Although a molecular monolayer is only a few nanometers thick it can completely change the properties of a surface. Molecular monolayers can be readily prepared using the Langmuir–Blodgett ...methodology or by chemisorption on metal and oxide surfaces. This Review focuses on the use of chemisorbed self‐assembled monolayers (SAMs) as a platform for the functionalization of silicon oxide surfaces. The controlled organization of molecules and molecular assemblies on silicon oxide will have a prominent place in “bottom‐up” nanofabrication, which could revolutionize fields such as nanoelectronics and biotechnology in the near future. In recent years, self‐assembled monolayers on silicon oxide have reached a high level of sophistication and have been combined with various lithographic patterning methods to develop new nanofabrication protocols and biological arrays. Nanoscale control over surface properties is of paramount importance to advance from 2D patterning to 3D fabrication.
Engineering on the nanometer scale: Nanoscale control over surface properties is of paramount importance in bottom‐up approaches to nanofabrication, which will revolutionize nanoelectronics and biotechnology in the near future. Self‐assembled monolayers can form an ideal platform for nanofabrication on silicon oxide (see picture). Their formation, derivatization, and patterning are discussed.
By combining upconversion nanoparticles with the cisplatin (IV) prodrug we have demonstrated that a stable and multifunctional drug delivery system can be designed that will both reduce the drawbacks ...of cisplatin and give insight in to its in vitro/in vivo imaging. The up/down‐conversion fluorescence are detectable and show obvious co‐localization, demonstrating that the nanoparticles are rather stable inside cells and retain the UCNPs and block copolymer.
The poor mechanical strength of graphene oxide (GO) membranes, caused by the weak interlamellar interactions, poses a critical challenge for any practical application. In addition, intrinsic but ...large‐sized 2D channels of stacked GO membranes lead to low selectivity for small molecules. To address the mechanical strength and 2D channel size control, thiourea covalent‐linked graphene oxide framework (TU‐GOF) membranes on porous ceramics are developed through a facile hydrothermal self‐assembly synthesis. With this strategy, thiourea‐bridged GO laminates periodically through the dehydration condensation reactions via NH2 and/or SH with OCOH as well as the nucleophilic addition reactions of NH2 to COC, leading to narrowed and structurally well‐defined 2D channels due to the small dimension of the covalent TU‐link and the deoxygenated processes. The resultant TU‐GOF/ceramic composite membranes feature excellent sieving capabilities for small species, leading to high hydrogen permselectivities and nearly complete rejections for methanol and small ions in gas, solvent, and saline water separations. Moreover, the covalent bonding formed at the GO/support and GO/GO interfaces endows the composite membrane with significantly enhanced stability.
A thiourea bridging graphene oxide framework membrane, which is defect‐free, and robust, and has narrowed and structurally well‐defined 2D channels, is prepared facilely by self‐assembly. This membrane exhibits excellent hydrogen permselectivity and complete rejection for the smallest alcohol.
The successful self‐assembly of tensegrity triangle DNA crystals heralded the ability to programmably construct macroscopic crystalline nanomaterials from rationally‐designed, nanoscale components. ...This 3D DNA tile owes its “tensegrity” nature to its three rotationally stacked double helices locked together by the tensile winding of a center strand segmented into 7 base pair (bp) inter‐junction regions, corresponding to two‐thirds of a helical turn of DNA. All reported tensegrity triangles to date have employed (Z+2/3)\\left( {Z{\bm{ + }}2{\bf /}3} \right)\ turn inter‐junction segments, yielding right‐handed, antiparallel, “J1” junctions. Here a minimal DNA triangle motif consisting of 3‐bp inter‐junction segments, or one‐third of a helical turn is reported. It is found that the minimal motif exhibits a reversed morphology with a left‐handed tertiary structure mediated by a locally‐parallel Holliday junction—the “L1” junction. This parallel junction yields a predicted helical groove matching pattern that breaks the pseudosymmetry between tile faces, and the junction morphology further suggests a folding mechanism. A Rule of Thirds by which supramolecular chirality can be programmed through inter‐junction DNA segment length is identified. These results underscore the role that global topological forces play in determining local DNA architecture and ultimately point to an under‐explored class of self‐assembling, chiral nanomaterials for topological processes in biological systems.
Designer DNA crystals from triangle tiles are self‐assembled using 7 bp (2/3 turn) and 3 bp (1/3 turn) inter‐junction segments and are analyzed by x‐ray diffraction. Triangles with 7 bp segments yielded known right‐handed, antiparallel “J1” junctions, while 3 bp triangles formed left‐handed, locally‐parallel “L1” junctions. A Rule of Thirds is elucidated that dictates tertiary chirality in 3D DNA triangles.
Biologically inspired self-assembly processes of amphiphilic copolymers have received an increasing attention for creating innovative and highly advanced functional materials for various biomedical ...applications. Polymersomes are versatile nanosystems with tremendous potential due to their increased colloidal stability, tunable membrane properties, chemical versatility, and the ability to accommodate a broad range of drugs and biomolecules. In this review, we present the principles of copolymers self-assembly and associated parameters that control the resulting self-assembled morphologies, and various methodologies developed for fabrication of polymersomes. We attempt to discuss how polymersome platforms can be applied for versatile biomedical research, from simple passive nanocarriers for drug delivery to functionalized polymersomes for active targeting approaches and advanced nanoreactors, and protocells to mimic structure and functions of biological systems.
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Block copolymer (BCP) self-assembly is one of the most versatile concepts for the bottom-up design of functional nanostructures in materials science, nanomedicine and nanotechnology. ...While BCPs have been extensively studied regarding their microphase separation in bulk and the self-assembly in solution, only recently BCPs were investigated for their ability to form internally ordered microparticles. In this review, we discuss two emerging concepts: (i) the microphase separation of BCPs in the spherical confinement of evaporating emulsion droplets and (ii) the self-assembly of highly asymmetric BCPs under concentrated conditions. While the first concept yields solid and compact multicompartment microparticles suited for the synthesis of shape-anisotropic nanoparticles, photonic colloids, and actuators, the latter produces highly regular porous microparticles with exceptional interfacial area (BCP cubosomes and hexosomes). Despite distinct differences in the origin of both fields, commonalities in shape and morphology suggest an underlying formation mechanism that may link both research directions.
The self-assembly of normally soluble proteins into fibrillar amyloid structures is associated with a range of neurodegenerative disorders, such as Parkinson’s and Alzheimer’s diseases. In the ...present study, we show that specific events in the kinetics of the complex, multistep aggregation process of one such protein, α-synuclein, whose aggregation is a characteristic hallmark of Parkinson’s disease, can be followed at the molecular level using optical super-resolution microscopy. We have explored in particular the elongation of preformed α-synuclein fibrils; using two-color single-molecule localization microscopy we are able to provide conclusive evidence that the elongation proceeds from both ends of the fibril seeds. Furthermore, the technique reveals a large heterogeneity in the growth rates of individual fibrils; some fibrils exhibit no detectable growth, whereas others extend to more than ten times their original length within hours. These large variations in the growth kinetics can be attributed to fibril structural polymorphism. Our technique offers new capabilities in the study of amyloid growth dynamics at the molecular level and is readily translated to the study of the self-assembly of other nanostructures.
Carbon nanotubes (CNTs) incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction. ...In this work, a strategy of efficient utilization of CNT in producing CNT incorporated aramid papers is demonstrated. The layer-by-layer self-assembly technique is used to coat the surfaces of meta-aramid fibers and fibrils with CNT, providing novel raw materials available for the large-scale papermaking. The hierarchical construction of CNT networks resolves the dilemma of increasing CNT content and avoiding the agglomeration of CNT, which is a frequent challenge for CNT incorporated polymeric composites. The composite paper, which contains abundant heterogeneous interfaces and long-range conductive networks, is capable of reaching a high permittivity and dielectric loss tangent at a low CNT loading, and its complex permittivity is, so far, adjustable in the range of (1.20–j0.05) to (25.17–j18.89) at 10 GHz. Some papers with optimal matching thicknesses achieve a high-efficiency microwave absorption with a reflection loss lower than −10 dB in the entire X-band.
Immunotherapy has received widespread attention for its effective and long‐term tumor‐eliminating ability. However, for immunogenic “cold” tumors, such as prostate cancer (PCa), the low ...immunogenicity of the tumor itself is a serious obstacle to efficacy. Here, this work reports a strategy to enhance PCa immunogenicity by triggering cascade self‐enhanced ferroptosis in tumor cells, turning the tumor from “cold” to “hot”. This work develops a transformable self‐assembled peptide TEP‐FFG‐CRApY with alkaline phosphatase (ALP) responsiveness and glutathione peroxidase 4 (GPX4) protein targeting. TEP‐FFG‐CRApY self‐assembles into nanoparticles under aqueous conditions and transforms into nanofibers in response to ALP during endosome/lysosome uptake into tumor cells, promoting lysosomal membrane permeabilization (LMP). On the one hand, the released TEP‐FFG‐CRAY nanofibers target GPX4 and selectively degrade the GPX4 protein under the light irradiation, inducing ferroptosis; on the other hand, the large amount of leaked Fe2+ further cascade to amplify the ferroptosis through the Fenton reaction. TEP‐FFG‐CRApY‐induced immunogenic ferroptosis improves tumor cell immunogenicity by promoting the maturation of dendritic cells (DCs) and increasing intratumor T‐cell infiltration. More importantly, recovered T cells further enhance ferroptosis by secreting large amounts of interferon‐gamma (IFN‐γ). This work provides a novel strategy for the molecular design of synergistic molecularly targeted therapy for immunogenic “cold” tumors.
This work develops a a smart supramolecular self‐assembled peptide TEP‐FFG‐CRApY for prostate cancer (PCa) immunotherapy. At tumor cells, TEP‐FFG‐CRApY initiates tumor cell cascade self‐enhanced immunogenic ferroptosis via enzyme‐triggered morphological transformation. The powerful immunomodulatory effect not only stimulates a solid antitumor immune response to suppress the primary tumor, but also creates a long‐term immune memory to prevent tumor metastasis.
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