Emergent chiral and topological nanoarchitectonics in self-assembled supramolecular systems

The fabrication of structures with designated topologies at the nanoscale is an intriguing issue, attributed to the possibility of both imparting unique properties to functional materials and unravelling the codes that lie in many natural systems. As a significant bottom-up approach, the self-assembly strategy is potent in formulating various exquisite structures. While the building of common types of miniaturized structures such as tubes, twists and spheres has been investigated in depth to gain insight into the intrinsic principles that dictate their formation and functions, the preparation of peculiar topological nanostructures is still scattered and unsystematic. In parallel, chirality is among the most ubiquitous phenomena of fundamental significance in nature and is in close relationship with the origin of life. Essentially, chirality represents a type of orderliness and thus may interplay with peculiar topologies in an orchestrated and serendipitous way. In this review, we describe the development of constructing emergent chiral and topological nanoarchitectures via the self-assembly method, mainly focusing on structures including toroids, catenanes, Möbius strips, spirals and fractals. In addition, other types involving toruloids/kebabs, trumpets and bamboos, screws, dendritic and lamellar twists are also exemplified. The design of building blocks and various self-assembling strategies towards these target architectures are highlighted in this review, in an effort to provide an overview of the feasible approaches that facilitate the tailored construction of mesoscopic structures.

Biomass-derived semiconductors for renewable energy technologies

Semiconductor materials play a crucial role in advancing renewable energy technologies, enabling efficient photocatalytic hydrogen production, energy conversion, and energy storage. Compared to traditional non-renewable semiconductors, next-generation semiconductor materials derived from abundant and renewable feedstocks have garnered increasing research interest. Integrating renewable semiconductors into emerging energy technologies provides unprecedented opportunities for achieving sustainability goals. Among renewable resources, biomass-derived materials have recently emerged as particularly promising candidates for semiconductor development, driven by progress in synthetic strategies. This review focuses on key synthetic approaches for producing semiconductors from biomass-derived materials, specifically tailored for sustainable energy systems. We classify various biomass-based molecular precursors and discuss their conversion methods, properties, associated challenges, and potential advantages in practical applications.

Reaction development: a student's checklist

So you've discovered a reaction. But how do you turn this new discovery into a fully-fledged program that maximises the potential of your novel transformation? Herein, we provide a student's checklist to serve as a helpful guide for synthesis development, allowing you to thoroughly investigate the chemistry in question while ensuring that no key aspect of the project is overlooked. A wide variety of the most illuminating synthetic and spectroscopic techniques will be summarised, in conjunction with literature examples and our own insights, to provide sound justifications for their implementation towards the goal of developing new reactions.

Deciphering the self-assembly mechanisms of three diphenylalanine derivatives using infrared probe technique and scanning electron microscopy

Understanding the nucleation mechanism of peptide self-assembly is fundamental for the design and application of peptide-based materials. To this end, we herein explored the self-assembly processes of three diphenylalanine (FF) derivatives, Boc-XF, Boc-FX, and Boc-FF, where X is p-cyanophenylalanine with the cyano group being an infrared (IR) probe. Using IR probe technique and scanning electron microscopy (SEM), we revealed that the self-assembly of Boc-XF followed a three-step non-classical nucleation mechanism. Such a complex mechanism involved the presence of metastable spherical and fibrillar intermediates towards the final mature fibril phase. We further compared the self-assembly mechanism of Boc-XF with that of Boc-FF and Boc-FX and explored the potential impact of side-chain mutation on the peptide self-assembly mechanism. Our research provided a nice example of how to use a combined approach of IR probe technique and SEM to reveal the complex nucleation mechanism of peptide self-assembly.

Nanomaterials for Flexible Neuromorphics

The quest to imbue machines with intelligence akin to that of humans, through the development of adaptable neuromorphic devices and the creation of artificial neural systems, has long stood as a pivotal goal in both scientific inquiry and industrial advancement. Recent advancements in flexible neuromorphic electronics primarily rely on nanomaterials and polymers owing to their inherent uniformity, superior mechanical and electrical capabilities, and versatile functionalities. However, this field is still in its nascent stage, necessitating continuous efforts in materials innovation and device/system design. Therefore, it is imperative to conduct an extensive and comprehensive analysis to summarize current progress. This review highlights the advancements and applications of flexible neuromorphics, involving inorganic nanomaterials (zero-/one-/two-dimensional, and heterostructure), carbon-based nanomaterials such as carbon nanotubes (CNTs) and graphene, and polymers. Additionally, a comprehensive comparison and summary of the structural compositions, design strategies, key performance, and significant applications of these devices are provided. Furthermore, the challenges and future directions pertaining to materials/devices/systems associated with flexible neuromorphics are also addressed. The aim of this review is to shed light on the rapidly growing field of flexible neuromorphics, attract experts from diverse disciplines (e.g., electronics, materials science, neurobiology), and foster further innovation for its accelerated development.

Boosting stability: a hierarchical approach for self-assembling peptide structures

The primary objective of this study was to implement a hierarchical approach to enhance the conformational stability of a selected group of peptides by incorporating trans-(1S,2S)-2-aminocyclopentanecarboxylic acid (trans-ACPC). The influence of residue mutation on the peptide structures was investigated using circular dichroism, analytical ultracentrifugation, and vibrational spectroscopy. The resulting nanostructures were examined via transmission electron microscopy. The incorporation of trans-ACPC led to increased conformational stability and self-assembling propensity in peptides containing constrained β-amino acid residues.

Gold Nanoparticles-Modified 2D Self-Assembled Amphiphilic Peptide Nanosheets with High Biocompatibility and Photothermal Therapy Efficiency

Amphiphilic peptides have garnered significant attention due to their highly designable and self-assembling behaviors. Self-assembled peptides hold excellent potential in various fields such as biosensing, environmental monitoring, and drug delivery, owing to their remarkable biological, physical, and chemical properties. While nanomaterials formed by peptide self-assembly have found widespread use in biomedical applications, the development of 2D peptide nanosheets based on the self-assembly of amphiphilic peptides remains challenging in terms of rational design and morphology modulation. In this study, rationally designed amphiphilic peptide molecules are self-assembled into peptide nanosheets (PNS) under specific conditions to encapsulate gold nanoparticles (AuNPs), resulting in the formation of AuNPs/PNS hybrid materials with high photothermal conversion efficiency. The findings demonstrate that 2D PNS enhances the overall photothermal therapy effect of the nanohybrid materials due to their larger hosting area for AuNPs and higher biocompatibility. The well-designed amphiphilic peptides in this study offer insights into the structural design and functional modulation of self-assembled molecules. In addition, the constructed biomimetic-functional 2D inorganic/organic nanohybrid materials hold potential applications in biomedical engineering.

Enteral Route Nanomedicine for Cancer Therapy

With the in-depth knowledge of the pathological and physiological characteristics of the intestinal barrier-portal vein/intestinal lymphatic vessels-systemic circulation axis, oral targeted drug delivery is frequently being renewed. With many advantages, such as high safety, convenient administration, and good patient compliance, many researchers have begun to explore targeted drug delivery from intravenous injections to oral administration. Over the past few decades, the fields of materials science and nanomedicine have produced various drug delivery platforms that hold great potential in overcoming the multiple barriers associated with oral drug delivery. However, the oral transport of particles into the systemic circulation is extremely difficult due to immune rejection and biochemical invasion in the intestine, which limits absorption and entry into the bloodstream. The feasibility of the oral delivery of targeted drugs to sites outside the gastrointestinal tract (GIT) is unknown. This article reviews the biological barriers to drug absorption, the in vivo fate and transport mechanisms of drug carriers, the theoretical basis for oral administration, and the impact of carrier structural evolution on oral administration to achieve this goal. Finally, this article reviews the characteristics of different nano-delivery systems that can enhance the bioavailability of oral therapeutics and highlights their applications in the efficient creation of oral anticancer nanomedicines.

Functional surfactant-directing ultrathin metallic nanoarchitectures as high-performance electrocatalysts

Ultrathin nanosheets possess a distinctive structure characterized by an abundance of active sites fully accessible on their surface. Concurrently, their nanoscale thickness confers an extraordinarily high specific surface area and promising electronic properties. To date, numerous strategies have been devised for synthesizing precious metal nanosheets that exhibit excellent electrocatalytic performance. In this paper, recent progress in the controlled synthesis of two-dimensional, ultrathin nanosheets by a self-assembly mechanism using functional surfactants is reviewed. The aim is to highlight the key role of functional surfactants in the assembly and synthesis of two-dimensional ultrathin nanosheets, as well as to discuss in depth how to enhance their electrochemical properties, thereby expanding their potential applications in catalysis. We provide a detailed exploration of the mechanisms employed by several long-carbon chain surfactants commonly used in the synthesis of nanosheets. These surfactants exhibit robust electrostatic and hydrophobic effects, effectively confining the crystalline growth of metals along lamellar micelles. Moreover, we present an overview of the electrocatalytic performance demonstrated by the ultrathin nanosheets synthesized through this innovative pathway. Furthermore, it offers valuable insights that may pave the way for further exploration of more functional long-chain surfactants, leading to the synthesis of ultrathin nanosheets with significantly enhanced electrocatalytic performance.

Advances in siRNA Drug Delivery Strategies for Targeted TNBC Therapy

Among breast cancers, triple-negative breast cancer (TNBC) has been recognized as the most aggressive type with a poor prognosis and low survival rate. Targeted therapy for TNBC is challenging because it lacks estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Chemotherapy, radiation therapy, and surgery are the common therapies for TNBC. Although TNBC is prone to chemotherapy, drug resistance and recurrence are commonly associated with treatment failure. Combination therapy approaches using chemotherapy, mAbs, ADC, and antibody-siRNA conjugates may be effective in TNBC. Recent advances with siRNA-based therapy approaches are promising for TNBC therapy with better prognosis and reduced mortality. This review discusses advances in nanomaterial- and nanobiomaterial-based siRNA delivery platforms for TNBC therapy exploring targeted therapy approaches for major genes, proteins, and TFs upregulated in TNBC tumors, which engage in molecular pathways associated with low TNBC prognosis. Bioengineered siRNA drugs targeting one or several genes simultaneously can downregulate desired genes, significantly reducing disease progression.

Multi-Responsive Peptide-Based Ultrathin Nanosheets Prepared by a Horizontal Monolayer Assembly

In this study, peptide-based self-assembled nanosheets with a thickness of approximately 1 nm were prepared using a hierarchical covalent physical fabrication strategy. The covalent alternating polymerization of helical peptide E3 with an azobenzene (AZO) structure yielded copolymers CoP(E3-AZO), which physically self-assembled into ultrathin nanosheets in an unanticipated two-dimensional horizontal monolayer arrangement. This special monolayer arrangement enabled the thickness of the nanosheets to be equal to the cross-sectional diameter of a single linear copolymer, which is a rare phenomenon. Molecular dynamics simulations suggested that the synergistic effect of multiple molecular interactions drives the self-assembly of CoP(E3-AZO) into nanosheets and that various methods, including phototreatment, pH adjustment, the addition of additives, and introduction of cosolvents, can alter the molecular interactions and modulate the self-assembly of CoP(E3-AZO), yielding diverse nanostructures. Remarkably, the ultrathin nanosheets selectively inhibited cancer cells at certain concentrations.

Shape-tunable two-dimensional assemblies from chromophore-conjugated crystallizable poly(L-lactides) with chain-length-dependent photophysical properties

This work reports temperature-dependent shape-changeable two-dimensional (2D) nanostructures by crystallization-driven self-assembly (CDSA) from a chromophore-conjugated poly(L-lactide) (PLLA) homopolymer (PTZ-P1) that contained a polar dye, phenothiazine (PTZ), at the chain-end of the crystallizable PLLA. The CDSA of PTZ-P1 in a polar solvent, isopropanol (iPrOH), by an uncontrolled heating-cooling process, majorly generates lozenge-shaped 2D platelets via chain-folding-mediated crystallization of the PLLA core, leading to the display of the phenothiazines on the 2D surface that confers colloidal stability and orange-emitting luminescent properties to the crystal lamellae. Isothermal crystallization at 60 °C causes a morphological change in PTZ-P1 platelets from lozenge to truncated-lozenge to perfect hexagon under different annealing times, while no shape change was noticed in the structurally similar PTZ-P2 polymer with a longer PLLA chain under similar conditions. This study unveils the complex link between the 2D platelet morphologies and degree of polymerization (DP) of PLLA and the corona-forming dye character. Further, the co-assembly potential of PTZ-P1 with hydrophobic pyrene-terminated PLLAs of varying chain lengths (PY-P1, PY-P2, and PY-P3) was examined, as these two dyes could form a Förster Resonance Energy Transfer (FRET) pair on the 2D surface. The impact of the length of the crystallizable PLLA on the photophysical properties of the surface-occupied chromophores revealed crucial insights into interchromophoric interactions on the platelet surface. A reduction in the propensity for π-stacking with increasing chain-folding in longer PLLAs is manifested in the chain-length-dependent FRET efficiencies and excimer emission lifetimes within the resultant monolayered 2D assemblies. The unconventional "butterfly-shaped" molecular architecture of the tested phenothiazine, combined with its varied functional features and polar character, adds a distinctive dimension to the underdeveloped field of CDSA of chromophore-conjugated poly(L-lactides), opening future avenues for the development of advanced nanostructured biodegradable 2D materials with programmable morphology and optical functions.

Metal Ion Responsive Luminescent Bio-Templated Co-Assemblies: Label-Free Detection of Multi-Metal Ions in Aqueous Media

Recently, anionic bio-templates have emerged as promising platforms for designing dynamic and stimuli-responsive chromophoric assemblies capable of light harvesting in aqueous media thereby mimicking natural photosynthesis. Here, we present multi-metal ion-responsive luminescent co-assemblies between cationic pyrene-imidazolium amphiphile and anionic bio-templates (ATP, heparin, and DNA) in aqueous media. The anionic bio-templates enhance Förster resonance energy transfer (FRET) in the co-assemblies, with pyrene serving as an excellent donor for generating tunable multi-luminescent materials with embedded acceptor dyes. However, a significant loss in energy transfer towards acceptor dyes was observed in the presence of various metal ions, attributed to excimeric emission quenching facilitated by electron transfer between the pyrene chromophore and metal ions. Interestingly, detailed studies revealed that only ATP-based co-assemblies exhibited quenching phenomena in the presence of metal ions, contrasting with heparin and ctDNA co-assemblies. Additionally, label-free detection of multi-metal ions in aqueous environments, such as Fe2+, Fe3+, and Cu2+ ions, was successfully achieved with lower detection limits of 0.01 μM (3 ppb), 0.12 μM (30 ppb), and 0.58 μM (150 ppb) respectively. These co-assemblies hold significant promise for practical applications in environmental and biomedical sensing, enabling sensitive monitoring of metal ion concentrations.

Controlling Spatial Morphology of Microparticle Deposits via Thermocapillary Flows: Effect of Boundary Geometry

The production of particle deposits with a desired distribution geometry has significant potential for materials science, printing, and coating technologies. Most methods for achieving well-defined assemblies rely on the spontaneous evaporation of colloidal solutions on substrates with predetermined properties, or on precise control of particle arrangement by external stimuli. Here, we present a combined method that enables the production of centimeter-scale microparticle deposits with a desired geometric shape. The method is based on controlling the massive transport of microparticles by thermocapillary flow in a layer of volatile liquid in a cell with borders of the desired geometry. Capillary forces cause the liquid to be distributed in the cell, forming corner wetting menisci and the flat layer in the central area. The formation of particle deposits occurs in two stages, determined by the flow regime. At the initial stage, the axisymmetric thermocapillary flow occurs in the flat part of the layer, resulting in the circular shape of the particle deposit. During the transition to the second stage of assembling thermocapillary flow is localized in the corner wetting menisci that results in reshaping the current particle deposit to match the geometry of the cell borders. Here, we demonstrated the creation of circular, square, and triangular shapes of the patterns of polystyrene microparticles using a point heater located at the geometric center of the cell. The proposed method is reliable, easy to implement, and potentially capable of producing a wide variety of deposit geometries, making it an attractive technique for patterning and modifying surface properties with particles of any type.

Assembling Ag2S quantum dots onto peptide nanosheet as a biomimetic two-dimensional nanoplatform for synergistic near infrared-II fluorescent imaging and photothermal therapy of tumor

Fluorescent bioimaging and photothermal therapy (PTT) techniques have potential significance in cancer diagnosis and treatment and have been widely applied in biomedical and practical clinical trials. This study proposes the molecular design and biofabrication of a two-dimensional (2D) nanoplatform, exhibiting promising prospects for synergistic bioimaging and PTT of tumors. First, biocompatible 2D peptide nanosheets (PNSs) were designed and prepared through peptide self-assembly. These served as a support matrix for assembling polyethylene glycol-modified Ag2S quantum dots (PEG-Ag2SQDs) to form a 2D nanoplatform (PNS/PEG-Ag2SQDs) with unique fluorescent and photothermal properties. The designed 2D nanoplatform not only showed improved photothermal efficacy and an elevated photothermal conversion efficiency of 52.46 %, but also demonstrated significant lethality against tumors in both in vitro and in vivo cases. Additionally, it displays excellent imaging effects in the near-infrared II region, making it suitable for synergistic fluorescent imaging-guided PTT of tumors. This study not only provides a facile approach for devising and synthesizing 2D peptide assemblies but also presents new biomimetic strategies to create functional 2D organic/inorganic nanoplatforms for biomedical applications.

Tailoring Biomaterials Ameliorate Inflammatory Bone Loss

Inflammatory diseases, such as rheumatoid arthritis, periodontitis, chronic obstructive pulmonary disease, and celiac disease, disrupt the delicate balance between bone resorption and formation, leading to inflammatory bone loss. Conventional approaches to tackle this issue encompass pharmaceutical interventions and surgical procedures. Nevertheless, pharmaceutical interventions exhibit limited efficacy, while surgical treatments impose trauma and significant financial burden upon patients. Biomaterials show outstanding spatiotemporal controllability, possess a remarkable specific surface area, and demonstrate exceptional reactivity. In the present era, the advancement of emerging biomaterials has bestowed upon more efficacious solutions for combatting the detrimental consequences of inflammatory bone loss. In this review, the advances of biomaterials for ameliorating inflammatory bone loss are listed. Additionally, the advantages and disadvantages of various biomaterials-mediated strategies are summarized. Finally, the challenges and perspectives of biomaterials are analyzed. This review aims to provide new possibilities for developing more advanced biomaterials toward inflammatory bone loss.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

Two-dimensional nanomaterials induced nano-bio interfacial effects and biomedical applications in cancer treatment

Two-dimensional nanomaterials (2D NMs), characterized by a large number of atoms or molecules arranged in one dimension (typically thickness) while having tiny dimensions in the other two dimensions, have emerged as a pivotal class of materials with unique properties. Their flat and sheet-like structure imparts distinctive physical, chemical, and electronic attributes, which offers several advantages in biomedical applications, including enhanced surface area for efficient drug loading, surface-exposed atoms allowing precise chemical modifications, and the ability to form hierarchical multilayer structures for synergistic functionality. Exploring their nano-bio interfacial interactions with biological components holds significant importance in comprehensively and systematically guiding safe applications. However, the current lack of in-depth analysis and comprehensive understanding of interfacial effects on cancer treatment motivates our ongoing efforts in this field. This study provides a comprehensive survey of recent advances in utilizing 2D NMs for cancer treatment. It offers insights into the structural characteristics, synthesis methods, and surface modifications of diverse 2D NMs. The investigation further delves into the formation of nano-bio interfaces during their in vivo utilization. Notably, the study discusses a wide array of biomedical applications in cancer treatment. With their potential to revolutionize therapeutic strategies and outcomes, 2D NMs are poised at the forefront of cancer treatment, holding the promise of transformative advancements.

Supramolecular nanosheet formation-induced photosensitisation mechanism change of Rose Bengal dye in aqueous media

Development of two-dimensional materials and exploration of their functionalities are significant challenges due to their potential. In this study, we successfully fabricated a supramolecular nanosheet composed of amphiphilic Rose Bengal dyes in an aqueous medium. Furthermore, we elucidated a distinct change in the photosensitisation mechanism induced by nanosheet formation.

Current Advances in Wound Healing and Regenerative Medicine

Treating chronic wounds is a common and costly challenge worldwide. More advanced treatments are needed to improve wound healing and prevent severe complications such as infection and amputation. Like other medical fields, there have been advances in new technologies promoting wound healing potential. Regenerative medicine as a new method has aroused hope in treating chronic wounds. The technology improving wound healing includes using customizable matrices based on synthetic and natural polymers, different types of autologous and allogeneic cells at different differentiation phases, small molecules, peptides, and proteins as a growth factor, RNA interference, and gene therapy. In the last decade, various types of wound dressings have been designed. Emerging dressings include a variety of interactive/ bioactive dressings and tissue-engineering skin options. However, there is still no suitable and effective dressing to treat all chronic wounds. This article reviews different wounds and common treatments, advanced technologies and wound dressings, the advanced wound care market, and some interactive/bioactive wound dressings in the market.

Mechanisms of Biomolecular Self-Assembly Investigated Through In Situ Observations of Structures and Dynamics

Biomolecular self-assembly of hierarchical materials is a precise and adaptable bottom-up approach to synthesizing across scales with considerable energy, health, environment, sustainability, and information technology applications. To achieve desired functions in biomaterials, it is essential to directly observe assembly dynamics and structural evolutions that reflect the underlying energy landscape and the assembly mechanism. This review will summarize the current understanding of biomolecular assembly mechanisms based on in situ characterization and discuss the broader significance and achievements of newly gained insights. In addition, we will also introduce how emerging deep learning/machine learning-based approaches, multiparametric characterization, and high-throughput methods can boost the development of biomolecular self-assembly. The objective of this review is to accelerate the development of in situ characterization approaches for biomolecular self-assembly and to inspire the next generation of biomimetic materials.

Phosphorylcholine-grafted graphene oxide loaded with irinotecan for potential oncology therapy

2-Methacryloyloxyethyl phosphorylcholine (MPC) zwitterions were modified onto self-made graphene oxide (GO) through the atom transfer radical polymerization method. The chemical structures of the products were verified using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), etc. It was found that the modified GO (GO-PCn) is well dispersed in water with an average hydrodynamic diameter of about 170 nm. By utilizing the 2D planar structure of this modified graphene, the irinotecan@GO-PCn composite can be loaded with about 20% of irinotecan via π-π stacking interaction and exhibit pH-sensitive drug release performance, releasing faster in the acidic environment. The in vitro cytotoxicity assessments confirmed that GO-PCn composed of phosphorylcholine moiety represented low cytotoxicity and acted as a certain effect on reducing the acute toxicity of irinotecan, which established a foundation for further studies of the system in oncology therapy.

Enhanced Photodynamic Therapy by Improved Light Energy Capture Efficiency of Porphyrin Photosensitizers

OPINION STATEMENT

Photodynamic therapy (PDT) has garnered increasing attention in cancer treatment because of its advantages such as minimal invasiveness and selective destruction. With the development of PDT, impressive progress has been made in the preparation of photosensitizers, particularly porphyrin photosensitizers. However, the limited tissue penetration of the activating light wavelengths and relatively low light energy capture efficiency of porphyrin photosensitizers are two major disadvantages in conventional photosensitizers. Therefore, tissue penetration needs to be enhanced and the light energy capture efficiency of porphyrin photosensitizers improved through structural modifications. The indirect excitation of porphyrin photosensitizers using fluorescent donors (fluorescence resonance energy transfer) has been successfully used to address these issues. In this review, the enhancement of the light energy capture efficiency of porphyrins is discussed.

DNA-Nanocrystal Assemblies for Environmentally Responsive and Highly Efficient Energy Harvesting and Storage

Natural polymer-based and self-powered bioelectronic devices are attracting attention owing to an increased interest in human health monitoring and human-machine interfaces. However, obtaining both high efficiency and multifunctionality from a single natural polymer-based bioelectronics platform is still challenging. Here, molybdenum disulfide (MoS2 ) nanoparticle- and carbon quantum dot (CQDs)-incorporated deoxyribonucleic acid (DNA) nanocomposites are reported for energy harvesting, motion sensing, and charge storing. With nanomaterial-based electrodes, the MoS2 -CQD-DNA nanocomposite exhibits a high triboelectric open-circuit voltage of 1.6 kV (average) and an output power density of 275 mW cm-2 , which is sufficient for turning on hundred light-emitting diodes and for a highly sensitive motion sensing. Notably, the triboelectric performance can be tuned by external stimuli (light and thermal energy). Thermal and photon energy absorptions by the nanocomposite generate additional charges, resulting in an enhanced triboelectric performance. The MoS2 -CQD-DNA nanocomposite can also be applied as a capacitor material. Based on the obtained electronic properties, such as capacitances, dielectric constants, work functions, and bandgaps, it is possible that the charges generated by the MoS2 -CQD-DNA triboelectric nanogenerator can be stored in the MoS2 -CQD-DNA capacitor. A new way is presented here to expand the application area of self-powered devices in wearable and implantable electronics.

Effect of the spacer on the structure and self-assembly of FF peptide mimetics

We have designed and synthesized a series of FF peptide mimetics with conformationally rigid and flexible spacers to study the effect of spacers on their structure and self-assembly. The results help in understanding biomolecular aggregation and provide a strategy to obtain fractal pattern materials. From X-ray single crystal analysis, the m-diaminobenzene appended FF peptide mimetic adopts a duplex structure stabilized by multiple intermolecular hydrogen bonds. There is also a water molecule bridging between two strands of the duplex. Moreover, the duplex is stabilized by three face-to-face, face-to-edge and edge-to-edge π-π interactions. The duplex formation is also supported by mass spectrometry. In higher order packing, the dimeric subunits further self-assembled to form a complex sheet-like structure stabilized by multiple intermolecular hydrogen bonding and π-π stacking interactions. Moreover, the 1,4-butadiene and m-xylylenediamine appended FF peptide mimetics form stimuli-responsive organogels in a wide range of solvents including methanol. The rheology data of FF peptide mimetic gels as a function of angular frequency and oscillatory strain also supported the formation of strong physically crosslinked gels. The FE-SEM images of the xerogels obtained from different organic solvents show that the network morphology of FF peptide mimetics varies depending on the nature of the solvents.

Long-term exposure of molybdenum disulfide nanosheets leads to hepatic lipid accumulation and atherogenesis in apolipoprotein E deficient mice

Before their large-scale applications, it is necessary to understand the biological effects of nanomaterials. Although two-dimensional nanomaterials (2D NMs) molybdenum disulfide nanosheets (MoS₂ NSs) are promising in biomedical fields, the current knowledge regarding their toxicities is inadequate. Using apolipoprotein E deficient (ApoE^-/-) mice as a long-term exposure model, this study demonstrated that intravenous (i.v.) injection of MoS₂ NSs most accumulated in the liver and caused in situ hepatic damage. Histopathological examination indicated severe infiltration of inflammatory cells and irregular central veins in the MoS₂ NSs-treated mouse liver. Meanwhile, the overwhelming expressions of inflammatory cytokines, dyslipidemia, and dysregulated hepatic lipid metabolism implied the potential vascular toxicity of MoS₂ NSs. Indeed, our result supported that MoS₂ NSs exposure is highly associated with atherosclerotic progression. This study provided the first line of evidence on the vascular toxicity of MoS₂ NSs, which remind scientists to pay attention to the rational use of MoS₂ NSs, especially in the biomedical fields.

Designing supramolecular self-assembly nanomaterials as stimuli-responsive drug delivery platforms for cancer therapy

Stimuli-responsive nanomaterials have attracted substantial interest in cancer therapy, as they hold promise to deliver anticancer agents to tumor sites in a precise and on-demand manner. Interestingly, supramolecular chemistry is a burgeoning discipline that entails the reversible bonding between components at the molecular and nanoscale levels, and the recent advances in this area offer the possibility to design nanotherapeutics with improved controllability and functionality for cancer therapy. Herein, we provide a comprehensive summary of typical non-covalent interaction modes, which primarily include hydrophobic interaction, hydrogel bonding, host-guest interaction, π-π stacking, and electrostatic interaction. Special emphasis is placed on the implications of these interaction modes to design novel stimuli-responsive drug delivery principles and concepts, aiming to enhance the spatial, temporal, and dosage precision of drug delivery to cancer cells. Finally, future perspectives are discussed to highlight current challenges and future opportunities in self-assembly-based stimuli-responsive drug delivery nanotechnologies for cancer therapy.

Nanozymes and nanoflower: Physiochemical properties, mechanism and biomedical applications

Natural enzymes possess several drawbacks which limits their application in industries, wastewater remediation and biomedical field. Therefore, in recent years researchers have developed enzyme mimicking nanomaterials and enzymatic hybrid nanoflower which are alternatives of enzyme. Nanozymes and organic inorganic hybrid nanoflower have been developed which mimics natural enzymes functionalities such as diverse enzyme mimicking activities, enhanced catalytic activities, low cost, ease of preparation, stability and biocompatibility. Nanozymes include metal and metal oxide nanoparticles mimicking oxidases, peroxidases, superoxide dismutase and catalases while enzymatic and non-enzymatic biomolecules were used for preparing hybrid nanoflower. In this review nanozymes and hybrid nanoflower have been compared in terms of physiochemical properties, common synthetic routes, mechanism of action, modification, green synthesis and application in the field of disease diagnosis, imaging, environmental remediation and disease treatment. We also address the current challenges facing nanozyme and hybrid nanoflower research and the possible way to fulfil their potential in future.

Interfacial Electrostatic Self-Assembly of Amyloid Fibrils into Multifunctional Protein Films

Amyloid fibrils have generated steadily increasing traction in the development of natural and artificial materials. However, it remains a challenge to construct bulk amyloid films directly from amyloid fibrils due to their intrinsic brittleness. Here, a facile and general methodology to fabricate macroscopic and tunable amyloid films via fast electrostatic self-assembly of amyloid fibrils at the air-water interface is introduced. Benefiting from the excellent templating properties of amyloid fibrils for nanoparticles (such as conductive carbon nanotubes or magnetic Fe₃ O₄ nanoparticles), multifunctional amyloid films with tunable properties are constructed. As proof-of-concept demonstrations, a magnetically oriented soft robotic swimmer with well-confined movement trajectory is prepared. In addition, a smart magnetic sensor with high sensitivity to external magnetic fields is fabricated via the combination of the conductive and magnetic amyloid films. This strategy provides a convenient, efficient, and controllable approach for the preparation of amyloid-based multifunctional films and related smart devices.

Polymeric Materials, Advances and Applications in Tissue Engineering: A Review

Tissue Engineering (TE) is an interdisciplinary field that encompasses materials science in combination with biological and engineering sciences. In recent years, an increase in the demand for therapeutic strategies for improving quality of life has necessitated innovative approaches to designing intelligent biomaterials aimed at the regeneration of tissues and organs. Polymeric porous scaffolds play a critical role in TE strategies for providing a favorable environment for tissue restoration and establishing the interaction of the biomaterial with cells and inducing substances. This article reviewed the various polymeric scaffold materials and their production techniques, as well as the basic elements and principles of TE. Several interesting strategies in eight main TE application areas of epithelial, bone, uterine, vascular, nerve, cartilaginous, cardiac, and urinary tissue were included with the aim of learning about current approaches in TE. Different polymer-based medical devices approved for use in clinical trials and a wide variety of polymeric biomaterials are currently available as commercial products. However, there still are obstacles that limit the clinical translation of TE implants for use wide in humans, and much research work is still needed in the field of regenerative medicine.

Orientational phase transition in monolayers of multipolar straight rigid rods: The case of 2-thiophene molecule adsorption on the Au(111) surface

Monte Carlo simulations and finite-size scaling theory have been carried out to study the critical behavior and universality for the isotropic-nematic (IN) phase transition in a system of straight rigid pentamers adsorbed on a triangular lattice with polarized nonhomogeneous intermolecular interactions. The model was inspired by the deposition of 2-thiophene molecules over the Au(111) surface, which was previously characterized by experimental techniques and density functional theory. A nematic phase, observed experimentally by the formation of a self-assembled monolayer of parallel molecules, is separated from the isotropic state by a continuous transition occurring at a finite density. The precise determination of the critical exponents indicates that the transition belongs to the three-state Potts universality class. The finite-size scaling analysis includes the study of mutability and diversity. These two quantities are derived from information theory and they have not previously been considered as part of the conventional treatment of critical phenomena for the determination of critical exponents. The results obtained here contribute to the understanding of formation processes of self-assembled monolayers, phase transitions, and critical phenomena from novel compression algorithms for studying mutual information in sequences of data.

"Swiss Army Knife" black phosphorus-based nanodelivery platform for synergistic antiparkinsonian therapy via remodeling the brain microenvironment

The combination of excessive reactive oxygen species (ROS) levels, neuroinflammation, and pathogenic protein aggregation disrupt the homeostasis of brain microenvironment, creating conditions conducive to the progression of Parkinson's disease (PD). Restoring homeostasis by remodeling the brain microenvironment could reverse this complex pathological progression. However, treatment strategies that can induce this effect are currently unavailable. Herein, we developed a "Swiss Army Knife" nanodelivery platform consisting of matrine (MT) and polyethylene glycol-modified black phosphorus nanosheets (BP) that enables PD treatment by restoring brain microenvironment homeostasis. Under NIR irradiation, the photothermal effect induced by BP allowed the nanomedicine to cross the blood-brain barrier (BBB) and entered the brain parenchyma. In PD brains, the biological effects of BP and MT resulted in the removal of excess ROS, effective reduction of neuroinflammation, decreased aggregation of pathogenic proteins, and improved neurotransmitter delivery, eventually restoring dopamine levels in the striatum. This study demonstrated the effective capacity of a BP-based nanodelivery platform to enter the brain parenchyma and trigger multiple neuropathological changes in PD brains. The platform serves as a safe and effective anti-PD nanomedicine with immense clinical potential.

Light-Triggered Self-Assembly of Peptide Nanoparticles into Nanofibers in Living Cells through Molecular Conformation Changes and H-Bond Interactions

Controlled self-assembly has attracted extensive interest in biological and nanotechnological applications. Enzymatic or biocatalytic triggered self-assembly is widely used for the diagnostic and prognostic marker in different pathologies because of their nanostructures and biological effects. However, it remains a great challenge to control the self-assembly of peptides in living cells with a high degree of spatial and temporal precision. Here we demonstrate a light-triggered platform that enables spatiotemporal control of self-assembly from nanoparticles into nanofibers in living cells through subtle molecular conformational changes and internal H-bonding interactions. The platform contained 3-methylene-2-(quinolin-8-yl) isoindolin-1-one, which acts as the light-controlled unit to disrupt the hydrophilic/lipophilic balance through the change of molecular conformation, and a peptide that can be a faster recombinant to assemble via H-bonding interactions. The process has good biocompatibility because it does not involve waste generation or oxygen consumption; moreover, the assembly rate constant was fast and up to 0.17 min^-1. It is applied to the regulation of molecular assembly in living cells. As such, our findings demonstrate that light-triggered controllable assembly can be applied for initiative regulating cellular behaviors in living systems.

Intracellular Enzyme-Instructed Self-Assembly of Peptides (IEISAP) for Biomedical Applications

Despite the remarkable significance and encouraging breakthroughs of intracellular enzyme-instructed self-assembly of peptides (IEISAP) in disease diagnosis and treatment, a comprehensive review that focuses on this topic is still desirable. In this article, we carefully review the advances in the applications of IEISAP, including the development of various bioimaging techniques, such as fluorescence imaging, photoacoustic imaging, magnetic resonance imaging, positron-emission tomography imaging, radiation imaging, and multimodal imaging, which are successfully leveraged in visualizing cancer tissues and cells, bacteria, and enzyme activity. We also summarize the utilization of IEISAP in disease treatments, including anticancer, antibacterial, and antiinflammation applications, among others. We present the design, action modes, structures, properties, functions, and performance of IEISAP materials, such as nanofibers, nanoparticles, nanoaggregates, and hydrogels. Finally, we conclude with an outlook towards future developments of IEISAP materials for biomedical applications. It is believed that this review may foster the future development of IEISAP with better performance in the biomedical field.

M. T, Cho G, Lee J. Control of the Drying Patterns for Complex Colloidal Solutions and Their Applications

The uneven deposition at the edges of an evaporating droplet, termed the coffee-ring effect, has been extensively studied during the past few decades to better understand the underlying cause, namely the flow dynamics, and the subsequent patterns formed after drying. The non-uniform evaporation rate across the colloidal droplet hampers the formation of a uniform and homogeneous film in printed electronics, rechargeable batteries, etc., and often causes device failures. This review aims to highlight the diverse range of techniques used to alleviate the coffee-ring effect, from classic methods such as adding chemical additives, applying external sources, and manipulating geometrical configurations to recently developed advancements, specifically using bubbles, humidity, confined systems, etc., which do not involve modification of surface, particle or liquid properties. Each of these methodologies mitigates the edge deposition via multi-body interactions, for example, particle-liquid, particle-particle, particle-solid interfaces and particle-flow interactions. The mechanisms behind each of these approaches help to find methods to inhibit the non-uniform film formation, and the corresponding applications have been discussed together with a critical comparison in detail. This review could pave the way for developing inks and processes to apply in functional coatings and printed electronic devices with improved efficiency and device yield.

Ru Colloidosome Catalysts for the Hydrogen Oxidation Reaction in Alkaline Media

Developing efficient hydrogen oxidation reaction (HOR) electrocatalysts in alkaline media is of great significance for anion exchange membrane fuel cells. Herein, we report the synthesis of hollow colloidosomes composed of Ru nanocrystals based on a novel gas/liquid interface self-assembly strategy. Structural characterizations reveal that much defects are present in the building block (Ru nanocrystals) of Ru colloidosomes. Theoretical calculations suggest that the defects in the Ru structure can optimize the adsorption binding energy of reaction intermediates for the HOR. Benefiting from the assembled colloidosome and optimized electronic structure, the Ru colloidosomes exhibit remarkable HOR catalytic performance in alkaline media with a mass activity higher than that of benchmark Pt/C. Our work may shed new light on the rational design of advanced electrocatalysts with an assembled structure for energy-related applications.

Enhanced Stability and Mechanical Properties of a Graphene–Protein Nanocomposite Film by a Facile Non-Covalent Self-Assembly Approach

Graphene-based nanocomposite films (NCFs) are in high demand due to their superior photoelectric and thermal properties, but their stability and mechanical properties form a bottleneck. Herein, a facile approach was used to prepare nacre-mimetic NCFs through the non-covalent self-assembly of graphene oxide (GO) and biocompatible proteins. Various characterization techniques were employed to characterize the as-prepared NCFs and to track the interactions between GO and proteins. The conformational changes of various proteins induced by GO determined the film-forming ability of NCFs, and the binding of bull serum albumin (BSA)/hemoglobin (HB) on GO’s surface was beneficial for improving the stability of as-prepared NCFs. Compared with the GO film without any additive, the indentation hardness and equivalent elastic modulus could be improved by 50.0% and 68.6% for GO–BSA NCF; and 100% and 87.5% for GO–HB NCF. Our strategy should be facile and effective for fabricating well-designed bio-nanocomposites for universal functional applications.

Bottom-up supramolecular assembly in two dimensions

The self-assembly of molecules in two dimensions (2D) is gathering attention from all disciplines across the chemical sciences. Attracted by the interesting properties of two-dimensional inorganic analogues, monomers of different chemical natures are being explored for the assembly of dynamic 2D systems. Although many important discoveries have been already achieved, great challenges are still to be addressed in this field. Hierarchical multicomponent assembly, directional non-covalent growth and internal structural control are a just a few of the examples that will be discussed in this perspective about the exciting present and the bright future of two-dimensional supramolecular assemblies.

The self-assembly of molecules in two dimensions (2D) is gathering attention from all disciplines across the chemical sciences. This perspective discusses the main strategies to direct the supramolecular self-assembly of organic monomers in 2D.

A Genetically Engineered, Chain Mail-Like Nanostructured Protein Material with Increased Fatigue Resistance and Enhanced Self-Healing

Protein-based nanostructured materials are being developed for many biomedical and nanotechnological applications. Despite their many desirable features, protein materials are highly susceptible to disruption by mechanical stress and fatigue. This study is aimed to increase fatigue resistance and enhance self-healing of a natural protein-based supramolecular nanomaterial through permanent genetic modification. The authors envisage the conversion of a model nanosheet, formed by a regular array of noncovalently bound human immunodeficiency virus capsid protein molecules, into a supramolecular "chain mail." Rationally engineered mutations allow the formation of a regular network of disulfide bridges in the protein lattice. This network links each molecule in the lattice to each adjacent molecule through one covalent bond, analogous to the rivetting of interlinked iron rings in the chain mail of a medieval knight. The engineered protein nanosheet shows greatly increased thermostability and resistance to mechanical stress and fatigue in particular, as well as enhanced self-healing, without undesirable stiffening compared to the original material. The results provide proof of concept for a genetic design to permanently increase fatigue resistance and enhance self-healing of protein-based nanostructured materials. They also provide insights into the molecular basis for fatigue of protein materials.

A generic self-assembly approach towards phototheranostics for NIR-II fluorescence imaging and phototherapy

Controllable self-assembly of photonic molecules for precise biomedicine is highly desirable but challenging to prepare multifunctional nano-phototheranostics. Herein, we developed a generic self-assembly approach to design nano-phototheranostics that provides NIR-II fluorescence imaging and phototherapy. We first designed and synthesized two amphiphilic photonic molecules, PEG₂₀₀₀-IR806 and BODIPY. Then, we prepared the co-self-assembled phototheranostic agents, PEG₂₀₀₀-IR806/BODIPY nanoparticles (PIBY NPs). The morphology of the PIBY NPs is controllable by adjusting the ratio of PEG₂₀₀₀-IR806 and BODIPY during self-assembly. The NIR-II fluorescence properties and phototherapy capability of the PIBY NPs were demonstrated in vitro and in vivo. By tuning the ratio of PEG₂₀₀₀-IR806 and BODIPY, the PIBY NPs showed various morphologies (e.g. spherical nanoparticles, nanovesicles and rod-like nanoparticles). The PEG₂₀₀₀-IR806 plays two roles in the co-self-assemblies, one is second near-infrared (NIR-II, 1000-1700 nm) agent, the other is the surfactant for BODIPY encapsulation. The phototherapeutic PIBY NPs all show bright NIR-II fluorescence and effective phototherapeutic (photothermal and photodynamic) properties, which are attributed to IR806 and BODIPY, respectively. The driving force of the self-assembly can be attributed to the electrostatic interaction between NIR806 and BODIPY and their hydrophobicity. The rod-like PIBY NPs (rPIBY NPs) demonstrated a low half inhibitory concentration (IC₅₀) of 3.96 µg/mL on U87MG cells. The NIR-II imaging showed the accumulation of rPIBY NPs in the tumor region. After systemic injection of rPIBY NPs at low dose (0.5 mg/kg), the tumor growth was greatly inhibited upon laser irradiation without noticeable side effects. This study provides a generic self-assembly approach to fabricate NIR-II imaging and phototherapeutic platform for cancer phototheranostics. STATEMENT OF SIGNIFICANCE: Nanophototheranostics providing NIR-II fluorescence imaging and phototherapy are expected to play a critical role in modern precision medicine. Controllable self-assembly of optical molecules for the fabrication of efficient nanophototheranostics is highly desirable but challenging. This work reports for the first time the co-assembly of a NIR-II imaging contrast agent and a phototherapeutic agent to yield nanophototheranostics with various morphologies. The design of molecular co-assembly with complementary optical functions can be a generic method for future the development of phototheranostics.

Multifunctional Hyphae Carbon Powering Lithium-Sulfur Batteries

Biotechnology can bring new breakthroughs on design and fabrication of energy materials and devices. In this work, a novel and facile biological self-assembly technology to fabricate multifunctional Rhizopus hyphae carbon fiber (RHCF) and its derivatives on a large scale for electrochemical energy storage is proposed. Crosslinked hollow carbon fibers are successfully prepared by conversion of Rhizopus hyphae, and macroscopic production of centimeter-level carbon balls consisting of hollow RHCFs is further realized. Moreover, the self-assembled RHCF balls show strong adsorption characteristics on metal ions and can be converted into a series of derivatives such as RHCF/metal oxides. Notably, the designed RHCF derivatives are demonstrated with powerful multifunctionability as cathode, anode, and separator for lithium-sulfur batteries (LSBs). The RHCF can act as the host material to combine with metal oxide (CoO) and S, Li metal, and a polypropylene (PP) separator to form a new RHCF/CoO-S cathode, an RHCF/Li anode, and an RHCF/PP separator, respectively. Consequently, the optimized LSB full cell presents excellent cycling performance and superior high-rate capacity (881.3 mA h g^-1 at 1 C). This work provides a new method for large-scale preparation of hollow carbon fibers and derivatives for advanced energy storage and conversion.

Dimension switchable auto-fluorescent peptide-based 1D and 2D nano-assemblies and their self-influence on intracellular fate and drug delivery

The production of dynamic, environment-responsive shape-tunable biomaterials marks a significant step forward in the construction of synthetic materials that can easily rival their natural counterparts. Significant progress has been made in the self-assembly of bio-materials. However, the self-assembly of a peptide into morphologically distinct auto-fluorescent nanostructures, without the incorporation of any external moiety is still in its infancy. Hence, in this study, we have developed peptide-based self-assembled auto-fluorescent nanostructures that can shuttle between 1D and 2D morphologies. Different morphological nanostructures are well known to have varied cellular internalization efficiencies. Taking advantage of our morphologically different particles emanating from the same peptide monomer, we further explored the intracellular fate of our nanostructures. We observed that the nanostructures' cellular internalization is a complex process that gets influenced by particle morphology and this might further affect their intracellular drug delivery potential. Overall, this study provides initial cues for the preparation of environment-responsive shape-shifting peptide-nano assemblies. Efforts have also been made to understand their shape driven cellular uptake behaviour, along with establishing them as nanocarriers for the cellular delivery of therapeutic molecules.

Bio-Scaffolds as Cell or Exosome Carriers for Nerve Injury Repair

Central and peripheral nerve injuries can lead to permanent paralysis and organ dysfunction. In recent years, many cell and exosome implantation techniques have been developed in an attempt to restore function after nerve injury with promising but generally unsatisfactory clinical results. Clinical outcome may be enhanced by bio-scaffolds specifically fabricated to provide the appropriate three-dimensional (3D) conduit, growth-permissive substrate, and trophic factor support required for cell survival and regeneration. In rodents, these scaffolds have been shown to promote axonal regrowth and restore limb motor function following experimental spinal cord or sciatic nerve injury. Combining the appropriate cell/exosome and scaffold type may thus achieve tissue repair and regeneration with safety and efficacy sufficient for routine clinical application. In this review, we describe the efficacies of bio-scaffolds composed of various natural polysaccharides (alginate, chitin, chitosan, and hyaluronic acid), protein polymers (gelatin, collagen, silk fibroin, fibrin, and keratin), and self-assembling peptides for repair of nerve injury. In addition, we review the capacities of these constructs for supporting in vitro cell-adhesion, mechano-transduction, proliferation, and differentiation as well as the in vivo properties critical for a successful clinical outcome, including controlled degradation and re-absorption. Finally, we describe recent advances in 3D bio-printing for nerve regeneration.