Exploring and Controlling the Polymorphism in Supramolecular Assemblies of Carbohydrates and Proteins

Is AMOEBA a Good Force Field for Molecular Dynamics Simulations of Carbohydrates?

Over the years, molecular dynamics (MD) simulations have been employed in the study of carbohydrates, with force fields such as CHARMM, AMBER/GLYCAM, and GROMOS. Although these force fields have achieved considerable success and played a pivotal role in our understanding of carbohydrate chemistry, growing interest has emerged in incorporating polarization effects to enhance the accuracy of simulations. In this perspective, we contemplate the advances that have been made in nonpolarizable and polarizable force fields to extract the key factors controlling accuracy in MD of carbohydrates. We find that the extreme hydrophilicity and conformational flexibility of carbohydrates pose challenges for most force fields. Overall, a force field suited for carbohydrates needs to include a water model developed consistently with the solute parameter sets, a soft van der Waals repulsion term at short distances, and polarization (whether implicit or explicit). We find that AMOEBA improves the prediction of hydration shell structure and dynamics, hydrogen bonding, and kinetics of diffusion, although it remains largely untested for conformational flexibility and glycosidic linkages. Nevertheless, AMOEBA's recent success in modeling monosaccharides without revisions of the potential energy functions or water model presents a promising avenue for future research. Such advances will provide deeper insights into the structure, dynamics, and interactions of these biologically and industrially relevant macromolecules.

Fluorescent Metallacycles via Coordination-Driven Self-Assembly: Preparation, Regulation, and Applications

ConspectusFluorescence by small molecular dyes is renowned for its real-time, dynamic, and noninvasive nature. It has become indispensable across scientific domains, including information storage, optoelectronic materials, biosensing, and both diagnosing and treating diseases. Despite their widespread use, these molecular dyes suffer from several limitations due to the sensitivity of their photophysical properties to environmental factors, such as concentration, solvent composition, and polarity. These challenges become particularly prominent when assembling or aggregating fluorescent molecules; their optical characteristics often become unpredictable or uncontrollable. Alternative strategies to stabilize and tune fluorescence during preparation are therefore crucial.Metal coordination, a classical approach in supramolecular chemistry, offers a promising solution. Coordinating fluorescent dyes to metals precisely directs self-assembly, ensuring defined stoichiometries, geometries, and reversibility. The resulting multifunctional metallacycles combine the advantages inherent to molecular design and fluorescence, pushing the boundaries of fluorescence-based assemblies. We present a modular, directional, and controllable strategy for the self-assembly of supramolecular metallacycles with well-defined geometries, providing a new avenue to address the limitations of traditional small molecular dyes.A key innovation in this research lies in the incorporation of photochromic units into the metallacycles, tuning their photophysical properties reversibly under external illumination. Their emission wavelengths, chiralities, and circularly polarized luminescence (CPL) signals can all be modulated dynamically. These characteristics offer the potential for holographic imaging, where fine control of fluorescence behavior is crucial. We introduce a novel multistep Förster resonance energy transfer (FRET) strategy that enables real-time monitoring of the metallacycle assembly dynamics. Our FRET approach has been employed to develop photosensitized oxygenation reactions and highly efficient light-harvesting systems, highlighting its versatility. The unique photophysical properties of our fluorescent metallacycles have been applied successfully in several fields. They detect heparin quantitatively, showcasing their potential in biosensing. They have been integrated into nanoagents for photothermal, photodynamic, and chemotherapeutic therapies guided by imaging, offering a multimodal approach to therapeutic intervention. Such precise control over fluorescence, energy transfer, and assembly dynamics not only opens new avenues in materials design but also underscores supramolecular metallacycles' potential for advancing fluorescence technologies. Integrating metal coordination into fluorescence represents a significant step in the design and application of functional fluorescent metallacycles. This design strategy both advances fundamental supramolecular chemistry and provides new insights into photophysical systems for sensing, imaging, and therapeutics.

A controlled co-assembly approach to tune temperature responsiveness of biomimetic proteins

The controlled co-assembly of biomacromolecules through tuneable interactions offers a simple and fascinating opportunity to assemble multiple molecules into a single entity with enhanced complexity and unique properties. Herein, our study presents a dynamic co-assembled system using the multistimuli responsive intrinsically disordered protein Rec1-resilin and the adhesive hydrophilic protein silk sericin (SS). We utilized advanced characterization techniques including circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and small/ultra-small angle neutron scattering (SANS/USANS) to elucidate the detailed co-assembly behavior of the system and its evolution over time and temperature. To achieve sufficient neutron contrast, we successfully biosynthesised deuterium-labeled Rec1-resilin (D-Rec1). Our research demonstrates that this co-assembly allows the formation of a robust entity with dynamic conformational assembly and disassembly, exhibiting both the upper critical solution temperature (UCST) and lower critical solution temperature (LCST) with reversibility. The assembly and disassembly dynamics of the co-assembled entity at UCST are very fast, while the process is kinetically controlled at LCST. This study provides significant new insights into the interplay of a hydrophilic, multi-responsive IDP and a highly hydrophilic protein, shaping the thermoresponsive and stable properties of the co-assembled entity.

Supramolecular Chiral Assembly of Dendritic Amphiphiles in Aqueous Media

Dendritic amphiphiles are a promising class of topological blocks for self-assembly to construct chiral supramolecular aggregates in aqueous media. Their unique dendritic geometry, structure variability and multivalence can mediate the assemblies with versatile morphologies and functions. The bulky dendritic moieties also enable the appropriate association-repulsion balance to control supramolecular growth, and simultaneously shield the assemblies with enhanced stabilities. Moreover, the crowded packing of dendritic segments facilitates the efficient chirality transfer from molecular level to supramolecular level, to achieve chirality amplification or enhancement. Dendritic moieties also provide chances to stabilize the assemblies in aqueous media through shielding and cooperative effects. The dendritic assemblies can be intriguingly made responsive to external stimuli including temperature, light, solvents or guests to switch their nanostructures or supramolecular chirality. Various dendritic amphiphiles bearing peptide or aromatic motifs have been reported in supramolecular chiral assembly, and their functional applications investigated. This review summarizes the significant progresses with a particular focus on the dendritic structural effects on supramolecular chiral assembly and the stimuli-responsiveness in aqueous media.

Strategies and Applications for Supramolecular Protein Self-Assembly

Supramolecular chemistry achieves higher-order molecular self-assembly through non-covalent interactions. Utilizing supramolecular methods to explore the polymorphism of proteins, the building blocks of life, from a "bottom-up" perspective is essential for constructing diverse and functional biomaterials. In recent years, significant progress has been achieved in the design strategies and functional applications of supramolecular protein self-assembly, becoming a focal point for researchers. This paper reviews classical supramolecular strategies driving protein self-assembly, including electrostatic interactions, metal coordination, hydrogen bonding, hydrophobic interactions, host-guest interactions, and other mechanisms. We discuss how these supramolecular interactions regulate protein assembly processes and highlight protein supramolecular assemblies' unique structural and functional advantages in constructing artificial photosynthetic systems, protein hydrogels, bio-delivery systems, and other functional materials. The enormous potential and significance of supramolecular protein materials are elucidated. Finally, the challenges in preparing and applying protein supramolecular assemblies are summarized, and future development directions are projected.

Photoresponsive Supramolecular Polymers Capable of Intrachain Folding and Interchain Aggregation

The competition between polymer chain folding and aggregation is a critical structuring process that determines the physical properties of synthetic and biopolymers. However, supramolecular polymer systems that exhibit both processes have not yet been reported. We herein introduce a system in which folded supramolecular polymers spontaneously undergo interchain aggregation due to a rearrangement in internal molecular order, converting them into crystalline aggregates. These folded supramolecular polymers slowly crystallize over the course of half a day, due to their characteristic higher-order structures. However, the photoisomerization of the trans-azobenzene incorporated into the monomer to the cis isomer leads to unfolding of the polymer, accelerating the intrachain and interchain molecular ordering to a few hours. The intermediate structures visualized by AFM demonstrate that the unfolding is coupled with interchain aggregation.

Intramolecular CH⋯π attraction mediated conformational polymorphism of constrained helical peptides

In nature, biochemical processes depend on polymorphism, a phenomenon by which discrete biomolecules can adopt specific conformations based on their environment. However, it is often difficult to explore the generation mechanism and achieve polymorphic control in artificial supramolecular assembly systems. In this work, we propose a feasible thought for exploring the transformation mechanism of polymorphism in peptide assembly from the perspective of thermodynamic regulation, which enables polymorphic composition to be limited by switchable intramolecular CH⋯π attraction within a certain temperature range. Combined with the density functional theory calculations, we obtained thermodynamic theoretical data supporting the conformation transition and the underlying polymorphism formation principle. Afterward, we properly designed the peptide to alter the probability of CH⋯π attraction occurring. Then, we selectively obtained a homogeneous morphological form with corresponding molecular conformation, which further demonstrated the important role of molecular conformational manipulation in polymorphism selection. This unique template-based strategy developed in this study may provide scientists with an additional line of thought to guide assembly paths in other polymorphic systems.

Handedness-Inverted and Stimuli-Responsive Circularly Polarized Luminescent Nano/Micromaterials Through Pathway-Dependent Chiral Supramolecular Polymorphism

The precise manipulation of supramolecular polymorphs has been widely applied to control the morphologies and functions of self-assemblies, but is rarely utilized for the fabrication of circularly polarized luminescence (CPL) materials with tailored properties. Here, this work reports that an amphiphilic naphthalene-histidine compound (NIHis) readily self-assembled into distinct chiral nanostructures through pathway-dependent supramolecular polymorphism, which shows opposite and multistimuli responsive CPL signals. Specifically, NIHis display assembly-induced CPL from the polymorphic keto tautomer, which become predominant during enol-keto tautomerization shifting controlled by a bulk solvent effect. Interestingly, chiral polymorphs of nanofiber and microbelt with inverted CPL signals can be prepared from the same NIHis monomer in exactly the same solvent compositions and concentrations by only changing the temperature. The tunable CPL performance of the solid microbelts is realized under multi external physical or chemical stimuli including grinding, acid fuming, and heating. In particular, an emission color and CPL on-off switch based on the microbelt polymorph by reversible heating-cooling protocol is developed. This work brings a new approach for developing smart CPL materials via supramolecular polymorphism engineering.

Using Chemistry To Recreate the Complexity of the Extracellular Matrix: Guidelines for Supramolecular Hydrogel-Cell Interactions

Hydrogels have emerged as a promising class of extracellular matrix (ECM)-mimicking materials in regenerative medicine. Here, we briefly describe current state-of-the-art of ECM-mimicking hydrogels, ranging from natural to hybrid to completely synthetic versions, giving the prelude to the importance of supramolecular interactions to make true ECM mimics. The potential of supramolecular interactions to create ECM mimics for cell culture is illustrated through a focus on two different supramolecular hydrogel systems, both developed in our laboratories. We use some recent, significant findings to present important design principles underlying the cell-material interaction. To achieve cell spreading, we propose that slow molecular dynamics (monomer exchange within fibers) is crucial to ensure the robust incorporation of cell adhesion ligands within supramolecular fibers. Slow bulk dynamics (stress-relaxation─fiber rearrangements, τ1/2 ≈ 1000 s) is required to achieve cell spreading in soft gels (<1 kPa), while gel stiffness overrules dynamics in stiffer gels. Importantly, this resonates with the findings of others which specialize in different material types: cell spreading is impaired in case substrate relaxation occurs faster than clutch binding and focal adhesion lifetime. We conclude with discussing considerations and limitations of the supramolecular approach as well as provide a forward thinking perspective to further understand supramolecular hydrogel-cell interactions. Future work may utilize the presented guidelines underlying cell-material interactions to not only arrive at the next generation of ECM-mimicking hydrogels but also advance other fields, such as bioelectronics, opening up new opportunities for innovative applications.

Intelligent Biomaterialomics: Molecular Design, Manufacturing, and Biomedical Applications

Materialomics integrates experiment, theory, and computation in a high-throughput manner, and has changed the paradigm for the research and development of new functional materials. Recently, with the rapid development of high-throughput characterization and machine-learning technologies, the establishment of biomaterialomics that tackles complex physiological behaviors has become accessible. Breakthroughs in the clinical translation of nanoparticle-based therapeutics and vaccines have been observed. Herein, recent advances in biomaterials, including polymers, lipid-like materials, and peptides/proteins, discovered through high-throughput screening or machine learning-assisted methods, are summarized. The molecular design of structure-diversified libraries; high-throughput characterization, screening, and preparation; and, their applications in drug delivery and clinical translation are discussed in detail. Furthermore, the prospects and main challenges in future biomaterialomics and high-throughput screening development are highlighted.

Morphological Transformation and Surface Engineering of Glycovesicles Driven by Bioinspired Hydrogen Bonds of Nucleobases

Glycopolymer-based supramolecular glycoassemblies with signal-driven cascade morphological deformation and accessible surface engineering toward bioinspired functional glycomaterials have attracted much attention due to their diverse applications in fundamental and practical scenarios. Herein, we achieved the cascade morphological transformation and surface engineering of a nucleobase-containing polymeric glycovesicle through exploiting the bioinspired complementary multiple hydrogen bonds of complementary nucleobases. First, the synthesized thymine-containing glycopolymers (PGal30-b-PTAm249) are capable of self-assembling into well-defined glycovesicles. Several kinds of amphiphilic adenine-containing block copolymers with neutral, positive, and negative charges were synthesized to engineer the glycovesicles through the multiple hydrogen bonds between adenine and thymine. A cascade of morphological transformations from vesicles to ruptured vesicles with tails, to worm-like micelles, and finally to spherical micelles were observed via continuously adding the adenine-containing polymer into the thymine-containing glycovesicles. Furthermore, the surface charge properties of these glyconano-objects can be facilely regulated through incorporating various adenine-containing polymers. This work demonstrates the potential application of a unique bioinspired approach to precisely engineer the morphology and surface properties of glycovesicles for boosting their biological applications.

Molecular Sensing and Manipulation of Protein Oligomerization in Membrane Nanotubes with Bolaamphiphilic Foldamers

Adaptive and reversible self-assembly of supramolecular protein structures is a fundamental characteristic of dynamic living matter. However, the quantitative detection and assessment of the emergence of mesoscale protein complexes from small and dynamic oligomeric precursors remains highly challenging. Here, we present a novel approach utilizing a short membrane nanotube (sNT) pulled from a planar membrane reservoir as nanotemplates for molecular reconstruction, manipulation, and sensing of protein oligomerization and self-assembly at the mesoscale. The sNT reports changes in membrane shape and rigidity caused by membrane-bound proteins as variations of the ionic conductivity of the sNT lumen. To confine oligomerization to the sNT, we have designed and synthesized rigid oligoamide foldamer tapes (ROFTs). Charged ROFTs incorporate into the planar and sNT membranes, mediate protein binding to the membranes, and, driven by the luminal electric field, shuttle the bound proteins between the sNT and planar membranes. Using Annexin-V (AnV) as a prototype, we show that the sNT detects AnV oligomers shuttled into the nanotube by ROFTs. Accumulation of AnV on the sNT induces its self-assembly into a curved lattice, restricting the sNT geometry and inhibiting the material uptake from the reservoir during the sNT extension, leading to the sNT fission. By comparing the spontaneous and ROFT-mediated entry of AnV into the sNT, we reveal how intricate membrane curvature sensing by small AnV oligomers controls the lattice self-assembly. These results establish sNT-ROFT as a powerful tool for molecular reconstruction and functional analyses of protein oligomerization and self-assembly, with broad application to various membrane processes.

Protein Nanotubes Assembled from Imidazole-Grafted Horseradish Peroxidase Nanogels

Protein assembly, a common phenomenon in nature, plays an important role in the evolution of life. Inspired by nature, assembling protein monomers into delicate nanostructures has emerged as an attractive research area. However, sophisticated protein assemblies usually need complicated designs or templates. In this work, we successfully fabricated protein nanotubes in a facile way by coordination interactions between imidazole-grafted horseradish peroxidase (HRP) nanogels (iHNs) and Cu2+. The iHNs were synthesized by polymerization on the surface of HRP by employing vinyl imidazole as a comonomer. By direct addition of Cu2+ into iHN solution, protein tubes were therefore formed. The size of the protein tubes could be adjusted by changing the added Cu2+ amount, and the mechanism behind the formation of protein nanotubes was elucidated. Furthermore, a highly sensitive H2O2 detection system was established based on the protein tubes. This work provides a facile method to construct diverse sophisticated functional protein nanomaterials.

Kaleidoscope megamolecules synthesis and application using self-assembly technology

The megamolecules with high ordered structures play an important role in chemical biology and biomedical engineering. Self-assembly, a long-discovered but very appealing technique, could induce many reactions between biomacromolecules and organic linking molecules, such as an enzyme domain and its covalent inhibitors. Enzyme and its small-molecule inhibitors have achieved many successes in medical application, which realize the catalysis process and theranostic function. By employing the protein engineering technology, the building blocks of enzyme fusion protein and small molecule linker can be assembled into a novel architecture with the specified organization and conformation. Molecular level recognition of enzyme domain could provide both covalent reaction sites and structural skeleton for the functional fusion protein. In this review, we will discuss the range of tools available to combine functional domains by using the recombinant protein technology, which can assemble them into precisely specified architectures/valences and develop the kaleidoscope megamolecules for catalytic and medical application.

Evolution of Protein Assemblies Driven by the Switching of Interplay Mode

A protein assembly with the ability to switch interplay modes of multiple driving forces has been achieved. Although biomolecular systems driven by multiple driving forces have been exploited, work on such a protein assembly capable of switching the interplay modes at nanoscale has been rarely reported so far as a result of their great fabrication challenge. In this work, two sets of driving forces such as ligand-ligand interaction and protein-protein interaction were leveraged to antagonistically underpin the multilayered stackings and trigger the hollow evolution to afford the well-defined hollow rectangular frame of proteins. While these protein frames further collapsed into aggregates, the ligand-ligand interactions were weakened, and the interplay of two sets of driving forces thereby tended to switch into synergistic mode, converting the protein packing mode from porously loose packing to axially dense packing and thus giving rise to a morphological evolution toward a nanosized protein tube. This strategy not only provides a nanoscale understanding on the mechanism underlying the switch of interplay modes in the context of biomacromolecules but also may provide access for diverse sophisticated biomacromolecular nanostructures that are historically inaccessible for conventional self-assembly strategies.

Adenosine Triphosphate-Responsive Glyconanorods through Self-Assembly of β-Cyclodextrin-Based Glycoconjugates for Targeted and Effective Bacterial Sensing and Killing

Polymer-based nanomaterials have exhibited promising alternative avenues to combat the globe challenge of multidrug-resistant bacterial infection. However, most of the reported polymeric nanomaterials have facially linear amphiphilic structures with positive net charges, which may lead to nonspecific binding, high hemolysis, and uncontrollable self-organization, limiting their practical applications. In this contribution, we report a one-dimensional glyconanorod (GNR) through self-assembly of well-defined β-cyclodextrin-based glycoconjugates (RMan) featuring hydrophobic carbon-based chains and amide rhodamines with an adenosine triphosphate (ATP)-recognition site and targeted and hydrophilic mannoses and positively net-charged ethylene amine groups. The GNRs show superior targeting sensing and killing for Gram-negative Escherichia coli (E. coli) dominantly through the multivalent recognition between mannoses on the nanorod and the lectin on the surface of E. coli. Moreover, red fluorescence was light on due to the hydrogen bonding between amide rhodamine and ATP. Benefiting from the designs, the GNRs are capable of possessing a higher therapeutic index and of encapsulating other antibiotics. They exhibit an enhanced effect against E. coli strains. Intriguingly, the GNRs displayed a more reduced hemolysis effect and lower cytotoxicity compared to that of ethylene glyco-modified nanorods. These results reveal that the glyconanomaterials not only feature superior and targeted bacterial sensing and antibacterial activity, but also better biocompatibility compared with the widely used PEG-covered nanomaterials. Furthermore, the in vivo studies demonstrate that the targeted and ATP-responsive GNRs complexed with antibiotics showed better treatment using a mouse model of abdominal sepsis following intraperitoneal E. coli infection. The present work describes a targeted and effective sensing and antibacterial platform based on glycoconjugates that have potential applications for the treatment of infections caused by pathogenic microorganisms.

Selection of diverse polymorphic structures from a small dynamic molecular network controlled by the environment

The complex interplay between systems and their environment plays an important role in processes ranging from self-assembly to evolution. Polymorphism, where, from the same ingredients different products can be formed, is likely to be an important enabler for evolutionary adaptation. Environmental pressures may induce polymorphic behaviour, where different pressures result in different structural organisation. Here we show that by combining covalent and non-covalent bond formation three distinct polymorphs can emerge from the same small dynamic molecular network: vesicular aggregates, self-replicating fibres and nanoribbons, depending on the nature of the solvent environment. Additionally, a particular set of conditions allows the transient co-existence of both vesicles and fibres.

Self-Assembled Peptide Hydrogel for Accelerated Wound Healing: Impact of N-Terminal and C-Terminal Modifications

Wound dressings are required to provide a moist environment for wounds, protect against invading infections, expedite tissue regeneration, and improve wound healing efficiency. Developing biomaterials with all aforesaid properties is still a big challenge. However, peptide-based hydrogels have the potential to overcome these challenges as they are biocompatible, biodegradable as well as have the ability to mimic the extracellular matrix and provide an appropriate moist environment which is important for wound healing. With this in mind, we report the preparation and comparison of three hexapeptide-based hydrogels, LIVAGD, with the aim to understand the importance of the N-terminal protecting group as well as the C-terminal amino acid substitution on its various biological efficacies. Fmoc and acetyl groups were used for N-terminal peptide protection, while aspartic acid was substituted with lysine at the C-terminus. The resulting peptide-based hydrogels were compared. Fmoc peptide-based hydrogels exhibited efficient anti-inflammatory action along with improved biocompatibility while lysine provided enhanced antibacterial effect to the hydrogel. Additionally, in vivo efficacy was examined using a mouse model, and Fmoc hydrogels demonstrated an improved wound healing ability with ∼40 % faster healing rate in comparison to the reported acetylated peptide hydrogels.

Construction of Active Protein Materials: Manipulation on Morphology of Salmon Calcitonin Assemblies with Enhanced Bone Regeneration Effect

The effect of protein drugs is always limited by their relatively low stability and fast degradation property; thus, various elegant efforts have been made to improve the bioactivity and biocompatibility of the protein drugs. Here, an alternative way is proposed to solve this problem. By simply adding a limited amount of small-molecular regulator, which tunes the subtle balance of protein-protein interactions (PPIs) and disulfide bond formation, the self-assembly property of the protein drug can be regulated, forming an "active protein material" itself. This means that, the resulting biomaterial is dominated by the protein drug and water, with significantly enhanced bone regeneration effect compared to the virgin protein in vitro and in vivo, through multivalent effect between the protein and receptor and the retarded degradation of the assembled proteins. In this active protein material, the protein drug is not only the active drug, but also the drug carrier, which greatly increases the drug-loading efficiency of the biomaterial, indicating the advantages of the easy preparation, high efficiency, and low cost of the active protein material with a bright future in biomedical applications.

Precise Assembly of Proteins and Carbohydrates for Next-Generation Biomaterials

The complexity and diversity of biomacromolecules make them a unique class of building blocks for generating precise assemblies. They are particularly available to a new generation of biomaterials integrated with living systems due to their intrinsic properties such as accurate recognition, self-organization, and adaptability. Therefore, many excellent approaches have been developed, leading to a variety of quite practical outcomes. Here, we review recent advances in the fabrication and application of artificially precise assemblies by employing proteins and carbohydrates as building blocks, followed by our perspectives on some of new challenges, goals, and opportunities for the future research directions in this field.

Surfactant-Free Green Synthesis of Au@Chlorophyll Nanorods for NIR PDT-Elicited CDT in Bladder Cancer Therapy

The facile and straightforward fabrication of NIR-responsive theranostic materials with high biocompatibility is still an unmet need for nanomedicine applications. Here, we used a natural photosensitizer, iron chlorophyll (Chl/Fe), for the J-aggregate template-assisted synthesis of Au@Chl/Fe nanorods with high stability. The assembly of a high amount of Chl/Fe J-aggregate onto the Au surface enabled red-NIR fluorescence for monitoring and tracking residential tumor lesions. The Chl/Fe moieties condensed on the nanorods could change the redox balance by the photon induction of reactive oxygen species and attenuate iron-mediated lipid peroxidation by inducing a Fenton-like reaction. After conjugation with carboxyphenylboronic acid (CPBA) to target the glycoprotein receptor on T24 bladder cancer (BC) cells, the enhanced delivery of Au@Chl/Fe-CPBA nanorods could induce over 85% cell death at extremely low concentrations of 0.16 ppm_[Au] at 660 nm and 1.6 ppm_[Au] at 785 nm. High lipid peroxidation, as shown by BODIPY staining and GSH depletion, was observed when treated T24 cells were exposed to laser irradiation, suggesting that preliminary photodynamic therapy (PDT) can revitalize Fenton-like reaction-mediated chemodynamic ferroptosis in T24 cells. We also manipulated the localized administration of Au@Chl-Fe combined with PDT at restricted regions in orthotopic tumor-bearing mice to cure malignant BC successfully without recurrence. By intravesical instillation of the Au@Chl/Fe-CPBA nanorods, this localized treatment could prevent the material from entering the systemic circulation, thus minimizing systemic toxicity. Upon activating NIR-PDT-elicited chemodynamic therapy, ultrasound imaging revealed almost complete tumor remission. Anti-tumor efficacy and survival benefit were achieved with a green photosensitizer.

From poly(vinylimidazole) to cationic glycopolymers and glyco-particles: effective antibacterial agents with enhanced biocompatibility and selectivity

Cationic glycopolymers have attracted great attention as a new type of antibacterial material.

Self-Assembled Polymeric Materials: Design, Morphology, and Functional-Oriented Applications

This Review focuses on the current research advances of the synthesis of various amphiphilic block copolymers (ABCs), such as conventional ABCs and newly-presented polyprodrug amphiphiles (PPAs), and the development of corresponding self-assemblies in selective solvents driven by the intermolecular interactions, like noncovalent hydrophobic interactions, π-π interactions, and hydrogen bonds, between ABCs or preformed small polymeric nanoparticles. The design of these assemblies is systematically introduced, and the diverse examples concerning the unique assembly structures along with the fast development of their exclusive properties and various applications in different fields were discussed. Possible perspectives on the existential challenges and glorious future were elucidated finally. We hope this review will provide a convenient way for readers to motivate more evolutional innovative concepts and methods to design next generation of novel polymeric nanoassemblies, and fill the gap between material design and practical applications. This article is protected by copyright. All rights reserved.

Dynamic Glycopeptide Dendrimers: Synthesis and Their Controllable Self-Assembly into Varied Glyco-Nanostructures for the Biomimicry of Glycans

A library of 14 dynamic glycopeptide amphiphilic dendrimers composed of 14 hydrophilic and bioactive saccharides (seven kinds) as dendrons and 7 hydrophobic peptides (di- and tetrapeptides) as arms with β-cyclodextrin (CD) as a core were facially designed and synthesized in several steps. Fourteen saccharides were first conjugated to the C-2 and C-3 positions of CD, forming glycodendrons. Subsequently, seven oligopeptide arms were introduced at the C-6 positions of a CD moiety by an acylhydrazone dynamic covalent bond, resulting in unique Janus amphiphilic glycopeptide dendrimers with precise and varied molecular structures. The kinds of hydrophilic parts of saccharides and hydrophobic parts of peptides were easily varied to prepare a series of amphiphilic Janus glycopeptide dendrimers. Intriguingly, these obtained amphiphilic glycopeptide dendrimers showcased very different self-assembly behaviors from the traditional amphiphilic linear block-copolymers and self-assembled into different glyco-nanostructures with controllable morphologies including glycospheres, worm-like micelles, and fibers depending upon the repeat unit ratio of saccharides and phenylalanine. Both glycodendrons and glycopeptide assemblies displayed strong and specific recognitions with C-type mannose-specific lectin. Moreover, these glycopeptide nanomaterials can encapsulate exemplary hydrophobic molecules such as Nile red (NR). The dye-loaded glycopeptide nanostructures showed a pH-controllable release behavior around the physiological and acidic tumor environment. Furthermore, cell experiments demonstrated that such glyco-nanostructures can further facilitate the functions of a model drug of the pyridone agent to reduce the expression of monocyte chemotactic protein-1 (MCP-1) and interleukin -1beta (IL-1β) in the primary peritoneal macrophages via encapsulating drugs. Considering all the abovementioned advantages including unique and precise structures, bioactivity, targeting, and controllable cargo release, we believe that these findings can not only enrich the library of glycopeptides but also provide a new avenue to the fabrication of smart and structure-controllable glyco-nanomaterials which hold great potential biological applications such as targeted delivery and release of therapeutic and bioactive molecules.

The Flexibility of Oligosaccharides Unveiled Through Residual Dipolar Coupling Analysis

The intrinsic flexibility of glycans complicates the study of their structures and dynamics, which are often important for their biological function. NMR has provided insights into the conformational, dynamic and recognition features of glycans, but suffers from severe chemical shift degeneracy. We employed labelled glycans to explore the conformational behaviour of a β(1-6)-Glc hexasaccharide model through residual dipolar couplings (RDCs). RDC delivered information on the relative orientation of specific residues along the glycan chain and provided experimental clues for the existence of certain geometries. The use of two different aligning media demonstrated the adaptability of flexible oligosaccharide structures to different environments.

Construction of Highly Ordered Glyco-Inside Nano-Assemblies through RAFT Dispersion Polymerization of Galactose-Decorated Monomer

Glyco-assemblies derived from amphiphilic sugar-decorated block copolymers (ASBCs) have emerged prominently due to their wide application, for example, in biomedicine and as drug carriers. However, to efficiently construct these glyco-assemblies is still a challenge. Herein, we report an efficient technology for the synthesis of glyco-inside nano-assemblies by utilizing RAFT polymerization of a galactose-decorated methacrylate for polymerization-induced self-assembly (PISA). Using this approach, a series of highly ordered glyco-inside nano-assemblies containing intermediate morphologies were fabricated by adjusting the length of the hydrophobic glycoblock and the polymerization solids content. A specific morphology of complex vesicles was captured during the PISA process and the formation mechanism is explained by the morphology of its precursor and intermediate. Thus, this method establishes a powerful route to fabricate glyco-assemblies with tunable morphologies and variable sizes, which is significant to enable the large-scale fabrication and wide application of glyco-assemblies.

Triple-Modulated Chiral Inversion of Co-Assembly System Based on Alanine Amphiphile and Cyanostilbene Derivative

The construction of chiroptical materials with controllable chirality is of special importance in biology and chemistry. Although tunable chirality can be realized in various systems, it remains a fundamental challenge to realize multimodulated chiral inversion. Herein, we report that chiral alanine derivative and fluorescent cyanostilbene derivative co-assemble to prepare supramolecular chiral systems, where twist nanofibers with totally inverted supramolecular chirality and circularly polarized luminescence are obtained through stoichiometric modulation. The supramolecular handedness can be inverted by means of altering the cooling rate and incorporating metal ions. The mechanism study reveals that the synergistic effect among hydrogen bonds, coordination interactions, and π-π stacking interactions contributes to the chirality inversion. This work establishes an effective strategy to precisely modulate supramolecular chirality in multiple ways, which shows great potential in developing smart chiroptical materials capable of achieving complex functionalities.

Hierarchical self-assembly of miktoarm star copolymers with pathway complexity

The self-assembly of amphiphilic miktoarm star copolymers shows hierarchical pathway complexity from molecular building blocks to miktoarm stars to micellar nano-objects to complex hierarchical assemblies.

Photoresponsive glyco-nanostructures integrated from supramolecular metallocarbohydrates for the reversible capture and release of lectins

Photo-controllable capture and release of proteins by glyco-nanostructures.

Molecular Dynamics Approach for Capturing Calixarene-Protein Interactions: The Case of Cytochrome C

Functionalized supramolecular cages are of growing importance in biology and biochemistry. They have recently been proposed as efficient auxiliaries to obtain high-resolution cocrystallized proteins. Here, we propose a molecular dynamics investigation of the supramolecular association of sulfonated calix-[8]-arenes to cytochrome c starting from initially distant proteins and ligands. We characterize two main binding sites for the sulfonated calixarene on the cytochrome c surface which are in perfect agreement with the previous experiments with regard to the structure (comparison with the X-ray structure PDB 6GD8) and the binding free energies [comparison between the molecular mechanics Poisson-Boltzmann surface area analysis and the isothermal titration calorimetry measurements]. The per-residue decomposition of the interaction energies reveals the detailed picture of this electrostatically driven association and notably the role of arginine R13 as a bridging residue between the two main anchoring sites. In addition, the analysis of the residue behavior by means of a supervised machine learning protocol unveils the formation of a hydrogen bond network far from the binding sites, increasing the rigidity of the protein. This study paves the way toward an automated procedure to predict the supramolecular protein-cage association, with the possibility of a computational screening of new promising derivatives for controlled protein assembly and protein surface recognition processes.