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Cross-linking induced thermoresponsive hydrogel with light emitting and self-healing property
摘要： Development of self-healing hydrogels with thermoresponse is very important for artificial smart materials. In this article, the self-healing hydrogels with reversible thermoresponse were designed through cross-linking-induced thermoresponse (CIT) mechanism. The hydrogels were prepared from ketone group containing copolymer bearing tetraphenyl ethylene (TPE) and cross-linked by naphthalene containing acylhydrazide cross-linker. The mechanical property, light emission, self-healing, and thermo-response of the hydrogels were investigated intensively. With regulation of the copolymer composition, hydrogels showed thermoresponse with the LCST varied from above to below body temperature. At the same time, the hydrogels showed self-healing property based on the reversible characteristic of the acylhydrazone bond. The hydrogel also showed temperature-regulated light emission behavior based on AIE property of the TPE unit.
关键词： TPE,cross-linking-induced thermoresponse,hydrogel,self-healing,light emission
更新于2025-11-14 15:27:09
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Cross-linking induced thermo-responsive self-healable hydrogels with temperature regulated light emission property
摘要： Self-healing hydrogels draw great attentions in past decade based on the self-healing property similar to living creatures and their potential application in bioscience. On the other hand, thermo-response of the hydrogel endow the hydrogel with smart characteristic for controlled drug loading and delivery, diagnosis, cell imaging, life simulation, etc. In this study, self-healable hydrogel with cross-linking induced thermo-response (CIT) property was prepared from TPE containing copolymer TPE-P(DMA-stat-DAA) and the LCST of the hydrogels could be regulated by copolymer composition and the structure of the cross-linkers. The light emission property, mechanical and self-healing performances of the hydrogels are also investigated intensively. The results showed the LCST of the hydrogels could be regulated to body temperature through cross-linking induced thermo-response (CIT) mechanism with PEO23 DNH cross-linking. At the same time, the hydrogels exhibit light emission property, excellent self-healing ability and good mechanical properties. Moreover, the hydrogels showed different light emission property regulated by temperature based on AIE property of the TPE.
关键词： Light emission,Self-healing hydrogel,Cross-linking induced thermo-response
更新于2025-11-14 15:26:12
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Pharmacologic Alternatives to Riboflavin Photochemical Corneal Cross-Linking: A Comparison Study of Cell Toxicity Thresholds
摘要： PURPOSE. The efficacy of therapeutic cross-linking of the cornea using riboflavin photochemistry (commonly abbreviated as CXL) has caused its use to become widespread. Because there are known chemical agents that cross-link collagenous tissues, it may be possible to cross-link tissue pharmacologically. The present study was undertaken to compare the cell toxicity of such agents. METHODS. Nine topical cross-linking agents (five nitroalcohols, glyceraldehyde [GLYC], genipin [GP], paraformaldehyde [FA], and glutaraldehyde [GLUT]) were tested with four different cell lines (immortalized human corneal epithelial cells, human skin fibroblasts, primary bovine corneal endothelial cells, and immortalized human retinal pigment epithelial cells [ARPE-19]). The cells were grown in planar culture and exposed to each agent in a range of concentrations (0.001 mM to 10 mM) for 24 hours followed by a 48-hour recovery phase. Toxicity thresholds were determined by using the trypan blue exclusion method. RESULTS. A semiquantitative analysis using five categories of toxicity/fixation was carried out, based on plate attachment, uptake of trypan blue stain, and cellular fixation. The toxicity levels varied by a factor of 103 with the least toxic being mononitroalcohols and GLYC, intermediate toxicity for a nitrodiol and nitrotriol, and the most toxic being GLUT, FA, GP, and bronopol, a brominated nitrodiol. When comparing toxicity between different cell lines, the levels were generally in agreement. CONCLUSIONS. There are significant differences in cell toxicity among potential topical cross-linking compounds. The balance between cross-linking of tissue and cell toxicity should be borne in mind as compounds and strategies to improve mechanical tissue properties through therapeutic tissue cross-linking continue to develop.
关键词： protein cross-linking,cornea,cellular toxicity,keratoconus
更新于2025-09-23 15:23:52
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Cross-linked lignin coatings produced by UV light and SF6 plasma treatments
摘要： Lignin is one of the most abundant macromolecules in vascular plants and has been studied for many years due to its high availability and low cost, regarding that lignin is the main by-product of the paper pulping process, and also typically burned as fuel. Despite that, lignin has only a few industrial applications. In this study, we found a simple method for preparing well-defined lignin surfaces. Lignin was extracted from sugar cane bagasse by Soda pulping and its coatings were prepared using solutions with different solvents on various substrates (silicon wafers, paper, steel and glass) by spin-coating. Two methods were tested in order to promote cross-linking on the surface of lignin coatings: SF6 plasma treatment and ultra-violet radiation. Both treatments reduced the amount of hydroxyl groups on the surface leading to more stable, cross-linked coatings as observed by FTIR and thermal analysis. Ultra-violet light radiation turned lignin coatings hydrophilic while stable super-hydrophobic lignin coatings were obtained using SF6 plasma.
关键词： Cross-linking,Surface modification,Coatings,Plasma,Superhydrophobicity,Lignin
更新于2025-09-23 15:23:52
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Photoactivated chromophore corneal cross-linking (PACK-CXL) for treatment of severe keratitis
摘要： Purpose: To report our experience with photoactivated chromophore corneal cross-linking (PACK-CXL) for treating keratitis patients. Methods: This retrospective study consists of 27 eyes of 26 patients with infectious keratitis treated with PACK-CXL at the Helsinki University Hospital between 2009 and 2017. Patients were treated with antibiotics/antifungal medications and underwent PACK-CXL procedure due to lack of clinical response or severe corneal melts. For twenty patients, amniotic membrane transplant (AMT) was done during the same day. Follow-up after cross-linking ranged from 1 week to 12 months. Results: Sixteen infections were related to contact lens wear. Of the 19 eyes showing positive culture, the predominant micro-organism was Pseudomonas aeruginosa (9 cases). The average re-epithelization time was 13 days and in 15 cases (56%) the re-epithelization occurred within one week. In 26 eyes, visual acuity increased and seven patients (26%) had a ?nal visual acuity more or equal to 0.5 (20/40) Snellen. Conclusions: PACK-CXL seems to be a safe and potential option for treating patient with infectious keratitis who do not respond to antibiotic therapy.
关键词： corneal cross-linking,infectious keratitis,ribo?avin,cornea,PACK-CXL
更新于2025-09-23 15:22:29
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Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution
摘要： Purpose: To analyze the short-term clinical and topographic outcomes in patients with keratoconus after corneal collagen cross-linking treatment (CXL) with dextran-free isotonic riboflavin solution. Methods: In this retrospective case series, 26 eyes from 26 patients with keratoconus were studied. The best corrected visual acuity (BCVA) and refractive and topographic findings were analyzed at a 6-month follow-up. Results: The mean BCVA (Snellen lines) values before and 1, 3, and 6 months after CXL were 0.51 ± 0.2, 0.48 ± 0.2, 0.57 ± 0.2, and 0.64 ± 0.2, respectively, and the difference between the preoperative and 6-month values was statistically significant (p=0.006). The mean spherical equivalent refraction decreased from -5.6 ± 2.4 diopters (D) preoperatively to -5.0 ± 2.1 D, and mean simulated keratometry decreased from 48.5 ± 2.5 D to 47.8 ± 2.6 D at 6 months. (p=0.145 and p=0.001, respectively). In addition, the maximum keratometry decreased progressively and significantly from the preoperative value during follow-up (p=0.003). The central and minimal corneal thicknesses, including those of the epithelium, also decreased from 442.8 ± 25.6 μm and 430.5 ± 23.9 μm preoperatively to 420.7 ± 31.8 μm and 409.3 ± 28.7 μm at the most recent follow-up (p<0.001), respectively. No intraoperative or postoperative complications were observed. Conclusions: CXL with dextran-free isotonic riboflavin solution appears to be a safe treatment alternative for keratoconus and yields sustained short-term improvements in visual acuity, keratometric readings, and corneal thickness. However, long-term results are needed to confirm these outcomes.
关键词： Dextrans,Riboflavin/therapeutic use,Collagen,Visual acuity,Ultraviolet rays,Cornea,Cross-linking reagents
更新于2025-09-23 15:22:29
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Tuning the Cross-Linker Crystallinity of a Stretchable Polymer Semiconductor
摘要： The cross-linking of conjugated polymers has been demonstrated to be an effective strategy to improve its elastic properties to give deformable semiconductors for plastic electronics. While there have been extensive studies of the structural requirements of the polymer host for good film ductility, no work to date has focused on the relevance of the structural design or chemistry of these cross-linker additives. In this study, urethane groups and tertiary carbon atoms are inserted into the alkyl backbone of perfluorophenyl azide-based cross-linkers to investigate the importance of cross-linker crystallinity with respect to polymer morphology and hence mechanical and electrical properties. Linear cross-linkers with hydrogen bonding from urethane groups readily phase separate and recrystallize in the polymer network to form cross-linked domains that obstruct the strain distribution of the polymer film. Branch cross-linkers with tertiary carbon on the other hand form an evenly cross-linked network in the polymer blend stemming from excellent miscibility and show a 4-fold increase in fracture strain. Furthermore, a stable hole mobility of 0.2 cm2 V?1 s?1 is achieved up to ε = 100%, and a stable hole mobility of 0.1 cm2 V?1 s?1 after 2000 cycles of ε = 25% on fully stretchable organic field-effect transistors.
关键词： cross-linking,deformable semiconductors,cross-linker crystallinity,electrical properties,polymer morphology,elastic properties,plastic electronics,conjugated polymers,mechanical properties
更新于2025-09-23 15:21:21
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Graphene Oxide - Applications and Opportunities || Graphene Oxide/Reduced Graphene Oxide Aerogels
摘要： In this chapter, we will discuss aerogels based on graphene oxide/reduced graphene oxide—promising composite materials, based on 2D carbon nanoparticles, with a certain architecture that prevents aggregation of graphene layers with a highly developed surface that have a high potential technological realization as materials for supercapacitors, sensors, batteries, and actuators. This chapter describes the existing methods for producing composite aerogels based on graphene oxide/reduced graphene oxide, the structural features of these materials, the most relevant studies in the areas of surface modification, architectural control, improvement of mechanical properties, and the most interesting applications. It has been shown that such materials have relatively high specific surface values and a high degree of exfoliation of graphene layers, but an urgent need is to improve them, which is due to the fragility of graphene aerogels and composite materials based on them, as well as the need to modify the surface to control porosity.
关键词： cross linking,hydrothermal synthesis,highly porous materials,carbon based materials,reduced graphene oxide aerogels,graphene oxide aerogels,self-gelation
更新于2025-09-23 15:21:21
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Modifying the thermomechanical properties of electrospun fibres of poly-vinyl cinnamate by photo-cross-linking
摘要： We explore the effects of cross-linking on some thermal and mechanical properties of polymer nanofibers of poly-vinyl cinnamate which were electro-spun from 1,2 dichloroethane. Scanning electron microscopy performed on the fibres revealed smooth fibres which were devoid of beading or ribbon-type features. When cross-linked, the Young’s moduli and glass transition temperatures of the fibres increase, owing to the formation of new covalent bonds which leads to higher overall binding energies. The glass transition temperatures increased by 20 K after 1 h of photo-polymerization while the Young’s modulus increased by 50% for the same exposure time. The glass transition temperatures as well as the heats of enthalpy indicate that a significant portion of cross-linking occurs within the first 10 min of exposure.
关键词： Photo-polymer,Young’s modulus,Enthalpy,Glass transition,Electro-spinning,Cross-linking
更新于2025-09-23 15:21:01
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A UV cross-linking method combined with infrared imaging to analyse RNA–protein interactions
摘要： Photo cross-linking of proteins with short RNA oligomers is a classical method to study RNA–protein interactions that are implicated in many aspects of RNA metabolism and function. Most commonly, this involves the use of [c-32P]-labeled RNA probes. Although very sensitive, these procedures are complicated by the safety issues associated with the use of radioisotopes. Here, we describe a modi?ed UV cross-linking method using oligonucleotide probes end labelled with the infrared dye IRDyeVR 800. After UV cross-linking, proteins are separated by SDS-PAGE and cross-linked products are visualized with the OdysseyVR Infrared Imaging system. This end labelling approach provides a streamlined alternative to random labelling which reduces the ef?ciency of in-vitro transcription. End labelling is also independent of the length of the probe, thus facili- tating quantitative comparisons. To validate the method, we have con?rmed the binding of HuD to the 30-UTR of the mRNA for the microtubule-associated protein tau, implicated in the pathogenesis of Alzheimer’s disease. UV cross-linking of HuD with a labeled 21-mer probe was successfully performed using a recombinant puri?ed glutathione-S-transferase–HuD fu- sion protein as well as with lysates from CHO cells transfected with HuD cDNA. UV cross-linking combined with infrared imaging offers a convenient and robust strategy to analyse RNA–protein interactions and their emerging importance in disease.
关键词： Tau,RNA-binding protein,UV cross-linking,neurodegeneration,HuD,OdysseyVR
更新于2025-09-23 15:19:57