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Although the physiochemical merits of g-C3N4-based photocatalysts have garnered increasing interest in the fields of energy and environmental science, insufficient layer detachment has created a gap between fundamental research and practical applications. To unlock the intrinsic potential of g-C3N4, a bio-transformation of the ZnMn2O4 ((6)ZM) gel was employed to introduce highly-ordered modulation caused by steric hindrance during melamine pyrolysis. Phytomediated (6)ZM reorganized traditional carbon nitride into crossed C3N4 (CCN) monolayers, simultaneously engineering an auspicious Z-schematic system ((6)ZM/CCN). Phytoconverted (6)ZM retained the crystalline-amorphous configuration for facile charge transfer and provided a large surface area (288 m2 g−1) that was 2.3 times greater than that of thermally prepared g-C3N4 (TCN) monolayers. Additionally, (6)ZM exhibited a quantum confinement-promoted reduction capability and induced bulging on CCN monolayers to fully utilize photons through multilevel light scattering and reflection. Specific sequential two-step calcination of (6)ZM/CCN, furnishing affordable dual Z-schematic VO–(6)ZM/CCN, was specifically developed to introduce a third component into the structure without incurring additional operational cost or complexity. V2O5 (VO) nanoparticles were thermally anchored on (6)ZM/CCN to achieve highly efficient levofloxacin (LFC) detoxification under visible-light irradiation. After optimizing all effective synthesis parameters and experimental variables, VO–(6)ZM/CCN exhibited unsurpassed activity, achieving complete LFC photodegradation (50 mg L−1) within 120 min, which was 10.7, 8.7, and 24.7 times more kinetically efficient than the photodegradations achieved by (6)ZM, TCN, and VO, respectively. The outstanding performance of VO–(6)ZM/CCN was evident through complete mineralization of LFC, excellent decontamination of pharmaceutical wastewater within 300 min, resistance to performance deterioration during successive cycling runs, and the corresponding postcharacterization. The combination of simultaneous Z-scheme formation with photogenic (6)ZM provides a promising strategy to bridge the gap between experimental investigations and industrial applications of g-C3N4. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Hyaluronic Acid/Collagen Nanofiber Tubular Scaffolds Support Endothelial Cell Proliferation, Phenotypic Shape and Endothelialization" published in the journal Nanomaterials. The correction addresses errors in Figures 1B, 2A, and 5A of the original publication. The corrected figures are provided in the document. The authors apologize for any inconvenience caused but state that the scientific conclusions of the article remain unaffected. [Extracted from the article]

Artificial intelligent actuators are extensively explored for emerging applications such as soft robots, human‐machine interfaces, and biomedical devices. However, intelligent actuating systems based on synthesized polymers suffer from challenges in renewability, sustainability, and safety, while natural polymer‐based actuators show limited capabilities and performances due to the presence of abundant hydrogen‐bond lockers. Here this study reports a new hydrogen bond‐mediated strategy to develop mimosa‐inspired starch actuators (SA). By harnessing the unique features of gelatinization and abundant hydrogen bonds, these SA enable high‐sensitivity and multi‐responsive actuation in various scenarios. The non‐gelatinized SA can be irreversibly programmed into diverse shapes, such as artificial flowers, bowl shapes, and helix structures, using near‐infrared light. Furthermore, the gelatinized SA exhibit reversibly multi‐responsive actuation when exposed to low humidity (10.2%), low temperature (37 °C), or low‐energy light (0.42 W cm−2). More importantly, the SA demonstrate robust applications in smart living, including artificial mimosa, intelligent lampshade, and morphing food. By overcoming the hydrogen‐bond lockers inherent in natural polymers, SA open new avenues for next‐generation recyclable materials and actuators, bringing them closer to practical applications. [ABSTRACT FROM AUTHOR]

Single- or few-layer forms of black phosphorus, so called phosphorene, were isolated by exfoliation in 2014 as 2D layered materials holding great promise in electronic and optoelectronic fields. In this perspective, we highlight recent developments in black phosphorus research, in particular, we will focus on the mechanical properties of its 2D form. Its unique puckered structure is responsible for strong anisotropy in mechanical and transport properties, different from graphene and transition-metal dichalcogenide 2D materials. This peculiar mechanical anisotropy can be exploited for applications such as nanomechanical resonators, thermoelectric devices, and motion sensors with tunable functions inaccessible by isotropic materials. Current bottlenecks hindering further progress in devices applications involve first surface degradation in environmental conditions which, in turn, can be exploited in surface friction mechanics to achieve superlubricity. In this framework, the investigation of mechanical properties of phosphorene will be pivotal for facile fabrication, transfer, and resolution of technical hurdles as well the discovery of novel applications. As research directions in next foreseeable future, we will discuss the challenge of crosstalk between mechanical and transport properties, in particular, how the stress–strain stimulations can be used to tune optoelectronic and thermoelectric performance. [ABSTRACT FROM AUTHOR]

The cytotoxicity of ionic liquids (ILs) has been receiving attention in the context of the biological and environmental impact of their vast field of applications. It has been ascertained that the cell membrane is the main target of ILs when they interact with microorganisms, cells and bacteria; nevertheless, studies at the micro- and nano-scale aiming at better understanding of the fundamental mechanisms of toxicity of ILs are lacking. In this work, we used atomic force microscopy (AFM) to investigate the impact of room-temperature ILs on the mechanical, morphological and electrostatic properties of solid-supported DOPC phospholipid bilayers, taken as models of biomembranes. In particular, we have characterized the concentration-dependent and time-dependent evolution of the morphological, structural and mechanical properties of DOPC lipid membranes in the presence of imidazolium-based ILs with different alkyl chain lengths and hydrophilic/hydrophobic characteristics. The majority of ILs investigated were found to possess the ability of restructuring the lipid bilayer, through the formation of new IL/lipid complexes, showing distinctive morphological features (increase of area and roughness). The nanomechanical analysis of the lipid membrane exposed to ILs revealed a progressive, concentration-dependent perturbation of the structural ordering and rigidity of the membrane, evidenced by a decrease in the breakthrough force, Young's modulus and area stretching modulus. AFM detected a modification of the electrostatic double-layer at the membrane surface, in terms of a reduction of the original negative surface charge density, suggesting a progressive stratification of cations on the exposed leaflet of the lipid membrane. Our findings may be helpful in designing novel ILs with tailored interaction with biological membranes. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the regulatory effect of hyaluronic acid (HA)—coating silk fibroin (SF) nanofibers during epithelialization of urinary tract for urethral regeneration. The obtained electrospun biomimetic tubular HA‐SF nanofiber scaffold is composed of a dense inner layer and a porous outer layer in order to mimic adhesion and cavernous layers of the native tissue, respectively. A thin layer of HA‐gel coating was fixed in the inner wall to provide SF nanofibers with a dense and smooth surface nano‐topography and higher hydrophilicity. Compared with pure SF nanofibers, HA‐SF nanofibers significantly promoted the adhesion, growth, and proliferation of primary urothelial cells, and up‐regulate the expression of uroplakin‐3 (terminal differentiation keratin protein in urothelium). Using the New Zealand male rabbit urethral injury model, the scaffold composed of tubular HA‐SF nanofibers could recruit lumen and myoepithelial cells from the adjacent area of the host, rapidly reconstructing the urothelial barrier in the wound area in order to keep the urinary tract unobstructed, thereby promoting luminal epithelialization, smooth muscle bundle structural remodeling, and capillary formation. Overall, the synergistic effects of nano‐topography and biophysical cues in a biomimetic scaffold design for effective endogenous regeneration. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT) is an emerging treatment that usually employs chemical agents to decompose hydrogen peroxide (H2O2) into hydroxyl radical (•OH) via Fenton or Fenton‐like reactions, inducing cell apoptosis or necrosis by damaging biomacromolecules such as, lipids, proteins, and DNA. Generally, CDT shows high tumor‐specificity and minimal‐invasiveness in patients, thus it has attracted extensive research interests. However, the catalytic reaction efficiency of CDT is largely limited by the relatively high pH at the tumor sites. Herein, a 808 nm laser‐potentiated peroxidase catalytic/mild‐photothermal therapy of molybdenum diphosphide nanorods (MoP2 NRs) is developed to improve CDT performance, and simultaneously achieve effective tumor eradication and anti‐infection. In this system, MoP2 NRs exhibit a favorable cytocompatibility due to their inherent excellent elemental biocompatibility. Upon irradiation with an 808 nm laser, MoP2 NRs act as photosensitizers to efficiently capture the photo‐excited band electrons and valance band holes, exhibiting enhanced peroxidase‐like catalytic activity to sustainedly decompose tumor endogenous H2O2 to •OH, which subsequently destroy the cellular biomacromolecules both in tumor cells and bacteria. As demonstrated both in vitro and in vivo, this system exhibits a superior therapeutic efficiency with inappreciable toxicity. Hence, the work may provide a promising therapeutic technique for further clinical applications. [ABSTRACT FROM AUTHOR]

One of the main challenges of tissue-engineered vascular prostheses is restenosis due to intimal hyperplasia. The aim of this study is to develop a material for scaffolds able to support cell growth while tolerating physiological conditions and maintaining the patency of carotid artery model. Tubular hyaluronic acid (HA)-functionalized collagen nanofibrous composite scaffolds were prepared by sequential electrospinning method. The tubular composite scaffold has well-controlled biophysical and biochemical signals, providing a good matrix for the adhesion and proliferation of vascular endothelial cells (ECs), but resisting to platelets adhesion when exposed to blood. Carotid artery replacement experiment from 6-week rabbits showed that the HA/collagen nanofibrous composite scaffold grafts with endothelialization on the luminal surface could maintain vascular patency. At retrieval, the composite scaffold maintained good structural integrity and had comparable mechanical strength as the native artery. This study indicating that electrospun scaffolds combined with cells may become an alternative to prosthetic grafts for vascular reconstruction. [ABSTRACT FROM AUTHOR]

Reconstruction of peripheral nerve defects with tissue engineered nerve scaffolds is an exciting field of biomedical research and holds potential for clinical application. However, due to poor neovascularization after the implantation, nerve regeneration is still not satisfactory, especially for large nerve defects. These obstacles hinder the investigation of basic neurobiological principles and development of a wide range of treatments for peripheral nerve diseases. Herein, we designed an amphiphilic alternating block polyurethane (abbreviated as PU) copolymer-based nerve guidance scaffold, which has good Schwann cell compatibility, and more importantly, a rapid vascularization of the scaffold in vivo. In the sciatic nerve transection model of SD rats, vascularized PU nerve guidance scaffolds induced rapid regeneration of nerve fibers and axons along the scaffold. Through the analysis of nerve electrophysiology, sciatic nerve functional index, histology, and immunofluorescence related to angiogenesis, we determined that PU with rapid vascularization function enhances recovery and re-obtains nerve conduction function. Our study points out a new strategy of using nerve tissue engineering scaffolds to treat large nerve defects. [ABSTRACT FROM AUTHOR]

The combination of thermoresponsive polymers with natural biomaterials can extend the properties portfolio, especially in the field of biomedicine, where a great cell adhesiveness and biodegradation is necessary for bone regeneration. The poly(N‐isopropylacrylamide)‐grafted‐gelatin gels were already reported where several synthetic parameters, such as polymer or gelatin were varied and final properties were studied. Nevertheless, the ratio of the cross‐linker was always the same, and consequently, their properties were not analyzed yet. There are various preparation methods of these systems but microwave synthesis was not deeply studied, and consequently, important benefits can be obtained due to its efficiency and time saving. In this work, we modified the ratio of cross‐linker and important changes are observed in the thermoresponsive and mechanical properties tested by calorimetry, thermogravimetry, rheology, and atomic force microscopy. The amount of cross‐linker modulates the homogeneity of the resulting gels, and consequently, the lower critical solution temperature, the absorption of water into surfaces and the mechanical behavior of the new materials. [ABSTRACT FROM AUTHOR]

Room temperature positive magnetoresistance (PMR) in graphene is a conventional phenomenon but we observed large negative magnetoresistance (NMR) in GF/polydimethylsiloxane (GF/PDMS) at room temperature for the first time. The largest NMR ~ 35% was detected at 250 K, while PMR is observed below 200 K. Furthermore, PMR at all temperatures is observed in regular GF specimens, hence, NMR is the result of the infiltration with the electrically insulating polymer. Forward interference and wavefunction shrinkage model has been employed to understand the transport mechanism in GF/PDMS. A critical temperature ~ 224 K for switching between NMR and PMR is observed at the crystallization temperature of PDMS, suggesting a change in polymer chain conformation may be a major reason leading to NMR in GF/PDMS specimens thus role of mechanical properties of PDMS in NMR cannot be ignored and observed locally via specially resolved atomic force microscopy. In addition, storage modulus and heat flow study shows similar transition temperature (~ 200 K) of NMR to PMR and provide an evidence of mechanical stable specimens. As is known, large, tunable, and unsaturated NMR at room temperature is very useful for future facile practical shapeable magnetoelectronic devices. [ABSTRACT FROM AUTHOR]

Random copolymer gels of N-isopropylacrylamide (NIPAM) and N-ethylacrylamide (NEAM) are synthesized using different monomer compositions in 1:1 methanol-water mixtures. The samples are characterized by scanning electron microscopy, atomic force microscopy (AFM), and rheological studies. It is observed that with the variation of the monomer compositions in the reaction mixture, the thermoresponsive, morphological, AFM, and rheological properties varied significantly. Porosity and roughness of the gels gradually increase with the gradual increase in NIPAM loading in the gels, lower critical solution temperature, mechanical strength (Young's modulus, storage modulus) significantly decreases with the increase in poly( N-isopropylacrylamide) loading in the gels. All results can be explained on the basis of the differences in thermoresponsive character of homo- and copolymer gels of NIPAM and NEAM in water, their composition in the reaction mixtures, and their different kind of interactions with solvents. [ABSTRACT FROM AUTHOR]

Background: Thanks to mechanotransductive components cells are competent to perceive nanoscale topographical features of their environment and to convert the immanent information into corresponding physiological responses. Due to its complex configuration, unraveling the role of the extracellular matrix is particularly challenging. Cell substrates with simplified topographical cues, fabricated by top-down micro- and nanofabrication approaches, have been useful in order to identify basic principles. However, the underlying molecular mechanisms of this conversion remain only partially understood. Results: Here we present the results of a broad, systematic and quantitative approach aimed at understanding how the surface nanoscale information is converted into cell response providing a profound causal link between mechanotransductive events, proceeding from the cell/nanostructure interface to the nucleus. We produced nanostructured ZrO2 substrates with disordered yet controlled topographic features by the bottom-up technique supersonic cluster beam deposition, i.e. the assembling of zirconia nanoparticles from the gas phase on a flat substrate through a supersonic expansion. We used PC12 cells, a well-established model in the context of neuronal differentiation. We found that the cell/nanotopography interaction enforces a nanoscopic architecture of the adhesion regions that affects the focal adhesion dynamics and the cytoskeletal organization, which thereby modulates the general biomechanical properties by decreasing the rigidity of the cell. The mechanotransduction impacts furthermore on transcription factors relevant for neuronal differentiation (e.g. CREB), and eventually the protein expression profile. Detailed proteomic data validated the observed differentiation. In particular, the abundance of proteins that are involved in adhesome and/or cytoskeletal organization is striking, and their up- or downregulation is in line with their demonstrated functions in neuronal differentiation processes. Conclusion: Our work provides a deep insight into the molecular mechanotransductive mechanisms that realize the conversion of the nanoscale topographical information of SCBD-fabricated surfaces into cellular responses, in this case neuronal differentiation. The results lay a profound cell biological foundation indicating the strong potential of these surfaces in promoting neuronal differentiation events which could be exploited for the development of prospective research and/or biomedical applications. These applications could be e.g. tools to study mechanotransductive processes, improved neural interfaces and circuits, or cell culture devices supporting neurogenic processes. [ABSTRACT FROM AUTHOR]

Atomic Force Microscopy (AFM) has a great potential as a tool to characterize mechanical and morphological properties of living cells; these properties have been shown to correlate with cells' fate and patho-physiological state in view of the development of novel early-diagnostic strategies. Although several reports have described experimental and technical approaches for the characterization of cellular elasticity by means of AFM, a robust and commonly accepted methodology is still lacking. Here, we show that micrometric spherical probes (also known as colloidal probes) are well suited for performing a combined topographic and mechanical analysis of living cells, with spatial resolution suitable for a complete and accurate mapping of cell morphological and elastic properties, and superior reliability and accuracy in the mechanical measurements with respect to conventional and widely used sharp AFM tips. We address a number of issues concerning the nanomechanical analysis, including the applicability of contact mechanical models and the impact of a constrained contact geometry on the measured Young's modulus (the finite-thickness effect). We have tested our protocol by imaging living PC12 and MDA-MB-231 cells, in order to demonstrate the importance of the correction of the finite-thickness effect and the change in Young's modulus induced by the action of a cytoskeleton-targeting drug. [ABSTRACT FROM AUTHOR]

The urokinase-type plasminogen activator receptor ( uPAR) is a non-integrin vitronectin (VN) cell adhesion receptor linked to the plasma membrane by a glycolipid anchor. Through structure-function analyses of uPAR, VN and integrins, we document that uPAR-mediated cell adhesion to VN triggers a novel type of integrin signalling that is independent of integrin-matrix engagement. The signalling is fully active on VN mutants deficient in integrin binding site and is also efficiently transduced by integrins deficient in ligand binding. Although integrin ligation is dispensable, signalling is crucially dependent upon an active conformation of the integrin and its association with intracellular adaptors such as talin. This non-canonical integrin signalling is not restricted to uPAR as it poses no structural constraints to the receptor mediating cell attachment. In contrast to canonical integrin signalling, where integrins form direct mechanical links between the ECM and the cytoskeleton, the molecular mechanism enabling the crosstalk between non-integrin adhesion receptors and integrins is dependent upon membrane tension. This suggests that for this type of signalling, the membrane represents a critical component of the molecular clutch. [ABSTRACT FROM AUTHOR]

Molybdenum Diphosphide Nanorods with Laser-Potentiated Peroxidase Catalytic/Mild-Photothermal Therapy of Oral Cancer (Adv. Sci. 1/2022) B Chemodynamic Therapy b In article number 2101527 by Yuehong Shen, Zhibin Li, Hongyu Yang, and co-workers, a promising therapeutic strategy of laser-potentiated peroxidase catalytic/mild-photothermal therapy of molybdenum diphosphide nanorods (MoP SB 2 sb NRs) is proposed to improve chemodynamic therapy (CDT) performance and achieve effective tumor eradication and anti-infection by decomposing tumor endogenous H SB 2 sb O SB 2 sb into •OH radicals. [Extracted from the article]

In this study, we designed and synthetized artificial vascular scaffolds based on nanofibers of collagen functionalized with hyaluronic acid (HA) in order to direct the phenotypic shape, proliferation, and complete endothelization of mouse primary aortic endothelial cells (PAECs). Layered tubular HA/collagen nanofibers were prepared using electrospinning and crosslinking process. The obtained scaffold is composed of a thin inner layer and a thick outer layer that structurally mimic the layer the intima and media layers of the native blood vessels, respectively. Compared with the pure tubular collagen nanofibers, the surface of HA functionalized collagen nanofibers has higher anisotropic wettability and mechanical flexibility. HA/collagen nanofibers can significantly promote the elongation, proliferation and phenotypic shape expression of PAECs. In vitro co-culture of mouse PAECs and their corresponding smooth muscle cells (SMCs) showed that the luminal endothelialization governs the biophysical integrity of the newly formed extracellular matrix (e.g., collagen and elastin fibers) and structural remodeling of SMCs. Furthermore, in vitro hemocompatibility assays indicated that HA/collagen nanofibers have no detectable degree of hemolysis and coagulation, suggesting their promise as engineered vascular implants. [ABSTRACT FROM AUTHOR]

Plasticity and functional diversity of macrophages play an important role in resisting pathogens invasion, tumor progression and tissue repair. At present, nanodrug formulations are becoming increasingly important to induce and control the functional diversity of macrophages. In this framework, the internalization process of nanodrugs is co-regulated by a complex interplay of biochemistry, cell physiology and cell mechanics. From a biophysical perspective, little is known about cellular mechanics' modulation induced by the nanodrug carrier's internalization. In this study, we used the polylactic-co-glycolic acid (PLGA)–polyethylene glycol (PEG) nanofibers as a model drug carrier, and we investigated their influence on macrophage mechanics. Interestingly, the nanofibers internalized in macrophages induced a local increase of stiffness detected by atomic force microscopy (AFM) nanomechanical investigation. Confocal laser scanning microscopy revealed a thickening of actin filaments around nanofibers during the internalization process. Following geometry and mechanical properties by AFM, indentation experiments are virtualized in a finite element model simulation. It turned out that it is necessary to include an additional actin wrapping layer around nanofiber in order to achieve similar reaction force of AFM experiments, consistent with confocal observation. The quantitative investigation of actin reconfiguration around internalized nanofibers can be exploited to develop novel strategies for drug delivery. [ABSTRACT FROM AUTHOR]

Atomic force microscopy has proven to be a valuable technique to characterize the mechanical and morphological properties of heterogeneous soft materials such as biological specimens in liquid environment. Here we propose a 3-step method in order to investigate biological specimens where heterogeneity hinder a quantitative characterization: (1) precise AFM calibration, (2) nano-indentation in force volume mode, (3) array of finite element simulations built from AFM indentation events. We combine simulations to determine internal geometries, multi-layer material properties, and interfacial friction. In order to easily perform this analysis from raw AFM data to simulation comparison, we propose a standalone software, AFMech Suite comprising five interacting interfaces for simultaneous calibration, morphology, adhesion, mechanical, and simulation analysis. We test the methodology on soft hydrogels with hard spherical inclusions, as a soft-matter model system. Finally, we apply the method on E. coli bacteria supported on soft/hard hydrogels to prove usefulness in biological field. Atomic force microscopy is an indispensable method in characterizing soft materials but the complexity of biological samples makes reproducible measurements difficult. Here the authors use a 3-step method to investigate biological specimens in which vertical and lateral heterogeneity hinders a precise quantitative characterization. [ABSTRACT FROM AUTHOR]

Nanohybrids of graphene with water soluble polymer were synthesized using 'grafting from' method. GO, prepared by modified Hummers' method, was first reacted with sodium azide. Alkyne-terminated RAFT-CTA was synthesized by reaction of propargyl alcohol and S-1-dodecyl-S'-(α,α'-dimethyl-α'-acetic acid) trithiocarbonate. RAFT-CTA was grafted onto the GO sheets by facile click-reaction and subsequently, N-isopropylacrylamide (NIPAM) and N-ethyleacrylamide (NEAM) were polymerized on graphene sheets via RAFT polymerization method. The respective copolymers with different ratios were also prepared. The nanohybrids were characterized by FTIR, XRD, TGA, Raman, SEM, and AFM. Both SEM and AFM clearly showed rod-like structures for rGO-PNEAM. XRD showed a small peak at 2θ = 19.21°, corresponding to d-spacing ≈ 4.6 Å. In addition, the nanohybrids showed a very broad temperature range for the LCST in water between ca. 30 and 70 °C. [ABSTRACT FROM AUTHOR]