共查询到20条相似文献，搜索用时 0 毫秒
1.
Mathias Dietrich Guillaume Delaittre James P. Blinco Andrew J. Inglis Michael Bruns Christopher Barner‐Kowollik 《Advanced functional materials》2012,22(2):304-312
The nitrile imine‐mediated tetrazole‐ene cycloaddition reaction (NITEC) is introduced as a powerful and versatile conjugation tool to covalently ligate macromolecules onto variable (bio)surfaces. The NITEC approach is initiated by UV irradiation and proceeds rapidly at ambient temperature yielding a highly fluorescent linkage. Initially, the formation of block copolymers by the NITEC methodology is studied to evidence its efficacy as a macromolecular conjugation tool. The grafting of polymers onto inorganic (silicon) and bioorganic (cellulose) surfaces is subsequently carried out employing the optimized reaction conditions obtained from the macromolecular ligation experiments and evidenced by surface characterization techniques, including X‐ray photoelectron spectroscopy and FT‐IR microscopy. In addition, the patterned immobilization of variable polymer chains onto profluorescent cellulose is achieved through a simple masking process during the irradiation. 相似文献
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Josef Horak Ronnie Jansson Apurba Dev Linnea Nilebäck Kiarash Behnam Jan Linnros My Hedhammar Amelie Eriksson Karlström 《Advanced functional materials》2018,28(21)
A unique strategy for effective, versatile, and facile surface biofunctionalization employing a recombinant spider silk protein genetically functionalized with the antibody‐binding Z domain (Z‐4RepCT) is reported. It is demonstrated that Z‐silk can be applied to a variety of materials and platform designs as a truly one‐step and chemical‐free surface modification that site specifically captures antibodies while simultaneously reducing nonspecific adsorption. As a model surface, SiO2 is used to optimize and characterize Z‐silk performance compared to the Z domain immobilized by a standard silanization method. First, Z‐silk adsorption is investigated and verified its biofunctionality in a long‐term stability experiment. To assess the binding capacity and protein–protein interaction stability of Z‐silk, the coating is used to capture human antibodies in various assay formats. An eightfold higher binding capacity and 40‐fold lower detection limit are obtained in the immunofluorescence assay, and the complex stability of captured antibodies is shown to be improved by a factor of 20. Applicability of Z‐silk to functionalize microfluidic devices is demonstrated by antibody detection in an electrokinetic microcapillary biosensor. To test Z‐silk for biomarker applications, real‐time detection and quantification of human immunoglobulin G are performed in a plasma sample and C1q capture from human serum using an anti‐C1q antibody. 相似文献
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《Advanced functional materials》2018,28(35)
The introduction of a stimulus‐responsive property is an effective way to increase the applicability of functional materials in the field of nanobiotechnology. Herein, a peptide platform is devised for constructing elastin‐like peptide amphiphiles (ELPAs) that exhibit a temperature‐responsiveness that can be easily tuned via a single N‐terminal amino acid substitution at the final step of peptide synthesis. Due to the modular property of peptides, the platform based on a miniaturized elastin‐like peptide (MELP) can be conjugated with various bioactive peptide sequences in diverse macromolecular topologies. First, the MELP platform is coupled with a short linear RGD peptide. The ELPAs of the peptide conjugates exhibit rapid aggregation (coacervation) and retard disaggregation in response to heating and cooling, respectively. Second, the platform is grafted with an α‐helical guest peptide in a lariat‐type structure, which forms ELPAs that undergo faster disassembly than the ELPAs without the guest peptide in response to temperature increases. Interestingly, the critical temperatures for the thermoresponsive behaviors are commonly dependent on the hydrophobic and aromatic properties of the N‐terminal amino acid residues. These results suggest that this peptide platform possesses great potential for use in the development of smart materials in wide‐ranging applications related to temperature change. 相似文献
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Zifeng Lin Mingming Wu Huimin He Qingfei Liang Chengshen Hu Zhiwen Zeng Delin Cheng Guocheng Wang Dafu Chen Haobo Pan Changshun Ruan 《Advanced functional materials》2019,29(9)
For the 3D printing of bioscaffolds, the importance of a suitable bioink cannot be overemphasized. With excellent printability and biocompatibility, alginate (Alg) is one of the most used bioinks. However, its bioinert nature and insufficient mechanical stability, due to only crosslinking via cation interactions, hinder the practical application of Alg‐based bioinks in the individualized therapy of tissue defects. To overcome these drawbacks, for the first time, an ε‐polylysine (ε‐PL)‐modified Alg‐based bioink (Alg/ε‐PL) is produced. The introduction of ε‐PL improves the printability of the Alg‐based bioink due to increasing electrostatic interactions, which enhances the self‐supporting stability of the as‐printed scaffolds. The presence of the functional crosslinking –COOH and –NH2 groups in Alg and ε‐PL under mild conditions further enhances the mechanical stability of the scaffolds, far exceeding that of Alg/Ca2+ scaffolds. The surface charge of the prepared scaffolds is finely tuned by the feed ratio of Alg to ε‐PL and postimmobilization of different quantities of additional ε‐PL, with a view to enhancing cell adhesion and further biofunctionalization. The results indicate that chondroitin sulfate, an extracellular matrix component, and vascular endothelial growth factor can be successfully applied to biofunctionalize the scaffolds via electrostatic adsorption for enhanced biological activity. 相似文献
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Zhi Li Joachim F. R. Van Guyse Victor R. de la Rosa Hans Van Gorp Peter Walke Miriam C. Rodríguez Gonzlez Hiroshi Uji‐i Richard Hoogenboom Steven De Feyter Stijn F. L. Mertens 《Advanced functional materials》2019,29(36)
The modification of solid surfaces with supramolecular hosts is a powerful method to tailor interfacial properties and confer chemical selectivity, but often involves multistep protocols that hinder facile upscaling. Here, the one‐step covalent modification of highly oriented pyrolytic graphite (HOPG) with a β‐cyclodextrin (β‐CD) derivative, which efficiently forms inclusion complexes with hydrophobic guests of suitable size, is demonstrated. The grafted β‐CD‐HOPG surface is investigated toward electrochemical detection of ferrocene and dopamine. The enrichment of the analytes at the electrode surface, through inclusion in β‐CD, leads to an enhanced electrochemical response and an improved detection limit. Furthermore, the modified β‐CD‐HOPG electrode discriminates analytes that form host–guest complexes with β‐CD against a 100‐fold higher background of electroactive substances that do not. Atomic force microscopy, scanning tunneling microscopy, and Raman spectroscopy confirm the covalent nature of the modification and reveal high stability toward solvent rinsing, ultrasonication, and temperatures up to 140 °C. The one‐step covalent modification therefore holds substantial promise for the routine production of inexpensive, yet robust and highly performant electrochemical sensors. Beyond electrochemical sensor development, our strategy is valuable to prepare materials where accurate spatial positioning of functional units and efficient current collection are crucial, e.g. in photoelectrodes or electrocatalysts. 相似文献
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Efficient use of (nano)particle self‐assembly for creating nanostructured materials requires sensitive control over the interactions between building blocks. Here, a very simple method for rendering the interactions between almost any hydrophobic nano‐ and microparticles thermoswitchable is described and this attraction is characterized using colloid probe atomic force microscopy (CP‐AFM). In a single‐step synthesis, a thermoresponsive surfactant is prepared that through physical adsorption generates a thermosensitive brush on hydrophobic surfaces. These surface layers can reversibly trigger gelation and crystallization of nano‐ and microparticles, and at the same time can be used to destabilize emulsions on demand. The method requires no chemical surface modification yet is universal, reproducible, and fully reversible. 相似文献
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Eva Mussig Simon Schulz Joachim P. Spatz Jens Ulmer Niels Grabe Annette Kohl Gerda Komposch Pascal Tomakidi 《Advanced functional materials》2008,18(19):2919-2929
Polydimethylsiloxane (PDMS) pillar arrays are applied as a biomechanical microenvironment to establish gingival connective‐tissue fibroblasts (GCTFs) and to further analyze the pivotal role of GCTFs in epithelial‐tissue morphogenesis. GCTFs are known to exert successful adhesion and growth on fibronectin immobilized on pillar heads, over time, concomitant with the increased gene expression of vimentin and collagen type‐I. GCTF‐populated pillar arrays clearly reveal that epithelial‐tissue morphogenesis of immortalized human gingival keratinocytes (IHGKs), co‐cultured for 7 and 14 days, parallels the in vivo phenotype more closely, when compared with GCTF‐free control arrays. This in vivo‐like phenotype is substantiated by higher mRNA levels for keratin 1, involucrin and filaggrin differentiation markers. Furthermore, it is reflected by a tissue‐specific protein orientation of the aforementioned molecules, and also of the cell‐to‐cell contact forming desmoplakin and the basement membrane constituents, laminin‐5, laminin‐1/10, and collagen type‐IV. These experiments suggest that the in vivo‐like phenotype of the IHGK is governed by the GCTFs growing on the micropillar interfaces. Moreover, they form the basis for the optimization or neogeneration of biomaterials by varying predefined microenvironmetal parameters to achieve an in vivo‐like cell growth and differentiation, indispensable for tissue morphogenesis during regeneration. 相似文献
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Biomimetic scaffolds mimic important features of the extracellular matrix (ECM) architecture and can be finely controlled at the nano‐ or microscale for tissue engineering. Rational design of biomimetic scaffolds is based on consideration of the ECM as a natural scaffold; the ECM provides cells with a variety of physical, chemical, and biological cues that affect cell growth and function. There are a number of approaches available to create 3D biomimetic scaffolds with control over their physical and mechanical properties, cell adhesion, and the temporal and spatial release of growth factors. Here, an overview of some biological features of the natural ECM is presented and a variety of original engineering methods that are currently used to produce synthetic polymer‐based scaffolds in pre‐fabricated form before implantation, to modify their surfaces with biochemical ligands, to incorporate growth factors, and to control their nano‐ and microscale geometry to create biomimetic scaffolds are discussed. Finally, in contrast to pre‐fabricated scaffolds composed of synthetic polymers, injectable biomimetic scaffolds based on either genetically engineered‐ or chemically synthesized‐peptides of which sequences are derived from the natural ECM are discussed. The presence of defined peptide sequences can trigger in situ hydrogelation via molecular self‐assembly and chemical crosslinking. A basic understanding of the entire spectrum of biomimetic scaffolds provides insight into how they can potentially be used in diverse tissue engineering, regenerative medicine, and drug delivery applications. 相似文献
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Sophia Schmitt Julia Hümmer Saskia Kraus Alexander Welle Sylvain Grosjean Maximilian Hanke‐Roos Axel Rosenhahn Stefan Bräse Christof Wöll Cornelia Lee‐Thedieck Manuel Tsotsalas 《Advanced functional materials》2016,26(46):8455-8462
The ability to control the structure and surface chemistry of biomaterials on a molecular level is crucial for optimizing their performance. Here, a novel type of nanoporous organic framework that is suited for the fabrication of thin films is described. These surface‐grafted gels (SURGELs) are prepared and functionalized using two orthogonal, metal‐free click chemistries. The SURGELs are shown to be cytocompatible and to efficiently mediate adhesion of osteoblast‐like cells. This process can be further enhanced by surface modification. In addition, the use of light‐triggered reactions in combination with photomasks allows a patterned functionalization of the substrates. The potential to vary and exactly adjust the parameters within the SURGEL polymer network (including porosity and exact network topology on the nanometer scale as well as addressable functional groups) combined with the ability to functionalize their surfaces with any clickable biomolecule of choice in any desired pattern allow the targeted design of novel SURGEL‐based biomaterials for applications in nanomedicine, tissue engineering scaffolds, wound dressing,and medical implants. 相似文献
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Yunnan Fang Vincent W. Chen Ye Cai John D. Berrigan Seth R. Marder Joseph W. Perry Kenneth H. Sandhage 《Advanced functional materials》2012,22(12):2550-2559
A scalable wet chemical process has been used to convert the intricate silica microshells (frustules) of diatoms into gold structures that retained the three‐dimensional (3‐D) frustule shapes and fine patterned features. Combined use of an amine‐enriching surface functionalization protocol and electroless deposition yielded thin (<100 nm) conformal nanocrystalline gold coatings that, upon selective silica dissolution, were converted into freestanding gold structures with frustule‐derived 3‐D morphologies. By selecting a diatom frustule template with a quasi‐regular hexagonal pore pattern (Coscinodiscus asteromphalus, CA), gold replica structures possessing such pore patterns were produced that exhibited infrared transmission maxima/reflection minima that were not observed for the starting silica diatom frustules or for flat nonporous gold films; that is, such extraordinary optical transmission (EOT) resulted from the combined effects of the quasi‐periodic hexagonal hole structure (inherited from the CA diatom frustules) and the gold chemistry. Calculated and measured IR transmission spectra obtained from planar gold films with quasi‐periodic hexagonal CA‐derived hole patterns, or with short‐range periodic hexagonal hole patterns, indicated that the enhanced IR transmission exhibited by the gold CA frustule replicas was enabled by the generation and transmission of surface plasmons. This scalable bio‐enabled process provides a new and attractive capability for fabricating self‐supporting, responsive, 3‐D metallic structures for use as dispersible/harvestable microparticles tailored for EOT‐based applications. 相似文献
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Sebastian Rauch Klaus‐Jochen Eichhorn Dirk Kuckling Manfred Stamm Petra Uhlmann 《Advanced functional materials》2013,23(45):5675-5681
Stimuli‐responsive polymer brushes are smart materials for the design of bio‐interactive and responsive interfaces. The “grafting‐to” approach is a convenient preparation procedure that allows the modification of surfaces with preformed and most notably well‐defined functionalized macromolecules. However, the shortcoming of this approach is an intrinsic limitation of the grafting density, which in turn affects the stimuli‐responsive properties of the brush system. Here, a general strategy to overcome this limitation and to simultaneously improve the switching behavior of a temperature‐responsive poly(N‐isopropylacrylamide) (PNiPAAm) brush is reported. A technically simple processing step is used in combination with the thermal azide–alkyne cycloaddition to perform the chain extension of alkyne‐functionalized PNiPAAm brushes with azide‐functionalized PNiPAAm molecules. 相似文献
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Joe W. Tavacoli Job H. J. Thijssen Andrew B. Schofield Paul S. Clegg 《Advanced functional materials》2011,21(11):1949-1949
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Joe W. Tavacoli Job H. J. Thijssen Andrew B. Schofield Paul S. Clegg 《Advanced functional materials》2011,21(11):2020-2027
Bicontinuous, interfacially jammed emulsion gels (bijels) are a class of soft solid materials in which interpenetrating domains of two immiscible fluids are stabilized by an interfacial colloidal monolayer. Such structures form through the arrest of the spinodal decomposition of an initially single‐phase liquid mixture containing a colloidal suspension. With the use of hexalmethyldisilazane, the wetting character of silica colloids, ranging in size and dye content, can be modified for fabricating a novel bijel system comprising the binary liquid ethanediol–nitromethane. Unlike the preceding water‐lutidine based system, this bijel is stable at room temperature and its fabrication and resultant manipulation are comparatively straightforward. The new system has facilitated three advancements: firstly, we use sub 100 nm silica particles to stabilize the first bijel made from low molecular weight liquids that has domains smaller than ten micrometers. Secondly, our new and robust bijel permits qualitative rheological work which reveals the bijel to be significantly elastic and self healing whilst its domains are able to break, reform and locally rearrange. Thirdly, we encapsulate the ethanediol–nitromethane bijel in Pickering drops to form novel particle‐stabilized bicontinuous multiple emulsions that we christen bijel capsules. These emulsions are stimuli responsive – they liberate their contained materials in response to changes in temperature and solvency, and hence they show potential for controlled release applications. 相似文献
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Micromachining of poly(tetrafluoroethylene) (Teflon) and poly(methyl methacrylate) (PMMA) samples was carried out using soft X‐rays from a laser‐produced Xe plasma source, which we developed. In the Teflon sample, the contact angle with a water droplet on a modified surface increased from 90° to 110° as a result of irradiation without a mirror or mask, while the angle decreased to 50° when using irradiation with them. Scanning electron microscopy showed numerous micro‐protuberances and a masked pattern with micro‐concavities on each sample surface. These results suggested that a change to the contact angle was caused by the microstructures on the Teflon surface. We succeeded in controlling the wettability of the Teflon surface, from hydrophobic to hydrophilic, by micromachining using laser plasma X‐rays. In the PMMA sample, the etching rate was investigated with irradiation using a large number of pulses (192,000 pulses) and a low power density of 8 × 104 W/cm2. The etching rate was calculated to be 5 pm/pulse. This was judged to be due only to photo‐etching without any thermal effects. We demonstrated a pure photo‐etching depth of about 1 μm. 相似文献
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Amanda Mahle Neeraja Dashaputre Philip DeShong Daniel C. Stein 《Advanced functional materials》2018,28(13)
Glycomics lags substantially behind proteomics and genomics in its ability to decipher and synthesize complex glycans. The slow progress in deciphering glycan interactions at a molecular level is in large part due to the absence of a functional system to express, on a large scale, carbohydrates of known structure, in the context of a biologically relevant assay system. Here, the characterization of glycan‐functionalized catanionic surfactant vesicles (CVs) as a platform for glycan synthesis is described, and it is demonstrated that the resulting glycan‐functionalized CVs can serve as a scaffold for the interrogation of protein‐glycan interactions. It is demonstrated that Neisseria gonorrhoeae lipooligosaccharide (LOS) glycosyltransferase LgtE, an enzyme that catalyzes the addition of galactose onto a terminal glucose found on LOS, can be used to biochemically modify LOS or glucose functionalized CVs. CVs are characterized by differential lectin binding using flow cytometry. LgtE activity is measured on whole cells and LOS functionalized vesicles and found to have approximately the same biochemical properties. It is further demonstrated that CVs can be inkjet printed. This paper presents proof‐of‐concept that glycan‐functionalized catanionic vesicles can be used to create a high‐specificity and high‐throughput glycan array that will allow for the investigation of a variety of protein–glycan interactions. 相似文献
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Olha Hoy Bogdan Zdyrko Robert Lupitskyy Roman Sheparovych Dennis Aulich Jiafang Wang Eva Bittrich Klaus‐Jochen Eichhorn Petra Uhlmann Karsten Hinrichs Marcus Müller Manfred Stamm Sergiy Minko Igor Luzinov 《Advanced functional materials》2010,20(14):2240-2247
The ability to vary, adjust, and control hydrophobic interactions is crucial in manipulating interactions between biological objects and the surface of synthetic materials in aqueous environment. To this end a grafted polymer layer (multi‐component mixed polymer brush) is synthesized that is capable of reversibly exposing nanometer‐sized hydrophobic fragments at its hydrophilic surface and of tuning, turning on, and turning off the hydrophobic interactions. The reversible switching occurs in response to changes in the environment and alters the strength and range of attractive interactions between the layer and hydrophobic or amphiphilic probes in water. The grafted layer retains its overall hydrophilicity, while local hydrophobic forces enable the grafted layer to sense and attract the hydrophobic domains of protein molecules dissolved in the aqueous environment. The hydrophobic interactions between the material and a hydrophobic probe are investigated using atomic force microscopy measurements and a long‐range attractive and contact‐adhesive interaction between the material and the probe is observed, which is controlled by environmental conditions. Switching of the layer exterior is also confirmed via protein adsorption measurements. 相似文献