Increasing the Order Parameter of Quasi-Hexagonal Micellar Nanostructures by Ultrasound Annealing

Williges, Christian; Chen, Wenwen; Morhard, Christoph; Spatz, Joachim P.; Brunner, Róbert

doi:10.1021/la303991x

Cited by 12 publications

(13 citation statements)

References 19 publications

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“…The disadvantage of BCP self-assembly stands in the formation of defects [210]. Instead, directed self-assembly [211] uses various external stimuli (e.g., thermal annealing [197,199,209,[212][213][214], solvent annealing [199,200,209,215], thermal and solvent annealing [199], ultrasounds [216], microwaves [217], magnetic fields [218], photoirradiation [219], shearing [220], addition of an ionic liquid [221], controlled spreading area [222], or epitaxy [210,223]) in order to induce and favor the self-assembly process. This process is also favored when employing click chemistry [214], and it displays a series of advantages: high-quality hierarchical [195,224] nanostructures exhibiting a low number of defects can be rapidly generated [195,213] over a large area [222].…”

Section: Block Copolymer Lithography Based On (Directed) Self-assemblymentioning

confidence: 99%

Multifunctional Structured Platforms: From Patterning of Polymer-Based Films to Their Subsequent Filling with Various Nanomaterials

Handrea-Dragan

Botiz

2021

Polymers

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There is an astonishing number of optoelectronic, photonic, biological, sensing, or storage media devices, just to name a few, that rely on a variety of extraordinary periodic surface relief miniaturized patterns fabricated on polymer-covered rigid or flexible substrates. Even more extraordinary is that these surface relief patterns can be further filled, in a more or less ordered fashion, with various functional nanomaterials and thus can lead to the realization of more complex structured architectures. These architectures can serve as multifunctional platforms for the design and the development of a multitude of novel, better performing nanotechnological applications. In this work, we aim to provide an extensive overview on how multifunctional structured platforms can be fabricated by outlining not only the main polymer patterning methodologies but also by emphasizing various deposition methods that can guide different structures of functional nanomaterials into periodic surface relief patterns. Our aim is to provide the readers with a toolbox of the most suitable patterning and deposition methodologies that could be easily identified and further combined when the fabrication of novel structured platforms exhibiting interesting properties is targeted.

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Section: Block Copolymer Lithography Based On (Directed) Self-assemblymentioning

confidence: 99%

Multifunctional Structured Platforms: From Patterning of Polymer-Based Films to Their Subsequent Filling with Various Nanomaterials

Handrea-Dragan

Botiz

2021

Polymers

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“…This plugin measures the interparticle distance between each gold nanoparticle and the surrounding nanoparticles, followed by a calculation of the average particle distance as well as the deviation. Additionally, the plugin is able to verify and evaluate the quality of hexagonal arrays based on a mathematical algorithm described by Williges et al (2013).…”

Section: Characterization and Technical Devicesmentioning

confidence: 99%

“…Nanostructured glass substrates were analyzed by SEM in order to assess the interparticle distance as well as the degree of order of the deposited GNPs ( Figure 1A and Supplementary Figure 1). For this purpose, the resulting SEM micrographs were analyzed using a custom-made ImageJ plugin in which a mathematical definition of hexagonallity defined by Williges (Williges et al, 2013) was applied (see section Characterization and Technical Devices). Here, the resulting hexagonal order parameter Ψ 6 is equal to one in case of perfect hexagonal ordering and approaches zero the more random the considered structure becomes.…”

Section: Nanostructuring and Functionalization Of Peg-based Hydrogelsmentioning

confidence: 99%

Nanostructured Bifunctional Hydrogels as Potential Instructing Platform for Hematopoietic Stem Cell Differentiation

et al. 2019

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Hematopoietic stem cells (HSCs) are blood forming cells which possess the ability to differentiate into all types of blood cells. T cells are one important cell type HSCs can differentiate into, via corresponding progenitor cells. T cells are part of the adaptive immune system as they mediate cellular immune responses. Due to this crucial function, in vitro differentiated T cells are the subject of current studies in the biomedical field in terms of cell transplantation. Studies show that the density of the immobilized Notch ligand Delta-like 1 (DLL1) presented in HSCs' environment can stimulate their differentiation toward T cells. The development of reliable synthetic cell culture systems presenting variable densities of DLL1 is promising for the future expansion of T cells' clinical applications. Here we introduce bifunctional polyethylene glycol-based (PEG-based) hydrogels as a potential instructing platform for the differentiation of human hematopoietic stem and progenitor cells (HSPCs) to T cells. PEG hydrogels bearing the cell adhesion supporting motif RGD (arginyl-glycyl-aspartic acid) were synthesized by UV-light induced radical copolymerization of PEG diacrylate and RGD modified PEG acrylate. The hydrogels were furthermore nanostructured by incorporation of gold nanoparticle arrays that were produced by block copolymer micelle nanolithography (BCML). BCML allows for the decoration of surfaces with gold nanoparticles in a hexagonal manner with well-defined interparticle distances. To determine the impact of DLL1 density on the cell differentiation, hydrogels with particle distances of ∼40 and 90 nm were synthesized and the gold nanoparticles were functionalized with DLL1. After 27 days in culture, HSPCs showed an unphysiological differentiation status and, therefore, the differentiation was evaluated as atypical T lymphoid differentiation. Cluster of differentiation (CD) 4 was the only tested T cell marker which was expressed clearly in all samples. Thus, although the applied nanopatterned hydrogels affected two important signaling pathways (integrins and Notch) for T cell differentiation, it appears that more functionalities that control T cell differentiation in nature need to be considered for achieving fully synthetic in vitro T cell differentiation strategies.

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“…Particle size and shape are determined by SEM, TEM and atomic force microscopy (AFM) (Kim et al , ); chemical composition and purity are determined by X‐ray diffraction, AFM, X‐ray photoelectron spectroscopy and UV‐Vis spectroscopy (Shrestha et al , ). ENM suspensions for experimental analysis are sonicated, forming aggregates/agglomerates with different characteristics depending on the type of dispersion solution, frequency, time and temperature of sonication (De Temmerman et al , ; Williges et al , ), which has an impact on toxicity (http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=env/jm/mono%282012%2940&doclanguage=en).…”

Section: Introductionmentioning

confidence: 99%

Difficulties in establishing regulations for engineered nanomaterials and considerations for policy makers: avoiding an unbalance between benefits and risks

Garduño-Balderas

Urrutia-Ortega

Medina‐Reyes

et al. 2015

J of Applied Toxicology

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Current evidence of engineered nanomaterials' (ENM) toxicity has led to a latent concern about hazards for both humans and the environment. For this reason, some efforts have been made to suggest frameworks or other guidance to regulate ENM handling; however, the real exposure risk to humans has not been well established. The aims of this work were to analyze the difficulties in establishing regulations for ENM and to discuss some considerations that may be helpful for policy makers involved in the regulation of ENM. Difficulties in establishing regulations are based on the novel properties of ENM associated with cytotoxic effects, the insufficiency of standardized methods to test those effects and the lack of epidemiological evidence of ENM toxicity, especially in occupational settings. Nevertheless, we offer some suggestions for establishing regulations, which include frameworks oriented towards protecting personnel exposed to ENM without decreasing production. In addition, we propose an ENM data sheet to offer available information of ENM. Finally, ethical aspects should also be considered in developing ENM regulations because every person who is working around or consuming ENM has the right to be informed about the potential risk.

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Increasing the Order Parameter of Quasi-Hexagonal Micellar Nanostructures by Ultrasound Annealing

Cited by 12 publications

References 19 publications

Multifunctional Structured Platforms: From Patterning of Polymer-Based Films to Their Subsequent Filling with Various Nanomaterials

Multifunctional Structured Platforms: From Patterning of Polymer-Based Films to Their Subsequent Filling with Various Nanomaterials

Nanostructured Bifunctional Hydrogels as Potential Instructing Platform for Hematopoietic Stem Cell Differentiation

Difficulties in establishing regulations for engineered nanomaterials and considerations for policy makers: avoiding an unbalance between benefits and risks

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