搜索结果：Biomacromolecules

Polysaccharides remain the least understood biomacromolecules, particularly in terms of the relationship between their chemical structure and physical properties. On the other hand, polysaccharides often serve as the main structural components in biofilms: surface-attached aggregates of bacterial cells encased within a mechanically resilient extracellular matrix. The large chemical space explored by bacteria within biofilms provides excellent opportunities to establish the structure-function relationship for polysaccharides. In this paper, we systematically characterize various polymer properties of Vibrio polysaccharide (VPS), the major exopolysaccharide in biofilms formed by Vibrio cholerae, the causative agent of pandemic cholera. Using a combination of shear rheology, dynamic and static light scattering, and small-angle X-ray scattering, we measure the viscosity, molecular weight, persistence length, radius of gyration, and hydrodynamic radius of this chemically unique biopolymer. Combining all-atom and coarse-grained simulations, we show how the conformational flexibility of a single glycosidic linkage within each VPS monomer can lead to dramatic compaction of the entire polymer chain and nonclassical entanglement behavior. Our comprehensive quantification represents a rare endeavor for bacterial biofilms, whose matrix composition and physical properties remain largely nebulous; it also represents a significant step towards a detailed understanding of the molecular origins of biofilm mechanics.

This paper describes, for the first time, the synthesis of cyclic aza- and oxa-dieneynes through intramolecular aza-Wittig, Wittig, and lactonization reactions as key steps. The synthesized 9- and 10-membered cyclic aza-compounds (75 and 81) undergo Hopf Cyclization (HC) under normal conditions, resulting in hydroxy dihydroisoquinoline derivatives. The 9- membered aza-analogue 75 exhibits DNA cleavage properties. We have also attempted the synthesis of cyclic dieneynes that incorporate an oxygen atom within their ring structure and have explored their thermal reactivity as well as the DNA cleavage properties. Our objective was to incorporate heteroatoms, specifically nitrogen and oxygen, into the carbocyclic dieneyne structure in different arrangements. In one configuration, a nitrogen and an oxygen atom substitute for one of the carbon atoms in the saturated moiety of the chain. The purpose was to explore the impact of introducing nitrogen and oxygen heteroatoms on the Hopf Cyclization temperature within the carbocyclic dieneyne framework. Furthermore, we aimed to determine whether intermediates from these oxa- and aza-Hopf cyclizations could cleave DNA, given that some intermediates might have sufficiently long half-lives to interact with external entities, such as biomacromolecules. The synthesis of target molecules involved palladium-catalyzed cross-coupling, followed by a series of group transfer reactions, and concluded with ring closure reactions using a high dilution technique. Subsequently, these molecules were exposed to thermal conditions to achieve the desired ring closure. We evaluated their DNA-cleavage activity by incubating the compounds with double-stranded DNA (plasmid) in millimolar concentrations. After completing the synthesis and examining the thermochemical reactivity of azadieneynes in relation to Hopf Cyclization, we evaluated their ability to cleave DNA. Consequently, when the 9-membered aza-compound 75 was incubated, it resulted in moderate DNA cleavage at millimolar concentrations after 48 and 72 hours. In the case of oxadieneyne synthesis, the final ring closure reaction, even under conditions of extreme dilution, led to the formation of dimeric oxa-dieneynes rather than the intended monomers and did not undergo cyclization under normal conditions. The 11-membered cyclic dieneyne lactone was successfully synthesized, but instead of the anticipated radical cyclization, decomposition occurred when subjected to cyclization conditions. These results underscore the interplay among ring size, heteroatom type, and substitution pattern in Hopf Cyclization reactions. Aza-dieneynes are promising because of their reactivity and ability to cleave DNA, whereas oxa-dieneynes are less feasible. Future studies should investigate modified substitution patterns or photochemical activation to overcome the challenges associated with oxygen incorporation. The DNA-cleaving activity of compound 75 illustrates that dieneynes with heteroatom substitutions can connect Hopf intermediates to biological reactivity. These systems can serve as templates for molecular tools in chemical biology, particularly in applications involving DNA cleavage. We have successfully synthesized the aza analogue of the 9- and 10-membered dieneyne (75 and 81) for the first time and conducted DNA cleavage experiments. The ninemembered imine 75 exhibited moderate DNA-cleaving activity. Our approach involved initially closing the ring, followed by forming a double bond within the cyclic molecule, which was effectively applied to create the 10- and 11-membered oxa-dieneynes. However, neither of these compounds underwent HC under normal conditions. When heated to 110ºC in toluene, they decomposed.

Proteins are increasingly used to guide the crystallization of metal-organic frameworks (MOFs), yielding protein@MOFs (p@MOFs) that encapsulate fragile biomacromolecules within stable crystalline hosts. These biohybrid materials offer tunable porosity and spatial organization that are difficult to achieve with conventional synthesis. Despite their growing importance, the mechanisms by which proteins influence MOF nucleation, crystal growth, and defect formation remain poorly understood. Here, we use a distributed electron microscopy approach to follow the full crystallization pathway of ferritin@ZIF-8 (Fn@ZIF-8). The method combines cryogenic transmission electron microscopy (cryo-TEM), cryogenic electron tomography (cryo-ET), and liquid-phase TEM (LP-TEM) to capture structural transitions over time. Using the ferritin iron oxide core as an intrinsic nanoscale tracer, we visualize the transformation of protein-rich amorphous precursors into crystalline particles that ripen, aggregate, and develop large, surface-accessible cavities. These cavities emerge only during later stages of growth, where localized dissolution and recrystallization restructure the framework. Concurrently, proteins become enriched near the crystal periphery and depleted from cavity-rich regions. Our results suggest that protein organization and dissolution-driven restructuring both contribute to defect formation. This work provides a mechanistic framework for understanding how hierarchical porosity develops in p@MOFs and establishes distributed electron microscopy as an approach for investigating biohybrid crystallization pathways.

Acute liver failure (ALF), characterized by severe hepatocyte necrosis with a high mortality rate, remains a major global health challenge. However, there are currently no effective drug options for the clinical treatment of ALF. Herein, inspired by the new concept of a full-API nanodrug (FAND), we have rationally developed a quadruplex bioactive FAND (termed FANDHP@FuEVs) composed entirely of active pharmaceutical ingredients (APIs). This FANDHP@FuEVs is constructed from fusion extracellular vesicles (FuEVs), which hybridize M2 macrophage-derived EVs (M2-EVs) with mesenchymal stem cell-derived EVs (MSC-EVs) and is subsequently engineered with two clinically therapeutic biomacromolecules: hepatocyte growth factor (HGF) and polyene phosphatidylcholine (PPC). Notably, FANDHP@FuEVs efficiently targets the damaged liver, benefiting from the dual inherent inflammation-tropism of the FuEVs. Moreover, FANDHP@FuEVs harnesses quadruplex biological activities by leveraging four natural bioactive components-M2-EVs, MSC-EVs, HGF, and PPC-to deliver pleiotropic therapies, including antioxidant, anti-inflammatory, pro-regenerative, and macrophage repolarization effects. These therapies are effective in treating ALF induced by both acetaminophen and hepatectomy, demonstrating significant clinical relevance based on data from patients with liver disease. Overall, the utilization of naturally derived or clinically approved APIs to construct full-bioactive nanodrugs creates opportunities for clinical translation as a safe, versatile, and multifaceted treatment for ALF.

Efficient detection of monomer mutations along polymer chains is critically important for functional materials, particularly for biomacromolecules, yet remains highly challenging. Here, we present an optical strategy capable of recognizing a single monomer mutation within a polymer chain or cluster containing up to 1000 repeating units. This approach relies on a rigidochromic fluorophore that interacts with polymer chains through polar-π interactions to form a charge-transfer complex (CTC), resulting in red-shifted emission relative to the intrinsic fluorescence of the fluorophore. Monomer mutations alter intra- and interchain interactions, modulate through-space conjugation (TSC) along the polymer backbone, and consequently change the molecular orbital energy bandgap, leading to distinct emission variations of the CTC. Leveraging this mechanism, we achieve visual discrimination among random copolymers (poly(A-r-B)), block copolymers (poly(A-b-B)) with identical A/B ratios and molecular weights, and corresponding blends of homopolymers (poly A + poly B)-a task that is inaccessible to conventional characterization methods. This strategy provides a powerful platform for high-throughput polymer screening during synthesis and modification, as well as for real-time monitoring of polymer structural evolution.

Inflammation is a physiological response of the body to infection and tissue damage; dysregulated inflammatory signaling can cause the initiation and aggravation of a variety of chronic diseases. Although anti-inflammatory drugs have been commercialized and showed beneficial effects clinically, their long-term application is often limited by loss of effects and adverse side effects. Natural polysaccharides are multifunctional biomacromolecules with strong potentials in inflammation therapy due to their inherent biocompatibility, wide immunomodulation property and drug capacity. In this Review, we offer a holistic summary of recent advances in polysaccharide anti-inflammatory strategies by coupling the characteristics of structure, biological mechanism and polysaccharide-based delivery systems. This review gives a comprehensive overview of the rational design of anti-inflammatory strategies based on polysaccharides, and also points out the current limitations of polysaccharide drugs in applications, translation difficulties and future trends.

Saliva-based point-of-care testing (POCT) is critical for the early diagnosis of periodontal disease. However, current wearable platforms, such as smart mouthguards, are predominantly limited to monitoring small metabolites (e.g., glucose) and cannot detect specific macromolecular proteins essential for disease characterization. To enable precise early diagnosis, we demonstrate a novel biosensor that integrates microfluidics with organic electrochemical transistors (OECTs). Functionally, this integration enables the simultaneous, multiplexed detection of a complementary biomarker combination: interleukin-6 (IL-6) and matrix metalloproteinase-8 (MMP-8). In terms of performance, the device leverages the high transconductance of OECTs to ensure high precision even at trace levels, achieving exceptional sensitivity with distinct dynamic ranges tailored for early-stage detection (IL-6: 1-80 pg/mL; MMP-8: 10-500 ng/mL). Validating its diagnostic utility, the sensor showed precise quantification (R2 > 0.97) correlated with gold-standard laboratory measurements in a rat model. By delivering clinical-grade precision for complex biomacromolecules, this platform overcomes the limitations of existing wearables and offers a viable path for translating advanced bioelectronics into practical periodontal healthcare.

Aqueous two-phase system (ATPS) droplets in cells act as fluidic microreactors by concentrating biomacromolecules. Inspired by this phenomenon, dextran-rich microdroplets formed in an ATPS with polyethylene glycol have been explored as artificial microreactors for sensitive detection and spatiotemporal control of biochemical reactions. However, the rapid fusion of the microdroplets into bulk phase separation has limited practical applications of this approach. Here, we report the stabilization of dextran-rich microdroplets using supramolecular nanofibers of an azobenzene-appending self-assembling peptide (AzSAP). Physicochemical characterization and structural analyses elucidate the mechanism of nanofiber formation and its role in droplet stabilization. The nanofiber network prevents droplet coalescence while maintaining macroscopic fluidity, thereby enabling highly sensitive quantitative virus detection via microfluidic analysis by confining infecting viruses within droplets. Furthermore, the photo-responsive properties of the AzSAP allow dynamic control over droplet size and intra-droplet virus activity, highlighting its exceptional potential as a platform for programmable artificial microreactors.

Amomum tsaoko is a medicinal and edible Zingiberaceae herb, while its stems and leaves are largely discarded and underutilized compared with its fruits. This study aimed to characterize the antibacterial active components of A. tsaoko stem and leaf ethyl acetate extract, clarify the antibacterial mechanism of core metabolite 5-indanol, and evaluate the application value of A. tsaoko stem-leaf by-products as green feed additives for Partridge Shank chickens. In vitro antibacterial assays combined with GC-MS metabolomics were performed on four Zingiberaceae species (A. tsaoko, Alpinia officinarum, A. villosum, A. oxyphylla); broth microdilution, time-kill curve, biofilm and cell membrane leakage tests were conducted to verify the bactericidal mode of 5-indanol. For the animal feeding trial, 30-day-old Partridge Shank chickens were randomly divided into five groups: control group (CK, basal diet), 0.05% A. tsaoko stem-leaf group (SL0.05), 0.10% stem-leaf group (SL0.10), 0.15% stem-leaf group (SL0.15), and positive control group supplemented with 0.10% A. tsaoko fruit (F0.10). Growth performance, meat quality, small intestinal morphology and cecal microbiota were systematically detected. The in vitro results revealed that ethyl acetate extract of A. tsaoko stems and leaves exhibited broad-spectrum antibacterial activity against Gram-positive and Gram-negative bacteria, with an MIC of 62.5 μg/mL against Staphylococcus aureus. Metabolomic screening identified 5-indanol as the dominant antibacterial marker compound, whose antibacterial efficacy was 20-fold higher than 2,3-dihydro-1H-indene-4-carbaldehyde. Mechanistically, 5-indanol disrupted bacterial membrane integrity, triggered leakage of intracellular biomacromolecules, suppressed biofilm formation and attenuated hemolytic virulence of S. aureus. In vivo data indicated that 0.10% dietary supplementation of A. tsaoko stems and leaves (SL0.10) achieved the optimal effect: Dietary supplementation with A. tsaoko significantly increased the average daily gain and reduced the feed conversion ratio of Partridge Shank chickens, with the most pronounced effect observed in the 0.10% stem-leaf group. The drip loss of breast and thigh muscle was decreased without adverse impacts on meat pH, color and tenderness. The villus height/crypt depth ratios of duodenum and ileum were elevated by 34.2% and 26.43%, respectively. Meanwhile, the relative abundances of beneficial phyla Firmicutes, Bacteroidetes and Ascomycota in gut microbiota were significantly enriched, and the alpha diversity of bacterial and fungal communities was improved. Collectively, 5-indanol is the key antibacterial component in the ethyl acetate extract of A. tsaoko. Waste stems and leaves of A. tsaoko can be developed as novel antibiotic-free phytogenic feed additives, which realizes full-plant high-value utilization of A. tsaoko agricultural by-products and provides theoretical support for sustainable green livestock breeding.

Robust cell adhesion within complex, diffusion-limited microenvironments hinges on the rapid recognition of extracellular matrix (ECM) collagen macromolecules by integrins. However, the traditional "lock-and-key" model, which emphasizes static thermodynamic affinity, fails to adequately explain the dynamic kinetics of this rapid recognition. A major bottleneck in resolving this mechanism has been the lack of precise macromolecular models capable of decoupling local charge density from spatial arrangement. Here, leveraging a programmable heterotrimeric collagen engineering platform, we systematically modulated charge valencies from Mut0 (EEE) to Mut3 (AAA) and uncovered a macromolecular "electrostatic steering" mechanism driven by specific charge topologies. Combining kinetic analysis with all-atom Molecular Dynamics (MD) simulations, we demonstrate that the full-valency EEE motif is not a structural redundancy but rather constructs a long-range electrostatic funnel. Crucially, this topology drives a non-linear ∼6-fold surge in the association rate (ka) while the dissociation rate (kd) exhibits no significant change, revealing a thermodynamic-kinetic decoupling. This discovery establishes that macromolecular electrostatic volume directly dictates the kinetic capture radius. Furthermore, phylogenetic analysis shows that the glutamate-containing motif is conserved among the vertebrate collagens examined, consistent with a potential functional role for this charge topology. Our findings support electrostatic steering as a quantitative physical mechanism underlying the association kinetics of integrin-collagen recognition and provide design criteria for kinetically responsive biomacromolecules.

Gaining control over DNA G-quadruplex topology bears potential to modulate and study their interaction with other biomacromolecules such as proteins. To achieve this, we introduced bipyridine ligands into short oligonucleotide strands derived from telomeric regions of humans and Tetrahymena as well as into an oncogenic promoter region capable of forming such G-quadruplexes. This modification makes it possible to dynamically access different G-quadruplex topologies through the formation of chelate complexes within the quadruplex loop regions using metals such as Cu2+, Ni2+, Zn2+, Co2+, and Cd2+. The metal-coordinated systems show enhanced stability towards thermal denaturation as well as a solvation-related response in the presence of molecular crowding reagents. Interestingly, these G-quadruplexes modified with bipyridine-metal complexes stay folded in cellulo and therefore show potential for creating new oligonucleotide-based diagnostic agents and therapeutics. Metal-stabilized G-quadruplexes could therefore be suitable as probes to explore protein-G4 interactions, as inducers for G4-dependent cellular processes, or decoys to sequester transcription factors.

Cucurbit[6]uril, CB[6], is an important host due to its aqueous molecular recognition and metal-free click chemistry properties. A crucial missing link in the field is the installation of appropriate functionalizable handles on these hosts, which could then be covalently coupled to biomacromolecules. This, in turn, would help realize the full potential of CB[6]-based systems, especially in biomedical and bioimaging applications. However, there has been no development of CB[6] derivatives that can undergo such direct one-to-one conjugations. Here, we demonstrate the first synthesis of a CB[6]-monoazide (CB[6]-N3) derivative that can be readily attached to DNA via strain-promoted azide-alkyne cycloaddition. Further, the orthogonal molecular recognition properties of the DNA and CB[6] domains of the covalent conjugates were harnessed to develop (a) a host-DNA rotaxane via CB[6] facilitated click chemistry and (b) a pseudorotaxane DNA duplex that can detect an input sequence via tandem DNA strand displacement and CB[6]-mediated xenon hyper-CEST signaling.

Chitosan (CS) and whey protein isolate (WPI) are promising biomacromolecules for wound healing; however, a rational understanding of how polymer-protein interactions influence the performance of wound dressings is still lacking. Herein, CS/WPI films were developed and optimized through a Design of Experiment (DoE) approach to investigate the influence of CS molecular weight (MW) and CS:WPI ratio on polymer-protein interactions, quantified by rheological synergism. The optimized formulation (CS:WPI 1:3 with medium-MW CS) demonstrated superior tensile strength (∼2.7 MPa), higher storage modulus (∼1 × 105 MPa in the dry state), and enhanced resistance to degradation (residual mass ∼50% after 7 days). These films showed the most pronounced antimicrobial activity against S. aureus, promoted fibroblast migration and proliferation without cytotoxic effects, and significantly enhanced wound regeneration in a murine model (5% residual wound area after 18 days). These results establish rheological synergism as an important parameter, an index of the extent of polymer-protein interactions, that are responsible of the formulation performance.

DNA-polymer conjugates are an emerging class of biohybrid materials with applications in therapeutics and biosensing, yet quantitative guidelines for optimizing conjugation conversion and purification remain unreported. Here, we systematically investigate the parameters governing the NHS ester-amine coupling of single-stranded DNA (ssDNA) to synthetic polymers and the subsequent purification of these DNA-polymer conjugates. Aqueous-phase size-exclusion chromatography was identified as the most reliable method to assess the conjugation conversion and purification efficacy. Using this approach, we found that increases in concentration, pH, and the ratio of polymer to ssDNA consistently improved conjugation conversion, while increasing the molar mass of either starting material decreased conversion. Subtle differences in the ssDNA sequence were also found to affect conjugation efficiency. In both low-throughput chromatographic and high-throughput spin-column purification settings, anion exchange achieved higher purity than all other techniques, although with reduced material recovery. Together, these findings provide a practical framework for reproducible coupling of chemically diverse macromolecules with broad implications for the development of oligonucleotide therapeutics and biosensors.

Hydrogels and hydrogel microspheres have emerged as highly adaptable biomaterial platforms for precision biomedicine, owing to their hydrated polymer networks, tissue-like physicochemical properties, and capacity to host drugs, biomacromolecules and living cells. In particular, hydrogel microspheres extend the utility of bulk hydrogels by introducing injectability, large interfacial area, modular assembly, tunable microporosity and spatially programmable microenvironments. These features make them attractive for localized drug delivery, cell transplantation, tissue regeneration and emerging therapeutic systems. In this review, we summarize the major physical and chemical strategies used to construct hydrogel networks, and compare representative fabrication methods for hydrogel microspheres, including emulsion polymerization, electrospraying, microfluidics and photolithography. We further discuss how network chemistry, particle geometry, fabrication precision and microsphere assembly influence cargo loading, release behavior, cell compatibility, mechanical performance and in vivo functionality. Representative biomedical applications are then reviewed, with emphasis on sustained drug delivery, cell delivery and tissue engineering, as well as emerging uses in soft tissue reconstruction, neural guidance and compartmentalized bioactive systems. Finally, we highlight key challenges that must be addressed for clinical translation, including scalable manufacturing, batch-to-batch reproducibility, sterilization, biosafety, degradation control and application-specific validation. Overall, this review bridges existing research gaps by elucidating the interplay between network chemistry and particle geometry. Furthermore, it establishes criteria for selecting optimal microfabrication techniques, guiding the evolution of hydrogel microspheres from simple delivery carriers to engineered therapeutic microenvironments through the integrated design of materials and bioengineering.

Biomacromolecules, including proteins, peptides, and nucleic acids, hold great promise for disease diagnosis and therapy because they can execute highly specific biological functions, including catalysis, molecular recognition, and gene regulation. Nevertheless, their clinical translation is limited by inefficient intracellular delivery due to poor membrane permeability, endo/lysosomal entrapment, and instability in complex biological environments. Metal-organic frameworks (MOFs), featuring high porosity, tunable structures, mild encapsulation conditions, versatile surface modification, and stimulus-responsive degradation, have emerged as attractive material platforms for biomacromolecule protection and intracellular delivery. This review summarizes the design evolution of biomacromolecule-MOF composites from empirical construction to rational design and AI-assisted screening. Recent advances in AI-assisted enzyme-MOF and drug-delivery MOF design are further discussed as emerging tools for synergistic integration of multiple functions. This review provides an overview of how MOFs can be developed into next-generation intracellular delivery platforms and how emerging design strategies enable the rapid and precise development of biomacromolecule-MOF composites tailored for specific biomedical applications.

Boron neutron capture therapy (BNCT) requires high, tumor-selective boron delivery, yet carboranes, boron-rich BNCT building blocks, often suffer from poor aqueous solubility and suboptimal in vivo behavior despite exceptional boron density and stability. We report a modular star-shaped poly(2-oxazoline) (POx) scaffold that carries a high carborane payload and can be followed by positron emission tomography (PET). An alkyne-bearing POx was conjugated with azidopropyl meta-carborane, yielding PBMM-mCB20-EIP that remained highly water-soluble (225 g/L, ∼26 g/L of boron, 20 carboranes/star). PBMM-mCB20-EIP exhibited good cytocompatibility in CAL 27 and FaDu head-and-neck cancer cells and showed higher cell-associated boron concentration than the clinical agent sodium borocaptate. A DOTA-modified analogue was prepared and radiolabeled with gallium-68 for PET imaging. In healthy mice, gallium-68-labeled DOTA-PBMM-mCB20 revealed substantial blood-pool activity (17%ID/g) at 90 min, predominant renal clearance, and low background uptake, providing a baseline for further macromolecular engineering of this carrier and irradiation-timing optimization in tumor models.

Glycopolymer-based nanostructures (glyco-nanostructures) have garnered significant interest in biomedicine due to their exceptional biocompatibility and programmable multivalent recognition. However, traditional fabrication methods driven by physical forces face critical limitations in reproducibility and solid content. To overcome these challenges, chemical reaction-induced self-assembly (RISA) has emerged as a transformative alternative. In this review, we introduce RISA as a generalized framework encompassing various reaction-driven processes, including polymerization, deprotection, enzymatic catalysis, and interfacial induction, which enable the quantitative, in situ preparation of well-defined glyco-nanoassemblies at high concentrations. While RISA is a universal strategy, this review specifically highlights its application to glycopolymers. We systematically summarize recent advances in fabrication methodologies, underlying chemical mechanisms, and expanding biomedical applications. By bridging chemical dynamics with nanostructural function, this work establishes a foundational framework for the rational design of next-generation glyconanomaterials, aiming to stimulate further innovation and clinical translation in this evolving field.

Conductive hydrogels have risen as a promising material for flexible wearable sensors. However, achieving a hydrogel that simultaneously possesses high mechanical properties, conductivity, self-healing ability, and adhesion remains a challenge. Herein, we developed a dual-network ionic conductive hydrogel (P-P(C-A)-PA) by incorporating poly(vinyl alcohol) and a copolymer of catechol-modified ionic liquid and acrylamide. The optimized hydrogel exhibited outstanding mechanical performance (stress: 883 kPa, strain: 1120%), self-healing efficiency (stress recovery of 58.6% ± 4.6% and toughness recovery of 57.7% ± 5.5%), ionic conductivity (3.91 S/m), and adhesion strength (50 kPa on Ecoflex). The hydrogel-based flexible sensor reliably monitored human motion with rapid and accurate signal response even after self-healing. The hydrogel-based triboelectric nanogenerator showed excellent output performance (180 V, 7.9 μA, and 65 nC), further identifying grasped objects and monitoring finger rehabilitation before and after self-healing. These results highlighted the considerable potential of our hydrogel for applications in advanced electronics.