Self-repair Capability Research Articles

Interactions between NAD+ metabolism and immune cell infiltration in ulcerative colitis: subtype identification and development of novel diagnostic models

BackgroundUlcerative colitis (UC) is a chronic inflammatory disease of the colonic mucosa with increasing incidence worldwide. Growing evidence highlights the pivotal role of nicotinamide adenine dinucleotide (NAD+) metabolism in UC pathogenesis, prompting our investigation into the subtype-specific molecular underpinnings and diagnostic potential of NAD+ metabolism-related genes (NMRGs).MethodsTranscriptome data from UC patients and healthy controls were downloaded from the GEO database, specifically GSE75214 and GSE87466. We performed unsupervised clustering based on differentially expressed NAD+ metabolism-related genes (DE-NMRGs) to classify UC cases into distinct subtypes. GSEA and GSVA identified potential biological pathways active within these subtypes, while the CIBERSORT algorithm assessed differential immune cell infiltration. Weighted gene co-expression network analysis (WGCNA) combined with differential gene expression analysis was used to pinpoint specific NMRGs in UC. Robust gene features for subtyping and diagnosis were selected using two machine learning algorithms. Nomograms were constructed and their effectiveness was evaluated using receiver operating characteristic (ROC) curves. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to verify gene expression in cell lines.ResultsIn our study, UC patients were classified into two subtypes based on DE-NMRGs expression levels, with Cluster A exhibiting enhanced self-repair capabilities during inflammatory responses and Cluster B showing greater inflammation and tissue damage. Through comprehensive bioinformatics analyses, we identified four key biomarkers (AOX1, NAMPT, NNMT, PTGS2) for UC subtyping, and two (NNMT, PARP9) for its diagnosis. These biomarkers are closely linked to various immune cells within the UC microenvironment, particularly NAMPT and PTGS2, which were strongly associated with neutrophil infiltration. Nomograms developed for subtyping and diagnosis demonstrated high predictive accuracy, achieving area under curve (AUC) values up to 0.989 and 0.997 in the training set and up to 0.998 and 0.988 in validation sets. RT-qPCR validation showed a significant upregulation of NNMT and PARP9 in inflamed versus normal colonic epithelia, underscoring their diagnostic relevance.ConclusionOur study reveals two NAD+ subtypes in UC, identifying four biomarkers for subtyping and two for diagnosis. These findings could suggest potential therapeutic targets and contribute to advancing personalized treatment strategies for UC, potentially improving patient outcomes.

Application of Self-Healing Hydrogels in the Treatment of Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IDD) is one of the leading causes of chronic pain and disability, and traditional treatment methods often struggle to restore its complex biomechanical properties. This article explores the innovative application of self-healing hydrogels in the treatment of IDD, offering new hope for disc repair due to their exceptional self-repair capabilities and adaptability. As a key support structure in the human body, intervertebral discs are often damaged by trauma or degenerative changes. Self-healing hydrogels not only mimic the mechanical properties of natural intervertebral discs but also self-repair when damaged, thereby maintaining stable functionality. This article reviews the self-healing mechanisms and design strategies of self-healing hydrogels and, for the first time, outlines their potential in the treatment of IDD. Furthermore, the article looks forward to future developments in the field, including intelligent material design, multifunctional integration, encapsulation and release of bioactive molecules, and innovative combinations with tissue engineering and stem cell therapy, offering new perspectives and strategies for IDD treatment.

Heat/light dual-stimulating shape memory acrylic ester resin with fast response, self-repairing and remolding capabilities

Heat/light dual-stimulating shape memory acrylic ester resin with fast response, self-repairing and remolding capabilities

Water-repellent and self-repairing capabilities integration: Enhancing longevity and practicality of fabric-based flexible devices

Water-repellent and self-repairing capabilities integration: Enhancing longevity and practicality of fabric-based flexible devices

A biomimetic injectable chitosan/alginate hydrogel biocopmosites encapsulating selenium- folic acid nanoparticles for regeneration of spinal cord injury: An in vitro study.

Spinal cord injury (SCI) poses significant challenges to regenerative medicine due to its limited self-repair capabilities. In this study, we engineered a biomimetic injectable hydrogel using modified chitosan and alginate biopolymers encapsulating selenium-folic acid nanoparticles (Se-FA NPs) to facilitate SCI regeneration. The hydrogel exhibited a unique porous structure attributed to the incorporation of nanofiber fragments, enhancing its biocompatibility and bioactivity. Through a series of in vitro evaluations, including cell viability assays, proliferation studies, gene expression analysis, we assessed the hydrogel's cytocompatibility and its potential for supporting neural cell growth. Our results demonstrate the promising efficacy of the hydrogel in providing a conducive microenvironment for neural tissue regeneration. Moreover, the sustained release of Se-FA NPs from the hydrogel system offers neuroprotective, antioxidative, and anti-inflammatory benefits crucial for SCI therapy. Overall, our biomimetic hydrogel biocomposites hold great potential as a therapeutic strategy for promoting spinal cord regeneration, highlighting their significance in advancing the field of regenerative medicine.

Enhanced fenton-like rate and anti-interference through designing materials with specific excellent sorption to pollutant

Fenton-like application is critical especially in wastewater treatment, but current catalysts face to the lack of anti-interference and low-utilization activity in high generated rate, due to the inherent contradiction between slow-sorption rate and ineffective fast-consumption of free radicals. Here, the abundant CuO nano-blade-sheets carbon-based material (Ns-CuO-LCelC) with much higher kinetic and selective capacity to pollutant than conventional adsorbents was designed and synthesized to evaluate the role of active-sorption on performance in Fenton-like applications. Due to favorable selectivity and rapid adsorptive-concentration for pollutants, the Fenton-like process rate on Ns-CuO-LCelC is 70.83 times greater than that of CuO and 3.44 times greater than powdered cellulose synthesized-catalyst. In variable systems involving pH, ions, and different pollutants, the catalytic rate and sorption performance remain highly consistent. This mitigates low-quality ROS conversion and self-consumption, achieving efficient pollutant elimination through concerted radical and non-radical reactions, with high peroxydisulfate (PDS) utilization efficiency (33.65 g/M) and unprecedented pollutant removal activity (rate constant: 40.54 min−1 M−1). The protection provided by the fiber structure and the electronic self-repair capability of the Cu Ns ensured strong stability in catalytic systems, with 100 % efficiency and 2800 L/m2/h/bar even after 900 min of continuous membrane operation in treating 2 mg/L TC, showing no significant decrease. It was the first case to underscores the value of fast adsorptive aggregation in Fenton-like application for eliminating interference and enhancing oxidant utilization.

Largemouth bronze gudgeon (Coreius guichienoti) responds positively to liver damage induced by high feeding rates via enhancing self-repair capability

Overfeeding intermittently induces metabolic liver diseases in aquaculture practice. Currently, less information regarding the impact of feeding rates on hepatic lipid metabolism was reported. Therefore, this study investigated the effects of feeding rates (2 %, 3 %, 4 %, and 5 % of body weight per day) on growth performance, hepatic lipid metabolism, immunity, inflammation, and apoptosis in juvenile largemouth bronze gudgeon (Coreius guichenoti) over 8 weeks. The results demonstrated that increasing feeding rates significantly enhanced weight gain rate and specific growth rate. Furthermore, the lipid content of the whole body increased progressively, with the highest levels observed in the 5 % group. High feeding rates also resulted in significant increases in hepatic TG, TC, and NEFA levels. This was accompanied by upregulated mRNA levels and enzyme activities of lipid synthesis-related genes (ACC1α and FASN). However, no significant differences were observed in mRNA levels and enzyme activities of lipolysis-related genes (HSL and CPT1). Histological observations identified two distinct hepatic phenotypes: no obvious abnormality liver and fatty liver. Overall, the proportion of fatty liver phenotype increased with the increasing feeding rate. Additionally, feeding rates significantly increased IgG, IgM, and lysozyme levels, and upregulated mRNA levels of inflammatory cytokines (TNFα and IL1β), apoptosis-related genes (CASP3, CASP8, and CASP9), and hepatic repair factors (YAP1, FGF10, FGF13, FGF18, FGF19, and PCNA). Nevertheless, hepatic function indices, including ALT, AST, and AKP levels, remained unchanged. In conclusion, these findings indicated that a feeding rate exceeding 3 % led to hepatic lipid metabolism disorders, characterized by the accumulation of TG and TC, thus promoting the development of fatty liver, inflammation response, and cellular apoptosis in largemouth bronze gudgeon. Moreover, the largemouth bronze gudgeon may exhibit self-repair capability to mitigate liver damage induced by lipid metabolism disorders. Consequently, we infer that largemouth bronze gudgeon possesses a robust capability for lipid accumulation and utilization.

Preparation of TiO2 hybrid SiO2 wall environment-friendly microcapsules based on interfacial polycondensation: Realize the integration of self-cleaning and self-healing functions

The purpose of this study is to extend the service life of decorative coating by repairing micro-cracks with self-healing microcapsules, while giving them hydrophobic self-cleaning and photocatalytic self-cleaning functions. The interfacial polycondensation approach was employed to synthesize TiO2/SiO2 hybrid microcapsules with self-cleaning and self-repairing capabilities. These microcapsules were made by employing TiO2 as the photocatalyst hybrid SiO2 wall material and linseed oil as the core material. The attributes of the microcapsules, including their particle characteristics, micromorphology, chemical structure, thermal stability, and self-cleaning properties, were evaluated. Additionally, the impacts of self-cleaning and self-repairing on coatings were also examined. The findings indicate that the microcapsules possess a rough surface, excellent sphericity, separation, and thermal stability, as well as a distinct core-shell structure. Moreover, the hybrid microcapsules exhibit a disintegration rate of over 70.0 % towards the 10.0 mg/L methylene blue solution. The contact angle can be augmented to 131.3°. At a microcapsule concentration of 20.0 % in the coating, the degradation rate of methylene blue is 44.4 %, the self-repairing rate of microcracks is as high as 58.7 %, and the contact angle measures 91.2°.

Multifunctional hydrogels loaded with tellurium nanozyme for spinal cord injury repair

Spinal cord injury (SCI) results in severe neurological deficits due to disrupted neural pathways. While the spinal cord possesses limited self-repair capabilities, recent advancements in hydrogel-based therapies have shown promise. Polyphenol-based hydrogels, known for their neuroprotective properties, offer a suitable microenvironment for neural regeneration. In this study, a novel poly(lipoic acid)/poly(dopamine) adhesive hydrogel was developed as a versatile platform for delivering therapeutic agents. This hydrogel was loaded with methylcobalamin, a neurotrophic factor, and tellurium nanoenzymes, potent antioxidants. The nanoenzymes effectively mitigated oxidative stress and inflammation, while methylcobalamin promoted nerve regeneration. The combined therapeutic effects of the nanoenzymatic hydrogel demonstrated significant efficacy in repairing spinal cord injuries, highlighting its potential as a promising strategy for treating this debilitating condition.

Research on Crack Sealing Performance of Polymer Microsphere/Hydrogel Composite System

Owing to their excellent water-absorption and swelling properties, polymer microspheres have been extensively applied as deep profile control agents in oilfields. These microspheres effectively seal large pore-throat channels in reservoirs, optimizing the water-absorption profile. In this study, a composite system was developed, comprising polymer microspheres and polyacrylamide polymers, with the inclusion of a cross-linking agent. The system leverages the synergistic effects of polymer microspheres and other plugging techniques to efficiently seal fractured reservoirs. Results indicate that the composite system exhibits strong blocking and scour resistance due to enhanced network integrity, higher viscosity, and improved elastic strength. Additionally, the composite system demonstrates a notable self-repairing capability, maintaining a high sealing efficiency even after a waterflood breakthrough.

Designing for the chemical conversion coating on AZ91 magnesium alloy by equalising interface potential difference

The formation of intermetallic compounds leads to heterogeneous chemical compositions and galvanic corrosion in alloy materials, which are widely recognised as primary contributors to non-uniform conversion coatings and poor corrosion resistance. This study implements a strategy aimed at regulating surface chemical composition and equalising interfacial potential differences to develop an Al-Mg-V chemical conversion coating on AZ91 magnesium alloy. The surface characteristics and corrosion resistance of the coating are investigated. The results demonstrate that the coating integrates the discretely distributed intermetallic compounds (Mg17Al12) into a continuous and stable cathode phase. The framework structure composed of Mg and Al effectively equalises the interfacial potential differences, reducing the potential difference from 300 mV to 40 mV. The coating enhances the polarization resistance of the AZ91 substrate by approximately 400 times and reduces the self-corrosion current density by three orders of magnitude. After a 186-h neutral salt spray test, no corrosion is observed. The corrosion inhibiting structure formed by V hydroxides/oxides fill the pores and acts as a passivator on the surface, and imparts self-repair capabilities to the coating. The design concept of this chemical conversion coating is expected to be applied to other alloy materials.

Self-Repairable Carbon Fiber-Reinforced Epoxy Vitrimer Actuator with Multistimulus Responses and Programmable Morphing.

Smart shape-changing structures in aerospace applications are vulnerable to damage in harsh environments. Balancing high mechanical performance with self-repair capabilities poses a challenge due to inherent trade-offs between strength and flexibility. To address this challenge, an asymmetric bilayer-structured actuator was fabricated using commercially available continuous carbon fiber tows (CFs) as the passive layer and a dynamic cross-linked epoxy vitrimer as the active layer. The construction of the vitrimer-CF actuator involves a simple and scalable hot-pressing process, resulting in a tensile strength of 234 MPa and an interfacial bonding strength of 405 N·m-1. This actuator exhibits remarkable deformation capability (210°/7 s) and an efficient self-repair ability under various stimuli, including thermal (60-160 °C), light (0.4-1.0 W·cm-2), electric (2-4 V), and solvent (acetone). By adjustment of the orientation angle of CFs, complex left-handed and right-handed curling structures can be achieved. Leveraging the insights from photothermal/electrothermal actuation mechanisms, a quadruped crawling robot is developed capable of crawling 4 cm with a single light illumination. The actuator can lift objects 45 times its weight when subjected to light stimuli. Additionally, a flap actuator is constructed to achieve an angle change of 63° within 10 s under an electric stimulus, enabling remote control over the aircraft flight angle. These results demonstrate the potential of the vitrimer-CF actuator for advanced applications in intelligent aerospace structures.

Future Strategies for Optic Nerve Protection and Repair

Disorders in the function of the optic nerve are defined as optic neuropathy. Etiologically, they can be classified into different groups including glaucomatous, inflammatory (infectious/demyelinating), traumatic, ischemic, infiltrative, toxic, and hereditary. Treatment approaches and disease prognoses vary significantly. Retinal ganglion cells lack the capacity for self-renewal and have limited self-repair capabilities; Therefore, optic neuropathies can lead to irreversible partial or complete vision loss by causing axonal damage and subsequent death of retinal ganglion cells. This review aims to discuss the known mechanisms and limitations of regeneration, as well as to summarize current approaches and future strategies for optic nerve neuroprotection and neuroregeneration.

High-strength self-healing multi-functional hydrogels with worm-like surface through hydrothermal-freeze-thaw method

Soft self-healing materials are promising candidates for flexible electronic devices due to their exceptional compatibility, extensibility, and self-restorability. Generally, these materials suffer from low tensile strength and susceptibility to fracture because of the restricted microstructure design. Herein, we propose a hydrothermal-freeze-thaw method to construct high-strength self-healing hydrogels with even interconnected networks and distinctive wrinkled surfaces. The integration of the wrinkled outer surface with the three-dimensional internal network confers the self-healing hydrogel with enhanced mechanical strength. This hydrogel achieves a tensile strength of 223 kPa, a breaking elongation of 442%, an adhesion strength of 57.6 kPa, and an adhesion energy of 237.2 J m-2. Meanwhile, the hydrogel demonstrates impressive self-repair capability (repair efficiency: 93%). Moreover, the density functional theory (DFT) calculations are used to substantiate the stable existence of hydrogen bonding between the PPPBG hydrogel and water molecules which ensures the durability of the PPPBG hydrogel for long-term application. The measurements demonstrate that this multifunctional hydrogel possesses the requisite sensitivity and durability to serve as a strain sensor, which monitors a spectrum of motion signals including subtle vocalizations, pronounced facial expressions, and limb articulations. This work presents a viable strategy for healthcare monitoring, soft robotics, and interactive electronic skins.

Three-Dimensional Printed Silk Fibroin/Hyaluronic Acid Scaffold with Functionalized Modification Results in Excellent Mechanical Strength and Efficient Endogenous Cell Recruitment for Articular Cartilage Regeneration.

Treatment of articular cartilage remains a great challenge due to its limited self-repair capability. In tissue engineering, a scaffold with both mechanical strength and regenerative capacity has been highly desired. This study developed a double-network scaffold based on natural biomaterials of silk fibroin (SF) and methacrylated hyaluronic acid (MAHA) using three-dimensional (3D) printing technology. Structural and mechanical characteristics of the scaffold was first investigated. To enhance its ability of recruiting endogenous bone marrow mesenchymal stem cells (BMSCs), the scaffold was conjugated with a proven BMSC-specific-affinity peptide E7, and its biocompatibility and capacity of cell recruitment were assessed in vitro. Animal experiments were conducted to evaluate cartilage regeneration after transplantation of the described scaffolds. The SF/HA scaffolds exhibited a hierarchical macro-microporous structure with ideal mechanical properties, and offered a 3D spatial microenvironment for cell migration and proliferation. In vitro experiments demonstrated excellent biocompatibility of the scaffolds to support BMSCs proliferation, differentiation, and extracellular matrix production. In vivo, superior capacity of cartilage regeneration was displayed by the SF/MAHA + E7 scaffold as compared with microfracture and unconjugated SF/MAHA scaffold based on macroscopic, histologic and imaging evaluation. In conclusion, this structurally and functionally optimized SF/MAHA + E7 scaffold may provide a promising approach to repair articular cartilage lesions in situ.

4D printing of polylactic acid (PLA)/PLA-thermoplastic polyurethane (TPU)-based metastructure: examining the mechanical, thermal, and shape memory properties

Abstract In the present day and age, increasing demand concerning the enhancement of the mechanical performance of Shape Memory Polymer (SMP) based structures has paved the way for developing newer metastructures of enhanced load-bearing, damping capacity, and durability. The present study focuses on developing SMP-based metastructures made of commercially available Polylactic Acid (PLA) and 30% by wt. of Thermoplastic Polyurethane (TPU) blended PLA. The designed metastructures are initially analyzed using numerical modeling to prevent lateral deformation, acute stress concentration zones, and row-wise collapse. Mechanical tests reveal that blending TPU with PLA enhances the material's flexibility and ductility, further improving the toughness and fracture resistance of the built metastructures. Loading-unloading and shape recovery tests (under compression mode) of the s-shape metastructure reveal that the PLA/TPU metastructure withstands ≅ 170 N load, less than neat PLA's ≅ 223 N due to TPU's flexibility. PLA/TPU endures 30 cycles, while PLA fails after the 9th cycle. In shape recovery plots, PLA/TPU metastructures exhibit a lower standard deviation (~0.32%) than PLA (~1.4%), attributed to the entropy decrease and cross-linkage disentanglements of PLA. Furthermore, a Dynamic Mechanical Analyzer (DMA) assesses glass transition temperature, energy storage capability, and dissipation in variation with the temperature. The nephograms of ABAQUS result divulge accurate fracture initiation locations of the metastructure unit cells, which involves implementing ductile damage behavior modeling by employing damage initiation and evolution parameters. Finally, assessing compression tests and shape recovery behavior results elucidates that these SMP-based metastructures are promising for load-bearing pallets in the transporting and packaging industries, providing superior damping and self-repairing capabilities during significant plastic deformations.

Tribological behavior and lubrication mechanism of polyalphaolefin with added Cu-Ni bimetallic nanoparticles on a TiN coating

In this study, the tribological behavior of TiN coatings lubricated with a polyalphaolefin (PAO)-based oil containing Cu-Ni bimetallic nanoparticles was investigated under a maximum contact pressure of 0.9 GPa in reciprocating ball-on-disk mode. The addition of 0.1 wt% Cu-Ni nanoparticles to PAO6 reduced the friction coefficient to 0.018 and also decreased the wear rate of TiN coatings to 4.23 × 10-7 mm3/Nm. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy revealed the deposition of Cu-Ni nanoparticles and carbon-based tribofilms on the contact region of the tribopairs. These originated from the tribo-induced degradation of the polyalphaolefin molecule in PAO6 + 0.1 %Cu-Ni nanoparticles, which helped decrease the COF and wear. Moreover, a comparative analysis suggested that the presence of nickel in the Cu-Ni nanoparticles had a catalytic effect during sliding. They facilitated the in situ formation of carbon-based film due to the degradation of polyalphaolefins under the combined effects of frictional heat and contact stress, demonstrating a self-repair capability.

Collagen-based 3D printed poly (glycerol sebacate) composite scaffold with biomimicking mechanical properties for enhanced cartilage defect repair

Cartilage defect repair with optimal efficiency remains a significant challenge due to the limited self-repair capability of native tissues. The development of bioactive scaffolds with biomimicking mechanical properties and degradation rates matched with cartilage regeneration while simultaneously driving chondrogenesis, plays a crucial role in enhancing cartilage defect repair. To this end, a novel composite scaffold with hierarchical porosity was manufactured by incorporating a pro-chondrogenic collagen type I/II-hyaluronic acid (CI/II-HyA) matrix to a 3D-printed poly(glycerol sebacate) (PGS) framework. Based on the mechanical enforcement of PGS framework, the composite scaffold exhibited a compressive modulus of 167.0 kPa, similar to that of native cartilage, as well as excellent fatigue resistance, similar to that of native joint tissue. In vitro degradation tests demonstrated that the composite scaffold maintained structural, mass, and mechanical stability during the initial cartilage regeneration period of 4 weeks, while degraded linearly over time. In vitro biological tests with rat-derived mesenchymal stem cell (MSC) revealed that, the composite scaffold displayed increased cell loading efficiency and improved overall cell viability due to the incorporation of CI/II-HyA matrix. Additionally, it also sustained an effective and high-quality MSC chondrogenesis and abundant de-novo cartilage-like matrix deposition up to day 28. Overall, the biomimetic composite scaffold with sufficient mechanical support, matched degradation rate with cartilage regeneration, and effective chondrogenesis stimulation shows great potential to be an ideal candidate for enhancing cartilage defect repair.

A Wireless Ad Hoc Network Communication Platform and Data Transmission Strategies for Multi-Bus Instruments

As automatic test technology advances, the number of programmable instruments in a single test system increases. Traditional wired communication methods have a limited range and involve complex cable layouts. Single-function wireless converters provide a viable alternative, but they have limitations. These include complicated configuration, issues with multi-system collaboration, and data blocking. This paper proposes a wireless ad hoc network platform for multi-bus instruments based on a low-cost ESP-12H WiFi module. The platform supports GPIB, RS232, RS485, and CAN bus interface instrument access. It features easy configuration, ad hoc networking, and self-repairing capabilities. A relay multi-hop network with a tree topology expands capacity and coverage. Additionally, a dynamic window-receiving mode and an improved multi-priority queue ensure data transmission integrity. The experimental results show that the platform’s networking time is less than 10 s, and the coverage range reaches 50 m in complex indoor environments. It also shows good stability when running for a long time. However, due to hardware and software design limitations, the actual upload speeds fall short of the theoretical values. For example, RS232 and RS485 are about 10% slower than the theoretical values, and GPIB is about 80% slower. Further optimization is required in the future.

Advanced eco-friendly dual-layer coating: Combining superhydrophobicity with smart self-healing for superior metal protection

In this study, a double-layer composite coating was developed by integrating a superhydrophobic top layer with a smart self-healing bottom layer. The superhydrophobic top coating demonstrated a high water contact angle of up to 153°, showcasing excellent mechanical properties, corrosion resistance, self-cleaning ability, and resistance to fouling, ice formation, and scaling. Notably, the anti-scaling property of the coating remained above 80 % after 36 h of immersion. The bottom layer, composed of waterborne epoxy resin and pH-responsive smart fillers, provided enhanced corrosion resistance and self-repairing capabilities while maintaining environmental friendliness. Experimental results indicated that the impedance value of the composite coating could reach 1010 Ω·cm2 at 0.01 Hz, significantly surpassing the corrosion resistance of traditional waterborne epoxy resin coatings. Additionally, the protective effect of the superhydrophobic top layer was evident even after the coating was damaged, suggesting a novel approach for employing superhydrophobic coatings in metal corrosion protection.