Fabrication of Core-Shell Hydrogel Bead Based on Sodium Alginate and Chitosan for Methylene Blue Adsorption

A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.

Fabrication and Characterization of One Interpenetrating Network Hydrogel Based on Sodium Alginate and Polyvinyl Alcohol

One interpenetrating network hydrogel based on sodium alginate (SA) and polyvinyl alcohol (PVA) was synthesized by combining the raw materials of PVA and SA with the double physical crosslinking methods of freezing thawing and Ca2+ crosslinking. The PVA-SA composite hydrogel have been characterized by scanning electron microscopy for surface morphology, infrared spectroscopy for investigating the chemical interactions between PVA and SA, X-ray diffraction for studying the PVA-SA composite structure property and thermal gravimetric for understanding the PVA-SA composite thermal stability. The swelling behavior and the degradation rate of the PVA-SA composite hydrogel were studied in simulated gastrointestinal fluid. Using bovine serum albumin (BSA) and salicylic acid as the model drugs, the release behavior of the PVASA composite hydrogel on macromolecular protein drugs and small molecule drug were evaluated. The results showed that the water absorption and degradation ability of the PVA-SA composite hydrogel was much better compared to the pure SA hydrogel or pure PVA hydrogel. The hydrogel exhibited remarkable pH sensitivity and the network was stable in the simulated intestinal fluid for more than 24 h. With the advantages such as mild preparation conditions, simple method, less reagent and none severe reaction, the PVA-SA composite hydrogel is expected to be a new prosperous facile sustained drug delivery carrier.

Preparation and Properties of Polyacrylamide/Sodium Alginate Hydrogel and the Effect of Fe^(3+)Adsorption on Its Mechanical Performance

The preparation and application of functional hydrogels based on natural polysaccharides have always been a hot research topic.In this study,using acrylamide(AM)monomer,N,N'-methylene bisacrylamide(MBA)as crosslinking agent,potassium persulfate(K2S2O8)as initiator,in the presence of natural polysaccharide sodium alginate(SA),the PAM/SA hydrogel was prepared by free radical polymerization.Fourier transform infrared spectroscopy(FT-IR),swelling performance tests,scanning electron microscope(SEM),thermogravimetric analysis(TGA),UV-visible spectrophotometer,mechanical property measurements were carried out to analyze the composition,morphology,and performance of the hydrogels.The swelling behavior,dye adsorption performance,and the mechanical properties of PAM/SA hydrogels before and after Fe^(3+)adsorption were studied.The experimental results showed that the introduction of SA with 4.7%,7.8%,and 10.3%effectively improved the mechanical and dye adsorption properties of PAM composite hydrogels.The adsorption capacity of PAM/4.7%SA and PAM/10.3%SA hydrogels at equilibrium can reach 40.01 and 44.02 mg/g for methylene blue,which is higher than the value 13.58 mg/g of pure PAM hydrogel.The compressive strength of pure PAM hydrogel is 0.124 MPa.When the SA content is 4.7%,7.8%,and 10.3%,the compressive strength of the PAM/SA hydrogel was corresponding to 0.130 MPa,0.134 MPa,and 0.152 MPa,respectively.Fe^(3+)was introduced into the PAM/SA hydrogels,and PAM/SA/Fe^(3+)double-network hydrogels with excellent mechanical properties could be prepared by adjusting the SA content(4.7%,7.8%,and 10.3%),soaking time(1 h,2 h,3 h,4 h,5 h,6 h),and Fe^(3+)concentration(4.76%,7.41%,9.09%,and 13.04%).Under the same Fe^(3+)concentration of 9.09%and adsorption time of 4 h,the compressive strengths of the PAM/4.7%SA,PAM/7.8%SA,and PAM/10.3%SA hydrogels could reach 0.354 MPa,0.767 MPa,and 0.778 MPa,respectively.

Preparation and Properties of Nanocellulose/Sodium Alginate Composite Hydrogel

Cellulose nanofiber(CNF)was isolated from Okara using deep eutectic solvent(DES)with high-speed stirring.The composite hydrogels obtained by using different proportions of CNF and sodium alginate(SA)had different properties.The CNF/SA composite hydrogels were analyzed using Fourier transform infrared spectroscopy and scanning electron microscopy and tested for compression properties,rheological properties,water content,and swelling degree.Physical crosslinking between SA and Ca^(2+),and different degrees of hydrogen bond formation between SA and CNF were observed.The CNF/SA composite hydrogel have great potential as reinforcements in eco-friendly composite hydrogels for diverse applications.

Swelling Performance Studies of Acrylamide/Potassium 3-Sulfopropyl Methacrylate/Sodium Alginate/Bentonite Biohybrid Sorbent Hydrogels in Binary Mixtures of Water-Solvent

In this study, it was to investigate the swelling performance of novel biohybrid composite hydrogel sorbents containing acrylamide/potassium 3-sulfopropyl methacrylate/sodium alginate/bentonite in water and binary mixtures of water-solvent. Novel hydrogels were synthesized with free radical solution polymerization by using ammonium persulfate/N,N,N’,N’-tetramethylethylenediamine as redox initiating pair in presence of poly(ethylene glycol) diacrylate as crosslinker. Swelling experiments were performed in water and binary mixtures of water-solvent (acetone, methanol and tetrahydrofuran) at 25°C, gravimetrically. Some swelling and diffusion properties of the hydrogels were calculated and they were discussed for the biohybrid/hybrid hydrogel systems prepared under various formulations. It has been seen the lower equilibrium percentage swelling ratio values (62% - 124%) in all solvent compositions in comparison with the equilibrium percentage swelling ratio values in water (718% - 2055%). Consequently, the hydrogel systems developed in this study could serve as a potential device for water and water-solvent binary mixtures.

Studies on the PEO-PPO-PEO Block Copolymer Release from Alginate Hydrogel

Alginate hydrogel is one of the most widely used carriers for the immobilization of microbial cells. If surfactants are encapsulated with alginate hydrogel, increasing temperature or concentration can make the encapsulated surfactants aggregate and form micelle.

壳聚糖/甘油磷酸钠/海藻酸钠/益母草碱水凝胶的抗炎与促成骨作用

背景:益母草碱具有改善微循环、抗氧化、抗细胞凋亡、清除自由基、抗炎、抗纤维化等多种生物活性作用,并且可促进骨髓间充质干细胞的成骨分化,具有应用于牙周炎治疗的潜能。目的:探讨益母草碱负载于壳聚糖/甘油磷酸钠/海藻酸钠水凝胶的抗炎与促成骨作用。方法:①分别制备壳聚糖/甘油磷酸钠/海藻酸钠水凝胶(空白水凝胶)与壳聚糖/甘油磷酸钠/海藻酸钠/益母草碱水凝胶(载药水凝胶),将两种水凝胶分别培养RAW 264.7细胞、MC3T3-E1细胞,利用CCK-8实验与活/死细胞染色检测水凝胶的细胞毒性。②将RAW 264.7细胞分5组培养:空白组常规培养24 h,脂多糖组加入脂多糖,单独水凝胶组加入脂多糖与空白水凝胶,载药水凝胶组加入脂多糖与载药水凝胶,抑制剂组加入脂多糖、载药水凝胶与PI3K抑制剂LY294002,处理24 h后,利用qRT-PCR法检测炎症相关因子mRNA表达,Western Blotting检测炎症相关因子与PI3K/AKT信号通路的蛋白表达。③将MC3T3-E1细胞分4组培养:空白组不加入任何材料,单独水凝胶组加入空白水凝胶,载药水凝胶组加入载药水凝胶,抑制剂组加入载药水凝胶与PI3K抑制剂LY294002,处理7 d后,进行碱性磷酸酶染色,利用qRT-PCR检测成骨相关因子mRNA表达水平,Western Blotting检测PI3K/AKT信号通路的蛋白表达。结果与结论:①CCK-8实验与活/死细胞染色结果显示,两种水凝胶无细胞毒性作用,具有良好的细胞相容性;②与空白组相比,脂多糖组白细胞介素6、肿瘤坏死因子α、白细胞介素1β的mRNA与蛋白表达升高(P<0.05),p-AKT、p-PI3K、p-p65、p-IκBα的蛋白表达升高(P<0.05);与脂多糖组比较,载药水凝胶组上述指标的mRNA与蛋白表达均降低(P<0.05);与载药水凝胶组相比,抑制剂组上述指标的mRNA与蛋白表达均降低(P<0.05);③载药水凝胶组碱性磷酸酶活性高于空白组、单独水凝胶组、抑制剂组(P<0.05);与空白组相比,单独水凝胶组碱性磷酸酶、Runx2、骨钙素与Ⅰ型胶原的mRNA表达升高(P<0.05),p-AKT、p-PI3K的蛋白表达升高(P<0.05);与单独水凝胶组相比,载药水凝胶组上述指标的mRNA与蛋白表达均升高(P<0.05);与载药水凝胶组相比,抑制剂组上述指标的mRNA与蛋白表达均降低(P<0.05);④结果表明,壳聚糖/甘油磷酸钠/海藻酸钠/益母草碱水凝胶具有抗炎与促成骨作用,该作用可能与调控PI3K/AKT信号通路相关。

负载外泌体的可注射水凝胶修复种植体周围骨缺损

背景:大量的研究已证实,外泌体具有促进成骨与血管化的作用,但是单纯的外泌体治疗存在靶向性差、负载分子含量无法达到治疗浓度等问题。目的:将外泌体负载于可注射葡萄糖酸内酯-海藻酸钠/β-磷酸三钙-聚乙二醇水凝胶中,通过体内与体外实验观察该水凝胶在种植体周围骨缺损中的作用。方法:从骨髓间充质干细胞中提取外泌体,并将其包裹于可注射葡萄糖酸内酯-海藻酸钠/β-磷酸三钙-聚乙二醇水凝胶中。①体外实验:将负载与未负载外泌体的水凝胶分别与内皮祖细胞共培养,进行外泌体摄取实验、小管形成实验以及细胞增殖、迁移能力、成血管基因检测。②体内实验:选取雄性新西兰大白兔12只,在一侧股骨长轴制备2个标准种植体窝洞及对应的骨缺损,在近心端的窝洞内植入种植体后,在骨缺损部位植入负载外泌体的水凝胶(实验组);在远心端的种植窝洞内植入种植体后,在骨缺损部位植入未负载外泌体的水凝胶(对照组),术后3,6,9周取带种植体的骨缺损部位,进行苏木精-伊红、Masson染色,同时,术后9周时进行成骨基因与成血管基因检测。结果与结论:①体外实验:外泌体可进入内皮祖细胞中,负载外泌体水凝胶组内皮祖细胞的增殖能力、迁移能力、成血管能力及成血管基因(CD31、血管内皮生长因子及碱性成纤维细胞生长因子)表达均高于未未负载外泌体水凝胶组(P<0.05)。②体内实验:苏木精-伊红、Masson染色显示,术后3周时,两组仅见少量新生骨,材料部分降解;术后6周时,两组新生骨量增加,其中实验组可见大量的新生骨,钙盐沉积明显;术后9周时,相较于对照组,实验组可见大量粗大于成熟的骨小梁,钙盐沉积更加明显,骨小梁周围可见大量排列的成骨细胞。实验组术后9周骨缺损部位的CD31、血管内生长因子、碱性成纤维细胞生长因子、骨形态发生蛋白2、Ⅰ型胶原及骨钙素的蛋白表达均高于对照组(P<0.05)。③负载外泌体的萄糖酸内酯-海藻酸钠/β-磷酸三钙-聚乙二醇水凝胶可促进内皮祖细胞的增殖、迁移与成血管分化,促进种植体周围骨缺损的修复再生。

海藻酸钠/聚丙烯酰胺复合水凝胶的壳聚糖增韧

以天然多糖海藻酸钠(SA)、丙烯酰胺(AM)单体为基础原料构筑双网络水凝胶,引入不同含量的壳聚糖(CS),增强水凝胶的力学韧性。通过扫描电子显微镜、红外光谱、X射线衍射仪及热失重分析仪等表征水凝胶的形貌特征、网络交联结构及热学性能,分析SA/聚丙烯酰胺(PAM)水凝胶的交联机理。结果表明,水凝胶的韧性随CS含量的增加而增加,CS低含量时韧性增加由伸长能力增加引起,而高添加时则因强度伸长同步增加引起,添加10%CS的水凝胶其韧性值达到2.50×10~5 kJ/m~3,明显高于添加5%和7.5%CS的水凝胶;对水凝胶定伸长循环拉伸,其弹性回复率随所定伸长率的增加而有所降低,在25%定伸长时均高于98%,而在200%时只高于90%,其中添加10%CS的水凝胶弹性最佳,且有较强的断裂应力(0.249 MPa)和断裂伸长率(1 635.65%),在200%及以内定伸长循环拉伸时具有优异的回复能力。

可注射海藻酸钠水凝胶的制备及应用

背景:天然来源的多糖海藻酸钠具有含量高、成本低、生物相容性好、生物可降解性好等特点,在可注射型水凝胶的生产中得到了广泛应用,成为制备可注射水凝胶的理想原料之一。目的:就海藻酸钠的性质、可注射海藻酸钠水凝胶的制备及其在组织工程中的应用进展进行综述。方法:利用计算机检索Web of Science、PubMed、中国知网等数据库,中文检索词为“海藻酸钠;水凝胶;可注射”,英文检索词为“alginate;hydrogel;inject*”,检索文献时间范围为2017年6月至2022年6月。结果与结论:由于海藻酸钠来源广泛,分子链结构上存在着许多可改性基团,可用各种共价交联或非共价交联的方法合成多种性能优良的可注射型水凝胶;将其他具有生物功能的分子引入海藻酸钠水凝胶中,可以调节其功能、拓宽其应用范围。另外,由于生物相容性和生物可降解性等优良的物理化学特性,可注射型海藻酸钠水凝胶在生物医学方面有着广泛的发展潜力,海藻酸钠水凝胶在体外与各种药物、细胞、因子或其他生物作用分子均匀调配,在人体内可形成凝胶,在基因载体、细胞支架和创口修复中起着举足轻重的作用。

智能水凝胶世界

智能水凝胶是一类具有三维网络结构的高亲水性高分子聚合物材料,能快速感知和响应环境的变化。本项目以食用海带为原料提取海藻酸,利用其与不同金属离子的交联能力不同,制得具有金属离子响应能力的海藻酸水凝胶,成功用于软硬水鉴别、维生素C和金属离子检测。项目通过设计趣味实验开展梯度科普,生动阐释智能水凝胶的形成原理和应用实例。学龄前儿童和小学生可以通过简单的操作制备出五彩缤纷的凝胶球,趣味性强。中学生和社会公众可用简单的生活器具从海带中提取海藻酸并制备出水凝胶,用于软硬水的鉴别和水果中维生素C的测定,生活化与科学性相结合,激发参与者学习化学的兴趣和热情。大学生可以通过实验研究智能水凝胶的分析检测性能,结合光度法检测铁离子和维生素C的含量,培养其综合素质。项目集趣味性、生活化和科学性于一体,层次丰富、可行性高。该项目有望助力化学从实验室走入生活,服务公众;也可推动更多人了解化学、走进化学、发展化学。

纤维素/海藻酸钠/明胶复合水凝胶的制备与性能

纤维素作为一种来源丰富的天然高分子材料,具有优异的生物相容性和可降解性,但其难溶特性限制了其应用。文中采用离子液体1-烯丙基-3-甲基咪唑氯化物(AmimCl)溶解纤维素(Cel),海藻酸钠(SA)与明胶(Gel)混合水溶液作为凝固浴进行纤维素再生,进一步通过浸泡氯化钙(CaCl_(2))溶液交联海藻酸钠,制备了一种透明、高强度的复合水凝胶。分别探究了纤维素浓度(3%,4%,5%,6%,7%和8%)及不同的海藻酸钠/明胶质量比(0:10,2:8,4:6,6:4,8:2和10:0)对水凝胶性能的影响。利用傅里叶变换红外光谱、扫描电子显微镜、X射线衍射仪、紫外可见分光光度计和万能材料试验机对水凝胶进行了表征。结果表明,水凝胶中各组分之间的氢键作用及海藻酸钠与Ca^(2+)之间的离子相互作用赋予水凝胶优异的力学性能,相比于纯水作为凝固浴制备的再生纤维素水凝胶,强度提高了26.36%。随着纤维素浓度的增加,水凝胶的结晶度和网络结构的致密性增加,水凝胶的力学性能显著提升。此外,海藻酸钠/明胶的比例也对水凝胶的力学性能有显著影响,当海藻酸钠与明胶质量比为6:4时,水凝胶力学性能最好,最高达到2.349 MPa。生物降解性分析表明,水凝胶具有良好的生物降解性,在食品包装和生物医药领域具有潜在应用价值。

改性胶原复合气凝胶的制备及其对Cr(Ⅵ)的吸附性能研究

采用冷冻干燥法制备了聚多巴胺修饰MXene和氧化海藻酸钠改性胶原(MPAC)复合气凝胶作为吸附剂处理水体中的Cr(Ⅵ)。通过透射电镜(TEM)和扫描电镜(SEM)对聚多巴胺修饰MXene(MXene@PDA)和MPAC复合气凝胶进行表征,并研究了氧化海藻酸钠(OSA)用量、胶原浓度、MXene@PDA用量、溶液pH、吸附温度和吸附时间对Cr(Ⅵ)吸附性能的影响。结果表明:通过PDA成功将MXene包覆,并制备出具有三维多孔网络结构的MPAC复合气凝胶。当MPAC复合气凝胶的OSA用量为10%、胶原浓度为5mg/mL、MXene@PDA用量为60%时,对Cr(Ⅵ)的吸附性能最佳。吸附过程在60min时达到平衡,且吸附容量随着pH和温度的增加而减小。

复方四黄双水凝胶的成型工艺优化、抑菌效果和表征结构研究

目的:研究中山市中医院的中药外用制剂复方四黄外洗液的剂型改造,探讨复方中药复合水凝胶成型工艺优化。方法:采用正交试验法,以人工皮肤专用膜作为透皮试验介质,通过体外透皮试验,选取经皮渗透液中的小檗碱与黄芩苷的含量为指标;通过抑菌实验,以复方四黄双水凝胶对金黄色葡萄球菌的抑菌圈大小为指标,综合二者指标数据,对复方四黄双水凝胶的成型工艺进行优化;最后通过抑菌试验,选金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌为考察对象,对比四黄外洗液及最佳工艺四黄双水凝胶二者的抑菌效果。最后采用扫描电子显微镜观察分析双水凝胶、卡波姆、海藻酸钠的表征结构。结果:复方四黄双凝胶的最佳配方为6%海藻酸钠、0.3%卡波姆、10%丙二醇及3%氮酮。三种致病菌抑菌实验中,四黄外洗液及凝胶剂二者对金黄色葡萄球菌抑菌效果最强,前者抑菌圈直径(14.5 mm)略强于后者(13.5 mm),对大肠杆菌具有微弱抑制效果,对铜绿假单胞菌无抑制作用,二者的抑菌效果相近,双扫描电镜观察得,双凝胶具有比海藻酸钠结构排列规律更细腻的多孔结构,又有卡波的光滑和丝状体特性。结论:该成型工艺及研究方法合理,稳定可行,可为复方四黄凝胶剂的进一步研究开发提供参考,四黄外洗液及凝胶剂对金黄色葡萄球菌敏感,双凝胶拥有海藻酸钠和卡波相表征结构。

基于苯硼酸-二醇环酯的水凝胶的构建及其抗菌性能研究

银纳米粒子在抗菌方面显示出诱人的前景。然而,银纳米粒子存在一定的毒副作用,因此构建智能响应载体体系有望实现银纳米粒子按需释放。本文通过海藻酸钠还原硝酸银制备海藻酸钠功能化银纳米粒子,并且通过调节反应时间,反应温度,硝酸银的浓度以及海藻酸钠的浓度来筛选银纳米粒子。同时,通过酰胺化反应将苯硼酸修饰到海藻酸钠上,构建苯硼酸功能化海藻酸钠。将苯硼酸功能化海藻酸钠和海藻酸钠功能化银纳米粒子复合,构建基于苯硼酸-二醇环酯的糖敏感水凝胶。通过体外抗菌实验证实,该水凝胶具有葡萄糖响应性的按需抗菌的特性。

载雷奈酸锶海藻酸钠/胶原水凝胶促进骨性关节炎骨缺损的修复

背景:软骨退行性变和软骨下骨损伤是骨性关节炎的主要病理特征,根据这一病理特征进行局部调控将是骨性关节炎治疗的有前景改进方案。目的:设计并研究一种可注射载雷奈酸锶药物递送系统,观察其在骨性关节炎局部促进软骨修复并改善软骨下骨结构的治疗效果。方法:①体外实验:将雷奈酸锶搭载于海藻酸钠/胶原水凝胶基质中构建原位药物递送系统,表征该系统的体外缓释性能。将载雷奈酸锶海藻酸钠/胶原水凝胶(实验组)、海藻酸钠/胶原水凝胶(对照组)分别与骨髓间充质干细胞共培养,以单独培养的细胞为空白对照组,检测细胞增殖活性;在成软骨诱导分化后,分别进行番红O染色、阿利新蓝染色及RT-qPCR检测。将两种水凝胶分别与成骨细胞共培养,以单独培养的细胞为空白对照组,进行免疫荧光染色及RT-qPCR检测。②体内实验:取18只成年SD大鼠,通过内侧半月板切除的方法建立右后侧膝骨性关节炎模型,造模后1周,采用随机数字表法分3组处理:空白组不进行任何处理,对照组膝关节腔内注射海藻酸钠/胶原水凝胶,实验组右膝关节腔内注射载雷奈酸锶海藻酸钠/胶原水凝胶,每组6只。造模后第6周取材,分别进行Micro-CT扫描、苏木精-伊红染色、番红O染色及免疫荧光染色。结果与结论:①体外实验:载雷奈酸锶海藻酸钠/胶原水凝胶具有疏松多孔的微观结构,可持续释放雷奈酸锶,至21 d时累计释放量(60.89±0.58)%。骨髓间充质干细胞活死染色显示,两种水凝胶均具有良好的细胞相容性。CCK-8检测显示,载雷奈酸锶海藻酸钠/胶原水凝胶可促进骨髓间充质干细胞的增殖;番红O染色、阿利新蓝染色、免疫荧光染色及RT-qPCR检测显示,载雷奈酸锶海藻酸钠/胶原水凝胶可促进骨髓间充质干细胞的成软骨分化。免疫荧光染色及RT-qPCR检测显示,载雷奈酸锶海藻酸钠/胶原水凝胶可通过增加骨保护素/核因子κB受体活化因子配体比值而降低骨吸收活性。②体内实验:Micro-CT扫描显示,与空白组、对照组比较,实验组大鼠膝关节软骨下骨骨体积分数与骨密度升高(P<0.05,P<0.01)。组织学染色显示,与空白组、对照组比较,实验组大鼠膝关节软骨损伤明显减轻,促进Ⅱ型胶原蛋白的表达、抑制基质金属蛋白酶2蛋白的表达(P<0.05,P<0.01)。③结果表明:载雷奈酸锶海藻酸钠/胶原水凝胶能促进骨性关节炎软骨缺损的修复、重建软骨和软骨下骨之间的复杂界面。

Smart superabsorbent alginate/carboxymethyl chitosan composite hydrogel beads as efficient biosorbents for methylene blue dye removal

The presence of toxic dyes in the aqueous medium has threatened environmental safety, and thereby re- moving them from wastewater in an efficient way is highly desired. Herein, the efficient biosorbents were successfully fabricated via a facile physical gelation process of sodium alginate (SA) and carboxymethyl chitosan (CMCTS) in an acidic aqueous solution. The as-prepared hydrogel beads not only displayed water superabsorbent properties and pH-responsive swelling characters but also exhibited excellent methylene blue (MB) adsorption capacity removal efficiency with experimental maximum MB adsorption capacity of 2518 and 1005 mg g -1 , which are comparable with most reported lignocellulosic and alginate-based hydrogels. The MB adsorption process fitted well in different kinetic and isotherm models and became more heterogeneous in concentrated MB solutions as verified by principal component analysis results. The adsorption mechanism was proposed, and the high dye absorbency was attributed to the strong electro- static forces between adsorbents and adsorbates. Our current study provides a promising and sustainable composite hydrogels platform targeted to dye decontamination.

大豆种皮纳米纤维素水凝胶制备工艺优化及性能分析

采用Box-Behnken响应面法优化大豆种皮纳米纤维素水凝胶的最佳制备工艺,并表征其结构和性能。在单因素实验基础上,以纳米纤维素水凝胶的最大应力为考察指标,选取3因素3水平的响应面法优化制备工艺;采用傅里叶红外变换光谱、X射线衍射、扫描电子显微镜、紫外分光光度计等对其结构和性能进行表征。最佳纳米纤维素水凝胶的制备工艺为:凝胶温度191℃、冷冻时间102 h、无水CaCl_(2)浓度7%,在此条件下纳米纤维素水凝胶的最大应力的实际值为84.11 kPa,与预测值83.7 kPa相近。大豆种皮纳米纤维素/海藻酸钠/无水氯化钙(SCNFs/SA/CaCl_(2))水凝胶内部呈现均匀的三维网状结构,并且表现出良好的拉伸性(断裂伸长率220%)、良好的机械强度(83.97 kPa)、透光率(82%)和导电性(1.58 S/cm),并且水凝胶经过5次循环拉伸仍具有良好的机械强度,表现出良好的抗疲劳性,增加了水凝胶的使用寿命。本文为制备一种强韧、透明、导电和抗疲劳的纳米纤维素水凝胶提供了一种新的方法。

海藻酸钠复合水凝胶的制备及在中药挥发油缓释领域的应用进展

海藻酸钠由于来源广泛、价格低廉,分子中含有大量的羧基、羟基,在较为温和的环境中,能够迅速地构成三维网状结构的水凝胶而受到了人们的广泛关注,但单一的海藻酸钠水凝胶力学性能和力学强度较差。当与其他物质形成复合水凝胶后则因其优异的生物相容性、生物降解性和pH敏感性被广泛应用于敏感药物的缓控释领域。文中主要介绍了海藻酸钠复合水凝胶的相应制备方法和性能,以及在中药挥发油缓释领域的应用进展,同时指出了海藻酸钠复合水凝胶在中药挥发油缓释领域存在的问题及未来主要的研究方向。

功能化海藻酸钠水凝胶促骨髓间充质干细胞增殖、成软骨向分化的研究

目的 探讨RGD多肽修饰的酰化海藻酸钠水凝胶基质能否调节骨髓间充质干细胞(BMSCs)的行为活性并促进其成软骨向分化。方法 RGD多肽通过迈克尔加成反应接枝于酰化的海藻酸钠。光引发剂与酰化海藻酸钠的双键在紫外光照射下交联成胶。通过CCK-8实验、扫描电镜、细胞骨架染色、免疫荧光染色、Western blot和RT-PCR评价功能化水凝胶对BMSCs增殖、成软骨向分化的作用。结果 相较于未接枝组,RGD多肽修饰的酰化海藻酸钠水凝胶可以促进基质内BMSCs形态延展并出现聚集。接枝RGD多肽后,无论在二维还是三维培养体系中,BMSCs的增殖活性明显高于未接枝组。经过成软骨诱导培养后,RGD多肽修饰的酰化海藻酸钠水凝胶可以更好地促进BMSCs凝聚和成软骨向分化。结论 接枝RGD多肽的酰化海藻酸钠水凝胶可以更好地促进BMSCs增殖、成软骨向分化。