Self-assembly Process Research Articles

Host-Guest Adduct as a Stimuli-Responsive Prodrug: Enzyme-Triggered Self-Assembly Process of a Short Peptide Within Mitochondria to Induce Cell Apoptosis.

To address the issue of nonspecific biodistribution of a chemotherapeutic drug, stable [2]pseudorotaxane complexes (PK@CAOPP and PR@CAOPP) are used to demonstrate a proof of concept. Cationic -PPh3 + moiety in CAOPP allows specific localization of the PK@CAOPP/ PR@CAOPP in the mitochondrial membrane (MM). Electrostatic interaction between the cationic LysinePK or ArgininePR moiety and the negatively charged phosphoesterCAOPP functionality in CAOPP favours strong adduct formation. The ALP-induced hydrolytic cleavage of the phosphoester moiety in cancer cells triggers dephosphorylation and releases PK/ PR moiety from PK@CAOPP/PR@CAOPP. PK or PR, derived from the Phe-Phe dipeptide, formed fibril-like molecular aggregates in the MM to induce dysfunction, depolarization, ROS generation and apoptotic MCF7 cell death. Such phenomena were not observed in ALP-negative HEK293 normal cells. These propositions were confirmed through control studies using NBDK and PE, other guest molecules. Smaller size and inclusion of the short peptides (PK or PR) within the hydrophobic interior of CAOPP, were attributed to their stability in blood serum. Thus, we have demonstrated the use of supramolecular adducts as a potential therapeutic option for treating cancer cells without affecting healthy cells. The efficacy was also established with an in-vivo MCF7 tumour xenograft model using Balb/c nude mice.

Molecularly imprinted electrochemical sensor based on APTES-functionalized indium tin oxide electrode for the determination of sulfadiazine.

Anelectrochemical sensor was developedfor the sensitive and selective detection of sulfadiazine(SDZ), based on a molecularly imprinted polymer (MIP) film formed on an indium tin oxide (ITO) electrode through a self-assembly process. The SDZ-imprinted ITO electrode (SDZ-MIP/APTES-ITO) was prepared through in situ polymerization using sulfadiazine, methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), and 2,2'-azobisisobutyronitrile (AIBN) as the template, functional monomer, cross-linker, and initiator respectively. Before polymerization, the ITO electrode was functionalized with 3-aminopropyltriethoxysilane (APTES) to promote covalent attachment of the polymer to the electrode. After polymerization, the template molecule SDZ was removed to create selective recognition sites, forming the molecularly imprinted polymer electrode (MIP/APTES-ITO), which facilitates sulfadiazine detection. The sensor's performance was evaluated using cyclic and differential pulse voltammetry, demonstrating a linear response in the sulfadiazine concentration range 0.1 to 300μM, with a detection limit of 0.11μM. The MIP-based sensor exhibited goodreproducibility, repeatability, selectivity, and stability in sulfadiazine detection. Its practical applicability was confirmed by the successful quantification of sulfadiazine in spiked milk samples.

Bio-sourced flexible supramolecular glasses for dynamic and full-color phosphorescence

Glass, a diverse family of amorphous materials, has significantly advanced human society across various fields. The demand for flexible ultrathin glass, driven by modern optical displays and portable optoelectronics, presents challenges in energy consumption, fabrication complexity, and recycling. Here, we demonstrate flexibility and full-color luminescence in large-scale ultrathin glasses derived from readily available natural resources, specifically egg albumen (EA) and gelatin (GEL), via an evaporation-driven self-assembly process. The dynamic crosslinked networks formed through hydrogen bonding between EA and GEL impart both high hardness and flexibility to the glasses, with hardness and flexural strength values comparable to state-of-the-art inorganic and organic glasses. Additionally, the EA–GEL-based glasses exhibit excitation-dependent and time-gated chiral ultralong phosphorescence with color from blue and red, and a lifetime of up to 180.4 ms. With their easy processability and full-color emission, these biogenic glasses can be fabricated into anti-counterfeiting patterns and optical information codes.

Insight into interfacial dynamics of photogenerated carriers in Cs3Bi2I9/Au heterostructure nanocomposites for high-sensitivity broadband photodetection with negative photoconductivity

The negative photoconductivity (NPC) effect is becoming an increasingly significant factor in the development of next-generation optoelectronics. However, research in the field of NPC-dominated optoelectronics remains in its infancy and frequently encounters challenges related to fabrication complexity, slow photoresponse speed, instability, and a limited spectral response range. Herein, a Cs3Bi2I9/Au heterostructure nanocomposite was prepared via a simple self-assembly process utilizing electrostatic interactions with Au nanoparticles (NPs) and lead-free Cs3Bi2I9 nanoplates. The Cs3Bi2I9/Au nanocomposite-based photodetectors (PDs) demonstrate a broadband photoresponse (405–1550 nm), enhanced rise/fall times (27.2/40.0 µs), and reduced noise density (4.7 × 10−13 A/Hz1/2 at 1 Hz). In contrast to the positive photoconductivity (PPC) effect observed in colloidally synthesized Cs3Bi2I9 nanoplate-based PDs, the NPC can be attributed to the decrease in photocurrent under light illumination during the processes of recombination and trapping of photogenerated carriers induced by the incorporation of Au NPs. These findings are expected to provide valuable insights into achieving high-performance NPC-dominated PDs by regulating the dynamics of photogenerated carriers in perovskite heterostructures.

Route to Measure Exact Parameters of Bio-Nanostructures Self-Assembly

Artificial bio-nanocoatings, primarily composed of proteins, offer a broad range of applications across various fields thanks to their unique properties. Proteins, as major components of these structures, enable a high degree of customization, such as mutations, conjugation with other molecules or nanoparticles, or the inclusion of an enzymatic activity. Their ability to self-assembly simplifies the production of bio-nanocoatings, making this process efficient and environment-friendly. Despite these advantages, a comprehensive understanding of the underlying self-assembly mechanism is lacking, and the reaction rates governing this process have not been characterized. In this article, we introduce a novel method to determine the key parameters describing the self-assembly mechanism of bio-nanostructures. For the first time, this approach enables an accurate calculation of the autocatalytic and self-inhibitory parameters controlling the process. Through mathematical modeling, our method enhances the understanding of how the protein-based nanocoatings form and opens new avenues for their application in nanotechnology and synthetic biology. Improved control over the self-assembly processes may enable the development of nanomaterials optimized for specific functions, such as drug delivery, biosensing, and bioactive surface fabrication.

Substrate as the primer of relay-race spin-driven self-assembly of chiral molecules

The molecules of chiral N-trifluoroacetylated α-aminoalcohols can self-assemble and form long and thin fiber-like supramolecular structures (strings). The strings effectively grow on the surface of the substrate and the amount of them, as well as their morphology, depend on the properties of the substrate. In particular, self-assembly was not observed on the electroconductive substrates, such as some metals (copper and aluminum) and graphite. The strings were found on the surface of titanium due to the peculiarities of the titanium oxide’s properties. The strings usually emanate from some nucleation zones, where the growth was initiated and then proceeded spontaneously outside these areas. We supposed the relay-race scheme of the transfer of spin polarization, which describes the mechanics and thermodynamics of the observed self-assembly process. The scheme implies the preliminary orientation of two molecules, their mutual polarization accompanied by spin-polarization, and finally the binding of the molecules. We also suppose this mechanism can play a significant role in various self-assembly processes in living cells.

Suppressing Static and Dynamic Disorder for High-Efficiency and Stable Thick-Film Organic Solar Cells via Synergistic Dilution Strategy.

Developing stable and highly efficient thick-film organic solar cells (OSCs) is crucial for the large-scale commercial application of organic photovoltaics. A novel synergistic dilution strategy to address this issue, using Polymethyl Methacrylate (PMMA) -modified zinc oxide (ZnO) as the interfacial layer, is introduced. This strategy effectively mitigates oxygen defects in ZnO while also regulating the self-assembly process of the active layer to achieve an ordered distribution of donors and acceptors. In synergistic diluted devices, the dynamic disorder is reduced owing to the suppression of electron-phonon coupling, while the static disorder is suppressed by improved molecular stacking and enhanced intermolecular interactions. Consequently, the 300nm PM6:L8-BO device post-synergistic dilution manifests a marked enhancement in device performance, achieving a photovoltaic power conversion efficiency (PCE) >17% with excellent thermal stability. A typical ternary system is selected to explore the general applicability of synergistic dilution strategy, the PCE has been enhanced significantly from 17.89% to 18.72%, which falls within the range of the highest values among inverted single junction OSCs. As a practical application that depends on the pivotal synergy between high efficiency and stability, this approach paves the way for large-scale implementation of OSCs and ensures cost-effectiveness.

Preferential Binding of Cations Modulates Electrostatically Driven Protein Aggregation and Disaggregation.

Protein aggregation resulting in either ordered amyloids or amorphous aggregates is not only restricted to deadly human diseases but also associated with biotechnological challenges encountered in the therapeutic and food industries. Elucidating the key structural determinants of protein aggregation is important to devise targeted inhibitory strategies, but it still remains a formidable task owing to the underlying hierarchy, stochasticity, and complexity associated with the self-assembly processes. Additionally, alterations in solution pH, salt types, and ionic strength modulate various noncovalent interactions, thus affecting the protein aggregation propensity and the aggregation kinetics. However, the molecular origin and a detailed understanding of the effects of weakly and strongly hydrated salts on protein aggregation and their plausible roles in the dissolution of aggregates remain elusive. In this study, using fluorescence and circular dichroism spectroscopy in combination with electron microscopy and light scattering techniques, we show that the ionic size, valency, and extent of hydration of cations play a crucial role in regulating the protein aggregation and disaggregation processes, which may elicit unique methods for governing the balance between protein self-assembly and disassembly.

Megamolecule Self-Assembly Networks: A Combined Computational and Experimental Design Strategy.

This work describes the use of computational strategies to design megamolecule building blocks for the self-assembly of lattice networks. The megamolecules are prepared by attaching four Cutinase-SnapTag fusion proteins (CS fusions) to a four-armed linker, followed by functionalizing each fusion with a terpyridine linker. This functionality is designed to participate in a metal-mediated self-assembly process to give networks. This article describes a simulation-guided strategy for the design of megamolecules to optimize the peptide linker in the fusion protein to give conformations that are best suited for self-assembly and therefore streamlines the typically time-consuming and labor-intensive experimental process. We designed 11 candidate megamolecules and identified the most promising linker, (EAAAK)2, along with the optimal experimental conditions through a combination of all-atom molecular dynamics, enhanced sampling, and larger-scale coarse-grained molecular dynamics simulations. Our simulation findings were validated and found to be consistent with the experimental results. Significantly, this study offers valuable insight into the self-assembly of megamolecule networks and provides a novel and general strategy for large biomolecular material designs by using systematic bottom-up coarse-grained simulations.

Scalable fabrication of flexible 3D PEDOT/rGO Scaffold for high-performance supercapacitors via a self-assembly method

Conducting polymers hold great prospects in energy storage, especially in the field of flexible energy storage, however, their broad applications are limited due to the poor processability, difficulty in structural design diversity and unsatisfactory performance when used alone. Herein, the processability of PEDOT in organic phase is significantly enhanced by surfactant modification via a self-assembly process, contributing to the convenient and low-cost construction of 3D PEDOT architecture. Importantly, the PEDOT and rGO can be introduced into the same porous structure synchronously and conveniently. Superior capacitive performance is shown for the porous PEDOT/rGO film benefits from the combination of PEDOT with excellent electrochemical stability, rGO with high conductivity and porous structure with abundant active sites and chambers for electrolyte storage. The porous PEDOT/rGO film can be used as a scaffold for the deposition of conductive polymers. For example, once PPy is deposited, a high specific capacitance of 407.8 F g-1 at a current density of 0.5 A g-1, accompanied by a prominent capacitance retention of 90% after 5000 cycles are achieved. When it is used to construct the symmetric supercapacitor (SSC), a high energy density of 52.9 Wh kg-1 at the power density of 200.2 W kg-1 is delivered, with a high capacitance retention of 85%. Moreover, it shows excellent mechanical flexibility upon multiple bending cycles, rendering great potential in portable or wearable energy storage devices.

Construction of cellulose 3D network composite membrane supported by hydroxylated boron nitride with high surface charge density to achieve high-efficiency osmotic energy harvesting

Ion selectivity and mechanical persistence are critical properties of membranes to harvest osmotic energy. Two-dimensional nanofluidic membranes have been studied to enhance those properties, whereas they are usually constrained due to unsatisfactory mass transfer performances. Herein, a ternary three-dimensional membrane (T-CNF/PVDF/BN-OH composite membrane, abbreviated as CPBN) with distinct mechanical strength and high surface charge density (−2.65 mC·m−2) for sustainable osmotic energy harvesting is designed. In CPBN, negatively charged TEMPO-oxidized cellulose acts as a scaffold and constructs a 3D network structure together with the hydroxylated boron nitride (BN-OH) via a self-assembly process. The affluent nano-constrained ion channels effectively enhance the controllability and effectiveness of ion transport. The abundant ionized carboxyl groups extremely facilitate the selective transportation of the cations, while the BN-OH also assist this process, promoting the one-way transmission of cations in the channel. Additionally, the participation of PVDF polymer forms a network interlock structure, which significantly improves mechanical performances and stability in water. The membrane demonstrates a high power density (10.6 W/m2), measured in minimal testing areas, and an average power density around 1 W/m2 in larger areas, with an energy conversion efficiency of up to 30.7 %. This study provides a promising exploration of replacing traditional two-dimensional layered structure with three-dimensional network structure of cellulose for osmotic energy harvesting.

From Double-Stranded Helicates to Abiotic Double Helical Supramolecular Assemblies.

The folding of oligomeric strands is the method that nature has selected to generate ordered assemblies presenting spectacular functions. In the purpose to mimic these biomacro-molecules and extend their properties and functions, chemists make important efforts to prepare artificial secondary, tertiary, and even quarternary structures based on folded abiotic backbones. A large variety of oligomers and polymers, encoded with chemical informations, were designed, synthesized and characterized, and the establishment of non-covalent interactions lead to complex and functional supramolecular architectures resulting from a spontaneous self-assembly process. The association of comple-mentary molecular strands into double helical structures is a common structural pattern of nucleic acids and proteins, so the synthesis of bio-inspired double helices has emerged as an important subject. In recent years, a number of synthetic oligo-mers have been reported to form stable double helices and it was shown that the equilibrium between single and double helices can be controlled via different stimuli like the modification of the solvent or the temperature. This kind of structure presents highly interesting functions, such as molecular recognition within the cavity of double helices, and some other potential applications will emerge in the future.

Integrating Single-Walled Carbon Nanotubes into Supramolecular Assemblies: From Basic Interactions to Emerging Applications.

Integrating single-walled carbon nanotubes (SWCNTs) into supramolecular self-assemblies harnesses the distinctive mechanical, optical, and electronic properties of the nanoparticles alongside the structural and chemical properties of the assemblies. Organic molecules capable of forming supramolecular assemblies through hydrophobic, van der Waals, and π-π interactions have been demonstrated to be particularly effective in dispersing and functionalizing SWCNTs, as these same interactions facilitate the binding to the hydrophobic graphene-like surface of the SWCNTs. This review discusses a variety of self-assembling structures that were shown to integrate SWCNTs, ranging from simple micelles and ring structures to complex DNA origami and three-dimensional hydrogels formed by low-molecular-weight gelators. We explore the integration of SWCNTs into various supramolecular assemblies and highlight emerging applications of these composite materials, such as the mechanical enforcement of self-assembling hydrogels and leveraging the near-infrared (NIR) fluorescence properties of SWCNTs for monitoring the molecular self-assembly process. Notably, the distinctive NIR fluorescence of SWCNTs, which overlaps with the biological transparency window, offers significant opportunities for noninvasive sensing applications within the supramolecular platforms. Future research into a deeper understanding of the interactions between SWCNTs and different supramolecular frameworks will expand the potential applications of SWCNT-integrated supramolecular assemblies in fields like biomedical engineering, electronic devices, and environmental sensing.

Unlocking Intracellular Protein Delivery by Harnessing Polymersomes Synthesized at Microliter Volumes using Photo-PISA.

Efficient delivery of therapeutic proteins and vaccine antigens to intracellular targets is challenging due to generally poor cell membrane permeation and endolysosomal entrapment causing degradation. Herein, these challenges are addressed by developing an oxygen-tolerant photoinitiated polymerization-induced self-assembly (Photo-PISA) process, allowing for the microliter-scale (10µL) synthesis of protein-loaded polymersomes directly in 1536-well plates. High-resolution techniques capable of analysis at a single particle level are employed to analyze protein encapsulation and release mechanisms. Using confocal microscopy and super-resolution stochastic optical reconstruction microscopy (STORM) imaging, their ability to deliver proteins into the cytosol following endosomal escape is subsequently visualized. Lastly, the adaptability of these polymersomes is exploited to encapsulate and deliver a prototype vaccine antigen, demonstrating its ability to activate antigen-presenting cells and support antigen cross-presentation for applications in subunit vaccines and cancer immunotherapy. This combination of ultralow volume synthesis and efficient intracellular delivery holds significant promise for unlocking the high throughput screening of a broad range of otherwise cost-prohibitive or early-stage therapeutic protein and vaccine antigen candidates that can be difficult to obtain in large quantities. The versatility of this platform for rapid screening of intracellular protein delivery can result in significant advancements across the fields of nanomedicine and biomedical engineering.

Designing injectable dermal matrix hydrogel combined with silver nanoparticles for methicillin-resistant Staphylococcus aureus infected wounds healing

Hydrogel-based delivery systems have now emerged as a pivotal platform for addressing chronic tissue defects, leveraging their innate capacity to suppress pathogenic infections and facilitate expedited tissue regeneration. In this work, an injectable hydrogel dressing, termed AgNPs-dermal matrix hydrogel (Ag@ADMH), has been designed to expedite the healing process of wounds afflicted with methicillin-resistant Staphylococcus aureus (MRSA), featuring sustained antibacterial efficacy. The synthesis of the hydrogel dressing entailed a self-assembly process of collagen fibers within an acellular dermal matrix to construct a three-dimensional scaffold, encapsulated with plant polyphenol-functionalized silver nanoparticles (AgNPs). The Ag@ADMH demonstrated exceptional biocompatibility, and enables a sustained release of AgNPs, ensuring prolonged antimicrobial activity. Moreover, the in vitro RT-qPCR analysis revealed that compared with ADMH, Ag@ADMH diminish the expression of iNOS while augmenting CD206 expression, thereby mitigating the inflammatory response and fostering wound healing. Especially, the Ag@ADMH facilitated a reduction in M1 macrophage polarization, as evidenced by a significant decrement in the M1 polarization trend and an enhanced M2/M1 ratio in dermal matrix hydrogels laden with AgNPs, corroborated by confocal microscopy and flow cytometry analyses of macrophage phenotypes. The in vivo assessments indicated that Ag@ADMH minimized fibrous capsule formation. In a full-thickness skin defect model of MRSA infection, the formulation significantly attenuated the inflammatory response by reducing MPO and CD68 expression levels, concurrently promoting collagen synthesis and CD34 expression, pivotal for vasculogenesis, thereby accelerating the resolution of MRSA-infected wounds. These attributes underscore the injectable extracellular matrix hydrogel as a formidable strategy for the remediation and regeneration of infected wounds.Graphical

Dynamic Surface Interactions Enable the Self-Assembly of Perfect Supramolecular Crystals.

Supramolecular crystals arise from noncovalent interactions between macromonomers and allow for the engineering of dynamic functional materials. For two-dimensional (2D) crystals, the substrate surface can induce the formation of new polymorphs not available in solution, adding a layer of complexity to the supramolecular self-assembly process. Despite extensive studies on the 2D self-assembly of supramolecular crystals, unknowns remain regarding substrate-monomer interactions and the effects on network self-assembly and defect repair. Here, we used a DNA-mica model system to modulate and understand the impact of substrate-monomer interactions on the crystalline order. We controlled the surface interactions by tuning the Mg2+ concentration, varying the divalent cation type, and adjusting the relative concentration of divalent and monovalent cations. The competition between monovalent and divalent cations yielded nearly defect-free crystals with minimal polygon defects. These findings highlight the critical role of surface interactions in achieving high crystalline order, which is essential for optimizing the efficiency and performance of supramolecular functional nanomaterials.

Synthesis and Self-Assembly of Poly(4-acetoxystyrene) Cubosomes.

Polymer cubosomes (PCs) are a recent class of self-assembled nanostructures with great application potential due to their high porosity and surface area. Currently, most reported PCs consist of polystyrene block copolymers (BCPs), for which self-assembly parameters are rather well understood. Changing the block chemistry would be desirable to introduce more functionality; however, knowledge of adapting the self-assembly process to new chemistries remains limited. This work, reports on synthesizing poly(ethylene oxide)-block-poly(4-acetoxystyrene) and its copolymers with styrene, and provide conditions for their self-assembly into PCs with high yield and high inner order. It is shown that the polarity of the starting solvent toward the corona block allows tuning of the final morphology by controlling the corona volume and packing parameter.

Control Patterning of Cyanobiphenyl Liquid Crystals for Electricity Applications.

Controlling molecular self-assembly from organic solution evaporation is an important strategy for developing many functional materials and systems. In this work, it is demonstrated that 4-octyloxy-4'-cyanobiphenyl (8OCB) liquid crystals can be patterned into well-oriented stripes with very high micrometer-scale precision using a sandwich system through a dewetting method. The preparation temperature, concentration, and surface energy are combined to control the morphology and orientation of 8OCB microstripe arrays assisted by silicon micropillars. Microstripes prepared below the isotropic temperature were uniform, well-ordered, and showed high electricity. In addition, 8OCB molecules have a strong tendency toward antiparallel alignment, nearly standing up on the substrate with long axes parallel to the microstripe. Also, we point out the mechanism for the self-assembly process of 8OCB on the air-liquid and liquid-solid surface.

Homologous Peptide Foldamer Promotes FUS Aggregation and Triggers Cancer Cell Death.

Fused in sarcoma (FUS), a multifunctional deoxyribonucleic acid (DNA)/ribonucleic acid (RNA)-binding protein, has been implicated in various cancer types, including sarcoma and leukemia. Despite its association with these diseases, there has been limited exploration of FUS as a cancer therapy target, primarily because its dynamic nature makes it difficult to target specifically. In this study, we explored a kind of β-sheet peptide foldamer, named β4-TAT, to influence FUS aggregation by targeting its RNA recognition motifs (RRM). This approach leverages the noncovalent interaction characteristics of peptide self-assembly processes. The β4 sequence, derived from the FUS RRM β-sheet, in combination with TAT, a peptide known for its nuclear targeting capability, enables β4-TAT to bind specifically to the analogous β4 sequence within FUS. Notably, β4-TAT effectively induces FUS aggregation within cells, leading to the death of cancer cells. Our work developed a novel peptide foldamer-based strategy for inducing protein aggregation, paving the way for innovative therapeutic approaches in targeting FUS-associated cancers.

Layered MXene Films via Self-Assembly.

MXene has attracted significant attention as a 2D material family due to its metallic conductivity and abundant surface functional groups and has been extensively studied and applied as bulk materials and microscale thin films. MXene possesses ionizable surfaces and edges, as well as high surface area. Its customizable dispersibility demonstrates unique advantages in self-assembly solution processing. Recent studies have demonstrated the application value of layered MXene films at the nanoscale thickness and the reliance of processing on self-assembly techniques. However, this field currently lacks sufficient attention. Here, the regulatory mechanisms are summarized for the preparation of layered MXene films through self-assembly techniques, as well as introduce their applications. Moreover, the future challenges of large-scale applications of MXene self-assembly techniques are proposed. It is believed that this review would provide a dynamic and promising path for the development of layered MXene self-assembly techniques.