Molecular Component Structures MediatedFormation of Self-assemblies

Molecular recognition directed self-assemblies from complementary molecular components, melamine and barbituric acid derivatives were studied by means of NMR, fluorescence, and TEM. It was found that both the process of the self-assembly and the morphologies of the result- ed self-assemblies could be mediated by modifying the structures of the molecular components used. The effect of the structures of the molecular components on the formation of the self-as- semblies was discussed in terms of intermolecular interactions.

A nitric oxide-triggered hydrolysis reaction to construct controlled self-assemblies with complex topologies

Hydrolysis reactions are capable of directing the non-equilibrium assembly of biomolecular scaffolds to realize sophisticated structures and functions in natural systems.However,utilizing the proper hydrolysis reactions to construct controlled assemblies with complex topologies is still an arduous challenge in artificial systems and needs to be addressed.Herein,we report a nitric oxide(NO)-triggered slow hydrolysis strategy for the controlled construction of biomimetic supramolecular toroids(STs),thus realizing their visualization of intermediate structures and regulation of geometry parameters.This presented protocol harnesses hydrolysis reactions to control of non-equilibrium self-assembly processes for the construction of self-assemblies with complex topologies successfully,which sheds light on how the hydrolysis reaction rate can modulate the kinetic pathway of assembly,thus realizing the artificial establishment of bio-inspired hierarchical structures.

Pillar[6]arene-based supramolecular self-assemblies for twopronged GSH-consumption-augmented chemo/photothermal therapy

The abundant intracellular glutathione(GSH)in cancer cells severely undermines the therapeutic efficacy of different treatments due to their role in protecting cancer cells from the associated oxidative stress.Developing a highly integrated system to consume GSH would help to improve the therapeutic outcomes.In this study,supramolecular prodrug self-assemblies(SPSAs)with IR825 loaded inside were developed to consume GSH via two-pronged pathways while augmenting the therapeutic potency of chemo/photothermal treatment.SPSAs were prepared using water-soluble pillar[6]arene(WP[6])as host units and H_(2)O_(2)-responsive nitrogen mustard prodrug,chlorambucil-(phenylboronic acid pinacol ester)conjugates(Cb-BE),as the guests.When SPSAs were internalized by cancer cells,the generation of quinone methide(QM)from Cb-BE and singlet oxygen(^(1)O_(2))from irradiation-activated IR825 could consume GSH in a concerted way.As such,the therapeutic efficacies of the released chlorambucil and the accompanied hyperthermia were augmented toward synergistically inhibiting tumor growth.

Nanostructured self-assemblies of photosensitive dyes: green and efficient theranostic approaches

Recently,nano theranostics,by integrating diagnostic and therapeutic functions into a nano system,have provided increasing opportunities for the design of personalized medicine in cancer.Among the construction method of various theranostic nano systems,the design of single component nanoparticles which are composed of organic photosensitive dyes has become a promising approach to constructing multifunctional nano-theranostic systems,thanks to its unique advantages such as defined structure,100%loading,and high repeatability.Specifically,depending on the inherent photonic imaging and therapeutic properties of the photosensitive dyes,the multifunctional purpose which integrates theranostic effects and targeting abilities can be realized via reasonable molecular modification and supramolecular assembly.In this review,recent advances in the development of nanostructured self-assemblies of porphyrins,phthalocyanines,and boron-dipyrromethanes for theranostics are summarized.Emphasis on their design consideration and theranostic applications are presented.Additionally,prospects for clinical practice and potential challenges of this rapidly growing field are also provided.

Interfacial Modification of NiO_(x)by Self-assembled Monolayer for Efficient and Stable Inverted Perovskite Solar Cells

NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.

Time-resolved luminescent nanoprobes based on lanthanide nucleotide self-assemblies for alkaline phosphatase detection

Currently,enzyme-responsive nanomaterials have shown great promise in prognosis or diagnosis of disease biomarker.However,the great obstacle for conventional enzyme-responsive nanomaterials frequently lies in autofluorescence interference,poor monodispersity,uncontrollable size and morphology,low optical stability,and biotoxicity,which fundamentally impede their practical application in biological systems.To overcome these deficiencies,we proposed a novel strategy for reliable and precise detection of an enzyme disease biomarker,alkaline phosphatase(ALP),through lanthanide(Ln^(3+))nucleotide nanoparticles(LNNPs)with extremely improved monodispersity and uniformity,which were achieved by the coordination self-assembly between ATP and Ln^(3+)inside micellar nanoreactor.Specifically,for ATP-Ce/Tb LNNPs,highly improved photoluminescence(PL)emission of Tb^(3+)can be achieved via efficient Ce^(3+)sensitization.We demonstrated that ALP could specifically cleave the phosphorus–oxygen(P–O)bonds of ATP and result in the collapse of ATP-Ce/Tb scaffold,finally leading to the PL quenching of Tb^(3+).By taking advantage of time-resolved(TR)PL technique,the fabricated ATP-Ce/Tb LNNPs presented superior selectivity and sensitivity for the ALP bioassay in complicated serum samples,thus revealing the great potential of ATP-Ce/Tb LNNPs in the areas of ALP-related disease prognosis and diagnosis.

Alcohol solvent effect on the self-assembly behaviors of lignin oligomers

The interactions between lignin oligomers and solvents determine the behaviors of lignin oligomers self-assembling into uniform lignin nanoparticles(LNPs).Herein,several alcohol solvents,which readily interact with the lignin oligomers,were adopted to study their effects during solvent shifting process for LNPs’production.The lignin oligomers with widely distributed molecular weight and abundant guaiacyl units were extracted from wood waste(mainly consists of pine wood),exerting outstanding self-assembly capability.Uniform and spherical LNPs were generated in H_(2)O-n-propanol cosolvent,whereas irregular LNPs were obtained in H_(2)O-methanol cosolvent.The unsatisfactory self-assembly performance of the lignin oligomers in H_(2)O-methanol cosolvent could be attributed to two aspects.On one hand,for the initial dissolution state,the distinguishing Hansen solubility parameter and polarity between methanol solvent and lignin oligomers resulted in the poor dispersion of the lignin oligomers.On the other hand,strong hydrogen bonds between methanol solvent and lignin oligomers during solvent shifting process,hindered the interactions among the lignin oligomers for self-assembly.

Intelligent responsive self-assembled micro-nanocapsules:Used to delay gel gelation time

In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel gelation time are complicated or have low responsiveness.There is an urgent need for an effective method for delaying gel gelation time with intelligent response.Inspired by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO_(2) in aqueous solution as a capsule to prepare an intelligent responsive self-assembled micro-nanocapsules.The capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation time.When the pH value is 2 and the concentration of gas-phase hydrophobic SiO_(2) particles is 10%,the gelation time of the capsule gel system at 30,60,90,and 120℃is12.5,13.2,15.2,and 21.1 times longer than that of the gel system without containing capsule,respectively.Compared with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 322 Pa.The intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel strength.The slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.

Self-assembly of perovskite nanocrystals:From driving forces to applications

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell field.This review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are detailed.Subsequently,we summarize the collective optoelectronic properties and application areas of perovskite superlattice structures.Finally,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

A self-assembled affibody-PROTAC conjugate nanomedicine for targeted cancer therapy

Proteolysis targeting chimeras (PROTACs) have recently emerged as promising therapeutic agents for cancer therapy. However, their clinical application is considerably hindered by the poor membrane permeability and insufficient tumor distribution of PROTACs. Here we proposed a nanoengineered targeting strategy to construct a self-assembled affibody-PROTAC conjugate nanomedicine (APCN) for tumor-specific delivery of PROTACs. As proof of concept, a hydrophobic PROTAC MZ1 (a bromodomain-containing protein 4 degrader) was selected to couple with a hydrophilic affibody ZHER2:342 (an affinity protein of human epidermal growth factor receptor 2, HER2) via a smart linker containing disulfide bond to form an amphiphilic ZHER2:342-MZ1 conjugate. It spontaneously self-assembled into nanoparticles (ZHER2:342-MZ1 APCN) in water. Upon the excellent targeting property of ZHER2:342 and HER2 receptor-mediated endocytosis, ZHER2:342-MZ1 APCN was accumulated in tumor sites and internalized by cancer cells effectively in vitro. Under the intracellular high level of glutathione (GSH), ZHER2:342-MZ1 APCN released MZ1 to specifically degrade bromodomain-containing protein 4 (BRD4) and subsequently induced BRD4 deficiency-mediated apoptosis of cancer cells. By the tail-vein injection, ZHER2:342-MZ1 APCN showed the outstanding tumor-specific targeting ability, drug accumulation capacity, enhanced BRD4 degradation and antitumor efficacy in vivo for an HER2-positive SKOV-3 tumor model. Such an affibody mediated nanoengineered strategy would facilitate the application of PROTACs for targeted cancer therapy.

Role of self-assembled molecules’anchoring groups for surface defect passivation and dipole modulation in inverted perovskite solar cells

Inverted perovskite solar cells have gained prominence in industrial advancement due to their easy fabrication,low hysteresis effects,and high stability.Despite these advantages,their efficiency is currently limited by excessive defects and poor carrier transport at the perovskite-electrode interface,particularly at the buried interface between the perovskite and transparent conductive oxide(TCO).Recent efforts in the perovskite community have focused on designing novel self-assembled molecules(SAMs)to improve the quality of the buried interface.However,a notable gap remains in understanding the regulation of atomic-scale interfacial properties of SAMs between the perovskite and TCO interfaces.This understanding is crucial,particularly in terms of identifying chemically active anchoring groups.In this study,we used the star SAM([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)as the base structure to investigate the defect passivation effects of eight common anchoring groups at the perovskite-TCO interface.Our findings indicate that the phosphonic and boric acid groups exhibit notable advantages.These groups fulfill three key criteria:they provide the greatest potential for defect passivation,exhibit stable adsorption with defects,and exert significant regulatory effects on interface dipoles.Ionized anchoring groups exhibit enhanced passivation capabilities for defect energy levels due to their superior Lewis base properties,which effectively neutralize local charges near defects.Among various defect types,iodine vacancies are the easiest to passivate,whereas iodine-substituted lead defects are the most challenging to passivate.Our study provides comprehensive theoretical insights and inspiration for the design of anchoring groups in SAMs,contributing to the ongoing development of more efficient inverted perovskite solar cells.

Factors resisting protein adsorption on hydrophilic/hydrophobic self-assembled monolayers terminated with hydrophilic hydroxyl groups

The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.

Hollow tubes constructed by carbon nanotubes self-assembly for CO_(2) capture

Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their macroscopic assembly.The present study employed a gentle and direct self-assembly technique,wherein controlled growth of CNT sheaths occurred on the metal wire’s surface,followed by etching of the remaining metal to obtain the hollow tubes composed of CNTs.By controlling the growth time and temperature,it is possible to alter the thickness of the CNTs sheath.After immersing in a solution containing 1 g/L of CNTs at 60℃ for 24 h,the resulting CNTs layer achieved a thickness of up to 60μm.These hollow CNTs tubes with varying inner diameters were prepared through surface reinforcement using polymers and sacrificing metal wires,thereby exhibiting exceptional attributes such as robustness,flexibility,air tightness,and high adsorption capacity that effectively capture CO_(2) from the gas mixture.

The sequence-dependent morphology of self-assembly peptides after binding with organophosphorus nerve agent VX

VX is a highly toxic organophosphorus nerve agent that the Chemical Weapons Convention classifies as a Schedule 1. In our previous study, we developed a method for detecting organophosphorus compounds using peptide self-assembly. Nevertheless, the self-assembly mechanisms of peptides that bind organophosphorus and the roles of each peptide residue remain elusive, restricting the design and application of peptide materials. Here, we use a multi-scale computational combined with experimental approach to illustrate the self-assembly mechanism of peptide-bound VX and the roles played by residues in different peptide sequences. We calculated that the self-assembly of peptides was accelerated after adding VX, and the final size of assembled nanofibers was larger than the original one, aligning with experimental findings. The atomic scale details offered by our approach enabled us to clarify the connection between the peptide sequences and nanostructures formation, as well as the contribution of various residues in binding VX and assembly process. Our investigation revealed a tight correlation between the number of Tyrosine residues and morphology of the assembly. These results indicate a self-assembly mechanism of peptide and VX, which can be used to design functional peptides for binding and hydrolyzing other organophosphorus nerve agents for detoxification and biomedical applications.

Confined cobalt single-atom catalysts with strong electronic metal-support interactions based on a biomimetic self-assembly strategy

Designing high-performance and low-cost electrocatalysts for oxygen evolu-tion reaction(OER)is critical for the conversion and storage of sustainable energy technologies.Inspired by the biomineralization process,we utilized the phosphorylation sites of collagen molecules to combine with cobalt-based mononuclear precursors at the molecular level and built a three-dimensional(3D)porous hierarchical material through a bottom-up biomimetic self-assembly strategy to obtain single-atom catalysts confined on carbonized biomimetic self-assembled carriers(Co SACs/cBSC)after subsequent high-temperature annealing.In this strategy,the biomolecule improved the anchoring efficiency of the metal precursor through precise functional groups;meanwhile,the binding-then-assembling strategy also effectively suppressed the nonspecific adsorption of metal ions,ultimately preventing atomic agglomeration and achieving strong electronic metal-support interactions(EMSIs).Experimental characterizations confirm that binding forms between cobalt metal and carbonized self-assembled substrate(Co–O_(4)–P).Theoretical calculations disclose that the local environment changes significantly tailored the Co d-band center,and optimized the binding energy of oxygenated intermediates and the energy barrier of oxygen release.As a result,the obtained Co SACs/cBSC catalyst can achieve remarkable OER activity and 24 h durability in 1 M KOH(η10 at 288 mV;Tafel slope of 44 mV dec-1),better than other transition metal-based catalysts and commercial IrO_(2).Overall,we presented a self-assembly strategy to prepare transition metal SACs with strong EMSIs,providing a new avenue for the preparation of efficient catalysts with fine atomic structures.

Layer by Layer Self-assembly Fiber-based Flexible Electrochemical Transistor

Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface morphology and electric property was investigated.The results confirmed the dense membrane of PEDOT:PSS and the lamellar structure of PDDA-rGO on the fibers.It has excellent electrical conductivity and mechanical properties.The fiber based electrochemical transistor(FECTs)prepared by the composite conductive fiber has a maximum output current of 8.7 mA,a transconductance peak of 10 mS,an on time of 1.37 s,an off time of 1.6 s and excellent switching stability.Most importantly,the devices by layer by layer self-assembly technology opens a path for the true integration of organic electronics with traditional textile technologies and materials,laying the foundation for their later widespread application.

A Non-parametric Gradient-Based Shape Optimization Approach for Solving Inverse Problems in Directed Self-Assemblyof Block Copolymers

We consider the inverse problem of finding guiding pattern shapes that result in desired self-assembly morphologies of block copolymer melts.Specifically,we model polymer selfassembly using the self-consistent field theory and derive,in a non-parametric setting,the sensitivity of the dissimilarity between the desired and the actual morphologies to arbitrary perturbations in the guiding pattern shape.The sensitivity is then used for the optimization of the confining pattern shapes such that the dissimilarity between the desired and the actual morphologies is minimized.The efficiency and robustness of the proposed gradient-based algorithm are demonstrated in a number of examples related to templating vertical interconnect accesses(VIA).

Chitosan/Sodium Alginate Multilayer pH-Sensitive Films Based on Layer-by-Layer Self-Assembly for Intelligent Packaging

The abuse of plastic food packaging has brought about severe white pollution issues around the world.Developing green and sustainable biomass packaging is an effective way to solve this problem.Hence,a chitosan/sodium alginate-based multilayer film is fabricated via a layer-by-layer(LBL)self-assembly method.With the help of superior interaction between the layers,the multilayer film possesses excellent mechanical properties(with a tensile strength of 50 MPa).Besides,the film displays outstanding water retention property(blocking moisture of 97.56%)and ultraviolet blocking property.Anthocyanin is introduced into the film to detect the food quality since it is one natural plant polyphenol that is sensitive to the pH changes ranging from 1 to 13 in food when spoilage occurs.It is noted that the film is also bacteriostatic which is desired for food packaging.This study describes a simple technique for the development of advanced multifunctional and fully biodegradable food packaging film and it is a sustainable alternative to plastic packaging.

Morphological Evolution of Self-Assembled Sodium Dodecyl Sulfate/Dodecyltrimethylammonium Bromide@Epoxy-β-Cyclodextrin Supramolecular Aggregates Induced by Temperature

Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.

Development of polyvinylpyrrolidone/paclitaxel self-assemblies for breast cancer

The goal of this investigation was to develop and demonstrate a polymer/paclitaxel selfassembly(PTX-SA) formulation. Polymer/PTX-SAs were screened based on smaller size of formulation using dynamic light scattering analysis. Additionally, fluorescence microscopy and flow cytometry studies exhibited that polyvinylpyrrolidone(PVP)-based PTX-SAs(PVP/PTX-SAs) had superior cellular internalization capability in MCF7 and MDA-MB-231 breast cancer cells. The optimized PVP/PTXSAs exhibited less toxicity to human red blood cells indicating a suitable formulation for reducing systemic toxicity. The formation of PVP and PTX self-assemblies was confirmed using fluorescence quenching and transmission electron microscopy which indicated that the PVP/PTX-SAs were spherical in shape with an average size range of 53.81 nm as detected by transmission electron microscopy(TEM).FTIR spectral analysis demonstrates incorporation of polymer and paclitaxel functional groups in PVP/PTX-SAs. Both proliferation(MTS) and clonogenic(colony formation) assays were used to validate superior anticancer activity of PVP/PTX-SAs in breast cancer cells over paclitaxel. Such superior anticancer activity was also demonstrated by downregulation of the expression of pro-survival protein(Bcl-x L), upregulation of apoptosis-associated proteins(Bid, Bax, cleaved caspase 7, and cleaved PARP)and β-tubulin stabilization. These results support the hypothesis that PVP/PTX-SAs improved paclitaxel delivery to cancer cells.