水凝胶微流控芯片的快速加工及在细胞培养检测中的应用

采用具有紫外光聚合性能的聚乙二醇(PEG)基水凝胶材料, 通过紫外光聚合作用快速加工双层水凝胶微流控芯片, 并验证了其对肿瘤细胞代谢液进行检测的可行性. 与传统微流控芯片材料相比, 该水凝胶芯片材料具有更好的生物相容性及可操控性, 可直接加工成形, 在生物学领域特别是细胞培养过程控制方面具有良好的应用前景. 实验结果表明, 该水凝胶微流控芯片可在微尺度空间有效模拟细胞生长环境, 并实现对细胞连续捕获后的原位培养. 将该芯片与卟啉可视阵列传感器系统结合, 经代谢特征分析可有效区分不同种类肿瘤细胞, 实现芯片细胞培养平台上的细胞代谢指纹快速可视化传感检测.     

新型纳米荧光探针在微流控细菌芯片检测中的应用

微流控芯片分析技术可以集成不同的生物化学分析功能单元,广泛应用于生化分析领域,在细菌检测方面具有传统检测方法不可比拟的优越性。近来年,在微流控细菌芯片中引入高荧光强度、低背景荧光干扰和高选择性的纳米荧光探针为实现细菌高效检测分析提供了新的研究途径和技术手段。本文通过对细菌检测中的几类新型荧光标记探针的介绍和比较,分析其荧光效应和应用特点,尤其是在细菌检测中的应用特性,重点综述了新型高效的纳米荧光探针与微流控细菌芯片分析方法和技术结合,实现微尺度空间和荧光检测模式下的细菌高效检测。     

导电水凝胶基柔性电子传感系统——柔性电子创新实验设计

导电水凝胶兼具生物医用材料和导电材料特征,可应用于医疗康复、运动监测和人机交互等领域。为提高柔性电子学专业本科生的创新意识与实验技能,本实验设计了一种纳米凝胶材料交联的导电水凝胶,通过探索加聚型水凝胶聚合过程中引发剂浓度和交联机制,阐明材料结构组分对水凝胶基柔性电子器件使用耐久性能及传感性能的影响。通过创新实验设计,柔性电子学专业本科生可以学习到高分子乳液聚合、水凝胶制备以及应力应变传感性能表征等知识点,深入理解交联剂结构设计对材料功能性的影响。此外,本实验还设计了基于水凝胶柔性电子传感器的可穿戴传感系统,通过集成可控制小车移动的智能手套,以及用于控制电脑游戏的水凝胶控制器,将前沿科研与本科实验教学任务紧密结合,有利于激发柔性电子、材料、电子信息等专业本科生对于科研的兴趣和创新探索的科研精神。     

水凝胶pH传感器新技术的研究进展

pH值是许多领域的重要监测指标之一.许多化工生产中需要精确、 实时地监测pH值,生物化学和生物医学领域对微环境的pH值监测有较大的需求.水凝胶pH传感器是一种将响应型水凝胶与传感器结合的新型pH值监测技术,由于其具有微型化和智能性等特点,可应用于化学化工、生物医疗、环境检测等领域.本文综述了近年来水凝胶pH传感技术的研...     

酶促水凝胶的合成及生物传感应用研究进展

近年来,聚合物基水凝胶材料已经成为一种独特的修饰材料,为新型生物传感器的设计提供了新思路.酶具有特异性高、毒性低、催化效率高等良好特性,已被用于催化聚合各种新型水凝胶.本文综述了几种酶促水凝胶的合成方法及其在细胞代谢物、组织工程、伤口愈合和癌症监测等方面的潜在应用,并对基于酶促水凝胶反应的生物传感器的制备与应用进行了总...     

微流控SERS芯片的设计制备及其在细菌检测中的应用

微流控芯片分析平台与表面增强拉曼散射(Surface enhanced Raman scattering,SERS)光谱分析方法结合,充分利用了SERS法所具备的样品前处理简便、检测无损、成分辨识度高以及适宜水环境检测等优点,在生化分析检测领域备受关注。微流控SERS芯片设计及芯片上SERS增强基质的制备是构建微流控SERS芯片分析方法和系统的关键,也是提高检测灵敏度和可重复性的核心问题。该文在介绍微流控SERS芯片的基本构型和功能的基础上,重点综述了微流控SERS芯片上SERS基质的制备方法及其测试效果。基于微电子机械系统(Micro-Electro-mechanical-System,MEMS)加工技术制备的SERS基质,具有纳米粒径有序可控、便于集成制备但增强基质材料种类有限的特点;基于化学沉积和自组装等理化方法制备的SERS基质具有基质种类易拓展、成本低、与微流控通道结合方法灵活等特点。在这些基础上构建的微流控SERS芯片及其分析测试方法和系统,在细菌等许多生化检测领域显示出强大的发展潜力。     

写字机器人绘制纸基微流控芯片便携检测Ca2+

纸基微流控芯片是一种纸质基底芯片,具有性能优良、价格低廉的优势,然而其制备技术多依赖专业昂贵的设备,限制了纸基微流控芯片的发展。该文采用成本低廉的家用写字机器人,将具有敏感特性的智能水凝胶绘制在纸质基底材料上,得到具有水凝胶阀门的纸基微流控芯片。以Ca2+为模型靶标,该纸基微流控芯片能实现不同浓度（0.1 ~ 50 mmol/L）Ca2+溶液的裸眼定量检测,并具有很好的易用性和重现性。同时采用ILX506 CCD传感器制作纸基微流控芯片的数字显示设备,以实现芯片测量结果的自动读取功能。该方法能快速便捷、低成本地制备多条纸基微流控芯片,为其普适化制备提供了新的研究思路,在发展中地区具有良好的推广前景。     

聚2-丙烯酰胺-2-甲基丙磺酸/糊化淀粉复合水凝胶的制备和应用研究

水凝胶是一种由亲水聚合物三维网络结构和大量水组成的新型软物质材料，其优异的生物相容性、性能可调节性和环境适应性，使其在仿生智能材料、生物医学、柔性传感和能源管理等领域有着巨大的应用潜力。然而水凝胶内部存在大量水，具有较低的力学性能，强度差、模量低，且表面湿滑，难以与基体形成有效粘附，这些都限制了水凝胶在软物质材料中的应用。在此，以糊化淀粉与聚2-丙烯酰胺-2-甲基丙磺酸水凝胶复合，制备了一种强韧导电水凝胶。当淀粉的添加量为4%时，所得复合水凝胶的拉伸强度从0.11 MPa提高到0.27 MPa,模量从15 kPa提升到35 kPa,断裂韧性从51 kJ·m^-2提升到210 kJ·m^-2,粘附性能提升幅度接近100%,且具有良好的导电传感能力(3.6 mS·cm^-1),在柔性传感领域具有较好的应用前景，这为用于柔性传感的软物质材料设计提供了思路。     

DNA水凝胶在生物传感中的应用和发展

脱氧核糖核酸(DNA)是一种重要的生物分子,具有许多独特的性质如:信息传递、分子识别、可编辑等。DNA水凝胶同时具有DNA分子和水凝胶材料的优势,并且可以引入其他纳米材料获得多功能杂化水凝胶。相比于传统水凝胶,DNA水凝胶具有良好的特异识别能力以及可以按需设计的性质,从而被广泛应用于生物传感领域。本文围绕DNA水凝胶的合成、响应机制以及在传感领域的应用进行综述。按照不同的合成方法可分为线性DNA链缠绕水凝胶、枝状DNA自组装水凝胶、杂合DNA水凝胶。根据传感机制的不同又可以分为包埋封装法和非包埋封装法,包埋封装发法又分为:酶的包埋释放、抗原-抗体的包埋释放、纳米材料的包埋释放。本文总结了近几年DNA水凝胶在重金属离子检测、核酸检测、葡萄糖检测、蛋白质和代谢小分子检测,以及细胞检测等热门领域的研究情况,最后对其未来的发展进行了展望。     

亲和型生物传感器在生物医学上的应用进展

近年来,生物传感器与纳米技术、流动注射和微流控等新技术的结合,获得了蓬勃而迅速的发展。 亲和型生物传感器是基于生物分子之间的特异的亲和性,即生物活性物质对底物的亲和与键合而建立起来的一种新型传感装置。 它具有特异性好、灵敏度高、成本低、能在复杂的体系中进行在线连续监测等优点,进而在生物医学领域,对生物医学标记物、核酸、蛋白质、病毒、细菌及毒素的检测、药物作用机理的研究、临床用药筛选等方面有着广泛的应用。 本文从光学、电化学、石英晶体微天平传感、表面等离子体共振等几个方面对近年来亲和型生物传感器,特别是用于检测肿瘤标记物的免疫传感器和基于核酸适体的生物传感器在生物医学领域的测定原理和应用现状进行了评述,并对其发展趋势进行了展望。     

Antibacterial,Adhesive, and Conductive Hydrogel for Diabetic Wound Healing

Diabetic mellitus is one of the leading causes of chronic wounds and remains a challenging issue to be resolved. Herein, a hydrogel with conformal tissue adhesivity, skin-like conductivity, robust mechanical characteristics, as well as active antibacterial function is developed. In this hydrogel, silver nanoparticles decorated polypyrrole nanotubes (AgPPy) and cobalt ions (Co²⁺) are introduced into an in situ polymerized poly(acrylic acid) (PAA) and branched poly(ethylenimine) (PEI) network (PPCA hydrogel). The PPCA hydrogel provides active antibacterial function through synergic effects from protonated PEI and AgPPy nanotubes, with a tissue-like mechanical property (≈16.8 ± 4.5 kPa) and skin-like electrical conductivity (≈0.048 S m⁻¹). The tensile and shear adhesive strength (≈15.88 and ≈12.76 kPa, respectively) of the PPCA hydrogel is about two- to threefold better than that of fibrin glue. In vitro studies show the PPCA hydrogel is highly effective against both gram-positive and gram-negative bacteria. In vivo results demonstrate that the PPCA hydrogel promotes diabetic wounds with accelerated healing, with notable inflammatory reduction and prominent angiogenesis regeneration. These results suggest the PPCA hydrogel provide a promising approach to promote diabetic wound healing.     

Synthesis and characteristic of the thermo- and pH-sensitive hydrogel and microporous hydrogel induced by the NP-10 aqueous two-phase system

A series of novel thermo- and pH-sensitive (NP10-AA TPS) hydrogels and microporous (NP10-AA MP) hydrogels, inducing by polyoxyethylene (10) nonyl phenyl ether (NP-10) aqueous two-phase system, was designed and fabricated with acrylic acid (AA) as the monomer for the first time. The resultant NP10-AA TPS hydrogel, compared with the traditional TPS hydrogel, was more advanced in both of the high swelling ratio and the variable lower critical solution temperature (LCST). A simple synthesis technique of the NP10-AA MP hydrogel was developed. The thermo-sensitivity of the NP10-AA TPS hydrogel including the initial swelling ratio, LCST, dehydrated efficiency, was depended strongly on the crosslinker (MBA), initiator (APS), NP-10 and AA concentration. The swelling rate of the NP10-AA MP hydrogel was much higher than that of AA hydrogel dehydrated in the same lyophilization condition.     

Synthesis and properties of a temperature-sensitive chelating hydrogel and its metal complexes

A temperature-sensitive chelating hydrogel was synthesized by the copolymerization of 1-(β-acrylamidoethyl)-3-hydroxy-2-methyl-4(1H)-pyridinone (AHMP) and N-isopropylacrylamide (NIPAA) in the presence of N,N' -ethylene-bis-acrylamide as a crosslinking agent. The AHMP-NIPAA hydrogel formed a red complex with iron(III) and a pale green complex with Cu(II), respectively. It was observed that the hydrogel and its metal complexes had a high swelling ratio below the temperature of 35°C, while above that temperature the swelling ratios were dramatically decreased. Furthermore, the swelling ratio of the metal complexes was much lower at the swelling temperature (below 35°C) than that of the hydrogel itself, which might be due to the lower flexibility of the complexes. The iron(III) chelating study showed that the hydrogel had a high chelating efficiency at its swelling temperature, while the chelating efficiency of the hydrogel was very low at its deswelling temperature (>35°C). It was found that the chelating efficiency depended on the swelling ratio of the hydrogel in water, which could be explained by the difference in contactable internal surfaces at different temperatures. The hydrogel and its metal complexes could be easily separated at their deswelling temperature. It was also convenient to regenerate the hydrogel with 1 M HCl for reuse.     

Current Intelligent Injectable Hydrogels for In Situ Articular Cartilage Regeneration

Abstract

A high number of sport injuries result in damage to articular cartilage, a tissue type with poor self-healing capacity. Articular cartilage tissue is a sophisticated hydrogel, which contains 80% water and possesses strong mechanical properties. For this reason, synthetic hydrogels are thought to be an optimal material for cartilage regeneration. In the last decade, more than 2,000 research papers pertaining to “hydrogel and cartilage” have been published. Due to its biomimetic properties and user-friendly nature, especially in the field of minimal invasive surgery, intelligent injectable hydrogel have gradually become a focal point in cartilage research in recent years. In this review, we systematically summarize current “state-of-the-art” manufacture technologies of injectable hydrogels including ion-induced, thermo-induced, non-induced chemical, and light-induced crosslinking. We also review current strategies for designing intelligent injectable hydrogels, such as component-based, mechanical property-based and structure-based intelligent design to simulate the natural articular cartilage. Lastly, the applications of intelligent injectable hydrogels for cartilage regeneration are presented, and their outlooks for future clinical translation is dicussed.     

N-异丙基甲基丙烯酰胺共聚热缩温敏水凝胶

从甲基丙烯腈与异丙醇反应制备了N-异丙基甲基丙烯酰胺(NIPM),研究了其以N,N′-亚甲基双丙烯酰胺(MBA)为交联剂在不同溶剂体系的聚合及所形成的水凝胶的性质。表明NIPM-MBA凝胶具有热缩温敏性。在NIPM-MBA体系引入丙烯酸钠、甲基丙烯酸钠等负离子单体时,凝胶的溶胀比明显增加,MBA所占比例较少的体系,具有热缩、热胀双重性。     

可拉伸超韧水凝胶的制备和应用

综述了可拉伸超韧水凝胶的设计原理及其在组织工程和柔性电子器件领域的应用.通过将网络结构层次、化学结构、增韧机制与宏观力学性能相结合,重点讨论了单网络水凝胶、双网络水凝胶、纳米复合水凝胶及其它水凝胶等可拉伸超韧水凝胶的研究进展,并总结和展望了新思路和新方向.     

Mechanically tough and recoverable hydrogels via dual physical crosslinkings

Development of functional tough hydrogels with new network structures and energy dissipation mechanisms has great promise for many applications. Here, a new type of physical hydrogel crosslinked by hydrophobic association and hydrogen bonds was synthesized by a facile micellar copolymerization of hydrophobic methyl acrylate (MA) monomers and hydrophilic N-hydroxyethyl acrylamide (HEAA) monomers in the presence of Tween80 micelles. Strong hydrophobic association between inner MA and Tween80 and hydrogen bonds between external polyHEAA and Tween80 provide two distinct crosslinkers to construct mechanically tough and recoverable network. Mechanical properties of polyHEAA-MA@Tween80 hydrogels strongly depended on network components (HEAA, MA; Tween80 concentrations). At optimal conditions, the hydrogels can achieve fracture stress of 700 kPa, fracture strain of 1687 mm/mm, elastic modulus of 195 kPa, and tearing energy of 1598 J/m². Due to the reversible nature of physical interactions, polyHEAA-MA@Tween80 hydrogels can achieve fast stiffness/toughness recovery of 60%/33% without any external stimuli and resting time at room temperature. This work demonstrates a new design strategy to fabricate a new a single-network hydrogel with high mechanical and self-recovery properties by incorporating both hydrophobic association and hydrogen bonds in the network, which may provide alternative viewpoint for the design of multifunctional tough hydrogels. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1294–1305     

Application of Polyvinyl Alcohol (PVA)/Carboxymethyl Cellulose (CMC) Hydrogel Produced by Conventional Crosslinking or by Freezing and Thawing

Hydrogels for this study were prepared from a mixture of PVA and CMC using three different techniques, i.e., freezing and thawing, electron‐beam irradiation or combined freezing and thawing and electron beam irradiation. A comparative study between the three techniques was carried out in terms of gel fraction (%) and swelling (%). It was found that the physical properties of the hydrogel were improved when the combination of freezing and thawing and irradiation were used rather than just freezing and thawing, or irradiation only. The effects of temperature and soil fertilizers on swelling (%) were examined to evaluate the usefulness of the hydrogel as a super absorbent in the soil. It was found that the swelling ratio increased as the composition of CMC increased in the blend. Hence, the blend having the composition 80/20 (CMC/PVA) was used as a super absorbent in the soil for agriculture. Moreover, the water retention increased in the soil containing this hydrogel. Thus, this type of hydrogel can be used to increase water retention in desert regions.     

Aggregation-induced emission-active antibacterial hydrogel with self-indicating ability for real-time monitoring of drug release process

Although antibacterial hydrogels are emerging as promising biomaterials for effective inhibition of bacterial infections, monitoring their dynamic release behaviors in a visual manner remains greatly challenging. Herein, non-conjugated luminescent polymers (NCLPs) with aggregation-induced emission (AIE) characteristics are used for the first time to develop a visualization strategy to monitor the release process of the drug-loaded hydrogel. The novel antimicrobial peptide polymers with intrinsic AIE effect, namely nanoengineered peptide-grafted hyperbranched polymers (NPGHPs), are encapsulated in an anionic polyelectrolyte to construct the AIE-active fluorescent polymeric hydrogel (NPGHPs/SA gel). Interestingly, the rigid environment mediated by hydrogen bonding and electrostatic interaction contributes to promoting the unconventional luminescence of fluorescent clusters. Moreover, the successive drug release process of NPGHPs/SA gel can be tracked in real time by using fluorescence microscopy. The hydrogel also has potent antibacterial activities against Gram-negative bacteria (E. coli, P. aeruginosa) and Gram-positive bacteria (S. aureus, B. subtilis). Overall, this work not only provides an advanced biomedical material with broad-spectrum antibacterial ability but also opens a facile avenue up for the investigation of drug release from gel systems.