Functional Cellular Mimics for the Spatiotemporal Control of Multiple Enzymatic Cascade Reactions

Next‐generation therapeutic approaches are expected to rely on the engineering of biomimetic cellular systems that can mimic specific cellular functions. Herein, we demonstrate a highly effective route for constructing structural and functional eukaryotic cell mimics by loading pH‐sensitive polymersomes as membrane‐associated and free‐floating organelle mimics inside the multifunctional cell membrane. Metabolism mimicry has been validated by performing successive enzymatic cascade reactions spatially separated at specific sites of cell mimics in the presence and absence of extracellular organelle mimics. These enzymatic reactions take place in a highly controllable, reproducible, efficient, and successive manner. Our biomimetic approach to material design for establishing functional principles brings considerable enrichment to the fields of biomedicine, biocatalysis, biotechnology, and systems biology.     

Transformation of Cell‐Derived Microparticles into Quantum‐Dot‐Labeled Nanovectors for Antitumor siRNA Delivery

Cell‐derived microparticles (MPs) have been recently recognized as critical intercellular information conveyors. However, further understanding of their biological behavior and potential application has been hampered by the limitations of current labeling techniques. Herein, a universal donor‐cell‐assisted membrane biotinylation strategy was proposed for labeling MPs by skillfully utilizing the natural membrane phospholipid exchange of their donor cells. This innovative strategy conveniently led to specific, efficient, reproducible, and biocompatible quantum dot (QD) labeling of MPs, thereby reliably conferring valuable traceability on MPs. By further loading with small interference RNA, QD‐labeled MPs that had inherent cell‐targeting and biomolecule‐conveying ability were successfully employed for combined bioimaging and tumor‐targeted therapy. This study provides the first reliable and biofriendly strategy for transforming biogenic MPs into functionalized nanovectors.     

Near‐Infrared‐Controlled,Targeted Hydrophobic Drug‐Delivery System for Synergistic Cancer Therapy

Hydrophobicity has been an obstacle that hinders the use of many anticancer drugs. A critical challenge for cancer therapy concerns the limited availability of effective biocompatible delivery systems for most hydrophobic therapeutic anticancer drugs. In this study, we have developed a targeted near‐infrared (NIR)‐regulated hydrophobic drug‐delivery platform based on gold nanorods incorporated within a mesoporous silica framework (AuMPs). Upon application of NIR light, the photothermal effect of the gold nanorods leads to a rapid rise in the local temperature, thus resulting in the release of the entrapped drug molecules. By integrating chemotherapy and photothermotherapy into one system, we have studied the therapeutic effects of camptothecin‐loaded AuMP‐polyethylene glycol‐folic acid nanocarrier. Results revealed a synergistic effect in vitro and in vivo, which would make it possible to enhance the therapeutic effect of hydrophobic drugs and decrease drug side effects. Studies have shown the feasibility of using this nanocarrier as a targeted and noninvasive remote‐controlled hydrophobic drug‐delivery system with high spatial/temperal resolution. Owing to these advantages, we envision that this NIR‐controlled, targeted drug‐delivery method would promote the development of high‐performance hydrophobic anticancer drug‐delivery system in future clinical applications.     

Cell membrane chromatography coupled online with LC‐MS to screen anti‐anaphylactoid components from Magnolia biondii Pamp. targeting on Mas‐related G protein‐coupled receptor X2

Mas‐related G protein‐coupled receptor X2 was a mast cell–specific receptor mediating anaphylactoid reactions by activating mast cells degranulation, and it was also identified as a target for modulating mast cell–mediated anaphylactoid and inflammatory diseases. The anti‐anaphylactoid drugs used clinically disturb the partial effect of partial mediators released by mast cells. The small molecule of Mas‐related G protein‐coupled receptor X2 specific antagonists may provide therapeutic action for the anaphylactoid and inflammatory diseases in the early stage. In this study, the Mas‐related G protein‐coupled receptor X2 high expression cell membrane chromatography was coupled online with liquid chromatography and mass spectrometry and successfully used to screen anti‐anaphylactoid components from Magnolia biondii Pamp. Fargesin and pinoresinol dimethyl ether were identified as potential anti‐anaphylactoid components. Bioactivity of these two components were investigated by β hexosaminidase and histamine release assays on mast cells, and it was found that these two components could inhibit β hexosaminidase and histamine release in a concentration‐dependent manner. This Mas‐related G protein‐coupled receptor X2 high expression cell membrane chromatography coupled online with liquid chromatography and mass spectrometry system could be applied for screening potential anti‐anaphylactoid components from natural medicinal herbs. This study also provided a powerful system for drug discovery in natural medicinal herbs.     

Ile‐Lys‐Val‐ala‐Val (IKVAV) peptide for neuronal tissue engineering

Despite the great advances in microsurgery, some neural injuries cannot be treated surgically. Stem cell therapy is a potential approach for treating neuroinjuries and neurodegenerative disease. Researchers have developed various bioactive scaffolds for tissue engineering, exhibiting enhanced cell viability, attachment, migration, neurite elongation, and neuronal differentiation, with the aim of developing functional tissue grafts that can be incorporated in vivo. Facilitating the appropriate interactions between the cells and extracellular matrix is crucial in scaffold design. Modification of scaffolds with biofunctional motifs such as growth factors, drugs, or peptides can improve this interaction. In this review, we focus on the laminin‐derived Ile‐Lys‐Val‐Ala‐Val peptide as a biofunctional epitope for neuronal tissue engineering. Inclusion of this bioactive peptide within a scaffold is known to enhance cell adhesion as well as neuronal differentiation in both 2‐dimensional and 3‐dimensional environments. The in vivo application of this peptide is also briefly described.     

Preparation and application of polyvinyl alcohol‐decorated cell membrane chromatography for screening anti‐osteoporosis components from Liuwei Dihuang decoction‐containing serum

Cell membrane chromatography is a powerful tool for screening active components from complex matrices. New cell membrane carriers need to be developed to increase the coverage of cell membranes on the surface of stationary phases, thereby improving cell membrane chromatographic retention. In this work, we prepared polyvinyl alcohol‐poly dimethyl diallyl ammonium chloride modified silica gel as a cell membrane carrier. Osteoblast cell was used as cell membrane source, which was widely used to evaluate the osteogenic activity of drugs. The new cell membrane chromatographic stationary phase was used to screen anti‐osteoporosis components in Liuwei Dihuang decoction‐containing serum. The chemical structures of the new modified materials were characterized by scanning electronic microscopy, Fourier transform infrared spectroscopy, and elemental analysis characterization. Compared with the common cell membrane column, the cell membrane coverage of this modified material was increased by 30%, and thus provided a stronger retention effect in positive drugs. Nineteen metabolites in rat serum samples were retained on the cell membrane chromatography and identified by ultra‐high‐performance liquid chromatography/time‐of‐flight mass spectrometry. Among those, four components (morroniside, catalpol, loganin, and acteoside) were selected for in vitro pharmacodynamics validation. They significantly increased the osteoblast proliferation. The new modified material was successfully applied to screen anti‐osteoporosis components from Liuwei Dihuang Decoction‐containing serum.     

Antimicrobial and Wound Treatment Aspects of Micro‐ and Nanoformulations of Carboxymethyl,Dialdehyde, and TEMPO‐Oxidized Derivatives of Cellulose: Recent Advances

The remedy for infected chronic wounds such as diabetic foot ulcers is more complicated particularly in the case of patients with an inefficient immune system. Also, fighting against microbial infections in the wound site by available antibiotics may not be effective because of emerging antibiotic resistance properties among pathogenic bacteria and fungi. Recently, applications of micro‐ and nanoformulations of biomaterials have demonstrated improved therapeutic abilities for wound dressings. In this way, carboxymethyl, dialdehyde, and 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐oxidized celluloses are common biomaterials having outstanding physicochemical and therapeutic properties compared to unmodified cellulose. Therefore, in this review, recent progress in the field of wound healing and antimicrobial activities of these derivatives are presented and discussed.     

Carbon‐Nanotube‐Supported Bio‐Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells

A biomimetic nickel bis‐diphosphine complex incorporating the amino acid arginine in the outer coordination sphere was immobilized on modified carbon nanotubes (CNTs) through electrostatic interactions. The functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H₂/2 H⁺ interconversion from pH 0 to 9, with catalytic preference for H₂ oxidation at all pH values. The high activity of the complex over a wide pH range allows us to integrate this bio‐inspired nanomaterial either in an enzymatic fuel cell together with a multicopper oxidase at the cathode, or in a proton exchange membrane fuel cell (PEMFC) using Pt/C at the cathode. The Ni‐based PEMFC reaches 14 mW cm⁻², only six‐times‐less as compared to full‐Pt conventional PEMFC. The Pt‐free enzyme‐based fuel cell delivers ≈2 mW cm⁻², a new efficiency record for a hydrogen biofuel cell with base metal catalysts.     

Induction of a Proton Gradient across a Gold‐Supported Biomimetic Membrane by Electroenzymatic H2 Oxidation

Energy‐transduction mechanisms in living organisms, such as photosynthesis and respiration, store light and chemical energy in the form of an electrochemical gradient created across a lipid bilayer. Herein we show that the proton concentration at an electrode/phospholipid‐bilayer interface can be controlled and monitored electrochemically by immobilizing a membrane‐bound hydrogenase. Thus, the energy derived from the electroenzymatic oxidation of H₂ can be used to generate a proton gradient across the supported biomimetic membrane.     

Human Elastin‐Based Recombinant Biopolymers Improve Mesenchymal Stem Cell Differentiation

Elastin‐based polypeptides are a class of smart biopolymers representing an important model in the design of biomaterials. The combination of biomimetic materials with cells that have great plasticity provides a promising strategy for the realization of highly engineered cell‐based constructs for regenerative medicine and tissue repair applications. Two recombinant biopolymers inspired by human elastin are assessed as coating agents to prepare biomimetic surfaces for cell culture. These substrates are assayed for hBM MSC culture. The coated surfaces are also characterized with AFM to evaluate the topographical features of the deposited biopolymers. The results suggest that the elastin‐derived biomimetic surfaces play a stimulatory role on osteogenic differentiation of MSCs.

     

The siRNAsome: A Cation‐Free and Versatile Nanostructure for siRNA and Drug Co‐delivery

Nanoparticles show great potential for drug delivery. However, suitable nanostructures capable of loading a range of drugs together with the co‐delivery of siRNAs, which avoid the problem of cation‐associated cytotoxicity, are lacking. Herein, we report an small interfering RNA (siRNA)‐based vesicle (siRNAsome), which consists of a hydrophilic siRNA shell, a thermal‐ and intracellular‐reduction‐sensitive hydrophobic median layer, and an empty aqueous interior that meets this need. The siRNAsome can serve as a versatile nanostructure to load drug agents with divergent chemical properties, therapeutic proteins as well as co‐delivering immobilized siRNAs without transfection agents. Importantly, the inherent thermal/reduction‐responsiveness enables controlled drug loading and release. When siRNAsomes are loaded with the hydrophilic drug doxorubicin hydrochloride and anti‐P‐glycoprotein siRNA, synergistic therapeutic activity is achieved in multidrug resistant cancer cells and a tumor model.     

A Convenient and Versatile Amino‐Acid‐Boosted Biomimetic Strategy for the Nondestructive Encapsulation of Biomacromolecules within Metal–Organic Frameworks

Herein, an amino‐acid‐boosted biomimetic strategy is reported that enabled the rapid encapsulation, or co‐encapsulation, of a broad range of proteins into microporous metal–organic frameworks (MOFs), with an ultrahigh loading efficiency. It relies on the accelerated formation of prenucleation clusters around proteins via a metallothionein‐like self‐assembly. The encapsulated proteins maintained their native conformations, and the structural confinement within porous MOFs endowed enzymes with excellent bioactivity, even in harsh conditions (e.g. in the presence of proteolytic or chemical agents or at high temperature). Furthermore, owing to the merits of nondestructive and protein surface charge‐independent encapsulation, the feasibility of this biomimetic strategy for biostorage, enzyme cascades, and biosensing was also verified. It is believed that this convenient and versatile encapsulation strategy has great promise in the important fields of biomedicine, catalysis, and biosensing.     

Nanoengineering of Stimuli‐Responsive Protein‐Based Biomimetic Protocells as Versatile Drug Delivery Tools

We present a general strategy to nanoengineer protein‐based colloidal spheres (biomimetic protocells) as versatile delivery carriers with stimuli responsiveness by the electrostatic assembly of binary components (proteins and polypeptides) in association with intermolecular disulfide cross‐linking. The size of the colloidal spheres, ranging from nanoscale to microscale, is readily tuned through parameters like protein and polypeptide concentration, the ratio between both, pH, and so on. Moreover, such colloidal spheres show versatile encapsulation of various guest molecules including small organic molecules and biomacromolecules. The pH and redox dual‐responsiveness facilitates the rapid release of the payload in an acidic and reductant‐enriched ambient such as in lysosomes. Thus, nanoengineering of protein‐based biomimetic protocells opens a new alternative avenue for developing delivery vehicles with multifunctional properties towards a range of therapeutic and diagnostic applications.     

Three‐Pronged Attack by Homologous Far‐red/NIR AIEgens to Achieve 1+1+1>3 Synergistic Enhanced Photodynamic Therapy

Photodynamic therapy (PDT) has long been shown to be a powerful therapeutic modality for cancer. However, PDT is undiversified and has become stereotyped in recent years. Exploration of distinctive PDT methods is thus highly in demand but remains a severe challenge. Herein, an unprecedented 1+1+1>3 synergistic strategy is proposed and validated for the first time. Three homologous luminogens with aggregation‐induced emission (AIE) characteristics were rationally designed based on a simple backbone. Through slight structural tuning, these far‐red/near‐infrared AIE luminogens are capable of specifically anchoring to mitochondria, cell membrane, and lysosome, and effectively generating reactive oxygen species (ROS). Notably, biological studies demonstrated combined usage of three AIE photosensitizers gives multiple ROS sources simultaneously derived from several organelles, which gives superior therapeutic effect than that from a single organelle at the same photosensitizers concentration. This strategy is conceptually and operationally simple, providing an innovative approach and renewed awareness of improving therapeutic effect through three‐pronged PDT.     

Particle‐Stabilized Water Droplets that Sprout Millimeter‐Scale Tubes

Millimeter‐scale tubes are observed to sprout from water droplets injected into a bath of toluene containing ethanol and silica colloids. This phenomenon requires that first a membrane is formed by the colloids which self‐assemble at the droplet interface, and second, that the ethanol preferentially partitions into the aqueous phase leading to an internal over‐pressure. Tube growth, eruption, and shuffling droplets are subsequently observed, depending on the concentration of ethanol and colloids selected. This work opens many possibilities in the field of biomimetic droplets for fundamental studies of artificial growth at the microscale and for emulsion‐related applications.     

Gold‐Nanoparticle‐Based Multifunctional Amyloid‐β Inhibitor against Alzheimer’s Disease

Targeting amyloid‐β (Aβ)‐induced complex neurotoxicity has received considerable attention in the therapeutic and preventive treatment of Alzheimer’s disease (AD). The complex pathogenesis of AD suggests that it requires comprehensive treatment, and drugs with multiple functions against AD are more desirable. Herein, AuNPs@POMD‐pep (AuNPs: gold nanoparticles, POMD: polyoxometalate with Wells–Dawson structure, pep: peptide) were designed as a novel multifunctional Aβ inhibitor. AuNPs@POMD‐pep shows synergistic effects in inhibiting Aβ aggregation, dissociating Aβ fibrils and decreasing Aβ‐mediated peroxidase activity and Aβ‐induced cytotoxicity. By taking advantage of AuNPs as vehicles that can cross the blood–brain barrier (BBB), AuNPs@POMD‐pep can cross the BBB and thus overcome the drawbacks of small‐molecule anti‐AD drugs. Thus, this work provides new insights into the design and synthesis of inorganic nanoparticles as multifunctional therapeutic agents for treatment of AD.     

The Human Host‐Defense Peptide Cathelicidin LL‐37 is a Nanomolar Inhibitor of Amyloid Self‐Assembly of Islet Amyloid Polypeptide (IAPP)

Amyloid self‐assembly of islet amyloid polypeptide (IAPP) is linked to pancreatic inflammation, β‐cell degeneration, and the pathogenesis of type 2 diabetes (T2D). The multifunctional host‐defence peptides (HDPs) cathelicidins play crucial roles in inflammation. Here, we show that the antimicrobial and immunomodulatory polypeptide human cathelicidin LL‐37 binds IAPP with nanomolar affinity and effectively suppresses its amyloid self‐assembly and related pancreatic β‐cell damage in vitro. In addition, we identify key LL‐37 segments that mediate its interaction with IAPP. Our results suggest a possible protective role for LL‐37 in T2D pathogenesis and offer a molecular basis for the design of LL‐37‐derived peptides that combine antimicrobial, immunomodulatory, and T2D‐related anti‐amyloid functions as promising candidates for multifunctional drugs.     

Design,Synthesis, and Phenotypic Profiling of Pyrano‐Furo‐Pyridone Pseudo Natural Products

Natural products (NPs) inspire the design and synthesis of novel biologically relevant chemical matter, for instance through biology‐oriented synthesis (BIOS). However, BIOS is limited by the partial coverage of NP‐like chemical space by the guiding NPs. The design and synthesis of “pseudo NPs” overcomes these limitations by combining NP‐inspired strategies with fragment‐based compound design through de novo combination of NP‐derived fragments to unprecedented compound classes not accessible through biosynthesis. We describe the development and biological evaluation of pyrano‐furo‐pyridone (PFP) pseudo NPs, which combine pyridone‐ and dihydropyran NP fragments in three isomeric arrangements. Cheminformatic analysis indicates that the PFPs reside in an area of NP‐like chemical space not covered by existing NPs but rather by drugs and related compounds. Phenotypic profiling in a target‐agnostic “cell painting” assay revealed that PFPs induce formation of reactive oxygen species and are structurally novel inhibitors of mitochondrial complex I.     

Covalent Self‐Assembly and One‐Step Photocrosslinking of Tyrosine‐Rich Oligopeptides to Form Diverse Nanostructures

We present covalently self‐assembled peptide hollow nanocapsule and peptide lamella. These biomimetic dityrosine peptide nanostructures are synthesized by one‐step photopolymerization of a tyrosine‐rich short peptide without the aid of a template. This simple approach offers direct synthesis of fluorescent peptide nanocages and free‐standing thin films. The simple crosslinked peptide lamella films provide robust mechanical properties with an elastic modulus of approximately 30 GPa and a hardness of 740 MPa. These nanostructures also allow for the design of peptidosomes. The approach taken here represents a rare example of covalent self‐assembly of short peptides into nano‐objects, which may be useful as microcompartments and separation membranes.