ABSTRACT The design and operation of blood pumps are very complex and expensive to save lives of patients suffering from heart ailments. Machine learning approaches may be those better affordable ones which can be used to enhance understanding of correlation between operating parameters and performance of the pumps that is between pressure rise in blood pumps and clearance, blade height and rotational speed of the pump. Four types of machine learning algorithms, that is multiple linear regression, polynomial regression, artificial neural network and random forest regression have been employed in the current study to predict pressure rise. Performance evaluation metrics have shown that machine learning approaches are efficiently able to predict the pressure rise in blood pumps using its operational parameters. Among all of the models used, the ANN (3‐12‐12‐1) model has shown the highest accuracy of 99.9% with RELU activation function for input and hidden layers, linear activation for the output layer using ADAMAX as an optimiser. The ANN model is found to be accurate with 0.0012 MSE, 0.023 MAE and 0.999 R 2 , which are significantly lower while predicting the pressure rise in the blood pump. The ANN model is also found to predict the physical behaviour of the blood pump efficiently.
ABSTRACT Chronic wounds represent a profound global healthcare burden, characterised by stalled healing cascades, excessive reactive oxygen species (ROS) accumulation and the severe attenuation of endogenous electric fields (EF). While conductive hydrogels have emerged as promising bioelectronic interfaces to restore impaired EF and enhance electrical signal transduction, conventional designs are fundamentally limited by heterogeneous filler dispersion, high interfacial impedance and suboptimal biocompatibility. This review systematically summarises the design paradigms and therapeutic mechanisms of polyphenol‐based conductive hydrogels for chronic wound management. By leveraging the versatile coordination chemistry of catechol and pyrogallol moieties, natural polyphenols function as structural architects that ensure uniform conductive networks, robust wet tissue adhesion and enhanced mechanical toughness. Moreover, they impart intrinsic bioactive attributes, including antioxidative and anti‐inflammatory effects. Furthermore, we critically detail how the synergistic interplay between the intrinsic bioactivities of polyphenols and the biophysical cues from the conductive network orchestrates the entire healing trajectory. This synergy actively resolves pathological inflammation, accelerates angiogenesis and guides organised extracellular matrix remodelling. Finally, we highlight the current translational bottlenecks and propose future directions, emphasising the integration of artificial intelligence (AI) and machine learning for the inverse design of smart hydrogels, alongside the imperative for standardised large‐animal clinical evaluations.
ABSTRACT Medicated moxa sticks were prepared by mixing the herbs in Juanbi decoction with moxa wool. The components of smoke produced by combustion of these medicated moxa sticks and pure moxa sticks were analysed by gas chromatography‐mass spectrometry. The smoke of the medicated moxa sticks contained 34 more active ingredients than that of the pure moxa sticks. Six of the active ingredients screened using network pharmacology and molecular docking can regulate joint diseases via the tumour necrosis factor pathway and have good binding affinities with core targets. The preparation process of the medicated moxa sticks was optimised using Box–Behnken design of response surface methodology. The smoke of the optimised product contained a high concentration of active ingredients and a low tar concentration. Molecular dynamics simulations and rat experiments demonstrated that the smoke derived from medicated moxa sticks possessed good skin permeability and detumescence activity. The developed medicated moxa sticks are environmentally friendly and show good prospects for the treatment of joint disease.
ABSTRACT Cancer progression has been shown to be accompanied by alterations in physical features of its microenvironment. In the study, we fabricated an aligned collagen fibre matrix, whose architecture in both micro‐level and nano‐level was similar to that of the matrix found around the breast tumour tissue. The modulus of matrix exhibited a stiffness similarly to that found in metastatic breast tumour tissue. On the tough substrate, MDA‐MB‐231 cells presented an increased migration rate along the alignment of fibre. The biomechanical properties of tumour cells were explored in situ by AFM. The stiffness of a single MDA‐MB‐231 cell on the aligned matrix was reduced when compared with that on the nonaligned one. Wound healing assay showed that tumour cells with compliant modulus moved fast along the alignment of collagen fibre matrix. The in vitro model effectively mimicked the tumour cell behaviour, which would be helpful for new therapeutic strategies to detect cancer progress.
Bioactive glass nanoparticles (BGNs) have attracted widespread attention in regenerative medicine owing to their excellent biocompatibility and tissue repair capacity. However, the ion release behaviour associated with the long-term degradation of BGNs doped with different functional elements remains unclear. Herein, binary silicate BGNs (BGN-Ca, BGN-Mg, BGN-Zn, BGN-Cu and BGN-Mn) were prepared, and their degradation behaviour in normal saline was systematically evaluated over a period of up to 150 days. The evolution of particle morphology and size, ion release and pH changes in solution was characterised in detail. The results showed that the degradation behaviours of BGNs doped with different elements differed markedly. BGN-Ca and BGN-Mg exhibited the fastest degradation rates characterised by rapid degradation accompanied by higher Si release, whereas BGN-Zn and BGN-Mn showed comparable total Si release but displayed 'fast-then-slow' and 'slow-then-fast' release patterns, respectively. Overall, the reactivity of metal ions can provide a preliminary prediction of early ion-exchange trends, but the actual degradation behaviour is also co-regulated by multiple factors, including doping content, crystalline structure and solubility. This study elucidates the intrinsic relationship among doped elements, structural state and degradation behaviour and provides an experimental support for the precise design and stability regulation of multicomponent functionalised BGNs.
ABSTRACT Artificial ligaments (ALs), as important grafts for reconstructing the anterior cruciate ligament, often fail in rupture owing to inadequate mechanical properties and frictional wear in clinical practice. Braiding parameters affect the properties of ALs. Previous studies have been limited to investigating the effects of braiding parameters on the mechanical or tribological properties of ALs in isolation and lacked a comprehensive investigation into their combined or synergistic impact. Therefore, in this study, ALs with different braiding parameters are prepared, and mechanical and tribological indicators are integrated to conduct a synergistic investigation. The results show that as the braiding angle and number of layers decrease, the breaking strain increases, while the ultimate tensile force, elastic modulus, and yield force decrease. The number of spindles positively correlates with the mechanical and tribological performance of ALs.
ABSTRACT Damage to the dental implant–alveolar bone interface is one of the key issues limiting the service life of implants, whereas the periodontal ligament between natural teeth and the alveolar bone provides a flexible cushioning function for the interface. Inspired by the flexible cushioning function of the periodontal ligament, this study comparatively analyses the mechanical properties of the dental implant–alveolar bone interface before and after adding a periodontal ligament‐like flexible composite coating to the implant surface through finite element computer simulations, aiming to investigate the interfacial cushioning effect of the flexible composite coating. The results demonstrate that the flexible composite coating reduces and redistributes the stress at the implant–alveolar bone interface, providing an interfacial cushioning effect. Furthermore, both the application method and thickness of the flexible composite coating influence the interfacial cushioning to a certain extent. This research holds theoretical significance for the development of next‐generation dental implants and offers theoretical support for designing implants with flexible cushioning capabilities.
ABSTRACT Catheter‐associated urinary tract infections (CAUTIs) are a significant complication of indwelling urinary catheters, primarily caused by bacterial adhesion, biofilm formation and catheter‐induced mechanical irritation. To reduce the risk of infection and enhance catheter safety and performance, this study developed an antibacterial lubricating coating. The coating was fabricated on a polytetrafluoroethylene (PTFE) substrate via electrostatic self‐assembly, combining dopamine‐modified hyaluronic acid–dopamine (HA–DN) as a biomimetic adhesive with aminated mesoporous silica nanoparticles (AMSN) serving as a long‐acting drug delivery carrier loaded with triclosan (TCS). The results demonstrated that the prepared AMSN exhibited a uniform particle size of approximately 80 nm, an ordered mesoporous structure and a high drug‐loading capacity, enabling sustained in vitro release of TCS for up to 144 h. Additionally, the composite multilayer coating significantly improved surface hydrophilicity and lubricity, exhibited strong antibacterial activity against Escherichia coli and Staphylococcus aureus and maintained good biocompatibility. These findings highlight its potential for preventing CAUTIs and enhancing the safety of indwelling urinary catheters.
ABSTRACT 3D fibre aerogels with aligned architecture, due to their high porosity, interconnected pore structure and high specific surface area, show great potential in sound absorption, oil‐water separation and air filtration. Herein, we present a novel and simple long straight bundle electrospinning strategy inspired by Darwin's bark spider to prepare 3D aligned fibre aerogels. Different from the conventional electrospinning, whipping instability of the fibre is effectively eliminated by manipulating the distribution of electric field lines during the long straight bundle electrospinning, resulting in the formation of a 3D aligned fibre aerogel. The detailed long straight bundle electrospinning process (formation of fibre bundle, flying path of fibre bundle and deposition of fibre bundle) along with the underlying mechanism are systematically studied. Based on this theoretical basis, scalable fabrication of the 3D flexible aligned fibre aerogel with an ultrahigh fibre alignment degree of 0.93 and an ultrathick structure (2.8 cm) is achieved in one step. As a proof of concept, we investigate the use of the 3D aligned fibre aerogel in air filtration. It is found that the fibre aerogel shows excellent PM 1.0 and PM 2.5 filtration performance in both perpendicular to and parallel to fibre alignment direction. Interestingly, the pressure drop in the direction parallel to fibre alignment is only 21 Pa, which is much lower than that in the direction perpendicular to fibre alignment. We also compare the filtration performance of our 3D fibre aerogel with other filters and find that the comprehensive performance of our aerogel is obviously better.
ABSTRACT Finger pad strain governs grip control and tactile feedback, yet in vivo measurements during sliding remain scarce. This feasibility study utilised 3D‐digital image correlation (3D‐DIC) and optical coherence tomography (OCT) for quantifying surface strains and subsurface deformation in a human finger pad during static/dynamic glass contact, linking both to the respective friction behaviour. Principal strains increase systematically with normal load (0.5–3 N), concentrating at the mechanoreceptor‐rich fingertip under dynamic sliding (peak ε 1 2%–7.5%). Friction (CoF 0.4–0.8) and apparent contact area follow load‐dependent power laws, with adhesion dominating. Multiscale imaging validates surface strain as a reliable friction predictor, providing good proof‐of‐concept for strain‐based human finger pad friction modelling despite subsurface measurement limitations.
The excessive and continuous contacting pressure tends to cause skin injury and pain when the lower limb contacting with prosthetic liners. To relate the subcutaneous pressure and the brain response induced by pain sensations, a mathematical model was established based on the finite element model, Hodgkin–Huxley model and GCT model. The results showed that stronger subcutaneous pressure stimulation can lead to higher frequency of the membrane potential and T‐cell potential. The frontal, prefrontal cortex, primary somatosensory cortex and occipital lobe were involved in the processing of pressure pain. A significant increase was observed in γ oscillations in pain states compared with no pain, but no significant differences in different pain level, indicating mathematical model and EEG methods can distinguish the pain but cannot distinguish the pain intensities when the stimulation exceeded the pain threshold. Compared with silicone materials, a higher T‐cell potential and a lower pressure pain threshold were observed as the skin contacted with foam materials, suggesting that the foam materials can induce more severe pain on the skin surface. This study is helpful to understand the mechanisms of pain from skin surface to brain response and to provide theoretical guidance for the optimal design of lower limb prostheses.
Cardiovascular disease (CVD) is regarded as the leading cause of morbidity and mortality worldwide within recent decades. Stent intervention is one of the main methods for treating CVD due to its advantages of minimal trauma, fast recovery and fewer complications. However, the main function of existing drug‐eluting stents is anti‐hyperplasia, and their re‐endothelialisation function is still insufficient and needs to be strengthened. In this study, a novel coating containing traditional Chinese medicine ingredient, Ophiopogon Saponin D (OPH), is designed to enhance the re‐endothelialisation function of stents: firstly, the dopamine (DA) and hexanediamine (HD) were co‐polymerised to the bare metal stent, endowing rich‐amino surface (PDA/HD) for conjugating functional molecules by chemical reaction; thereafter hyaluronic acid (HA) containing OPH were conjugated to the PDA/HD. Our data suggested that the OPH coating promoted surface re‐endothelialisation not only by directly enhancing proliferation/migration and inhibiting apoptosis of endothelial cells, but also by regulating macrophages to M2 phenotype and smooth muscle cells to contractile phenotype. Our study may provide inspiration for designing more novel biomaterial coatings using traditional Chinese medicine ingredient.
Silver-based printed circuits have demonstrated significant potential in the field of flexible electronics, particularly for applications such as wearable devices, owing to their high conductivity, low cost, and ease of mass production. However, their structural and performance degradation under continuous mechanical and electrical loads during service poses a major challenge to achieving long-term stable functionality. Herein, this study investigates the performance and microstructural evolution of silver-based printed circuits under electromechanical coupling loads and unveils the underlying material degradation mechanisms. Resistance change curves reveal that, under identical bending loads, lower current density (208.3 A/cm(2)) accelerates circuit degradation more significantly than higher current density (1164.7 A/cm(2)). By analysing the thermal characteristics, conductive phase structure, and conductive network of printed circuits under mechanical loading, electric field stimulation, and electromechanical coupling, it is evident that heat plays a critical role in determining resistance changes in silver-based printed circuits. At lower temperatures, heat-induced oxidation of nanosilver to nonconductive silver oxide emerges as the primary driver of resistance increase. Conversely, at higher temperatures, heat-induced sintering of silver forms new conductive pathways that offset the resistance increase caused by the oxidation of silver nanoparticles. These findings not only elucidate the fatigue degradation mechanisms of silver-based printed circuits but also offer theoretical guidance for the development of high-performance silver-based printed circuits.
Reducing surface friction resistance (SFR) is beneficial for the performance of high-speed marine equipment surfaces. To reduce SFR, a biomimetic surface was developed through a collaborative multi-process strategy involving a combination of laser ablation and spraying techniques. Initially, biomimetic fish scale (BFS) arrays with five different spacing (s) values were fabricated on an aluminium (Al) substrate using laser ablation, which was then replicated with polydimethylsiloxane (PDMS). Subsequently, a mixture of superhydrophobic nanoscale SiO2 particles (SH-SiO2), PDMS and n-hexane solution was uniformly sprayed onto the BFS surface to enhance its hydrophobic properties. The morphology of these biomimetic surfaces was characterised using a scanning electron microscope (SEM) and ultra-depth field microscope. The drag reduction (DR) performance of the biomimetic surfaces was evaluated within a Reynolds (Re) number range of 4.2 x 10(4)-2.2 x 10(5) in a circulating water tunnel. The results indicated that a drag reduction rate of 11.82% was achieved with the modified BFS at s = 300 mu m and Re = 1.7 x 10(5). Additionally, the drag reduction mechanism of the modified BFS surface was analysed using the computational fluid dynamics (CFD) method. The excellent drag reduction performance was attributed to the combined effects of the 'rolling bearing' caused by streamwise vortices, high-low velocity streaks and the velocity slip effect caused by hydrophobic properties at the interface. These findings offer a novel approach for creating multi-effect coupled drag reduction surfaces.
Implants with high coefficients of friction reduce tightening torque requirements while mitigating fracture risks at bone-implant interfaces. This study engineered flexible nanowire textures on titanium surfaces to significantly increase the coefficient of friction without accelerating surface wear. Results demonstrate that these textures maintain a friction coefficient exceeding 0.8 during reciprocating sliding tests under both dry and water conditions. Our analysis reveals that this friction enhancement stems not from surface roughness but from increased tangential resistance during nanowire-textured deformation. Implementing such high-friction nanostructures on the implant surface is critical for enhancing preload and improving connection reliability.
Sensory properties of food, such as creaminess and smoothness, enhance the overall consumption experience. These properties are also linked to swallowing difficulties in elderly individuals. The direct characterisation of lubrication under soft oral conditions remains a challenge. In this study, relative optical interference intensity (ROII) technique was employed to measure the lubrication film thickness under compliant contact with improved image processing to correct the accuracy loss due to the interface's low reflectivity. Interferogram analysis revealed that oil exhibited a hydrodynamic lubrication state at a low entrainment speed. The minimum film thickness occurred near the edge of the contact zone. The whey protein isolate (WPI) reached to a soft-elastohydrodynamic state until the entrainment speed exceeded 7.5 mm/s. The variation in the Stribeck curve was influenced by the shape of the soft contacts. Both oil and WPI exhibited the state of soft-elastohydrodynamic lubrication when a compliant PDMS pin slid on a rigid steel disc, consistent with the film thickness measurements. When a rigid steel ball slid on a PDMS pad, the hydrodynamic state was delayed. These findings provide new insights into the in vitro development of oral soft friction and enhance our understanding of oral sensory perception.
Loading modes and parameters on wear testing of unicompartmental knee prostheses are important. The difference in wear assessments of unicompartmental knee prosthesis under total knee loading mode and unicompartmental loading mode was investigated via computational simulation. The ISO standard testing protocol and the measured personalised load and kinematic data were further used to reveal the influence of the testing parameters on wear assessments. Compared with the total knee loading mode, the unicompartmental loading mode produced a larger peak contact pressure of the tibial insert throughout the wear cycle. Under ISO 14243-3 and Stan's CAMS testing parameters, the predicted volumetric wear of tibial inserts of the unicompartmental loading mode increased by 28.21% and 15.18%, respectively, compared with the total loading mode. Compared with ISO 14243-3, volumetric wear increased by 42.64% for total knee loading mode and 28.14% for unicompartmental loading mode under Stan's CAMS loading conditions. Both loading mode and parameters played an important role in the wear of unicompartmental knee arthroplasty simulation. Therefore, wear testing and computational simulation of wear predictions for unicompartmental knee prostheses should be performed in a unicompartmental loading mode, and it is more reasonable to use the patient's in vivo measurement data.
The development of multifunctional surfaces for titanium implants has become a hot research area due to their potential to elicit specific responses from various cells and infection agents. Solid-binding peptides are increasingly exhibiting their distinct advantages as a novel noncovalent surface modification method for titanium implants. In this study, titanium-binding peptide (TiBP2), a titanium-binding peptide with higher affinity for acid-alkali treatment titanium (AA) substrate, was screened using the phage display technique. The excellent affinity and stable binding of TiBP2 to the AA substrate was due to the interaction of its COO- group with Ti4+ on the AA substrate. Linker-conjugated RGD-TiBP (TPR/TGR) was constructed, and its binding capacity and biofunctionality were analysed. RGD-TiBP exhibited high affinity and stable binding properties with AA substrate, as well as excellent biocompatibility (no toxic effect on L929 cells) and remarkable H2O2 scavenging ability. Notably, 40 mu g/mL of TPR effectively promoted the polarisation shift of macrophages from a pro-inflammatory phenotype (M1) to an anti-inflammatory phenotype (M2). The present results indicated that TPR-based biofunctional modification of titanium implants can improve interfacial stability and immunomodulatory activity, making it a promising technique for application.
Patients undergoing posterior cruciate ligament (PCL) reconstruction may experience changes in the mechanical environment of cartilage and meniscus; however, limited information is available regarding the contact mechanism of the tibiofemoral joint following different PCL reconstruction techniques. In this study, finite element (FE) models of the PCL-reconstructed tibiofemoral joint-including the femur, tibia, fibula, menisci, cartilage and ligaments (ACL, PCL, MCL and LCL)-were developed with contact interactions among these tissues considered. Joint angles and axial forces based on the ISO 14243-3 were used as inputs. Using these FE models, the effect of different PCL reconstruction techniques on contact pressure, stresses of the cartilages and menisci and tibiofemoral kinematics was evaluated. Compared to the intact model, PCL-reconstructed models exhibited reduced anterior translation during swing phase and reduced external rotation during stance phase. The external rotation of the TA model was greater than that of the intact model, TI model and TL model during swing phase. The medial meniscus of the PCL-reconstructed models experienced lower contact pressure and stresses compared to that in the intact model. The altered kinematics and contact mechanics of the PCL-reconstructed models demonstrate that the typical PCL reconstruction techniques should be improved or adjusted to better restore the natural biomechanical function of the joint.
ABSTRACT Periodontitis is a common and serious oral health problem. It not only damages the health of periodontal tissues but also has potential impacts on the whole body. Existing treatment methods, such as mechanical debridement and antibiotic treatment, have obvious limitations. Functional hydrogels can be used as drug carriers to deliver medications for treating periodontitis. Meanwhile, depending on different designs, hydrogels can achieve functions such as antioxidant, antibacterial, anti‐inflammatory effects and osteoinduction, making them a promising material for periodontitis treatment. In this review, we first elaborate on the preparation methods of hydrogels for periodontitis, as well as the pathological characteristics and hazards of periodontitis. Then, we introduce the applications of hydrogels in antibacterial, anti‐inflammatory, antioxidant and osteoinduction aspects related to periodontitis. Finally, we discuss the current challenges and future research directions in this field.
