Hybrid cell membrane coating orchestrates foreign-body reactions, anti-adhesion, and pro-regeneration in abdominal wall reconstruction

Tension-free synthetic meshes are the clinical standard for hernia repair, but they often trigger immune response-mediated complications such as severe foreign-body reactions (FBR), visceral adhesions, and fibrotic healing, increasing the risk of recurrence. Herein, we developed a hybrid cell membrane coating for macroscale mesh fibers that acts as an immune orchestrator, capable of balancing immune responses with tissue regeneration. Cell membranes derived from red blood cells (RBCs) and platelets (PLTs) were covalently bonded to fiber surfaces using functionalized-liposomes and click chemistry. The fusion of clickable liposomes with cell membranes significantly improved coating efficiency, coverage uniformity, and in vivo stability. Histological and flow cytometric analyses of subcutaneous implantation in rats and mice demonstrated significant biofunctional heterogeneity among various cell membrane coatings in FBR. Specifically, the RBC-PLT-liposome hybrid cell membrane coating markedly mitigated FBR, facilitated host cell infiltration, and promoted M2-type macrophage polarization. Importantly, experimental results of abdominal wall defect repairs in rats indicate that the hybrid cell membrane coating effectively prevented visceral adhesions, promoted muscle regenerative healing, and enhanced the recruitment of Pax7+/MyoD+ muscle satellite cells. Our findings suggest that the clickable hybrid cell membrane coating offers a promising approach to enhance clinical outcomes of hernia mesh in abdominal wall reconstruction.

Tailoring hyaluronic acid hydrogels: Impact of cross-linker length and density on skin rejuvenation as injectable dermal fillers and their potential effects on the MAPK signaling pathway suppression

Hyaluronic acid (HA) hydrogels, obtained through cross-linking, provide a stable 3D environment that is important for controlled delivery and tissue engineering applications. Cross-linking density has a significant impact on the physicochemical properties of hydrogels, including their shape stability, mechanical stiffness and macromolecular diffusivity. However, often cross-linking chemistries require photoinitiator and catalyst that may be toxic and cause unwanted tissue response. Here, we prepared a series of HA hydrogel with varying cross-linker length and cross-linking density, which can be obtained by altering the feed ratio of three different cross-linkers from small molecules to macromolecules (e.g., 1,4-butanediol diglycidyl ether (BDDE), ferulic acid (FA), pluronic (PLU)), to ameliorate skin wrinkles in mice models. HA cross-linked with FA and PLU exhibited enzyme and temperature-dependent sol-to-gel phase transition, respectively, and the gels possess good injectability. In vitro test confirmed that HA hydrogels co-cultured with RAW 264.7 and HDF cells showed good biocompatibility. In particular, HA cross-linked with PLU stimulated the growth of HDF cells and HaCaT cells. HA cross-linked with PLU suppressed the expression levels of proteins involved in collagen degradation including mitogen-activated protein kinases (ERK, JNK, p38) and matrix metalloproteases (MMP-1, MMP-3, and MMP-9) resulting in increased deposition of Collagen I. The free-flowing sols of HA hydrogel precursors are subcutaneously injected into the back of BALB/c mice and form stable gels at the dermis layer and found to be non-toxic. More importantly, HA hydrogel cross-linked with PLU showed an enhanced anti-wrinkling effect in the wrinkled mice model. Thus, properties of HA hydrogels such as injectability, biocompatibility, and good anti-wrinkling effect altered through varying cross-linking density must be considered in the context of soft tissue engineering applications.

Intraocular injectable hydrogels for the delivery of cells and nanoparticles

The rising global life expectancy has led to a growing prevalence of ophthalmic diseases, while current treatments face important limitations in terms of efficacy, costs, and patient compliance. The use of injectable hydrogels as drug and cell carriers is a promising approach, compared to the injection of drug solutions or cell suspensions. This is because the hydrogel matrix may offer protection against clearance or degradation, may modulate drug/cell release, and provide a biomimetic substrate for differentiating cells while being minimally invasive. On one hand, injectable hydrogels for ocular drug delivery have been traditionally designed to host and release small drugs or proteins. However, limitations such as high burst release and difficulty of entrapping hydrophobic molecules led to the emergence of nanocomposite hydrogels, where the drug is entrapped in nanoparticles prior hydrogel incorporation. Composite systems offer great advantages over the injection of particle suspensions, improving particle fate and drug release kinetics. On the other hand, injectable hydrogels offer a cell-friendly environment to seek tissue regeneration, providing biomechanical and biochemical cues for cellular cross-talk, differentiation, and formation of new extracellular matrix. This review critically discusses recent advancements in the development of novel injectable hydrogels as delivery vehicles for drug-loaded nanoparticles and cells, with a major focus on the formulation components, administration routes, and other factors affecting performance, highlighting promising aspects and challenges to address in the future.

Nanobody-based drug delivery systems for cancer therapy

Targeted delivery can elevate the local drug concentration within tumor tissues, while minimizing drug distribution to normal tissues, thus enhancing the effectiveness of anti-tumor medications and reducing adverse effects and systemic toxicities. Nanobodies, the novel molecular pattern of antibodies characterized by their small size, high stability, strong specificity, and low immunogenicity, have been extensively applied in targeted drug delivery for tumor therapy. This review discusses structural disparities and functional advantages of nanobodies compared to other antibody fragments and full-length antibody. It also highlights nanobody applications in targeted tumor therapy, focusing on their use in modifying delivery systems, e.g., liposomes, EVs, micelles, albumin nanoparticles, gold nanoparticles, polymeric nanoparticles, and as nanobody-drug conjugates. This review delves into the methods applied for integrating nanobodies into different drug delivery carriers, in order to provide useful information for researchers developing nanobody-based targeted drug delivery systems.

Progress in the mechanical properties of nanoparticles for tumor-targeting delivery

Cancer nanomedicines have attracted significant attention in the past several decades, and the physicochemical properties, such as the size, shape, composition, surface charge, hydrophobicity, and mechanical properties, of nanoparticles have been optimized for potent cancer therapy. Since publishing our 2020 tutorial review "Influence of nanomedicine mechanical properties on tumor targeting delivery" in Chemical Society Reviews, substantial advancements have been made in understanding the role of mechanical properties in cancer nanomedicine. Notably, in vivo transport processes that are dependent on the mechanical properties of nanomedicine, including long circulation, tumor accumulation, and deep penetration, have been extensively studied using various nano-drug delivery systems. These studies have demonstrated that leveraging these mechanical properties can significantly enhance the antitumor efficacy of nanomedicine. In this review, we categorize the advancements in the mechanical properties of cancer nanomedicine into three distinct themes: the interactions between nanoparticles with varied mechanical properties and cells (2002 - present), the impact of these properties on in vivo delivery processes (2007 - present), and the strategic use of mechanical properties to boost cancer therapy (2023 - present). We analyze how different mechanical properties of organic, inorganic, hybrid, and biological nanoparticles affect their delivery processes at the macroscopic level, i.e., in tissues, organs and cells. At the microscopic level, their biological and physical interactions with biological barriers, physiological structures, cell membranes, organelles, and other structures reveal the potential mechanism of nanoparticles' mechanical properties in determining their antitumor efficacy. Furthermore, we address the current challenges and future prospects in the mechanical properties of cancer nanomedicine, as well as the clinical translation potential of nanoparticles with diverse mechanical characteristics.

Highly Sensitive Wearable Chromic Force Sensor Utilizing In-Plane Anisotropy in Polydiacetylene Mechanochromism

Force sensitivity is a crucial parameter in mechanochromic materials, determining their application range and practical success. In this study, we reveal an unexplored degree of freedom─in-plane anisotropy─for significantly enhancing the force sensitivity of polydiacetylene. Utilizing our newly developed dual nanofriction force/fluorescence microscopy setup, we discovered that force sensitivity reaches its peak when external forces are applied perpendicular to the polymer backbones in-plane. This phenomenon is explained by a "domino effect", where point loads propagate along the backbones and affect the polymer structure even hundreds of nanometers from the contact point. Leveraging this finding, we developed a highly sensitive, stretchable force sensor and demonstrated that aligning polydiacetylene crystals perpendicular to the force direction increased the sensor's sensitivity by up to 14-fold.

Development of a bioactive hyaluronic acid hydrogel functionalised with antimicrobial peptides for the treatment of chronic wounds

Chronic wounds present significant clinical challenges due to delayed healing and high infection risk. This study presents the development and characterisation of acrylated hyaluronic acid (AcHyA) hydrogels functionalised with gelatin (G) and the antimicrobial peptide (AMP) PP4-3.1 to enhance cellular responses while providing antimicrobial activity. AcHyA-G and AcHyA-AMP hydrogels were formed via thiol-acrylate crosslinking, enabling in situ AcHyA hydrogel formation with stable mechanical properties across varying gelatin concentrations. Biophysical characterisation of AcHyA-G hydrogels showed rapid gelation, elastic behaviour, uniform mesh size, and consistent molecular diffusion across all formulations. Moreover, the presence of gelatin enhanced stability without affecting the hydrogel's degradation kinetics. AcHyA-G hydrogels supported the adhesion and spreading of key cell types involved in wound repair (dermal fibroblasts and endothelial cells), with 0.5% gelatin identified as the optimal effective concentration. Furthermore, the conjugation of the AMP conferred bactericidal activity against Staphylococcus aureus and Escherichia coli, two of the most prevalent bacterial species found in chronically infected wounds. These results highlight the dual function of AcHyA-AMP hydrogels in promoting cellular responses and antimicrobial activity, offering a promising strategy for chronic wound treatment. Further in vivo studies are needed to evaluate their efficacy, including in diabetic foot ulcers.

Encapsulation of Small Extracellular Vesicles into Selectively Disassemblable Shells of PEGylated Metal-Phenolic Networks

Small extracellular vesicles (sEVs) are cell-derived particles used for intercellular communication in living organisms that have gained great interest from researchers for their use as drug carriers and diagnostic agents. However, the isolation and storage of sEVs lead to issues including lipid membrane disruption, protein denaturation, and nucleic acid degradation. Herein, a surface functionalization strategy is reported for encapsulating single sEV into selectively disassemblable protective shells composed of metal-phenolic networks (MPNs) post-modified with poly(ethylene glycol) (PEG). Disassemblable MPN shells can be rapidly deposited on sEVs in a one-step manner and post-modified with PEG. These coatings enhance the colloidal stability of sEVs and protect them against harsh storage conditions, while the non-covalent and selectively disassemblable nature of the MPN shell allows recovery after storage without compromising their surface integrity and functionality. It is demonstrated that various triggers, such as pH adjustment, competitive chelation, and redox reactions, can be used to disassemble the MPN shell, thereby offering widely adoptable strategies depending on the target applications. This approach potentially overcomes conventional challenges associated with sEV processing and storage and may contribute to reducing cold-chain requirements and transportation costs of future sEVs-based therapeutics and diagnostics.

Rapid and Additive-Free Synthesis of β-Sulfido Sulfonyl Fluorides through N-Methyl-2-pyrrolidinone (NMP)-Promoted Thia-Michael Addition

β-Sulfido sulfonyl fluorides, incorporating a clickable sulfonyl fluoride and a thioether motif, are valuable intermediates in chemical biology, materials science, and drug discovery. Herein, we developed a rapid and additive-free synthesis of these compounds via N-methyl-2-pyrrolidinone (NMP)-promoted thia-Michael addition of thiols to ethene sulfonyl fluoride (ESF). The reaction proceeds smoothly under neutral conditions without the need for a base or catalyst, achieving high efficiency within 20 min. This method demonstrates a broad substrate scope, tolerating thiophenols, alkylthiols, thioglycosides, and cysteine-containing peptides. The resulting β-sulfido sulfonyl fluorides enable diverse transformations, such as sulfur(VI) fluoride exchange (SuFEx) reaction and thioether oxidation, facilitating applications in drug conjugates and materials, such as additives for lithium-ion battery electrolyte components.

Gallol-containing chitosan/hyaluronic acid composite hydrogel patches as wound sealing and dressing materials

Recently, various adhesive materials have been developed for versatile biomedical applications owing to their rapid and strong adhesion to tissues in water-rich environments. One such example is gallol-containing chitosan (CHI-G), which contains multiple gallol and amine groups in its backbone. However, the practical application of CHI-G alone is limited owing to its intrinsic mechanical strength and undesirable immune responses. In this study, we developed Ca2+ ions- and hyaluronic acid-containing CHI-G (CHC) patches to prevent anastomotic leakage and accelerate wound healing. CHC hydrogel patches showed increased elastic modulus values (809.4 ± 181.7 Pa) compared to that of CHI-G hydrogel patches (137.0 ± 16.3 Pa). In addition, the bursting pressure (78.2 ± 3.5 mmHg) of CHC hydrogel patch-applied porcine intestine was far higher than those of the control (4.13 ± 0.4 mmHg) and HA groups (14.5 ± 2.5 mmHg). CHC hydrogel patches showed suitable mechanical properties and biocompatibility for wound-sealing and dressing applications in water-rich environments. Notably, the CHC hydrogel patch-applied wound healing animal model exhibited a healing rate of over 90 % at 14 days post-surgery, notably higher than that of the control group (76 %). These findings suggest that CHC patches have considerable potential as effective wound dressings and sealing materials.

Antibiotic-based micelles with bone-targeting and pH-responsive properties for infectious osteomyelitis treatment

We developed antibiotic-based micelles with bone-targeting and charge-switchable properties (P-CASMs) for treating infectious osteomyelitis. The amphiphilic molecules are formed by combining ciprofloxacin (CIP) with ligand 1 through a mild salifying reaction, and spontaneously self-assemble into antibiotic-based micelles (ASMs) in aqueous solution. Acrylate groups on ligand 1 enable cross-linking of ASMs with pentaerythritol tetra(mercaptopropionate) via a click reaction, forming pH-sensitive cross-linked micelles (CASMs). The incorporation of vinylphosphonates imparts bone-targeting and charge-switchable properties of CASMs, creating P-CASMs. These P-CASMs exhibit good biocompatibility at physiological pH and strong adhesion to bone infection sites (pH 5.5) due to electrostatic interactions. They can effectively penetrate bacterial biofilms and release antibiotics in response to the local microenvironment, thereby eradicating bacteria. Compared to previous systems, the P-CASMs show higher drug loading (∼23 %), improved stability, and better biosafety. This innovative system holds substantial potential for clinical applications in the treatment of osteomyelitis.

Comparative Study of Click Handle Stability in Common Ligation Conditions

Click chemistry efficiently ligates molecular building blocks in a robust and high-yielding manner and has found major application in the rapid modification of important molecular actors in biological systems. However, the high reactivity of click handles often correlates with decreased stability, which presents a significant challenge in the practical application of these systems. In the current study, we describe a survey of the stability of commonly deployed click manifolds across a range of widely used ligation conditions. Incompatible click handle and ligation condition combinations are identified, with kinetic half-lives and side products of each undesired reaction determined, including the assessment of stability over extended periods and in a protein environment. This data set provides researchers with a roadmap to expediently determine the most appropriate click reaction conditions for any given bioorthogonal application, thus elevating the probability of success of procedures that utilize click chemistry.

The nucleic acid reactions on the nanomaterials surface for biomedicine

Integrating nucleic acids (NAs) with nanomaterials has substantially advanced biomedical research, enabling critical applications in biosensing, drug delivery, therapeutics, and the synthesis of nanomaterials. At the core of these advances are the reactions of NAs on nanomaterial surfaces, encompassing conjugation (covalent and non-covalent), detachment (physical and chemical), and signal amplification (enzyme-mediated signal amplification, enzyme-free signal amplification, and DNA Walker). Here, we review the fundamental mechanisms and recent progress in nucleic acid reactions on nanomaterial surfaces, discuss emerging applications for diagnostics, nanomedicine, and gene therapy, and explore persistent challenges in the field. We offer a forward-looking perspective on how future developments could better control, optimize, and harness these reactions for transformative advances in nanomedicine and biomedical engineering.

Multicomponent Polymerizations Provide Sustainable Sulfur (Selenium)-Containing Polyesters

ConspectusWith the rapid development of the polymer industry, the contradiction between synthetic polymers and the sustainable development of human society is becoming more and more prominent. The advancement of degradable plastics greatly contributes to the sustainability of our society. Synthetic polymers containing precisely placed in-chain ester groups are expected to be degradable in a controlled manner. Their potential as environmentally benign plastics is significant. For this purpose, there is a clear need for their improved performance. Incorporating sulfur functional groups into polyesters can improve the diverse crucial properties of their counterparts. However, there is a lack of related high-efficiency polymer synthesis methods.In response to this issue, we designed a series of multicomponent polymerization methods for the synthesis of a library of degradable polyesters with tunable structure and properties. This Account summarizes our recent efforts to discover the polymerization approach. The method uses readily available monomers including diols, diamines, H2O, diacrylates, carbonyl sulfide (COS), cyclic thioanhydrides, CO, and selenium powder. The polymerization is usually carried out under mild conditions: at 60 to 90 °C, for 2 to 12 h, using organobases as the catalysts or catalyst-free. This approach achieves the simultaneous incorporation of in-chain ester and sulfur/selenium functional groups including thiocarbonate, thioether, thioester, thiourethane, and selenoether.The method has a wide monomer scope and yields diverse polymers with tunable structures. The obtained polyesters possess weight-average molecular weights of up to 175.4 kDa. Most of these polyesters are thermally stable, exhibiting decomposition temperatures of >200 °C. Due to the diversity of structure, these polymers demonstrate extensively tunable performance covering crystalline plastics, thermoplastic elastomers, and amorphous plastics. These polymers exhibit a wide range of glass-transition temperatures of -60 to 72 °C and a wide range of melting temperatures of 43 to 274 °C. Notably, the polymers containing long alkyl chains (number of carbon atoms ≥ 9) exhibit polyethylene-like crystallinity and mechanical properties. The in-chain thiourethane or amide groups enable enhanced thermal and mechanical properties due to the incorporation of inter/intramolecular hydrogen bonding. These polymers are also easy to degrade via alkali hydrolysis, alcohol hydrolysis, enzymatic hydrolysis, oxidation, etc. The degradation products often have well-defined structure and value-added properties and can even be directly used for repolymerization to achieve a closed-loop chemical cycle. Overall, the multicomponent polymerization presented in this Account furnishes a facile and versatile synthesis of sustainable polymers with tunable structure and properties.

Hydrophobic vehicles for hydrophilic drugs: Sustained intravitreal caffeine delivery with oleogels

Caffeine is the most widely consumed bioactive ingredient in the world, which has been found to show great therapeutic potential in several posterior eye diseases. While intravitreal injection represents the ideal administration route for these disorders, it remains challenging to achieve sustained release of caffeine in the vitreous. Herein, we address this issue by loading crystalline caffeine within oleogels (Ca@oleogels), oily delivery vehicles which provide a hydrophobic environment that is opposite to the hydrophilic nature of their cargos. Mathematical modeling of the in vitro release profiles indicated the diffusion process of the drug from Ca@oleogels was playing a dominating role in caffeine release. Furthermore, sustained intravitreal delivery was evidenced by higher drug levels from 12 h until the end of the pharmacokinetic study (240 h) and a 3.2-fold reduction in Cmax in Ca@oleogel dosed rabbits compared to their caffeine dosed counterparts. Superior therapeutic effects were obtained with Ca@oleogels in a laser-induced mouse choroidal neovascularization model. Advantages of Ca@oleogels as caffeine delivery vehicles included excellent biocompatibility, low cost and simplicity of manufacturing as well, which indicated they can be administrated safely and were readily amenable to scale-up production cost-effectively. Moreover, sustained release of another hydrophilic model drug (congo red) was also demonstrated with the same formulation design. Therefore, this strategy serves as a general solution to sustained intravitreal delivery of hydrophilic small molecule drugs.

A Sprayable Polyelectrolyte Coating to Mitigate the Foreign Body Response of Implants

The foreign body response (FBR) presents a significant challenge to biomedical implants, leading to fibrotic capsule formation that compromises implant functionality. In this study, we report a straightforward method for fabricating stable anti-fibrotic polyelectrolyte coatings on implant surfaces using industrialized ultrasonic spraying technology. The coating thickness and surface charge can be adjusted through variations in spraying time and polyelectrolyte ratio, respectively. We investigate the fibrotic response of polyelectrolyte-coated implants with varying surface charges and thicknesses. Our findings reveal that surface charge significantly influences the fibrotic response, while electronegative polyelectrolyte coatings most effectively inhibit FBR compared to electrically neutral, positively charged, and uncoated surfaces. Meanwhile, coating thickness beyond 10 μm resulted in thinner capsules than coatings at a 1 μm or nanometer scale. The simple and versatile polyelectrolyte coating method reported here holds great potential to enhance and extend the functionality of implants in a mass-produced manner by mitigating host responses to implantable biomaterials.

Engineered Cell Membrane Coating Technologies for Biomedical Applications: From Nanoscale to Macroscale

Cell membrane coating has emerged as a promising strategy for the surface modification of biomaterials with biological membranes, serving as a cloak that can carry more functions. The cloaked biomaterials inherit diverse intrinsic biofunctions derived from different cell sources, including enhanced biocompatibility, immunity evasion, specific targeting capacity, and immune regulation of the regenerative microenvironment. The intrinsic characteristics of biomimicry and biointerfacing have demonstrated the versatility of cell membrane coating technology on a variety of biomaterials, thus, furthering the research into a wide range of biomedical applications and clinical translation. Here, the preparation of cell membrane coatings is emphasized, and different sizes of coated biomaterials from nanoscale to macroscale as well as the engineering strategies to introduce additional biofunctions are summarized. Subsequently, the utilization of biomimetic membrane-cloaked biomaterials in biomedical applications is discussed, including drug delivery, imaging and phototherapy, cancer immunotherapy, anti-infection and detoxification, and implant modification. In conclusion, the latest advancements in clinical and preclinical studies, along with the multiple benefits of cell membrane-coated nanoparticles (NPs) in biomimetic systems, are elucidated.

Diverse reactivity of maleimides in polymer science and beyond

Maleimides are remarkably versatile functional groups, capable of participating in homo- and copolymerizations, Diels-Alder and (photo)cycloadditions, Michael additions, and other reactions. Their reactivity has afforded materials ranging from polyimides with high upper service temperatures to hydrogels for regenerative medicine applications. Moreover, maleimides have proven to be an enabling chemistry for pharmaceutical development and bioconjugation via straightforward modification of cysteine residues. To exert spatiotemporal control over reactions with maleimides, multiple approaches have been developed to photocage nucleophiles, dienes, and dipoles. Additionally, further substitution of the maleimide alkene (e.g., mono- and di-halo-, thio-, amino-, and methyl-maleimides, among other substituents) confers tunable reactivity and dynamicity, as well as responsive mechanical and optical properties. In this mini-review, we highlight the diverse functionality of maleimides, underscoring their notable impact in polymer science. This moiety and related heterocycles will play an important role in future innovations in chemistry, biomedical, and materials research.

Combined treatment strategy of hydrogel dressing and physiotherapy for rapid wound healing

Wound care for open wounds is essential for reducing pain, protecting open wounds, speeding up the healing process and avoiding scar formation. Among the various three-dimensional (3D) carrier biomaterials such as films, sponges, and hydrogels, hydrogels are chemically and physically most similar to the natural extracellular matrix (ECM). Meanwhile, hydrogels are also common 3D carriers that can be efficiently loaded with drugs or cells. In addition, it forms a protective barrier on the wound surface to prevent secondary external infections and has the effect of directing skin cell expansion, tissue infiltration, and wound closure. However, the role of functional drugs in wound healing also faces a number of issues such as resistance, dosage, activity, and stability; therefore, a richer array of therapies is needed for wound repair and other areas of development. Physiotherapy, also known as nonpharmacological therapy, is a commonly used clinical treatment. Recently, more and more physiotherapy have been used for wound repair due to their high efficiency and low irritation. In recent reports, many researchers have tended to use hydrogel dressings in combination with physiotherapy, and this combination therapy is beneficial because it can both protect the wound microenvironment and accelerates wound healing. Therefore, this paper reviews the combined use of hydrogel dressings and physiotherapy in wound healing. We present the characteristics of hydrogel and physiotherapy and focus on the progress and problems of these two combined therapies in recent years.

Rapid synthesis of degradable ester/thioether monomers and their incorporation into thermoset polyurethane foams for traumatic wound healing

Polyurethane (PUr) foam hemostatic dressings are highly effective at controlling bleeding in traumatic wounds, but their traditionally slow degradation rate requires dressing removal, which could result in wound rebleeding. Incorporating degradable linkages into the PUr network can provide a biodegradable dressing that could be left in place during healing, eliminating rebleeding upon removal and providing scaffolding for new tissue ingrowth with no remains of the applied dressing after healing. In this work, a library of degradable PUr foams was synthesized from degradable monomers based on hydrolytically labile esters and oxidatively labile thioethers using rapid click-chemistry reactions. In a twelve-week in vitro degradation study in 3% hydrogen peroxide and 0.1 M sodium hydroxide, incorporation of degradable monomers resulted in significantly increased PUr foam mass loss, offering biodegradable foam dressings that could better match the rate of traumatic wound healing. Changes to foam chemical, mechanical, thermal, and physical properties throughout degradation were also analyzed. Furthermore, the degradable PUr foams had increased platelet interactions, which could improve foam-induced clotting for a more effective hemostatic dressing. Overall, a biodegradable PUr foam hemostatic dressing could significantly improve healing outcomes in traumatic wounds. STATEMENT OF SIGNIFICANCE: A simple, solvent-free, rapid synthesis technique was developed to provide degradable polythiol monomers for use in polyurethane synthesis. The degradable monomers were incorporated into hemostatic polyurethane foams to provide materials with tunable degradation rates within clinically-relevant time frames. The resulting foams and their degradation byproducts were cytocompatible and hemocompatible, and foams made with the new degradable monomers had enhanced blood clotting, enabling their future use as hemostatic dressings.

Surface Modification of Poly(dimethylsiloxane) Blood Flow Chambers with a Poly(ethylene glycol) Conjugate and Factor XII Inhibitor

This study is focused on the application of a dual surface coating on poly(dimethylsiloxane) (PDMS) flow chambers, which aims to inhibit the contact activation pathway of coagulation. Polyethylene glycol (PEG) is a commonly used biocompatible molecule due to its hydrophilic nature and capacity to reduce protein adsorption. Corn trypsin inhibitor (CTI) is a selective inhibitor of Factor XII, which is the initial factor responsible for activating the intrinsic pathway of coagulation. By sequentially applying these two coatings to PDMS substrates, we expect the PEG-CTI coating to decrease blood clot formation and reduce fibrinogen deposition on surfaces compared to uncoated surfaces. Our results indicate that the PEG-CTI coating was successful in significantly reducing both cell adsorption and fibrinogen deposition to the surfaces of PDMS flow chambers. This study is a step toward applying PEG-CTI surface coatings to PDMS microfluidic artificial lungs, in which the surface interaction between the PDMS lungs and blood is a critical issue that must be mitigated to realize the full potential of this exciting therapeutic tool.

Smart Polymeric 3D Microscaffolds Hosting Spheroids for Neuronal Research via Quantum Metrology

Toward the aim of reducing animal testing, innovative in vitro models are required. Here, this study proposes a novel smart polymeric microscaffold to establish an advanced 3D model of dopaminergic neurons. These scaffolds are fabricated with Ormocomp via Two-Photon Polymerization. The scaffolds are further enhanced by functionalization with fluorescent nanodiamonds (FNDs), which can serve as quantum nanosensors for both magnetic and temperature sensing. The material biocompatibility is tested using two different cell lines, SH-SY5Y and A431, with cell viability over 98%. A total of 69% of the FNDs are grafted on the structure compared to those that remained on the glass surface. Cells are tested with the scaffolds in several microenvironments, and the final assembly required for 3D quantum metrology experiments achieved 91% biocompatibility. Subsequently, embryoid bodies containing dopaminergic neurons, the cell type affected by Parkinson's disease (PD), are integrated with FND-functionalized scaffolds. This 3D model is successfully established, demonstrated by strong interactions between dopaminergic neurons and the scaffold, with the directional growth of neurites along the 3D scaffold. Ultimately, this study have developed a 3D platform that enables the readout of signaling in a model that holds great potential for future PD research.

Melanin-Inspired Maleimide Coatings on Various Substrates for Rapid Thiol Functionalization

In this study, a substrate-independent maleimide film is developed that can be formed under mild aqueous conditions (pH 7.4), and which allows rapid and efficient external thiol immobilization onto the coated surfaces. For the coating block, tyrosine-conjugated maleimide (Tyr-Mal) containing a phenolic amine moiety is prepared as a substrate-independent dormant coating precursor, wherein the maleimide component permits a rapid Michael addition reaction with the thiol moiety of interest. By mimicking natural melanogenesis, Tyr-Mal acts as a substrate for tyrosinase under physiological conditions (pH 7.4) to form a melanin-inspired maleimide (Mel-Mal) film on various substrates, including living cell surfaces. The resulting film undergoes a rapid surface reaction (< 30 min) with external thiol groups under mild aqueous conditions. Considering that a typical polydopamine film requires a long reaction time (≈3 h) under alkaline conditions (pH 8.5) to achieve thiol functionalization with low efficiency, the current surface platform demonstrates significant improvements in terms of its reaction kinetics and usability. Moreover, considering that thiol functionalization and surface coating are performed under mild aqueous conditions, it is expected that the developed Mel-Mal film will be a useful tool in the fields of cell surface engineering, microarrays, and high-throughput screening.

Reprocessable and Recyclable Materials for 3D Printing via Reversible Thia-Michael Reactions

The development of chemically recyclable polymers for sustainable 3D printing is crucial to reducing plastic waste and advancing towards a circular polymer economy. Here, we introduce a new class of polythioenones (PCTE) synthesized via Michael addition-elimination ring-opening polymerization (MAEROP) of cyclic thioenone (CTE) monomers. The designed monomers are straightforward to synthesize, scalable and highly modular, and the resulting polymers display mechanical performance superior to commodity polyolefins such as polyethylene and polypropylene. The material was successfully employed in 3D printing using fused-filament fabrication (FFF), showcasing excellent printability and mechanical recyclability. Notably, PCTE-Ph retains its tensile strength and thermal stability after multiple mechanical recycling cycles. Furthermore, PCTE-Ph can be depolymerized back to its original monomer with a 90 % yield, allowing for repolymerization and establishing a successful closed-loop life cycle, making it a sustainable alternative for additive manufacturing applications.

Magnetic Nanoparticles and Drug Delivery Systems for Anti-Cancer Applications: A Review

Cancer continues to be a prominent fatal health issue worldwide, driving the urgent need for more effective treatment strategies. The pressing demand has sparked significant interest in the development of advanced drug delivery systems for chemotherapeutics. The advent of nanotechnology offers a groundbreaking approach, presenting a promising pathway to revolutionize cancer treatment and improve patient outcomes. Nanomedicine-based drug delivery systems have demonstrated the capability of improving the pharmacokinetic properties and accumulation of chemotherapeutic agents in cancer sites while minimizing the adverse side effects. Despite these advantages, most NDDSs exhibit only limited improvement in cancer treatment during clinical trials. The recent development of magnetic nanoparticles (MNPs) for biomedical applications has revealed a potential opportunity to further enhance the performance of NDDSs. The magnetic properties of MNPs can be utilized to increase the targeting capabilities of NDDSs, improve the controlled release of chemotherapeutic agents, and weaken the chemoresistance of tumors with magnetic hyperthermia. In this review, we will explore recent advancements in research for NDDSs for oncology applications, how MNPs and their properties can augment the capabilities of NDDSs when complexed with them and emphasize the challenges and safety concerns of incorporating these systems into cancer treatment.

Metformin-encapsulating immunoliposomes conjugated with anti-TROP 2 antibody fragments for the active targeting of triple-negative breast cancer

Trophoblast cell-surface antigen 2 (TROP 2) has re-emerged as a promising biomarker in triple-negative breast cancer (TNBC), with high overexpression in many TNBC cases. However, despite its potential and approval as an antibody-drug-conjugate for TNBC treatment, TROP 2-targeted delivery systems are currently underexplored. Therefore, this study was aimed at exploiting the potential of TROP 2 targeting by encapsulating metformin (Met), an antidiabetic drug associated with tumor growth inhibitory properties, inside liposomes decorated with TROP 2-targeting single-chain variable fragments (scFvs). The optimization of scFv grafting resulted in Met-immunoliposomes with an average diameter of less than 200 nm, low polydispersity index (∼0.1), negative surface charge (<-10 mV), high Met drug loading (>150 mg g-1), and high affinity towards TROP 2 binding. Furthermore, Met-immunoliposomes were reproducible, and the scFv conjugation was stable in the presence of serum for five days. Their cellular uptake increased 4 folds in two-dimensional and 9 folds in three-dimensional TNBC models owing to the high affinity towards TROP 2 binding. Finally, it was observed that the therapeutic effect of Met in suppressing cancer cell growth and proliferation was superior when using anti-TROP 2 scFv-grafted Met-immunoliposomes, which completely stopped the spheroid growth and inhibited the expression of adenosine triphosphate. This study is one of the first reports to explore the combination of nanoparticle-based drug delivery systems to target the TROP 2 protein in TNBC, and to the best of our knowledge, this is the first report to specifically combine the use of scFvs with TROP 2 targeting to deliver therapeutics for TNBC treatment.

Unlocking a radioactive pertechnetate (TcO4 -) treatment process with functionalized metal-organic frameworks (MOFs)

Technetium-99 (99Tc), a troublesome radioisotope prevalent in nuclear liquid waste, poses significant environmental and human health hazards due to its long half-life, high fission yield, and fast environmental mobility. The successful mitigation of 99Tc is imperative for nuclear waste management; however, it continues to present a significant obstacle. In this comprehensive review, we explore the state-of-the-art developments in separating TcO4 - ions using functionalized metal-organic framework (MOF) materials, spanning from 2010 to the present. We delve into the intricate separation mechanisms of TcO4 - ions, shedding light on advanced research avenues in this field. Furthermore, we aim to provide a comprehensive understanding of the underlying receptor chemistry that is necessary for the specific targeting of pertechnetate anion-based materials. This will provide valuable insights into the molecular characteristics that are crucial for the separation of TcO4 - ions from solutions containing nuclear waste. The review outlines perspectives and conclusions that pave a promising path for the comprehensive investigation of materials poised to revolutionize TcO4 - separation. Finally, we provide forward-looking recommendations for future research directions, opportunities, and associated challenges, to encourage more researchers to leverage TcO4 - selective materials for better management of environmental pollution.

Novel Maleimide Linkers Based on a Piperazine Motif for Strongly Increased Aqueous Solubility

Maleimides remain very popular conjugation moieties in the fields of bio(in)organic chemistry and biotechnology. They are particularly interesting for endogenous albumin binding in the bloodstream to exploit the enhanced permeability and retention (EPR) effect and to increase tumor accumulation of anticancer drugs. However, during drug development, insufficient aqueous solubility is frequently a limiting factor. In the present study, four new maleimide linkers were synthesized containing a water-soluble piperazine scaffold. Respective maleimide-platinum(IV)-acetato complexes demonstrated similar hydrolytic stability, albumin-binding kinetics, in vivo serum pharmacokinetics and tissue distribution compared to a reference platinum(IV)-PEG4-maleimide complex. To test the aqueous solubility, platinum(IV)-maleimide complexes containing the highly lipophilic drug ibuprofen were synthesized. Indeed, the compounds containing the new piperazine linkers displayed increased solubility (up to 370 mM) in different aqueous media, whereas the PEG4-maleimide reference was only marginally soluble. Finally, the synthetic toolbox of the new piperazine maleimides was also expanded to pure organic derivatives by conjugation to valine-citrulline-para-aminobenzyl-OH derivatives via peptide and thiourea bonds.

Photobase-Catalyzed Thiol-ene Click Chemistry for Light-Based Additive Manufacturing

Photo-mediated additive manufacturing from liquid resins (vat photopolymerization) is a rapidly growing field that will enable a new generation of electronic devices, sensors, and soft robotics. Radical-based polymerization remains the standard for photo-curing resins during the printing process due to its fast polymerization kinetics and the range of available photoinitiators. Comparatively, there are fewer examples of non-radical chemical reactions for vat photopolymerization, despite the potential for expanding the range of functional materials and devices. Herein, we demonstrate ionic liquid resins for vat photopolymerization that utilize photo-base generators (PBGs) to catalyze thiol-Michael additions as the network forming reaction. The ionic liquid increased the rate of curing, while also introducing ionic conductivity to the printed structures. Among the PBGs explored, 2-(2-nitrophenyl)-propyloxycarbonyl tetramethylguanidine (NPPOC-TMG) was the most effective for the vat photopolymerization process wherein 250 μm features were successfully printed. Lastly, we compared the mechanical properties of the PBG catalyzed thiol-Michael network versus the radical polymerized network. Interestingly, the thiol-Michael network had an overall improvement in ductility compared to the radical initiated resin, since step-growth methodologies afford more defined networks than chain growth. These ionic liquid resins for thiol-Michael additions expand the chemistries available for vat photopolymerization and present opportunities for fabricating devices such as sensors.

Progress in injectable hydrogels for hard tissue regeneration in the last decade

Bone disorders have increased with increasing the human lifespan, and despite the tissue's ability to self-regeneration, in many congenital problems and hard fractures, bone grafting such as autograft, allograft, and biomaterials implantation through surgery is traditionally used. Because of the adverse effects of these methods, the emergence of injectable hydrogels without the need for surgery and causing more pain for the patient is stunning to develop a new pattern for hard tissue engineering. These materials are formed with various natural and synthetic polymers with a crosslinked network through various chemical methods such as click chemistry, Michael enhancement, Schiff's base and enzymatic reaction and physical interactions with high water absorption which can mimic the environment of cells. The purpose of this research is to review the capabilities of this class of materials in hard tissue regeneration in the last decade through adaptable physical and chemical properties, the ability to fill defect sites with an irregular shape, and the ability to grow hormones or release drugs, in response to external stimuli.

Surface charge switchable fluorinated small molecular micelles for enhanced photodynamic therapy for bacterial infections

Photodynamic therapy (PDT) employs reactive oxygen species (ROS) from a photosensitizer (PS) under light, inhibiting multi-drug resistance in bacteria. However, hypoxic conditions in infection sites and biofilms challenge PDT efficiency. We developed fluorinated small molecular micelles (PF-CBMs) as PS carriers to address this, relieving hypoxia and enhancing PS penetration into biofilms. Perfluorocarbons in PF-CBMs transport more oxygen due to their excellent oxygen-dissolving capability. Fluorination enhances loading capacity and serum stability, reduces premature release, and improves cellular uptake, to improve PDT efficacy. PF-CBMs, with acid-induced surface charge transformation, exhibit superior biofilm penetration, resulting in increased antibiofilm activity of PDT. Compared to fluorine-free micelles (PC-CBMs), PF-CBMs demonstrate better serum stability, higher drug loading, and reduced premature release, leading to significantly improved antibacterial efficacy in vitro and in vivo. In conclusion, fluorinated micelles with surface charge reversal enhance PDT for antibacterial and antibiofilm applications.

Facile Synthesis of Nanostructured Lithium-Incorporated Titanium Oxides (Li-TiO x ) by Means of Wet Corrosion Process (WCP) and Their Potential Application for Batteries

Currently, there is a growing demand for nanomaterials in the fields of materials and energy. Nanostructured metal oxides have been widely studied, owing to their unique and diverse physicochemical properties and potential applications in various fields. In recent years, considerable attention has been directed toward metal oxides, particularly lithium-incorporated titanium oxides (Li-TiO x ), owing to their exceptional safety profiles. This material has been used in automotive battery systems, which has prompted extensive research efforts to enhance its functional properties. In response to the demand for superior nanomaterials, this study attempts to fabricate nanostructured Li-TiO x using a wet corrosion process (WCP). WCP refers to a novel method for fabricating nanostructures that employ alkaline solutions. This technique offers numerous advantages, such as short processing times, high reproducibility, and low cost. As a result of experiments, nanostructured Li-TiO x were successfully fabricated using LiOH solutions ranging in concentration from 0.5 to 2 mol/L. The fabricated nanostructures exhibited superior characteristic properties, such as increased surface area and enhanced electrical properties, when compared with those of untreated titanium. This study demonstrates that WCP is a simple, versatile, and scalable method for producing nanostructured Li-TiO x tailored for battery applications.

Multidrug Resistance Reversed by Maleimide Interactions. A Biological and Synthetic Overview for an Emerging Field

Multidrug Resistance (MDR) can be considered one of the most frightening adaptation types in bacteria, fungi, protozoa, and eukaryotic cells. It allows the organisms to survive the attack of many drugs used in the daily basis. This forces the development of new and more complex, highly specific drugs to fight diseases. Given the high usage of medicaments, poor variation in active chemical cores, and self-medication, the appearance of MDR is more frequent each time, and has been established as a serious medical and social problem. Over the years it has been possible the identification of several genes and proteins responsible for MDR and with that the development of blockers of them to reach MDR reversion and try to avoid a global problem. These mechanisms also have been observed in cancer cells, and several calcium channel blockers have been successful in MDR reversion, and the maleimide can be found included in them. In this review, we explore particularly the tree main proteins involved in cancer chemoresistance, MRP1 (encoded by ABCC1), BCRP (encoded by ABCG2) and P-gp (encoded by ABCB1). The participation of P-gp is remarkably important, and several aspects of its regulations are discussed. Additionally, we address the history, mechanisms, reversion efforts, and we specifically focused on the maleimide synthesis as MDR-reversers in co-administration, as well as on how their biological applications are imperative to expand the available information and explore a very plausible MDR reversion source.

Loosening metal nodes in metal-organic frameworks to facilitate the regulation of valence

The valence of metal nodes in metal-organic frameworks (MOFs) determines their performance in applications while developing an efficient approach for valence regulation is challenging. Here we present a strategy to make the valence regulation much easier by loosening metal nodes by thermal pretreatment. The typical MOF, HKUST-1, with the tunable valence of Cu nodes, was used as a proof of concept. Thermal pretreatment (producing HK-T) changes the chemical environment and loosens Cu nodes, endowing them with enhanced reducibility. In the subsequent vapor-induced reduction, the yield of Cu+ from Cu2+ conversion in HK-T (producing HK-T-V) reaches 69%, which is higher than that in pristine HKUST-1 (producing HK-V) with a Cu+ yield of 19% as well as the reported yields of target-valence metal nodes in various MOFs (6%-30%). The obtained HK-T-V possessing abundant Cu+ sites can capture 0.809 mmol/g thiophene in adsorptive desulfurization, 2.5 times higher than HK-V and superior to most reported adsorbents.

Quantum dots enhanced stability of in-situ fabricated perovskite nanocrystals based light-emitting diodes: Electrical field distribution effects

With the development in fabricating efficient perovskite light emitting diodes (PeLEDs), improving the operating stability becomes an urgent task. Here we report quantum dot (QD) enhanced stability of PeLEDs by introducing CdSe/ZnS core-shell QDs in toluene anti-solvent during in-situ fabrication of FAPbBr3 perovskite nanocrystals (PNCs) films. In comparison with PNC films with pristine toluene as the anti-solvent, the as-prepared FAPbBr3 PNC films with a QD monolayer on the surface exhibit improved photoluminescence quantum yield, enhanced photostability and better reproducibility. Benefiting from these advantages, the peak luminance and the maximum external quantum efficiency of the PeLED containing QD monolayer are increased from 6807 cd/m2 to 86,670 cd/m2 and 2.4% to 7.1%, respectively. The T 50 lifetime under the initial luminance of 1021 cd/m2 approaches 83 minutes. Based on electrical field simulation and transient electroluminescence measurements, the enhanced stability can be mainly attributed to the electrical field redistribution induced by the QD monolayer. This work demonstrates that the combination of QDs and perovskites provides an effective strategy to address the operational stability of PeLEDs. The insights into electrical field distribution effect will make great impact on stability improvement of other perovskite based devices.

An orally administered gold nanocluster with ROS scavenging for inflammatory bowel disease treatment

Oxidative stress that is induced by excessive reactive oxygen species (ROS) is considered to be a key pathophysiological mechanism of inflammatory bowel disease (IBD), and restoring redox homeostasis in the inflammatory region by eliminating ROS is an effective way to treat IBD. Herein, ultrasmall Au25 nanoclusters (Au25 NCs) were synthesized using a simple improved protocol, which has good physiological stability and biosafety and can be noninvasively monitored by clinical computed tomography (CT) after oral administration. Au25 NCs can eliminate ROS such as ABTS radicals, superoxide free radicals (•O2 -), and hydroxyl free radicals (•OH), upregulate the expression level of antioxidant enzymes, inhibit the expression of proinflammatory cytokines, and finally interrupt the inflammatory circuit of IBD to achieve the effective prevention and delayed treatment of IBD. This work will demonstrate the protective effect of Au25 NCs on IBD in living animals, which suggests a new nanomedicine strategy for IBD treatment.

Adsorbate-driven dynamic active sites in stannosilicate zeolites

Elucidating the nature of the active sites in heterogeneous catalysts is fundamental for understanding their reactivity and catalytic performances. Although stannosilicate zeolites have tremendous application potential for catalyzing biomass-related compounds in aqueous media, the detailed local structures and features of the real active sites and their possible structural variations under reaction conditions are poorly understood to date. In this study, a dynamic transformation of framework Sn-O-Si sites to Sn-OH/Si-OH pairs and subsequently a pseudo-Brønsted acid in stannosilicate zeolites upon molecular adsorption, which is analogous to various adsorbates/reactants under working conditions, was identified by solid-state nuclear magnetic resonance (NMR) spectroscopy for the first time, which challenges the widespread assumption that the active center structures remain rigid/stable during the catalytic process. These results provide new comprehensive insights for the fundamental understanding of the dynamic and flexible active centers and involved reaction mechanisms of novel zeolite catalysts with heterometal atoms, such as Sn, Ti, and Zr.

Strong absorption in ultra-wide band by surface nano engineering of metallic glass

Broadband light absorption is important for applications such as infrared detectors, solar energy collectors, and photothermal conversion. We propose a facile and common strategy to fabricate light absorbers with strong ultra-wideband absorption. Due to their excellent thermoplastic forming ability, metallic glasses could be patterned into finely arranged nanowire arrays, which show extremely low reflectivity (∼0.6%) in the visible and near-infrared regimes, and a low reflectivity (∼15%) in the mid-infrared regime as caused by multiscale nano spacing, multiple reflections, and plasmonic behavior. The strong absorption at surfaces with nanowires provides excellent photothermal conversion properties. The photothermal properties show that a surface with nanowires can be rapidly heated up to ∼160 °C at a rate of 28.75 °C/s, which is 30 times higher than smooth surfaces. Meanwhile, a surface with nanowires shows a high photothermal conversion efficiency (ηPT = 56.36%). The fabricated metallic glass absorbers exhibit adaptability as they can be easily formed into various complex shapes and meet the requirements under harsh conditions. The outcomes of our research open the door to manufacturing high-performance absorbers for applications in photothermal electric power generation, desalination, and photodetectors.

Engineering core-shell mesoporous silica and Fe3O4@Au nanosystems for targeted cancer therapeutics: a review

The extensive utilization of nanoparticles in cancer therapies has inspired a new field of study called cancer nanomedicine. In contrast to traditional anticancer medications, nanomedicines offer a targeted strategy that eliminates side effects and has high efficacy. With its vast surface area, variable pore size, high pore volume, abundant surface chemistry and specific binding affinity, mesoporous silica nanoparticles (MPSNPs) are a potential candidate for cancer diagnosis and treatment. However, there are several bottlenecks associated with nanoparticles, including specific toxicity or affinity towards particular body fluid, which can cater by architecting core-shell nanosystems. The core-shell chemistries, synergistic effects, and interfacial heterojunctions in core-shell nanosystems enhance their stability, catalytic and physicochemical attributes, which possess high performance in cancer therapeutics. This review article summarizes research and development dedicated to engineering mesoporous core-shell nanosystems, especially silica nanoparticles and Fe3O4@Au nanoparticles, owing to their unique physicochemical characteristics. Moreover, it highlights state-of-the-art magnetic and optical attributes of Fe3O4@Au and MPSNP-based cancer therapy strategies. It details the designing of Fe3O4@Au and MPSN to bind with drugs, receptors, ligands, and destroy tumour cells and targeted drug delivery. This review serves as a fundamental comprehensive structure to guide future research towards prospects of core-shell nanosystems based on Fe3O4@Au and MPSNP for cancer theranostics.

Accelerating defect analysis of solar cells via machine learning of the modulated transient photovoltage

Fast and non-destructive analysis of material defect is a crucial demand for semiconductor devices. Herein, we are devoted to exploring a solar-cell defect analysis method based on machine learning of the modulated transient photovoltage (m-TPV) measurement. The perturbation photovoltage generation and decay mechanism of the solar cell is firstly clarified for this study. High-throughput electrical transient simulations are further carried out to establish a database containing millions of m-TPV curves. This database is subsequently used to train an artificial neural network to correlate the m-TPV and defect properties of the perovskite solar cell. A Back Propagation neural network has been screened out and applied to provide a multiple parameter defect analysis of the cell. This analysis reveals that in a practical solar cell, compared to the defect density, the charge capturing cross-section plays a more critical role in influencing the charge recombination properties. We believe this defect analysis approach will play a more important and diverse role for solar cell studies.

The role of pentacoordinate Al3+ sites of Pt/Al2O3 catalysts in propane dehydrogenation

Pentacoordinate Al3+ (Al3+ penta) sites on alumina (Al2O3) could anchor and stabilize the active site over the catalyst surface. The paper describes the specific effect of Al3+ penta sites on the structure and the catalytic performance of Al2O3 supported Pt catalysts by modulating the quantity of Al3+ penta sites. The Al3+ penta site content of Al2O3 exhibits a volcano-type profile as a function of calcination temperature due to the structural rearrangement. The loading of Pt and subsequent calcination can consume a significant portion of Al3+ penta sites over the Al2O3 support. We further find that, when the calcination temperature of the impregnated Al2O3 is higher than the calcination temperature of Al2O3 precursor, the structural rearrangement of Al3+ penta sites could make Pt partially buried in Al2O3. Consequently, this partially buried structure leads to relatively low conversion but high stability for propane dehydrogenation. This work further elucidates the stabilization mechanism of the Al3+ penta site over Al2O3 support.

The dead lithium formation under mechano-electrochemical coupling in lithium metal batteries

Lithium metal is one of the most promising anode materials for next-generation high-energy-density rechargeable batteries. A fundamental mechanism understanding of the dead lithium formation under the interplay of electrochemistry and mechanics in lithium metal batteries is strongly considered. Herein, we proposed a mechano-electrochemical phase-field model to describe the lithium stripping process and quantify the dead lithium formation under stress. In particular, the rupture of solid electrolyte interphase and the shift of equilibrium potential caused by stress are coupled into stripping kinetics. The impact of external pressure on dead lithium formation with various electrolyte properties and initial electrodeposited morphologies is revealed. The overlooked detrimental effect of external pressure on Li stripping affords fresh insights into cell configuration and pressure management, which is critical for practical applications of lithium metal batteries.

Prediction of novel tetravalent metal pentazolate salts with anharmonic effect

In recent decades, pentazolate salts have gained considerable attention as high energy density materials (HEDMs). Using the machine-learning accelerated structure searching method, we predicted four pentazolate salts stabilized with tetravalent metals (Ti-N and Zr-N). Specifically, the ground state MN20 (M = Ti, Zr) adopts the space-group P4/mcc under ambient conditions, transforming into the I-4 phase at higher pressure. Moreover, the I-4-MN20 becomes energetically stable at moderate pressure (46.8 GPa for TiN20 , 38.7 GPa for ZrN20 ). Anharmonic phonon spectrum calculations demonstrate the dynamic stabilities of these MN20 phases. Among them, the P4/mcc phase can be quenched to 0 GPa. Further ab-initio molecular dynamic simulations suggest that the N5 rings within these MN20 systems can still maintain integrity at finite temperatures. Calculations of the projected crystal orbital Hamilton population and reduced density gradient revealed their covalent and noncovalent interactions, respectively. The aromaticity of the N5 ring was investigated by molecular orbital theory. Finally, we predicted that these MN20 compounds have very high energy densities and exhibit good detonation velocities and pressures, compared to the HMX explosive. These calculations enrich the family of pentazolate compounds and may also guide future experiments.

Hierarchical Self-Assembly of Water-Soluble Fullerene Derivatives into Supramolecular Hydrogels

Controlling the self-assembly of nanoparticle building blocks into macroscale soft matter structures is an open question and of fundamental importance to fields as diverse as nanomedicine and next-generation energy storage. Within the vast library of nanoparticles, the fullerenes-a family of quasi-spherical carbon allotropes-are not explored beyond the most common, C60. Herein, a facile one-pot method is demonstrated for functionalizing fullerenes of different sizes (C60, C70, C84, and C90-92), yielding derivatives that self-assemble in aqueous solution into supramolecular hydrogels with distinct hierarchical structures. It is shown that the mechanical properties of these resultant structures vary drastically depending on the starting material. This work opens new avenues in the search for control of macroscale soft matter structures through tuning of nanoscale building blocks.

Exploring Naturally Tailored Bacterial Outer Membrane Vesicles for Selective Bacteriostatic Implant Coatings

In treating infectious diseases, achieving selective bacterial inhibition is crucial for preserving the microecological equilibrium. The current approaches predominantly rely on synthetic materials tailored to specific bacteria, considering their cell walls or oxygen requirements. Herein, inspired by intricate bacterial communication, a natural implant is proposed coating utilizing bacterial outer membrane vesicles (OMVs), essential components in bacterial signaling, integrated onto diverse implant surfaces through a universal poly (tannic acid) bridging layer. This coating is homogenous and stable, unexpectedly promoting the proliferation of parental bacteria while inhibiting heterologous bacteria both in vitro and in vivo. Through high-throughput sequencing and bioinformatics analysis, the selective bacteriostatic ability arises from OMVs, upregulating anti-oxidative stress genes in heterologous bacteria and activating biofilm-related genes in parental bacteria. This study positions OMVs as an appealing biomaterial for selective bacterial inhibition through a biological approach, showcasing their potential in regulating the microecological balance through a natural interface modification strategy.

Interfacial Assembly of Free-Standing Polymer-Phenolic Films for Antibacterial and Antiultraviolet Applications

We report a facile interfacial assembly strategy for the preparation of flexible polyphenol-based films for antibacterial and antiultraviolet applications. The free-standing films can be instantaneously formed via spraying tannic acid (TA) at the surface of carboxymethyl chitosan (CMCS) solutions. Compared with the traditional casting-evaporation procedure on solid substrates, the liquid interfacial assembly method for the construction of free-standing films is rapid and facile, which prevents the interface separation procedure from the substrates. The thickness and mechanical properties of the films are well controlled by changing the incubation time. The low-field nuclear magnetic resonance was used to analyze the water distributions inside the films and to distinguish the cross-linked structure of CMCS-TA films with different thicknesses, revealing the dynamics of the film formation process. Importantly, the films exhibit outstanding antibacterial and antiultraviolet properties, which are promising in the applications of wound dressings. This study provides a new avenue for the assembly of flexible free-standing films with multifunctionality via a facile and low-cost fabrication process.

Recent Advances of Light/Hypoxia-Responsive Azobenzene in Nanomedicine Design

Azobenzene (Azo) and its derivatives are versatile stimuli-responsive molecules. Their reversible photoisomerization and susceptibility to reduction-mediated cleavage make them valuable for various biomedical applications. Upon exposure to the UV light, Azo units undergo a thermodynamically stable trans-to-cis transition, which can be reversed by heating in the dark or irradiation with visible light. Additionally, the N=N bonds in azobenzenes can be cleaved under hypoxic conditions by azoreductase, making azobenzenes useful as hypoxia-responsive linkers. The integration of azobenzenes into nanomedicines holds promise for enhancing therapeutic efficacy, particularly in tumor targeting and controllable drug release. In this Concept paper, recent advances in the design and applications of azobenzene-based nanomedicines are updated, and future development opportunities are also summarized.

Double safety guarantees: Food-grade photothermal complex with a pH-triggered NIR absorption from zero to one

Photothermal therapy has aroused great attention and showed promising potential in minimally invasive tumor ablation, but the clinical translation is still stifled by the concerns of unwanted injury to normal tissues. The safety concerns might be completely solved only when the two security obstacles of "material-toxicity" and "photo-toxicity" were overcome simultaneously. Herein, a completely non-toxic food-grade photothermal transduction agent (PTA) with double safety guarantees was invented, which shows an absolute transformation of the photothermal effect from "0" to "1" after being triggered by an acidic tumor microenvironment. Inspired by the classical starch-iodine test, a preprogrammed [starch-KI-KIO3] complex was prepared in large quantities through a modified wet-milling procedure. It's demonstrated that a macroscopic consecutive reaction could be triggered by low pH to produce the starch-iodine complex which can generate lethal temperature under the near-infrared light irradiation. Meanwhile, the PTA shows excellent biocompatibility with no "material-toxicity" owing to the raw materials drawn from our daily food. Animal experiments reveal that the tumor microenvironment can activate the switch of photothermal effect from "0" to "1" successfully, which is thus responsible for the discriminative photo-damage to the tumor region while no "photo-toxicity" to normal tissue. The good treatment efficacy confirms the feasibility of such photothermal transduction agents with double safety guarantees in clinical applications.

Large-scale heterogeneous synthesis of monodisperse high performance colloidal CsPbBr3 nanocrystals

Colloidal lead halide perovskite nanocrystals (LHP NCs) are promising semiconductor materials for optoelectronic devices, but the high ionicity of LHP NCs makes their crystallization control and post-treatment difficult. Here, phosphonic acids (PAs) are employed as ligands to design a solid-liquid heterogeneous reaction system to regulate the LHP NC crystallization and achieve the desired focusing growth. During the heterogeneous synthesis, the precursors in the liquid phase are responsible for the burst nucleation and initial growth of NCs. Afterwards, the focusing growth of NCs is supported by the precursors released from the solid phase. In addition, the strong binding ability of PAs enables effective passivation of LHP NCs. Without post-treatment, gram-scale monodisperse CsPbBr3 NCs having photoluminescence with a full width at half-maximum of 18 nm and a quantum yield of near-unity are obtained. The CsPbBr3 NCs covered by a compact ligand layer keep initial quantum yield even after 18 cycles of purification, exhibiting excellent stability against polar solvents, ultraviolet irradiation and heat treatment. As scintillators, the prepared CsPbBr3 NCs show strong radioluminescence emission and high-resolution X-ray imaging.