β-环糊精包合薄荷油制备工艺的研究

目的:建立一种β-环糊精包合薄荷油的方法。方法:采用饱和水溶液法对薄荷油的β-环糊精包合工艺进行了考察,并对工艺条件进行优选。结果:饱和水溶液法对薄荷油的β-环糊精包合工艺是可行。结论:优选的包合条件为β-环糊精与薄荷油的投料比为6:1,包合温度为50℃,搅拌3h。在此条件下包合率较高。     

舒筋颗粒中丁香油β-环糊精包合工艺研究

目的:优选舒筋颗粒中丁香油β-环糊精包合工艺。方法:采用正交试验法,以丁香酚包合率为指标,对丁香油β-环糊精包合物的制备工艺进行研究。结果:最佳包合条件为A3B1C1,即丁香油与β-CD用量的比值为1:8,包合温度为40℃,包合时间为1h。结论:优选的制备工艺稳定可行。     

β-环糊精包合当归、薄荷挥发油的工艺研究

目的:探讨β-环糊精包合当归、薄荷挥发油的最佳工艺。方法:采用L9(34)正交实验法优选包合工艺,再以挥发油包合率为评价指标。结果:优选出包合工艺条件为:β-环糊精:挥发油为6:0.5,包合温度为60℃,包合时间为3h。结论:挥发油包合工艺合理可行。     

满山红挥发油的β-环糊精包合工艺研究

目的：以挥发油包合率和包合产率为指标筛选β-环糊精包合满山红油包合的最佳工艺条件。方法：采用正交试验方法对包合工艺进行考察。结果：采用方差分析方法表明与满山红油的比例对试验结果有显著性影响。包合工艺最佳条件是β-环糊精与挥发油用量比例为9：1（g：m1），包合温度为45℃，包合时间为4小时。结论：此包合工艺可以提高挥发油的稳定性。     

硝苯地平β-环糊精包合物的制备

目的：探索硝苯地平β-环糊精包合的最佳生产工艺，提高硝苯地平在制剂中的稳定性。方法：采用正交实验法，通过测包合物收得率及硝苯地平含量考察包合工艺。结果：筛选出最佳生产工艺条件：A3B2C3（β-环糊精和硝苯地平的比例为8：1，油硝苯地平和乙醇的比例为1：1．5，包合温度为60℃，时间为2小时）。     

β-环糊精对次氯酸钠溶液稳定性影响的研究

以不同浓度的β-环糊精作稳定剂,观察对含有效氯0.2％的次氯酸钠溶液化学稳定性及抗菌活性的影响。试验结果表明,加入0.03％β-环糊精能显著提高次氯酸钠溶液的稳定性。在室温下,密闭容器中放置60天,有效氯仍保留初始浓度的95.84％。而未加β-环糊精的对照样本仅有74.55％;开放容器内放置14天,有效氯可保留初始浓度的93.32％。而对照样本只有76.50％。0.03％β-环糊精对次氯酸钠溶液的抗菌活性有增强作用,但随其浓度增大而减弱。     

新型β-环糊精制备及性能的实验研究

目的 探讨新型β-环糊精制备和物理性能,开发治疗高脂血症的药物.方法 β-环糊精与甘油醚-四氯乙烯在碱性条件下深度交联得到不能溶解、只能溶胀的交联环糊精高分子.采用胆酸钠溶解和吸附实验测定新型β-环糊精性能.结果 新型β-环糊精50℃下最大吸附量约为68.07±0.55 mg/g,60℃最大吸附量约为72.05±0.48 mg/g.而其它常用交联法得到的聚合物部分溶解,60℃下平衡吸附量约为63.01±1.08 mg/g.结论 新型β-环糊精应用前景广阔.     

新型消毒剂β-环糊精包合碘的结构确证

摘要 目的 研究一种新型消毒剂β 环糊精包合碘(简称环糊精碘)的结构。方法 通过饱和溶液法工艺和仪器分析方法,对环糊精碘及其结构进行研究和确证。结果 经饱和溶液法工艺制备的环糊精碘为固体粉剂,其碘收率为质量分数92.1%,游离碘＜0.1%,可溶于水并可释放出游离碘。经仪器法联合分析证明,氢的化学位移最大为0.03 ppm,该环糊精碘为一种超分子包合结构,未发现本品形成新的化学结构。结论 本研究确证饱和溶液法生产的环糊精碘形成了新的"超分子"包合结构,包合率＞99.9%。     

阳离子β-环糊精聚合物复合胰岛素的海藻酸钠/壳聚糖载药微球

背景:大多数蛋白质类药物采用注射剂型是因为口服时生物利用度低,为了提高口服给药的生物利用度,目前常用的方法是将蛋白质药物包裹在脂质体或微球中,并且在这些体系中引入多糖类化合物可促进生物吸收或降低蛋白酶破坏.目的:构建载有阳离子β-环糊精聚合物/胰岛素复合物的海藻酸钠/壳聚糖微球做为口服给药系统,考察阳离子β-环糊精聚合物的电荷密度对胰岛素在模拟胃肠液中释放行为的影响.设计、时间及地点:对比观察实验,于2006-10/2008-07在四川大学高分子科学与工程实验楼完成.材料:β-环糊精、环氧氯丙烷由天津市博迪化工有限公酬提供,氯化胆碱、海藻酸钠由成都科龙试剂公司提供,壳聚糖由浙江金壳生物化学有限公司提供,胰岛素由江苏万邦生化医药股份有限公司提供.方法:将β-环糊精、环氧氯丙烷和氯化胆碱经过一步缩聚反应制得阳离子β-环糊精聚合物,并通过投料比控制其电荷密度.将该聚合物与胰岛素形成复合物,采用锐孔-凝固法制备含有该复合物的海藻酸钠/壳聚糖载药微球.并对所得微球进行模拟胃肠液中释药行为研究.主要观察指标:微球的胰岛素包封率及在模拟胃肠液中胰岛素的释放行为.结果:微球的胰岛素包封率与阳离子β-环糊精聚合物的电荷密度相关,最高能达到(76.3+1.5)%.体外释药实验显示,在模拟胃液中微球药物损失小于不加入阳离子β-环糊精聚合物的载有胰岛素的微球;在模拟肠液中累积释放的胰岛素量为5.8 IU,大于不加入阳离子β-环糊精聚合物的载有胰岛素的微球.结论:载有阳离子β-环糊精聚合物/胰岛素复合物的海藻酸钠/壳聚糖微球作为口服给药系统能有效地提高包封率和改善胰岛素在模拟胃肠液中的释放.     

β-环糊精包合物增加氢氯噻嗪溶解度和溶出度的实验

目的：研究β-环糊精包合物对氢氯噻嗪溶解度和溶出度的影响。方法：采用饱和水溶液法制备β-环糊精-氢氯噻嗪包合物，并与原料药及其物理混合物作比较，分别测定其在人工胃液中的药物溶解度和溶出度。结果：测得其在人工胃液中的药物溶解度分别为：原料药0.0628g、物理混合物0．0950g、β-环糊精包合物0．1957g；其溶出50％的药物T50分别为：原料药15min、物理混合物12min、β-环糊精包合物7.5min。结论：β-环糊精包合物能增加氢氯噻嗪的溶解度和溶出度。     

缓释、控释药用高分子材料的临床应用

目的:分析缓释、控释药用高分子材料的特点,探讨其应用前景.方法:以"缓释药物,控释药物,高分子材料,药物载体,临床应用为中文关键词;以"controlled drug release,drug delivery,drug release material,polymer material,clinical application"为英文关键词,采用计算机检索2003-01/2010-03相关文章.纳入与有关缓释、控释药用高分子材料的临床应用的文章;排除重复研究或Meta分析类文章.以30篇文献为主重点进行了讨论缓释、控释药用高分子材料的种类及性能特点.结果:近年来缓释、控释技术发展迅速,缓释、控释制剂的研究、开发和利用,充分满足了临床的需要,为广大患者防病治病提供了有力的保证.临床上适宜于制成缓释、控释制剂的药物范围广泛,各种类型的缓控释制剂,如骨架型缓释制剂、包衣缓释制剂、缓释胶囊、微囊缓释制剂、缓释膜剂、缓释栓剂等被广泛应用于临床.结论:在缓控释制剂中,高分子材料几乎成了药物在传递、渗透过程中的不可分割的组成部分.缓控释制剂的发展虽然与制药设备都在不断的更新,但是完全达到理想的应用标准还有一定的差距,研制使用新型材料和高质量的缓控释制剂还有待于临床工作者的进一步开发.     

胸腺五肽-聚乳酸-羟基乙酸微球的制备及释药性能

背景:国内外所用的胸腺肽多为注射液,其保存、运输困难,成本升高,给患者带来不便,限制了它的广泛使用.因此胸腺肽口服缓释制剂的研究正逐步受到人们的关注.目的:观察胸腺五肽-聚乳酸-羟基乙酸缓释微球的释药性能.设计、时间及地点:体外观察实验,于2005-02/2007-10在武警医学院化学教研室科研室完成.材料:胸腺五肽标准品(含量99.17%)由成都川抗派德生物医药科技有限公司提供,胸腺五肽(含量97.16%)由杭州中肽生化有限公司提供,聚乳酸-羟基乙酸共聚物(50:50,Mr10 000)由山东省医疗器械研究院提供,聚乙烯醇(聚合度1 750±50)由天津市天大化工实验厂提供,三氟乙酸由上海吉尔生化公司提供,二氯甲烷(分析纯).方法:称胸腺五肽溶丁二聚乙烯醇溶液为内水相;溶解于二氯甲烷中,超声形成W/O初乳;将初乳加入聚乙烯醇溶液快速搅拌到W/ONV复乳,再缓慢搅拌,待二氯甲烷完全挥发后得固化胸腺五肽-聚乳酸-羟基乙酸缓释微球.主要观察指标:①扫描电镜观察微球的形态.②反相高压液相色谱法测定胸腺五肽含量,计算微球载药量、包封率.③体外释药情况.结果:制备的微球表面光滑,球体均匀:微球中胸腺五肽的载药量和包封率分别为1.87%和67%左右;微球在10d内累积释药率达70%.结论:胸腺五肽-聚乳酸-羟基乙酸缓释微球对胸腺五肽具有明显的缓释作用.     

聚乙烯醇及其复合材料在组织工程支架中的应用

背景：聚乙烯醇是具有良好生物相容性和生物降解特性的聚合物,因其水溶性、成膜性、乳化性、胶黏性,而且无味无毒,被广泛用于临床领域。
　　目的：综述聚乙烯醇及其复合材料在骨、软骨、皮肤、血管等组织工程支架中的应用。
　　方法：由第一作者检索2000年1月至2011年12月中国知网数据库、1980年1月至2012年12月Pubmed数据库及 Elsevier数据库中,有关聚乙烯醇及其复合材料在骨、软骨、皮肤、血管等组织工程支架中应用的文章,中文关键词为“聚乙烯醇,复合材料,组织工程支架”,英文关键词为“Poly (vinyl alcohol),composite material, tissue engineering scaffold”。
　　结果与结论：虽然聚乙烯醇及其复合材料还存在强度不够高、植入后有并发症等缺点,但这类材料具有良好的生物相容性和生物可降解特性,在组织工程中的应用从实验室到临床前研究都有很大的进展。对于其修复的长期效果还需要进一步深入研究。通过对材料表面进行修饰,改善细胞与支架材料的相互作用;通过模拟细胞生长微环境,制备仿生材料,提高材料的亲水性、对细胞的黏附性,促进细胞的分化增殖;构建具有可控三维多孔结构的支架,并赋予其控制释放细胞生长因子等功能,更好地仿生天然细胞外基质的结构和功能;制备出降解速度与机械强度能够完全适应组织再生需要的支架,研制复合、仿生材料是今后支架材料研究的主要方向。     

Preparation of triazine containing porous organic polymer for high performance supercapacitor applications

By condensing M and TFP under solvothermal conditions, a new porous organic polymer POP_M–TFP was obtained. The electrode modified with triazine containing POP_M–TFP exhibits well-defined rapid redox processes and showed a high specific capacitance of 130.5 F g⁻¹ at 2 A g⁻¹, suggesting well electrochemical performance.

POP_M–TFP which exhibit well-defined rapid redox processes and high capacitance was prepared under solvothermal conditions.

Due to the overconsumption of oil and coal over the past few decades, it is highly desirable to develop safe sources of energy, as well as the eco-friendly use of conventional energy through energy storage devices.^1,2 Supercapacitors have attracted much attention because of their high power density, long recycle life and a wide temperature range.³ Generally, supercapacitors are classified into two types: electrochemical double layer capacitor and pseudocapacitor.^4–6 Electrode materials are the key ingredient for this electrochemically occurring process.⁷ The applied voltage depended ion adsorption on the electrode surface depending on the structure of the material used for the electrodes. To obtain a device with good performance, significant study has been paid to the exploration of redox-active materials for supercapacitors.^8,9 In order to improve the electronic performance of electrode materials, the functionalized porous structure having a high surface area and hierarchical porosity is important.¹⁰Nanoporous organic polymers with high nitrogen content have got great interest because of their applications in semiconductors, gas storage, and electrochemical supercapacitors etc.^11–13 Recently, nitrogen-doped carbon materials exhibit good electrical properties because the pseudocapacitance effect provided by N atoms.¹⁴ Nanoporous organic polymers, such as covalent organic frameworks (COFs), covalent triazine-based frameworks (CTFs), porous organic polymers (POPs) which have controllable pore structure and heteroatom doping are promising electrode materials in supercapacitors.^15–19 Among them, POPs which are built by the polymerization of rigid organic molecules showing good supercapacitor applications are TaPa-Py COF, HCPANIs, TpDAB and Aza-CMPs etc.^20–23 POPs have micropores with high specific surface area and heteroatom doping, which should be quite conductive to the electrochemical performance when applied as electrode materials. Consequently, polytriazines with high surface area stand out due to their high nitrogen content.²⁴Nowadays, nitrogen-enriched polymers attract increasing attention for application in supercapacitors.²⁵ It is a challenge to synthesize nitrogen-enriched nanoporous polymers by using cheap reagents.²⁶ POPs or COFs are prepared by using different synthetic method such as ultrahigh vacuum surface synthesis,²⁷ microwave assisted solvothermal synthesis,²⁸ ionthermal synthesis²⁹ and vapor-assisted conversion etc.³⁰ Solvothermal synthesis often used to produce nanoporous materials through exploring reaction conditions appropriately.^31–33 CTFs represent a class of functionalized polymers which are obtained by the trimerization of aromatic nitriles under ionthermal conditions in the presence of a catalyst. This method involves harsh experimental conditions such as very high temperature.²⁹ Melamine is a trimer of aromatic nitriles, with a 1,3,5-triazine skeleton considered as Lewis base.³⁴ The lone pair of electrons in N plays an important role in electrochemical applications. Introducing triazine skeleton into POP materials by using precursor bearing triazine moieties is a straightforward approach in POP synthesis.Herein, we choose a trigonal-symmetrical nitrogen-containing melamine (M) as a monomer, which can be used to construct conjugated microporous covalent triazine-based organic polymer through the coupling with triformylphloroglucinol (TFP) monomer under solvothermal conditions without any catalysts. The doping of nitrogen atoms in POP_M–TFP can affect the electron distribution of the materials and further enhance the wettability and the electro-active surface area of the electrode. Otherwise, the nitrogen atom can also introduce pseudocapacitance to the supercapacitors, which are beneficial for enhancing the supercapacitor performance. Scheme 1 illustrates the synthesis of POP_M–TFP at 160 °C. The synthesized POP_M–TFP was employed as an electrode material for supercapacitor application. The electrodes which are modified with POP_M–TFP exhibit well-defined rapid redox processes and high capacitance.Open in a separate windowScheme 1Schematic representation of the structure of POP_M–TFP.The crystalline structure of POP_M–TFP was first characterized by powder X-ray diffraction (XRD). The XRD pattern of POP_M–TFP material has been shown in Fig. 1a which reveals the crystalline nature of the material. As seen from Fig. 1a, the peaks at 5.2°, 9.5° and 27.6° are attributed to the corresponding (100), (200) and (201) planes diffractions of POP_M–TFP respectively. Successful condensation of M and TFP under a simple solvothermal conditions without any catalysts yields product, which has been confirmed by ¹³C CP-MAS NMR and The Fourier transform infrared (FT-IR) spectroscopic investigations. In order to further understand the chemical environment of various types of carbon atoms in POP_M–TFP, ¹³C solid state NMR spectroscopy was performed. POP_M–TFP exhibits a clear signal at 167.8 ppm confirms the presence of the triazine skeletons (Fig. 1b).^35–37 The additional characteristic ¹³C resonance in the C–N was observed to be located at 153.8 ppm. The characteristic peak of C O appearing at 189.5 ppm. In summary, it can be confirmed that the M has successfully reacted with TFP to form POP_M–TFP material.Open in a separate windowFig. 1(a) XRD pattern of POP_M–TFP (red) and simulated XRD pattern (black) of POP_M–TFP. (b) ¹³C NMR spectra of POP_M–TFP. (c) FT-IR spectrum of M, TFP, and POP_M–TFP. (d) Nitrogen adsorption/desorption isotherm pattern of POP_M–TFP where black square indicates the adsorption and red circle represents the desorption isotherm.The FT-IR spectra of M, TFP and POP_M–TFP between 4000 to 400 cm⁻¹ are shown in Fig. 1c. The two separated peaks at 3470 and 3419 cm⁻¹ originate from stretching vibrations of amine (–NH₂) groups in M. The peak at 1649 cm⁻¹ belongs to stretching vibrations of C O in TFP. The FT-IR spectra of POP_M–TFP shows the disappearance of the –NH₂ stretching bands of the M. The appearance of a broad –NH peak at 3379 cm⁻¹ further indicates the formation of POP_M–TFP. Additionally, the emergence of a new band at 1234 cm⁻¹ is characteristic of C–N stretch moieties. The peak at 1535 cm⁻¹ belongs to stretching vibrations of C C in POP_M–TFP.^16,38 Further, the chemical environment of the elements present in the specimen was studied using X-ray photoelectron spectroscopy (XPS). Full scan XPS spectra of POP_M–TFP showed in Fig. S1^† reveals the peaks of C, N and O. To analyze the detailed chemical states of N elements, the high-resolution XPS scan was also recorded (Fig. S2^†). The N 1s spectra of POP_M–TFP split into two peaks located at 398.8 eV and 399.8 eV, respectively. The peak at 398.8 eV can be assigned to triazine N, while the peak at 399.8 eV can be assigned to the N in the –C C–NH–. These peak positions are in agreement with previous reports.^20,35 The N₂ adsorption/desorption was carried out for POP_M–TFP in order to evaluate the permanent porosity. The N₂ sorption isotherm measured at 77 K as showed in Fig. 1d. POP_M–TFP exhibits characteristics of type-I adsorption isotherms with sharp uptake at a low pressure region indicating the microporous nature of this material. The Brunauer–Emmett–Teller (BET) surface area of POP_M–TFP was found to be 317 m² g⁻¹. The pore size distribution plot has been demonstrated in Fig. S3.^† The two sharp peaks at 1.5 and 2.5 nm are observed from the pore size distribution plot. Micropores of dimension 1.5 nm could be attributed to the porous network of the POP_M–TFP, whereas mesopores of 2.5 nm could be originated due to void spaces associated to the grain boundary.The morphology of the synthesized POP_M–TFP can be well investigated by field emission scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM) analysis respectively. FE-SEM images of POP_M–TFP at two different magnifications are shown in Fig. 2a and b. SEM images show that POP_M–TFP reveals irregular nanowires morphologies. The TEM characterization further confirms the nanowire structures morphology with porous architecture (Fig. 2c and d.). Fig. 2d represents the high-resolution TEM image of POP_M–TFP where the micropores of about 1.5 nm (white spot) are spread throughout the specimen.Open in a separate windowFig. 2(a and b) FE-SEM images of POP_M–TFP at two different magnifications. (c and d) TEM images of POP_M–TFP at two different magnifications.Considering the synthesized POP_M–TFP with 1,3,5-triazine skeleton distributed in nanopores, this may hold promising applications in electrode materials for supercapacitors. The pore channels and triazine units in POP_M–TFP could render this material able to store electric energy. The electrochemical performance of POP_M–TFP was investigated by using a typical three-electrode system in 2 M KOH aqueous electrolyte. The working electrodes were fabricated by mixing POP_M–TFP, acetylene black and binder (polyvinylidene fluoride) in a weight ratio of 80 : 10 : 10 and loaded to a piece of nickel foam. A Pt plate and Hg/HgO electrode were used as the counter electrode and reference electrode, respectively. The electrochemical charge storage activity of the POP_M–TFP was analysed by cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) in 2 M KOH electrolyte. The CV curves of POP_M–TFP at 5 mV s⁻¹, 10 mV s⁻¹, 20 mV s⁻¹, 50 mV s⁻¹, and 100 mV s⁻¹ are presented in Fig. 3a. The CV recorded with the as-prepared electrode over different scan rates shows redox peaks at ∼0.34–0.45 V during forward and backward sweeps, suggesting its pseudo capacitive nature. The redox signature is attributed to the oxidation and reduction of the triazine skeleton in the polymer. The small separation between cathodic and anodic peaks indicated that the fast electron transfer kinetics between POP_M–TFP and the electrode interface. The current plateau of CV over the increasing scan rate increased, suggesting fast accessible ions electrolyte through the pore channel of POP_M–TFP.Open in a separate windowFig. 3(a) CV curves of POP_M–TFP at different scan rates in 2 M KOH electrolyte. (b) Peak current vs. mV^1/2 plots of POP_M–TFP. (c) GCD curves of POP_M–TFP at different current densities. (d) Cycling performance of the electrochemical capacitor based on POP_M–TFP at 2 A g⁻¹.The specific capacitance of the electrode materials is estimated from the follow equation,³⁹C_sp = (∫IdV)/vmV1where I represents current, V represents the potential window (V), v indicates scan rate and m stands for the mass of active material in the electrode. The estimated specific capacitance of POP_M–TFP material was found to be 105.8 F g⁻¹ at 5 mV s⁻¹ scan rate (Fig. S4^†). With the increase of scan rate the specific capacitance was gradually decreased down. This may be due to the restriction of ion insertion into the pore channels and weak redox kinetics of POP_M–TFP at fast scan rates. The appearance of small humps in CV curves around 0.34–0.45 V can be attributed to the redox reactions of the heteroatom (N) functionalities of the POP_M–TFP and nickel foam. Additionally, the N atoms embedded in POP_M–TFP are desirable to improve the capacitance by enhancing the electrolyte solution wettability of the electrode materials.⁴⁰ At the slow scan rates, ions have sufficient time to arrive at the surface of POP_M–TFP, can be able to penetrate through channel of POP_M–TFP. Moreover, the peak current is proportional to the root scan rate over the range of 5 to 100 mV s⁻¹, implies that the redox reaction is diffusion-controlled electron-transfer process presented in Fig. 3b.⁴¹ A more detailed investigations on electronic performance for its applicability as a supercapacitor electrode material is analyzed by GCD. The GCD curves of POP_M–TFP at various current densities (0.5 to 8 A g⁻¹, Fig. 3c) corroborate with the above CV results and display clear voltage plateaus at the same voltage position. The nonlinearity of the charge–discharge curve verifies the pseudo capacitance behavior of POP_M–TFP due to faradic reaction occurs at the electrode surface. Their symmetric shapes reveal the fast reaction kinetics and high electrochemical reversibility.⁴² An almost negligible IR drop was observed in the GCD curve indicating a minute ohmic resistance and good capacitive performance. The specific capacitance of POP_M–TFP over different current densities is estimated from eqn (2),2where I is current, ΔV represents potential window (V), Δt signifies discharge time (s) and m represents the mass of active material. The highest specific capacitance of POP_M–TFP is calculated to be 130.5 F g⁻¹ at 2 A g⁻¹. The cycle performance of POP_M–TFP was evaluated by GCD test at 2 A g⁻¹ as showed in Fig. 4d. The highest specific capacitance 130.5 F g⁻¹ achieved after 130 cycling. The high specific capacitance of POP_M–TFP is attributed to better utilization of the porous structure, presence of triazine units, which could provide numerous active sites for ion transfer. It shows a slow loss of the specific capacitance, which reaches 120.2 F g⁻¹ after 1000 cycles. Long-term GCD cycling revealed a decrease of specific capacitance could be ascribed to the collapse of the electrode structures. The specific capacitances of POP_M–TFP were also calculated from GCDs and compared as showed in Fig. S5.^† The highest specific capacitance of POP_M–TFP is calculated to be 178.0 F g⁻¹ at 0.5 A g⁻¹, 137.4 F g⁻¹ at 1 A g⁻¹, 130.5 F g⁻¹ at 2 A g⁻¹, 86.4 F g⁻¹ at 4 A g⁻¹ and 76.9 F g⁻¹ at 8 A g⁻¹ respectively. With increasing the current density, the specific capacitance of POP_M–TFP tends to decrease. A slight decrease in the specific capacitance values with the increased current density is believed to be due to the hierarchical pore structure, which facilitates the smooth transfer of ions at higher current densities. Additionally, most of the active sites triazine moieties on the electrode surface are accessible to electrolyte. This material has the advantage as electrode material because of inherent stacking behavior between two adjacent layers, which can provide a nanoscale channel to the stacking direction. Owing to the presence of stacking phenomena, the presence of triazine moieties in the POP_M–TFP can expedite the ion transfer through porous channels. Extended π-conjugation and ion conduction inside the pores throughout POP_M–TFP, the redox processes arising from triazine units could be responsible for this high supercapacitor performance.Open in a separate windowFig. 4Electrochemical performance of POP_M–TFP in an asymmetry supercapacitor cell in 2 M KOH. (a) CV curves of POP_M–TFP at different scan rates in the potential window of 0–1.5 V. (b) GCD profiles at various current densities. (c) Corresponding specific capacitances of the asymmetric cell. (d) Cycling performance test of POP_M–TFP at 0.5 A g⁻¹.Furthermore, the interfacial charge transfer activity and electrocapacitive characteristics of POP_M–TFP are studied by EIS analysis. The impedance characteristic of the electrode is represented by a Nyquist plot (Fig. S6^†). From the analysis of the Nyquist plots, POP_M–TFP displays a near vertical line within the low-frequency region, indicative of a well capacitive behavior. The slope of the line at low frequency region is related to the diffusive resistivity of the electrolyte ions within the nanopores. The small semicircular shapes in the EIS plots in the high frequency could be neglected indicates a low charge transfer resistance at the electrode/electrolyte interface (inset in Fig. S3^†).⁴³ We also estimated the accessible electro-active sites of POP_M–TFP system by the method already discussed in the previous literature.^16,20 These calculations suggest the about 1.99% of the triazine moieties are accessible.To evaluate the energy and power density, the supercapacitor performance of POP_M–TFP was tested in two electrode system using 2 M KOH as electrolyte. Activated carbon and as-prepared POP_M–TFP were used as negative and positive electrodes in the asymmetric supercapacitor fabrication, respectively. The asymmetric supercapacitor was investigated in the potential window of 0 to 1.5 V at different scan rates (Fig. 4a). The current increases with increasing scan rate suggesting a good rate capability for energy storage. The CV curves and GCD curves (Fig. 4b) indicated their typical pseudo capacitive behaviour. The calculated specific capacitances of the supercapacitor at different current densities are summarized in Fig. 4c. The specific capacitance at current density of 0.2 A g⁻¹ was 91.7 F g⁻¹. The highest energy density and power density were calculated to be 25.8 W h kg⁻¹ and 727 W kg⁻¹, respectively (Fig. S7^†). The cycle life of the asymmetric supercapacitor was further investigated at 0.5 A g⁻¹ (Fig. 4d). The specific capacitance retained 72.5 after 4500 GCD cycles at current density of 0.5 A g⁻¹, demonstrating the outstanding stability of the device.In summary, by a simple solvothermal synthesis method, we have successfully synthesized a crystalline triazine containing porous organic polymer POP_M–TFP through simple condensation reaction between M and TFP using dimethyl sulfoxide solvent without any catalysts. Further, we have used POP_M–TFP as an electrode material for supercapacitor application. The electrochemical measurement of POP_M–TFP material showed well electro-chemical performance in supercapacitors. The wonderful electrochemical properties of the POP_M–TFP can be ascribed to the synergistic effect of the π-conjugated triazine contained POP_M–TFP and nanopores structure. Active sites triazine moieties which put up redox behavior distributed in the pore channels. These findings will meet the requirements like energy storage ability and help more energy efficient electrode materials in the near future.     

包裹阿霉素的高分子材料微泡声学造影剂制备及显影效果实验研究

目的探索包裹药物的微泡声学造影剂制备方法,观察其体内外显影效果。方法采用在体内能生物降解的人工合成高分子聚合物乳酸／羟基乙酸共聚物（PICA）作为成膜材料,通过双乳化法和冷冻干燥技术制备包裹阿霉素（ADM）和空气的PICA微泡声学造影剂（ADM-PICA声学造影剂）。光学显微镜进行形态学观察。体外和动物实验观察其显影效果。结果采用本法成功制备了ADM-PICA声学造影剂;光镜观察其形态规则,呈球型,大小均匀,最大粒径〈4μm;体内外显影效果好。结论通过本方法可以合成包裹水溶性药物的微泡声学造影剂,为应用超声波和微泡造影剂进行体内药物定位释放研究打下了基础。     

Synthesis of high drug loading,reactive oxygen species and esterase dual-responsive polymeric micelles for drug delivery

Stimulus-responsive, controlled-release systems are of great importance in medical science and have drawn significant research attention, leading to the development of many stimulus-responsive materials over the past few decades. However, these materials are mainly designed to respond to external stimuli and ignore the key problem of the amount of drug loading. In this study, exploiting the synergistic effect of boronic esters and N-isopropylacrylamide (NIPAM) pendant, we present a copolymer as an ROS and esterase dual-stimulus responsive drug delivery system that has a drug loading of up to 6.99 wt% and an entrapment efficiency of 76.9%. This copolymer can successfully self-assemble into polymer micelles in water with a narrow distribution. Additionally, the measured CMC hinted at the good stability of the polymeric micelles in water solution, ensuing long circulation time in the body. This strategy for increasing the drug loading on the basis of stimulus response opens up a new avenue for the development of drug delivery systems.

A novel high drug loading, controlled-release drug delivery system was constructed with dual-stimulus responsive abilities in cells.