有1%维生素E的标题化合物中药物具有很好的小鼠皮肤透过性。标题化合物是一种具有发展潜力的新剂型。     

基于纤维素模板的聚合物空心微球作为药物载体的性能研究及分析

以羟丙基纤维素为模板材料,分别采用不同的聚合方法制备了2种不同形态和结构的聚合物空心微球--聚N-异丙基丙烯酰胺-co-聚丙烯酸(PNIPAm-co-PAA)微凝胶和聚N-异丙基丙烯酰胺-聚丙烯酸(PNIPAm-PAA)水凝胶微囊。以盐酸阿霉素(Dox)作为模型药物,考察了聚合物空心微球作为药物载体的载药能力和体外释放性能。研究表明,PNIPAm-co-PAA微凝胶、PNIPAm-PAA水凝胶微囊和Dox分子能够通过正负电荷的相互吸引实现有效结合;载药微球具有良好的缓释性能,并对Dox的释放表现出明显的pH值敏感性和温度敏感性。体外细胞毒性实验表明,载药PNIPAm-co-PAA微凝胶、PNIPAm-PAA水凝胶微囊具有很高的抗肿瘤活性,细胞相对存活率均可达20%左右。PNIPAm-co-PAA微凝胶、PNIPAm-PAA水凝胶微囊在作为水溶性药物或蛋白类药物载体方面,具有潜在的应用价值,同时有望应用于木材胶黏剂防腐等。     

pH敏感型半纤维素水凝胶的制备及释药性能研究

利用自由基聚合方法制备了丙烯酸和丙烯酰胺共聚接枝半纤维素水凝胶,研究了水凝胶在不同pH(1.5、7.4、10)缓冲液中的溶胀动力学,并以阿司匹林作为模型药物,研究了其在模拟胃肠液(pH=1.5、7.4)中的释放性能。结果显示,制备的半纤维素水凝胶对阿司匹林具有明显的缓释效果,有望实现药物的控制释放。     

聚丙烯酸/聚乙烯醇互穿网络水凝胶制备及其对结晶紫的控制释放性能的研究

以过硫酸铵为引发剂,采用溶液聚合和连续的互穿网络技术,制备了一系列聚丙烯酸(PAA)/聚乙烯醇(PVA)互穿网络水凝胶。测量了水凝胶在不同pH缓冲溶液中的溶胀性能。以结晶紫为模板药物,考察了在不同的pH缓冲溶液中的PAA/PVA互穿网络水凝胶控释作用。结果表明,药物的释放量可以通过改变体系的pH值加以调控。     

智能型高分子水凝胶合成的研究进展

高分子功能材料是现代高分子科学研究的热点,其中具有刺激响应性的高分子水凝胶材料在化学机械、人工肌肉、药物传递与释放、膜分离、化学阀等诸多领域具有广阔的应用前景而受到越来越多的重视。无论从学术价值还是应用价值,对这一领域的研究都有重要的意义。作为功能高分子材料之一,本文综述了常见的高分子水凝胶的制备方法,介绍了其应用和发展方向。     

基于pH敏感型葡聚糖水凝胶微球的药物载体

以葡聚糖为原料,采用反相微乳液技术制备了一种含有席夫碱结构的葡聚糖基水凝胶纳米微球作为载体,通过交联剂聚乙烯亚胺(PEI)的静电吸附作用对药物模型8-羟基芘-1,3,6-三磺酸三钠盐(HPTS)进行了包埋,利用FTIR、SEM和DLS等对微球的结构和形貌进行了表征。结果表明,这种葡聚糖纳米水凝胶载药前后均具有良好的球形结构,平均粒径分别在459和648 nm左右。载药效果及药物释放行为研究发现,该葡聚糖纳米水凝胶可对HPTS进行有效负载,且其释放行为具有明显的酸性环境敏感性,酸性越强,释放越快。含有席夫碱结构的葡聚糖纳米凝胶微球可作为pH敏感型载体应用于药物递送领域。     

透明质酸水凝胶制备的研究进展

透明质酸具有亲水性强,无毒、可降解及生物相容性好等优点,以其为主要原料制备的透明质酸基水凝胶常用于可控药物释放、防术后粘连、软骨支架、角膜支架、黏膜填充剂、组织修复和再生等领域。本文综述了透明质酸水凝胶的制备方法,并对其发展方向进行了展望。     

甲壳质类水凝胶的制备及性能研究

水凝胶是指具有高吸水保水性能的一种亲水性高分子材料。甲壳质类水凝胶的制备过程:把甲壳质溶解于醋酸溶液中,对得到的溶液进行过滤,然后加入戊二醛进行搅拌,最后放入恒温箱恒温一定时间后即得产品甲壳质类水凝胶。     

导电复合水凝胶的制备及性能测试

本文首先通过化学交联法制备聚乙二醇二丙烯酸酯-聚丙烯酰胺（PEGDA-PAAm）水凝胶修饰层，而后运用界面聚合法使导电聚合物聚吡咯（PPy）于水凝胶中聚合，则得到性能良好的导电水凝胶。选用316L不锈钢片为负载导电水凝胶的基底，制备掺杂药物地塞米松的水凝胶，通过电化学CV法刺激控制药物释放，实验结果表明，我们到了性能良好的药物释放体系。     

纤维素/海藻酸钠基双膜水凝胶的制备及其药物控释研究

用阳离子纤维素(CC)和阴离子海藻酸钠(SA)制备出具有双膜结构的生物相容性水凝胶,探究了水凝胶在不同pH值环境下的药物控制释放行为。结果表明,在pH为7.4,进行单膜水凝胶释放牛血清白蛋白时,纯海藻酸钠水凝胶SA、SA/CC-1水凝胶、SA/CC-2水凝胶的药物释放时间分别为3,6,8 d,累积释放量分别为86%,84%,83%,即纤维素阳离子化程度更高的水凝胶释放药物更缓慢;在pH为2.0的条件下,单膜水凝胶释放牛血清白蛋白的累积释放量的最大值仅为6%,水凝胶的药物释放行为表现出pH敏感性。此外,在pH为7.4条件下,复合药物从双膜水凝胶中有序释放出来,外膜中的茶碱在药物释放的第3 d达到释放平衡,累积释放量为87%;内膜中的牛血清白蛋白在第4 d开始释放,在第11 d达到平衡,累积释放量为84%。该水凝胶有明显的药物控释作用,在生物医学领域有很大的应用前景。     

温敏凝胶原位植入给药系统的研究进展

采用温敏凝胶的原位给药系统是理想的长效给药系统。该文从凝胶材料和给药系统的制备、凝胶的机体反应和体内降解以及药物控释三方面,综述了该给药系统的研究进展,总结了关键技术和科学问题,分析了面临的挑战与解决途径。水凝胶网络的不规则形态和较低的机械强度,其植入后引起的机体炎性反应、组织融合与水分快速流失及这些反应造成的凝胶网络结构和降解速率的个体差异性变化,是控制药物释放的主要困难。通过提高凝胶表面亲水性,降低其表面正电荷,或在其表面修饰抗炎性多肽,可减轻炎性作用、减缓组织融合;通过与亲水性高分子形成共混凝胶或互穿凝胶网络以及共价交联等方式,可提高凝胶强度,保持凝胶网络的空间结构和水分;通过在凝胶表面建立扩散屏障、加强药物和凝胶骨架的相互作用、构建微粒/原位凝胶复合释药系统等技术,可进一步改善药物释放特征。     

温敏凝胶原位植入给药系统：进展与挑战

采用温敏凝胶的原位给药系统是理想的长效给药系统。本文从凝胶材料和给药系统的制备、凝胶的机体反应和体内降解以及药物控释三方面,综述了该给药系统的研究进展,总结了关键技术和科学问题,分析了面临的挑战与解决途径。水凝胶网络的不规则形态和较低的机械轻度,其植入后引起的机体炎性反应、组织融合与水分快速流失及这些反应造成的凝胶网络结构和降解速率的个体差异性变化,是控制药物释放的主要困难。通过提高凝胶表面亲水性,降低其表面正电荷,或在其表面修饰抗炎性多肽,可减轻炎性作用、减缓组织融合;通过与亲水性高分子形成共混凝胶或互穿凝胶网络,以及共价交联等方式,可提高凝胶强度,保持凝胶网络的空间结构和水分;通过在凝胶表面建立扩散屏障、加强药物和凝胶骨架的相互作用、构建微粒/原位凝胶复合释药系统等技术,可进一步改善药物释放特征。     

皮肤用亲水性聚氨酯压敏胶的制备及性能研究

针对目前我国透皮制剂所用橡胶类压敏胶的缺点,制备了一种亲水性聚氨酯压敏胶,并对其性能进行了研究。该压敏胶是由二异氰酸酯与多元醇的混合物进行反应生成预聚体,再经扩链制得的。通过在聚氨酯主链上引入亲水的聚乙二醇嵌段来赋予压敏胶亲水性。研究结果表明该聚氨酯压敏胶具有优良的粘结性能及反复揭帖性,具有良好的药物、皮肤相容性及良好的药物控释性能。     

丙烯酸酯压敏胶基贴片制备工艺中的质量控制

以丙烯酸酯PSA(压敏胶)和乳癖消浸膏共混作为药用PSA基质,考察了载药量、过程水的加入量、环境湿度、存放时间和制备工艺等因素对PSA基质的黏附性、抗老化性能和药物释放度等影响。结果表明:药用PSA基质中,当w(中药浸膏)≈38%(相对于基质总量而言)、w(水)=8%～10%(相对于基质总量而言)且贴片密封保存时,压敏胶基质的抗老化性能得到明显提高,其180°剥离强度为0.1～0.6kN/m,持粘力超过6h,并保持良好的稳定性;以50r/min左右的搅拌速率制取的PSA基质,其贴片的芍药苷12h释放度为83.61%(相对于芍药苷总量而言);当贴片存放时间超过60d时,药物释放度基本趋于稳定。     

Characterization of shape memory behaviour of CTBN-epoxy resin system

The temperature-responsive poly(vinyl alcohol)/ poly(N-isopropylacrylamide) hydrogel was prepared as a drug delivery carrier. The vitamin B12 release behavior of hydrogel was controlled by direct oxyfluorination. The oxyfluorination of hydrogel changed the surface characteristics to have hydrophilic functional groups. On the other hand, the hydrophobicity of hydrogel increased by fluorination treatment due to the induced hydrophobic functional groups. C-O bond and C-F bond were mainly formed by oxyfluorination and fluorination, respectively. The surface morphology showed the significant variation depending on the oxyfluorination conditions. Both swelling ratio and drug release rate were strongly dependent on the oxyfluorination conditions. The swelling of hydrogel increased further by the surface modification with oxyfluorination in a higher oxygen content to give more hydrophilic properties. The drug release from hydrogel also increased as more hydrophilic functional groups were introduced by oxyfluorination because the favorable affinity at the interface resulted in a higher swelling ratio. On the other hand, the relatively low swelling ratio and slower drug release from hydrogel were observed with more hydrophobic functional groups introduced by fluorination.     

Mechanical properties and drug release rate of poly(vinyl alcohol)/poly(ethylene glycol)/clay nanocomposite hydrogels: Correlation with structure and physical properties

Poly(vinyl alcohol)/poly(ethylene glycol) hydrogels containing curcumin as a drug and the various amounts of a montmorillonite nanoclay are prepared using the freezing–thawing method. Nanoclay quantity influence on the physicomechanical properties and the drug release rate of the hydrogel as well as relationship between them is investigated. X-Ray diffraction and Atomic force microscopy analysis reveal the nanoclays have an intercalation structure in the hydrogel, and the hydrogel crystallization decreases with increasing the nanoclay inclusion. From the SEM micrographs observation, it was revealed that due to the presence of the nanoclay in the hydrogel, its porosity decreased. The naonoclay has an amount-depended dual effect on the hydrogel swelling. The swelling mechanism is a normal Fickian diffusion for all the hydrogel samples. Strong physical interactions between the nanoclays and the polymer chains in the nanocomposite hydrogels are evidenced by the rheological studies. These interactions lead to significant reinforcement of the hydrogel tensile strength, intensified by the nanoclay amount. Interestingly, the nanoclays show the capability of accelerating and, also, decelerating the drug release of the hydrogel. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47843.     

智能水凝胶在生物载药领域的研究进展

智能水凝胶是一类具有三维网络结构、膨胀性好、吸水性强、易保水、超仿生等特点的新型功能高分子材料。由于其合成过程中加入了具有特殊结构、基团的单体或者大分子原料,如聚丙烯酰胺(PNIPA)类大分子、酸/碱基团(如羧基和氨基)、丙烯酸、聚氨类、偶氮苯(As)、聚电解质(高分子链上有可以离子化的基团)等,因此智能水凝胶是能够根据环境的温度、酸度、电场、磁场等变化做出有规律的结构和体积调整,或者导致凝胶组成发生变化的新型智能生物化学水凝胶材料,具有较高的智能性和响应性。本文根据水凝胶对外界环境的刺激不同表现出不同的响应情况,将凝胶分为:温度敏感性水凝胶、pH敏感性水凝胶、光敏感性水凝胶、压力敏感性水凝胶、电场敏感性水凝胶等。近年来,随着人们对医用水凝胶和药物缓释研究的深入,具有环境敏感性和较好生物相容性的智能水凝胶成为临床上药物控释材料的首选。     

MXene Reinforced PAA/PEDOT:PSS/MXene Conductive Hydrogel for Highly Sensitive Strain Sensors

Conductive hydrogel has a vital application prospect in flexible electronic fields such as electronic skin and force sensors. Developing conductive hydrogel with significant toughness and high sensitivity is urgently needed for application research. In this work, a strong and sensitive strain sensor based on conductive hydrogel is demonstrated by introducing MXene (Ti3C2Tx) into the micelle crosslinked polyacrylic acid (PAA)/poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) hydrogel network. The functional polymer micelle crosslinkers can dissipate external stress by deformation, endowing the hydrogel with high strength. The combination of MXene both improves the polymer network structure and the conductive pathways, further enhancing the mechanical properties and sensing performance. Resultantly, the flexible strain sensor base on PAA/PEDOT:PSS/MXene conductive hydrogel exhibits excellent sensing performance with a high gauge factor of 20.86, a large strain detection range of 1000%, as well as good adhesion on different interfaces. Thus, it can be used to monitor various movements of the human body and identify all kinds of handwriting, showing great potential into wearable electronics.     

Effect of hydrophobicity of a drug on its release from hydrogels with different topological structures

The effect of the topological structure; that is, the network heterogeneity, of hydrophobically modified, slightly acidic hydrogels on the binding and release of low molar mass drugs has been studied using ibuprofen and ephedrine as model compounds with varying water solubility. The difference in the heterogeneity of the gels has been produced by the choice of the hydrophobe copolymerized into the polymer network. The effect of the drug loading on the release kinetics has been investigated as well. The release of hydrophobic ibuprofen was slower from a strongly aggregated heterogeneous gel than from a more homogeneous one, because of the strong hydrophobic interaction between ibuprofen and the heterogeneous hydrogel. The release of hydrophilic ephedrine from the homogeneous gel with an initial drug content of 30 wt % of dry polymer showed negative time dependence, indicating that during and after the swelling of the gel, ephedrine started to bind to the polymer. However, the release of ephedrine from a heterogeneous hydrogel increased with time. This shows that the heterogeneous, aggregated polymer binds the hydrophobic substance more strongly than the homogeneous one does, and that the homogeneous network has higher affinity for the basic hydrophilic substance than the heterogeneous one does. The loading contents of ibuprofen and ephedrine affect the release rates in different ways because of the different binding and release mechanisms. The number of binding sites accessible for ephedrine inside the polymer network is assumed to change upon the swelling of the gel. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1031–1039, 1999     

Thermosensitive chitosan hydrogel for implantable drug delivery: Blending PVA to mitigate body response and promote bioavailability

Thermosensitive hydrogels promise to be the injectable implants for long-term controlled drug release; however, body response to the implanted hydrogels and its unpredictable impacts on drug release complicates their applications. In the present study, hydrophilic polymer poly(vinyl alcohol) (PVA) was blended into the thermosensitive hydrogel composed of chitosan and glycerophosphate to mitigate the body responses and promote the drug bioavailability. The effects of PVA on the surface properties of the hydrogel were evaluated by zeta-potential, water contact angle, and cell attachment. Body responses were explored by histological examination via subcutaneously implanting the hydrogels into Sprague-Dawley rats. Drug release in vivo and bioavailability were determined with cyclosporine A (CsA) employed as the model drug. The results showed that, on one hand, the presence of PVA improved the surface hydrophilicity of the hydrogel and inhibited the cell attachment on the hydrogel, which alleviated the further cell infiltration and tissue integration in body; and on the other hand, blending of PVA led to the more rapid gel formation and more compact network, which resisted the dehydration and survived the hydrogel from cell division. These advantages benefited the controlled release and absorption of CsA, and contributed to the higher drug bioavailability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012