透明温敏性羧甲基壳聚糖配合物凝胶的制备

利用羧甲基壳聚糖(CM CS)与甘油磷酸盐(GP)互配,制备了在25℃~70℃具有响应功能的透明水凝胶体系。探讨了CM CS羧甲基取代度(D S)、GP的浓度和盐酸的浓度等因素对凝胶性能和透明度的影响。结果表明,D S介于0.3~0.6的CM CS与GP互配,可以得到温敏性透明状水凝胶,其透明度随着D S的增大而递增;随环境温度的升高和恒温时间的延长,其透明度降低;随着D S的增大,环境温度和恒温时间对配合物凝胶透明度的影响减弱。     

壳聚糖-甘油磷酸钠温敏凝胶的制备与表征

制备了壳聚糖-甘油磷酸钠温敏凝胶,讨论了壳聚糖的脱乙酰度,浓度和β-GP的浓度等工艺参数对温敏凝胶理化性能的影响,通过X射线,红外光谱和扫描电镜等测试手段表征了温敏凝胶材料的成分组成和微观结构,讨论了该体系的自凝化机理.     

壳聚糖镓配合物的制备及抗菌性能研究

通过金属鳌合法制备了壳聚糖镓配合物,运用有机元素分析及电感耦合等离子发射光谱(ICP)法测定了 C、H、O、N等元素比重,并运用粘度法、扫描电子显微镜(SEM)、傅里叶红外光谱分析(FTIR)、热失重分析(TGA)、X射线衍射(XRD)对壳聚糖镓配合物进行了表征,考察了壳聚糖镓配合物的抗菌性能.结果表明,在55℃水浴中...     

壳聚糖/Fmoc-FF自组装水凝胶的制备及其流变性研究

九芴甲氧羰基-二苯丙氨酸(Fmoc-FF)自组装水凝胶作为一种新型肽类材料,存在许多潜在应用,但因其自组装可调控性差,对酶稳定性差等特点严重制约了其在生物、医学等领域的应用。壳聚糖具有良好的成膜性、低毒性、生物相容性、体内可降解性以及一定的抗菌抗肿瘤等优异性能,广泛应用于水凝胶的制备。本研究以壳聚糖作为Fmoc-FF自组装的调控剂制备了自组装复合水凝胶,利用红外光谱(FT-IR)对其分子结构进行表征,扫描电镜(SEM)观察其微观形貌,旋转流变仪对其流变性能进行评价。结果表明,在研究范围内,体系中壳聚糖浓度为40mg/mL时,复合水凝胶形成最快,结构稳定性最好,对于Fmoc-FF自组装水凝胶的应用有了进一步的进展。     

壳聚糖/聚乙烯醇水凝胶的硬度研究

探讨了壳聚糖/聚乙烯醇水凝胶的制备方法,研究了聚乙烯醇与壳聚糖质量比、溶剂醋酸溶液体积、交联剂戊二醛浓度等对水凝胶硬度的影响.正交实验结果表明当聚乙烯醇与壳聚糖质量比为6、溶剂醋酸体积为80mL、交联剂戊二醛浓度为0.426mol/L时,凝胶硬度为132.643kPa.凝胶硬度随着聚乙烯醇与壳聚糖质量比和交联剂戊二醛浓度的增大而增大,随着溶剂醋酸溶液体积的增加而减小,随着凝胶温度的升高先增大后减小,壳聚糖/聚乙烯醇凝胶硬度随着放置时间的延长而逐渐增大,PVA-124与壳聚糖制备的凝胶硬度最大.     

聚乙烯醇/壳聚糖凝胶的制备及性能研究

通过壳聚糖与聚乙烯醇共混,用戊二醛作交联剂制备了聚乙烯醇/壳聚糖凝胶,并考察了不同质量比、交联剂浓度以及温度对凝胶的硬度和溶胀性能的影响.结果表明:随着聚乙烯醇与壳聚糖的质量比、交联剂浓度的增大,凝胶的硬度增大而溶胀性能减小.随着成胶温度的升高,凝胶的硬度和溶胀性能均先增大后减小.在此基础上,通过两种方法将银粒子分散到凝胶中:(1)在成胶过程中加入硝酸银,成胶后用还原剂硼氢化钠还原;(2)制成凝胶以后,将凝胶依次浸泡在硝酸银和硼氢化钠溶液中.通过XRD和SEM表征,说明两种方法均能将银粒子均匀分散在凝胶中,从而表明壳聚糖凝胶可以作为金属纳米粒子的载体,这将在生物医学方面具有良好的应用前景.     

壳聚糖即型水凝胶的体内代谢研究

壳聚糖及其衍生物作为生物医用高分子材料已被广泛应用,研究其在动物体内的吸收降解是此类生物医用材料应用于人体的必要前提。壳聚糖即型水凝胶是以壳聚糖为主要材料制备的新型生物医用材料,可在体内降解吸收。以异硫氰酸酯(FITC)标记法研究了该水凝胶经大鼠腹腔注射后的吸收、降解和分布,为该水凝胶应用于体内提供实验数据。实验结果显示,壳聚糖即型水凝胶经大鼠腹腔注射后能够较快被腹腔吸收,并经血液转运至各代谢器官,在肝脏内有一过性的积累,在其它脏器内分布较少,其主要代谢途径是血液→肝脏→肾脏→尿液,在17d时,通过此途径排出的量占注射量的88%,排出体外的分子量均小于10kD。     

树枝状铱配合物的合成与发光性能研究

设计、合成了3个新颖的环金属配体1-苯甲基-2-苯基-苯并咪唑[BPBM]、1-(4-甲氧基-苯甲基)-2-(4-甲氧基-苯基)-苯并咪唑[MBMPB]和1-(4-N,N-二甲基-苯甲基)-2-(4-N,N-二甲基-苯基)-苯并咪唑[DBPA],并以乙酰丙酮(Hacac)为辅助配体合成了3个高效绿色铱配合物Ir(BPBM)2(acac)(1)、Ir(MBMPB)2(acac)(2)和Ir(DPBA)2(acac)(3)。由于在配体上引入了大的非平面取代基,分子间的浓度猝灭被有效地抑制;室温下,3个配合物在纯固态下都展示了明亮的绿光发射,且详细研究了它们的热稳定性和光物理性能。结果表明:该类配合物具有短的激发态寿命和高的光致磷光效率,在制备非掺杂有机电致发光器件方面具有潜在的应用前景。     

羧甲基纤维素/壳聚糖/膨润土凝胶的制备及吸附性能研究

以壳聚糖、膨润土和羧甲基纤维素为原料制备了羧甲基纤维素/壳聚糖/膨润土凝胶吸附剂。通过红外光谱和扫描电镜对凝胶结构进行了表征,并考察了其吸附性能。结果表明凝胶各物质之间形成了结合。凝胶吸附剂对溶液中的苯酚具有很好的吸附效果,在适当条件下对苯酚的去除率可以达到92.6%以上。再生实验表明凝胶可回收利用。     

聚乙烯醇/壳聚糖/明胶水凝胶的合成及其对苯酚的吸附研究

以聚乙烯醇(PVA)、壳聚糖和明胶为原料、戊二醛为交联剂,在酸性溶液中通过共混交联反应合成了聚乙烯醇/壳聚糖/明胶水凝胶,单因素法讨论了影响水凝胶性能的因素如:反应物质量比、交联剂用量、反应温度、反应时间等聚乙烯醇/壳聚糖/明胶水凝胶,对不同浓度苯酚溶液的吸附研究.研究结果表明聚乙烯醇/壳聚糖/明胶水凝胶对苯酚有较好的吸附性能.     

Preparation,fabrication and biocompatibility of novel injectable temperature-sensitive chitosan/glycerophosphate/collagen hydrogels

This paper introduces a novel type of injectable temperature-sensitive chitosan/glycerophosphate/collagen (C/GP/Co) hydrogel that possesses great biocompatibility for the culture of adipose tissue-derived stem cells. The C/GP/Co hydrogel is prepared by mixing 2.2% (v/v) chitosan with 50% (w/w) β-glycerophosphate at different proportions and afterwards adding 2 mg/ml of collagen. The gelation time of the prepared solution at 37°C was found to be of around 12 min. The inner structure of the hydrogel presented a porous spongy structure, as observed by scanning electron microscopy. Moreover, the osmolality of the medium in contact with the hydrogel was in the range of 310–330 mmol kg⁻¹. These analyses have shown that the C/GP/Co hydrogels are structurally feasible for cell culture, while their biocompatibility was further examined. Human adipose tissue-derived stem cells (ADSCs) were seeded into the developed C/GP and C/GP/Co hydrogels (The ratios of C/GP and C/GP/Co were 5:1 and 5:1:6, respectively), and the cellular growth was periodically observed under an inverted microscope. The proliferation of ADSCs was detected using cck-8 kits, while cell apoptosis was determined by a Live/Dead Viability/Cytotoxicity kit. After 7 days of culture, cells within the C/GP/Co hydrogels displayed a typical adherent cell morphology and good proliferation with very high cellular viability. It was thus demonstrated that the novel C/GP/Co hydrogel herein described possess excellent cellular compatibility, representing a new alternative as a scaffold for tissue engineering, with the added advantage of being a gel at the body’s temperature that turns liquid at room temperature.     

纳米SiO2增强聚乙烯醇缩乙醛凝胶的温敏性研究

以正硅酸乙酯(TEOS)前驱体,采用溶胶-凝胶法向部分缩醛的聚乙烯醇(APVA)水溶液中引入二氧化硅(SiC2)粒子,再通过冷冻/解冻法制备了温敏性聚乙烯醇缩乙醛(APVA)/二氧化硅(SiO2)复合凝胶.用扫描电镜、红外光谱和力学性能分析仪对产物的结构、微观形貌和力学性能进行了表征,并对其温敏性的影响因素进行了研究....     

Preparation and properties of an injectable thermo-sensitive double crosslinking hydrogel based on thiolated chitosan/beta-glycerophosphate

An injectable thermo-sensitive double crosslinking hydrogel based on thiolated chitosan (CS-TGA)/beta-glycerophosphate (β-GP) was prepared by combining physical and chemical crosslinking. The effect of the concentrations of CS-TGA and β-GP on gelation temperature of CS-TGA-GP hydrogel was investigated. The gelation and mechanical properties of CS-TGA-GP in situ gel system were studied by oscillatory rheology and unconfined compression testing. By the physical interaction of CS-TGA and β-GP, CS-TGA-GP system undergoes a fast gelation at body temperature within 2 min. In addition, CS-TGA-GP hydrogel contains a low concentration of β-GP, which significantly decreases the toxicity of the gel. Owing to the chemical crosslinking of disulfide bonds, the gel is durable and possesses high-mechanical strength without introducing any potential cytotoxicity. The integrity of CS-TGA-GP hydrogel maintains for more than 30 days both in vitro and in vivo, and the interior morphology visualized by scanning electron microscopy reveals that the gel has interconnected porous network structure. In vitro release behavior of protein from CS-TGA-GP hydrogel was investigated using BSA as model protein. There is a sustained protein release from the gel without any initial burst. In vitro cytotoxicity, hemolysis, and histopathological analysis reveal that the gel is biocompatible. These features indicate that CS-TGA-GP hydrogel is a promising candidate for injectable protein delivery system and biomedical applications.     

Hydroxybutyl chitosan thermo-sensitive hydrogel: a potential drug delivery system

Drug delivery mediated by hydrogel has shown great promise in controlled drug release field. We report here the development of a hydroxybutyl chitosan (HBC) thermo-sensitive gel to deliver doxorubicine hydrochloride (DOX·HCl) for cancer treatment. Concentrated HBC aqueous solution could transform into hydrogel within 30 s after injection under physiological temperature in non-chemical fashion. The properties of the HBC gels including chemical structure, surface morphology, and rheologic properties were studied. Gelation temperature and gelation time of HBC could be adjusted by HBC concentrations. The gel erosion rate in vivo was faster than solubilization rate in vitro. The mild inflammatory response caused by implantation of the hydrogel was acceptable. The DOX·HCl (1 mg/ml) loaded HBC gels displayed slow release rates that were independent of the HBC concentration, and significantly reduced viability of 4T-1 cells compared with the HBC gels after 1 day incubation. These results indicate that thermo-sensitive HBC hydrogels have promising potential as an injectable drug carrier for pharmaceutical applications.     

Superporous polyacrylate/chitosan IPN hydrogels for protein delivery

In this study, poly(acrylamide), poly(AAm), and poly(acrylamide-co-acrylic acid), poly(AAm-co-AA) superporous hydrogels (SPHs) were synthesized by radical polymerization in the presence of gas blowing agent, sodium bicarbonate. In addition, ionically crosslinked chitosan (CH) superporous hydrogels were synthesized to form interpenetrating superporous hydrogels, i.e. poly(AAm)-CH and poly(AAm-co-AA)-CH SPH-IPNs. The hydrogels have a structure of interconnected pores with pore sizes of approximately 100-150 μm. Although the extent of swelling increased when AA were incorporated to the poly(AAm) structure, the time to reach the equilibrium swelling (~30 s) was not affected so much. In the presence of chitosan network mechanical properties significantly improved when compared with SPHs, however, equilibrium swelling time (~30 min) was prolonged significantly as due to the lower porosities and pore sizes of SPH-IPNs than that of SPHs. Model protein bovine serum albumin (BSA) was loaded into SPHs and SPH-IPNs by solvent sorption in very short time (<1 h) and very high capacities (~30-300 mg BSA/g dry gel) when compared to conventional hydrogels. BSA release profiles from SPHs and SPH-IPNs were characterized by an initial burst of protein during the first 20 min followed by a completed release within 1 h. However, total releasable amount of BSA from SPH-IPNs was lower than that of SPHs as due to the electrostatic interactions between chitosan and BSA.     

D-萘普生温敏分子印迹凝胶的制备及吸附性能研究

采用热聚合方法,以D-萘普生(D-Npx)为模板分子,N-异丙基丙烯酰胺(NIPAAm)为功能单体,N,N’-亚甲基双丙烯酰胺(MBAA)和二甲基丙烯酸乙二醇酯(EGDMA)分别为交联剂,制备了一种温敏DNpx分子印迹凝胶(MIH),研究了凝胶的温敏性以及交联剂的种类和浓度对凝胶结构和分离性能等的影响。研究结果表明,随着MBAA含量的增加,MIH的平衡溶胀率降低,且MIH对D-Npx的吸附和脱附量先增加后逐渐减少;随EGDMA含量的增加,MIH对D-Npx的吸附和脱附量逐渐增大。MIH具有明显的温敏性,MBAA含量对凝胶的最低临界溶解温度(LCST)几乎没有影响,凝胶表现出较好的溶胀-退胀性,脱附率可达90%以上。     

基于溶剂置换的壳聚糖水凝胶的构建及力学性能研究

采用碱液置换丙二醇的方法制备物理交联壳聚糖水凝胶,研究了碱液浓度及三聚磷酸钠（TPP）离子交联预处理对凝胶结构和力学性能的影响。SEM观察结果表明水凝胶微观结构为富有纳米纤维的三维网络结构,且离子交联预处理在一定程度上会影响水凝胶内部结构的形成。无侧限压缩测试和动态力学分析（DMA）结果显示,未经离子交联的水凝胶在NaOH溶液浓度≤4mol/L时,力学性能随碱溶液浓度增大而增加,在NaOH溶液浓度为4mol/L时获得最优的力学性能;TPP交联后再经NaOH溶液处理的水凝胶其力学性能有所下降,当NaOH溶液浓度为2mol/L时可获得最优的力学性能。采用的2种物理交联方式在水凝胶形成过程中具有竞争关系。     

壳聚糖水凝胶的制备及性能研究

以壳聚糖为原料,用戊二醛作为交联剂,在醋酸溶液中合成壳聚糖水凝胶。用正交实验优化了制备壳聚糖水凝胶的工艺条件,实验结果表明:当壳聚糖浓度为3%、戊二醛浓度为3%、凝胶温度为55℃时制得的水凝胶硬度最大;当壳聚糖浓度为2%、戊二醛浓度为1%、凝胶温度为45℃时,制得的水凝胶溶胀度最大。壳聚糖水凝胶具有良好的生物相容性。     

空心羟基磷灰石亚微球/壳聚糖可注射水凝胶的制备及表征

采用W/O/W复乳法制备空心羟基磷灰石(HAP)亚微球,将空心HAP亚微球均匀分布在壳聚糖/甘油磷酸钠(CS/GP)体系中制备可注射HAP/CS水凝胶(gel 1),同时制备可注射CS水凝胶(gel 2).用X射线衍射仪、场发射透射电镜、红外光谱、扫描电镜对空心HAP亚微球和水凝胶进行了表征,并比较分析了两种溶胶的成胶...     

Cytocompatibility evaluation in cell-culture systems of chemically crosslinked chitosan/PVA hydrogels

In the present study we report the preparation, characterization and cytocompatibility of novel polymeric systems based on blends of chitosan and poly(vinyl alcohol) (PVA) and chemically crosslinked by glutaraldehyde for biomedical applications. The structure of the hydrogels was characterized through Fourier Transform Infrared spectroscopy (FTIR) and their swelling behavior was investigated as preliminary in vitro test. Bioactivity, cytotoxicity and cell viability were assessed via MTT assay with 2 cell cultures and cell spreading-adhesion analysis. Moreover, the cell viability and potential biocompatibility were assessed by the secretion of nitric oxide by activated macrophages with gamma interferon (IFN-γ) cytokine and lipopolysaccharide (LPS). It was found that by increasing the chitosan to PVA ratio the swelling behavior was significantly altered. In addition, all tested hydrogels have clearly presented adequate cell viability, non-toxicity and suitable properties which can be tailored for prospective use in tissue engineering.