Abstract Cellulose nanocrystals are rod-like nanoparticles obtained from different cellulose sources (plants, bacteria, algae, or tunicates) and represent a class of renewable, biodegradable, and mechanically robust nanomaterials with great potential for the design of advanced functional materials. In this study, we report on the preparation of multilayer composites based on tunicate cellulose nanocrystals and poly(vinyl amine) using the layer-by-layer assembly technique. The assembly of these nanostructured films was characterized by ellipsometry. Surprisingly, films composed of tunicin nanocrystals and poly(vinyl amine) showed a highly unusual film growth behavior by dipping, spray- and spin-assisted assembly, and grazing incidence spraying methods, which contrasted with previous reports. When the film thickness reached approximately 50–60 nm, the deposition of additional layers induced a sharp increase in thickness that nearly doubled the volume of the film by expansion in the direction normal to the surface. This behavior was also observed by atomic force microscopy, ruling out any optical artifact due to ellipsometry. Ellipsometry measurements revealed that this thickness jump (i) was independent of the assembly conditions, (ii) was associated with an increase in film porosity, and (iii) clearly correlated with the aspect ratio and rigidity of the tunicate cellulose nanocrystals. This unexpected phenomenon was not observed for films assembled from either shorter cellulose nanocrystals extracted from cotton or wood, or from longer and more flexible cellulose nanofibrils in combination with poly(vinyl amine). Such a pronounced structural transition has never been previously observed, and its origin remains unexplained despite the experiments performed to date.
Abstract Nonbenzenoid carbon frameworks expand the design landscape of low-dimensional materials by introducing controlled departures from hexagonal symmetry. Here, we demonstrate that the experimentally realized 4–5–6–8 carbon nanoribbon establishes a topology-driven paradigm for multiproperty engineering rather than representing a simple structural variant of graphene nanoribbons. Combining hybrid density functional theory, parametrized tight-binding, and molecular dynamics within a coherent multiscale framework, we show that the symmetry-broken lattice stabilizes a hierarchy of bonds while remaining in the same energy range with ribbons of comparable width. This geometric organization produces a robust semiconducting state with a hybrid-functional electronic band gap exceeding 1 eV and enables strain to function as a controllable parameter for electronic modulation. Notably, a tight-binding Hamiltonian fitted only at equilibrium, accurately captures the strain-dependent electronic band evolution, indicating that the essential physics is dominated by the topology itself. Mechanical analysis reveals high stiffness with fracture governed by the largest polygonal motifs, demonstrating that geometric asymmetry redistributes stress without compromising structural integrity. In addition, intrinsic phonon scattering suppresses lattice thermal conductance, allowing favorable thermoelectric performance to emerge without extrinsic disorder. The optical response further confirms that nonequivalent ring connectivity reorganizes interband transitions, promoting strong absorption within the visible range and efficient photocarrier generation. These results position the topology as a governing physical parameter capable of coupling elasticity, electronic structure, thermal transport, and optical activity, establishing the 4–5–6–8 nanoribbon as a unified platform for the predictive design of multifunctional carbon materials.
Deep eutectic solvents (DESs) are promising ionic media owing to their abundance, ionic conductivity, and wide potential windows. Bioderived DESs based on choline chloride are attractive due to their biodegradability and biocompatibility; however, their strong hygroscopicity leads to severe moisture uptake and instability. Here, we report a bioderived moisture-resistant DES of acetylcholine chloride as a hydrogen bond acceptor (HBA) and 3-phenylpropionic acid as a hydrophobic hydrogen bond donor. The hydrophobic component acts as a molecular seal, shielding the hygroscopic HBA from moisture through hydrogen-bond network reconfiguration. Systematic variation of the molar ratio reveals four distinct regimes: immiscible mixtures (1:1), saturated states (1:1.5), a homogeneous glass-forming liquid at the eutectic composition (1:2, T-g = -57.9 degrees C), and crystallizable phases at higher HBD contents (1:3 and 1:4). Only the eutectic composition stabilizes a uniform liquid without observable melting transitions, exhibiting over 75% reduction in moisture uptake relative to the parent salt at 58% relative humidity. The DES demonstrated a high ionic conductivity (197 mu S cm(-1)) and a wide potential window (2.43 V). Moreover, the DES exhibited high biodegradability (>90%), exceeding the OECD criterion for ready biodegradability (>60% within 28 days). These findings establish stoichiometry as a governing parameter coupling phase stability with moisture affinity in robust, biodegradable DESs.
Polymerization-induced phase separation (PIPS) allows for the control of thermoset morphologies and properties, enabling the tuning of domain sizes and thermomechanical response. However, its use in generating substructural features in additively manufactured materials has been limited. In this work, we combine epoxy PIPS with UV curable acrylate and rheological modifiers to print nano- to macro-phase separating materials via a two-step, dual-cure approach. This method enables direct ink write printing of hierarchical structures with both controlled morphologies through phase separation and macroscale architecture through print design. We find that formulations for phase-separating materials require judicious incorporation of additives to enable printability and to provide sufficient green strength. Atomic force microscopy-nano infrared mapping reveals tunable, reticulated nano- to micron-scale domains of the resultant multiphase materials and their morphology changes due to additives, resulting in alterations to thermomechanical and tensile properties. Shape memory behavior is also demonstrated through multimaterial additive manufacturing of epoxies with functionally graded internal morphology using active mixing techniques, highlighting this method's ability to fabricate complex architectures with controlled morphologies and thermomechanical response.
Abstract LNPs are the basis of mRNA and nucleic acid-based therapeutics. However, their remarkable clinical potential is limited by a persistent challenge, i.e., nonspecific accumulation in the liver and associated hepatotoxicity. Traditional strategies, such as PEGylation and lipid ionization modification, have reached a point of low therapeutic value-add to control biodistribution. Recently published studies present an innovative concept: LNPs that recruit albumin, exploiting interactions with endogenous albumin to avoid liver accumulation and simultaneously improve delivery through the lymphatic system for immune-modulation. This review provides a concise incursion into such strategies that redefine stealth nanomedicine, not as chemical camouflage but as a biological alliance with plasma transport proteins, paving the way for a new paradigm of self-protecting nanocarriers for safer and more precise mRNA therapeutics.
Abstract Obesity, considered a chronic and multifactorial disease, is one of the most urgent public health challenges, affecting about 13% of the global population. It is strongly associated with comorbidities such as type 2 diabetes, hypertension, cardiovascular disease, and certain types of cancer. Conventional management strategies, including lifestyle interventions, pharmacotherapy, and bariatric surgery, often provide limited or short-term benefits that encompass adverse effects or poor adherence depending on the patients’ response. Hence, there is a need for innovative and minimally invasive treatments. In this context, hydrogels have emerged as promising and versatile platforms. Hydrogels are biocompatible three-dimensional polymeric networks that absorb and retain large amounts of water inside their structure. They can be engineered as stimuli-responsive materials in response to environmental changes, including pH, temperature, and enzymes. These capabilities position hydrogels as malleable tools applicable across several obesity-related fields, ranging from controlled drug delivery and gastric volume modulation to the development of nontoxic ingestible systems. Recent advances highlight superabsorbent hydrogels that expand in the stomach to induce satiety; targeted hydrogels that deliver antiobesogenic compounds; and smart hydrogels that integrate nanomaterials to enhance mechanical strength and functionality. This review summarizes the classification of hydrogels, fabrication processes, and principal characteristics required in the biomedical field. The current evidence for hydrogel development as a basis for obesity management is analyzed, focusing on the main results from preclinical and clinical trials. Finally, hydrogels are highlighted as multifunctional and transformative platforms that offer new strategies to overcome the limitations and drawbacks of current obesity treatment therapies.
Abstract Controlling phase selectivity for especially metastable multimetal oxides remains a central challenge, even though they are attractive for catalysis and energy conversion applications. The conventional synthesis method, like aqueous redox-precipitation, typically uses dilute reactant solutions, in which thermodynamic equilibrium favors stable products, limiting the selective synthesis of metastable phases. Here, we demonstrate a water-assisted reaction that plays a dual and decisive role in liquid-assisted redox synthesis (LRS) to obtain a metastable tetragonal cobalt–manganese spinel (CMO), rather than the readily formed cubic spinel. Limited initial hydration (0.5–1.5 mL) creates a highly concentrated microenvironment that enhances local acidity and shifts redox toward Mn3+ formation rather than Mn4+. Dehydration at 160 °C enables the incorporation of unstable Mn3+ into the solid lattice, resulting in high selectivity and phase purity toward the metastable tetragonal spinel. A low liquid-to-solid ratio (η = 0.27–0.81 μL mg–1) coupled with elevated dehydration temperatures (up to 200 °C) enabled the selective formation of metastable tetragonal spinel. Increasing the initial water content (≥3.0 mL) without complete water dehydration further restores bulk-solution-like behavior, promotes Mn3+/Mn4+ equilibration, and yields the thermodynamic cubic spinel. The optimized condition delivers 88% yield (∼27× higher than conventional aqueous ARP, 3.2%), and the tetragonal phase exhibits enhanced alkaline (oxygen evolution reaction) OER activity relative to the cubic analog.
Block copolymers (BCPs) are macromolecules made up of two or more chemically different polymer blocks that are covalently bound together. Their mutual incompatibility causes them to separate into nanoscale microphases, which allows the blocks to self-assemble into ordered shapes, such as lamellae, spheres, and cylinders. The ability to self-assemble offers a versatile route for forming well-ordered nanoscale architectures relevant to nanolithography, membranes, and functional materials. Incorporating hydrogen-bonding small molecules to form supramolecular BCP complexes expands structural diversity by altering domain size, interfacial energies, and chain mobility. These complexes expand the range of parameters for precise control over nanoscale morphology while also providing highly ordered nanostructures that can be used as soft templates for the formation of inorganic films and porous networks. However, the added complexity raises challenges in obtaining vertically oriented nanostructures, which are crucial in nanopatterning applications. In the case of solvent vapor annealed films, the effect of swelling parameters on vertical orientation has not been thoroughly investigated. Here, we demonstrate that swelling-induced surface neutrality promotes vertical orientation in PS-b-P4VP(PDP) thin films, where P4VP(PDP) is the majority block and PS the minority block. Morphological transitions were observed, including horizontal, mixed, and vertical orientations, as film thickness, PDP ratio, and swelling ratio were varied. A swelling ratio window ranging from similar to 1.6 to 1.8 that reliably stabilizes vertical orientation was discovered. Significantly, vertical structures require a balance between selective swelling for surface energy neutrality and sufficient chain mobility for domain re-organization. These findings depart from previous reports where the formation of hierarchical lamellar structures within P4VP(PDP) was described as a key requirement for vertical orientation. Overall, this study identified solvent and wetting parameters that influence the BCP orientation, thereby advancing supramolecular block copolymer thin films for nanopatterning and functional material applications.
Enzyme immobilization on solid supports enhances stability and reusability, yet nanoscale carriers such as metal-organic frameworks (MOFs) still face challenges in efficient recovery. While pyrolysis can magnetize Fe-MOFs, conventional methods often compromise either enzyme activity or structural integrity. This study presents a rational two-step oxidation-reduction (O-R) pyrolysis strategy to convert Meso-MIL-88A into a magnetically recyclable, mesoporous biocatalyst support (O-R500). Unlike one-step carbonization, which generates enzyme-incompatible Fe3O4, or carbonization-oxidation routes that collapse the framework, our approach first transforms the MOF into a robust α-Fe2O3 template while preserving its morphology. Citric acid then acts as a mild, slow-releasing reductant, selectively producing a γ-Fe2O3-rich phase without damaging the mesostructure. The resulting O-R500 exhibits well-defined mesopores (∼13 nm), sufficient magnetization (16 emu/g) for rapid separation, and a biocompatible surface that maintains the native conformation of immobilized Candida antarctica lipase B (CalB). In the synthesis of phosphatidyl EPA/DHA, CalB@O-R500 achieved 84.5% incorporation and retained 90.3% activity over five cycles, outperforming nonmagnetic counterparts. This work not only provides a high-performance magnetic biocatalyst but also establishes a generalizable design principle for converting Fe-MOFs into structured, biocompatible, and functionally integrated carriers.
Bioactive surface modification of degradable zinc (Zn) vascular implants is essential for controlling biodegradation and supporting vascular healing. Here, we describe the fabrication of polydopamine coating (PDA-Cu) containing up to ∼0.8 wt % Cu2+ ions on Zn substrates using an immersion-assisted mussel-inspired polymerization strategy. The coating is composed of densely packed PDA-Cu nanospheres with diameters of ∼130-170 nm, exhibiting an even distribution of Cu ions within the PDA matrix via Cu2+-catechol coordination. Thirty-day leaching tests confirmed a steady release of 0.01-0.04 ppm of Cu ions per 5 days from Zn/PDA-Cu samples in Hank's balanced salt solution (HBSS). In vitro nitric oxide (NO) assay demonstrated enhanced catalytic NO generation in 1 mM SNAP (S-nitroso-N-acetylpenicillamine) solution. Additionally, the PDA-Cu coating reduced the Zn corrosion rate from ∼0.8 mm/year to ∼0.4 mm/year and increased its corrosion resistance in HBSS.
Rare-earth (RE) MOFs are notable for their structural tunability and diverse connectivity, making them promising for applications in gas separation, storage, and sensing. This work reports two new isostructural RE-based MOFs, Y-TNDI and Eu-TNDI, synthesized by using a rigid tetracarboxylate linker bearing a naphthalenediimide (TNDI) core. Unlike their Zr-TNDI counterpart, which features a single 4-c hexanuclear cluster and structural interpenetration, the RE-TNDI MOFs possess dual molecular building blocks: an 8-c hexanuclear cluster (RE6) and a 4-c mononuclear RE center. This discovery challenges the notion that dual-cluster formation arises solely from a linker asymmetry, showing that a symmetric rigid TNDI linker can also give rise to such structural heterogeneity. Building on this structural ingenuity, we investigated the Eu-TNDI MOF for the rapid and visual detection of volatile organic amines, chemicals with well-documented health hazards. The MOF displayed an almost 100% quenching efficiency. Interestingly, the MOF exhibits photochromic behavior upon exposure to visible light due to the formation of radicals, as confirmed by EPR. When embedded in a mixed-matrix membrane, this MOF exhibits remarkable colorimetric changes upon exposure to amines, transforming molecular design into an effective strategy for real-time detection. This work underscores the crucial role of metal and ligand selection as well as the structural characteristics of RE MOFs in driving advancements in both materials science and environmental monitoring.
Self-supported nanoparticle-based aerogels are highly porous macroscopic networks that partially preserve the properties of the nanoparticle building blocks. Heating of such a material above its melting point without destruction of its porous structure has not been possible so far. Here, for the first time, we develop a technique that allows laser-induced heating of highly porous nanoparticle-based aerogels above the melting point of the AuCu nanoparticle building block while preserving the porous structure of the aerogel. Successful melting and hence alloy formation of the building block nanoparticles within the aerogel network are supported by means of transmission electron microscopy (TEM). The technique is based on laser irradiation of the nanoparticle-based gel structure while it is frozen (the frozen state occurs during the preparation of the aerogel by cryogelation). Interestingly, the macroscopic structure of the 3D network is preserved, and the microscopic structure is partially preserved only when the laser irradiation is done while the nanoparticle-based gel is still embedded in frozen ice (followed by a lyophilization step to obtain the aerogel structure). Meanwhile, heat treatment by laser irradiation of the lyophilized aerogel structure generally destroys the porous 3D-network structure. Since cryogelation can be applied to any type of water-dispersible nanocrystals, this method appears to be generic for the destruction-free heat treatment of porous self-supported nanoparticle-based gel-type structures.
The development of β-Ga2O3 thin films has received over the past years an increasing interest for power electronics devices. Here, we investigate the relatively unexplored growth of β-Ga2O3 thin films on a c-plane sapphire substrate using pulsed-liquid injection metal-organic chemical vapor deposition (PLI-MOCVD). In contrast to conventional MOCVD, the atomization and flash vaporization processes allow for a more precise dosing of the chemical precursors kept at room temperature for the sake of sustainability and gallium criticality. By using triethyl gallium and O2 molecules, we show the PLI-MOCVD of epitaxial β-Ga2O3 thin films with a growth rate of around 148 ± 5 nm/h and a RMS surface roughness of 1.5 ± 0.1 nm. The single-crystalline nature of the β-Ga2O3 thin films, composed of multiple rotational domains, reveals the following epitaxial relationships: β-Ga2O3 (-201) || α-Al2O3 (003) and β-Ga2O3 (020) || α-Al2O3 (300). The β-Ga2O3 thin films are fully stoichiometric with an optical bandgap energy of 4.8 ± 0.2 eV. The presence of carbon, likely substituting, to some extent, for oxygen sites, eventually explains some of the yellow-to-UV emission bands using optical spectroscopy. These findings demonstrate that PLI-MOCVD in a vertical cold-wall configuration represents a promising alternative, reproducible chemical route to obtain epitaxial β-Ga2O3 thin films with high quality, while being well aligned with the efficiency- and safety-related principles of green chemistry.
The chiral 432 helicoids II and III gold (Au) nanoparticles have been successfully synthesized using l-glutathione (L-GSH) as the chiral shape modifier; however, how L-GSH interacts with Au surfaces to trigger and promote the formation of chiral shapes remains unknown. In this work, the selectivity of L-GSH on enantiomeric Au(321) R/S is investigated using first-principles density functional theory (DFT). To avoid a resource- and time-consuming brute-force geometric scan of a full L-GSH molecule adsorbed on Au(321) R/S , we first decomposed L-GSH into three amino acid analogues, namely, l-glutamic acid (l-Glu), l-cysteine (l-Cys), and glycine (Gly), and reduced the chiral Au(321) R/S facets into constituent microfacets, namely, Au(111), Au(100), and Au(110). By understanding how each molecular building block interacts with these three low-Miller-index facets, we rationally designed six sets of initial configurations of L-GSH adsorbed on Au(321) R/S and performed optimization to identify the most thermodynamically stable structures. We find that L-GSH enantioselectively binds more strongly to Au(321) R , but the enantiomeric shift in binding energy is small. Regardless of the facet chirality, all strong-binding configurations exhibit a "reach-and-stretch" mechanism to maximize contact between L-GSH and kinks, multiple steps, and terraces, where both thiol and amine groups play critical roles. The enantioselectivity reported herein supports experiments where L-GSH is observed to promote the expression of Au(321) R , and the laterally extended conformation of L-GSH on Au(321) can inspire future studies on the roles of L-GSH in inducing chiral shape formation.
Adsorption measurements belong to the primary characterization tools used to determine the textural properties of porous solids such as Brunauer-Emmett-Teller (BET) area, pore volume, and pore size distribution as well as to estimate the energy of host-guest interactions. Accurate description of gas sorption in metal-organic frameworks (MOFs) is crucial for evaluating their performance and provides key insights into textural properties such as adsorption capacity, pore volume, and pore size distribution. This tutorial paper aspires to provide a practical guide for graduate and undergraduate students, as well as researchers who are new to the field, on low-pressure gas adsorption measurements (up to atmospheric pressure). Key aspects such as sample preparation, activation strategies, adsorption measurement techniques, data analysis, and reporting are discussed in detail. We believe that this Tutorial could serve as an entry-level teaching resource for gas sorption measurements in MOFs.
Biopolymer-based hydrogels are attractive therapeutic carriers, offering tunable physicochemical properties and therapeutic release kinetics. Major limitations include low rheological strength, poor physical and thermal stability, limited swelling, and achieving controlled therapeutic delivery. To address these challenges, a library of innovative metal-organic framework (MOF)-biopolymer-based hydrogels was developed. The MOFs, zeolitic imidazole framework-8 (ZIF-8), and zinc adeninate framework (ZAF) were integrated into chitosan/alginate (C/A) and chitosan/gelatin (C/G) hydrogels, at increasing chitosan content. The MOF-hydrogels presented distinct immunoglobulin G (IgG) release rates and greater rheological strengths, swelling capabilities, and thermostabilities compared to the MOF lacking hydrogels. The MOF-C/A-hydrogels showed higher rheological strengths compared to the MOF-C/G-hydrogels. The ZIF-8-hydrogels presented greater rheological strengths, yet lower thermostabilities, and higher IgG release rates compared to the ZAF-hydrogels. This is attributed to the greater flexibility of ZAF, containing bulky adenine groups, which could lead to steric hindrance and limited zinc ion-dipole interactions. Holistically, exploiting ion-dipole, electrostatic, and hydrogen bonding interactions between the MOFs and biopolymers enabled therapeutic release rate control and balanced the typical trade-off between hydrogel swelling and rheological strength. The MOF-hydrogels offer adaptable platforms, advancing the design of next-generation MOF-biopolymer-based carriers for target applications.
This work examines the response of semicrystalline polyethylene under triaxial strain. The Shinoda-DeVane-Klein (SDK) model of polyethylene (PE) was used in coarse-grained (CG) molecular dynamics (MD) simulations of more than 2 × 106 particles, representing more than 2 × 107 atoms and a volume of greater than 105 nm3. For strains in the range of ϵ = 0.25-0.5, the stress was related to the overall orientation of the polymer backbone with respect to the extension axis. However, at intermediate strains (ϵ = 0.05-0.3), where strain softening typically occurs, there were large variations in mechanical response as a result of the initial distribution of crystallite orientations. At intermediate strains, both the compressive and tensile stress also depended strongly on the initial distribution of crystallite orientations. The orientation distribution also determined the onset of the strain-hardening regime. We found that, due to the inextensible nature of the crystallites, compressive stresses drove rotation for crystallites oriented away from the extension axis, which in turn strongly decreased the tensile stress. Results from MD simulations suggested that, while spatial averaging smooths the overall macroscopic response of semicrystalline samples, intermediate scale or local stress imbalances due to crystallite rotation have a key role in driving strong local strain and potentially leading to plastic deformation like banding or cavitation.
Hydrogels are everyday materials characterized by their remarkable properties, of bridging the gap between liquid and solid states. While most hydrogels are traditionally formed from polymers, biomolecules can also undergo gelation, as seen with proteins (e.g., collagen), enabling numerous applications. Peptide-based low-molecular-weight hydrogels (LMWHs), composed of amino acids, have emerged as innovative materials with a broad range of biomedical and biotechnological applications, gaining commercial interest in the 2010s. However, natural peptides composed solely of proteinogenic amino acids present several drawbacks, requiring structural or chemical modifications to enhance their performance. Additionally, multicomponent approaches, which involve combining multiple compounds to form hydrogels, have recently gained prominence as a promising strategy for developing more versatile and efficient systems. In this context, we explore emerging hybrid molecules, i.e., peptides functionalized with DNA bases (i.e., adenine, thymine, guanine, and cytosine), known as nucleopeptides. These compounds have shown encouraging results, yet much remains to be explored to unlock their full potential. In this study, we present a novel series of six (nucleo)peptides derived from two distinct peptide sequences, Phe-Glu-Phe-Glu and Phe-Lys-Phe-Lys, negatively and positively charged at physiological pH, respectively, making them complementary in terms of electrostatic interactions. These peptides are functionalized with one of the four DNA nucleobases, introduced via a peptide nucleic acid (PNA) moiety. Thus, through a comprehensive multiscale systematic study, we report herein on the impact of charge complementarity and/or nucleobase-pair complementarity on the mechanical and physicochemical properties of the resulting multicomponent hydrogels (including gelation time, sol-gel transition temperature, stiffness, resistance to external stress, fibrillar network morphology, etc.). Then, the results highlight the undeniable potential of this approach, demonstrating that careful selection of components allows the fine-tuning of hydrogel properties. Interestingly, our findings reveal unexpected behaviors, underscoring the complexity of these bioinspired hybrid multicomponent systems while reinforcing their potential for the development of high-performance and innovative supramolecular hydrogels.
Triply Periodic Minimal Surface (TPMS) Al2O3 ceramic structures hold significant potential for applications in biomedical engineering, catalytic systems, and thermal management technologies, which can be fabricated with high precision using vat photopolymerization-based digital light processing (DLP). However, conventional homogeneous designs for TPMS often do not fully meet advanced performance requirements, while the curing depth, a key parameter governing the dimensional accuracy and mechanical performance, has not been thoroughly investigated. To address these limitations, this study proposes an algorithm based on target porosity for designing complex graded and heterogeneous TPMS structures, followed by fabrication via DLP with optimized process parameters. The results demonstrate that the fabricated gradient-porosity TPMS scaffold under optimal parameters exhibited high performance, including dimensional accuracy exceeding 98.5%, a surface roughness as low as 1.21 μm, and a compressive strength of 38.44 MPa. These findings provide valuable references for both the design optimization and reliable DLP strategies of complex ceramic heterogeneous TPMS structures.
