Association between triglyceride-glucose index trajectories and radiofrequency ablation outcomes in patients with stage 3D atrial fibrillation.

BACKGROUND: This study investigates the relationship between triglyceride-glucose (TyG) index trajectories and the results of ablation in patients with stage 3D atrial fibrillation (AF). METHODS: A retrospective cohort study was carried out on patients who underwent AF Radiofrequency Catheter Ablation (RFCA) at the Cardiology Department of the Fourth Affiliated Hospital of Zhejiang University and Taizhou Hospital of Zhejiang Province from January 2016 to December 2022. The main clinical endpoint was determined as the occurrence of atrial arrhythmia for at least 30 s following a 3-month period after ablation. Using a latent class trajectory model, different trajectory groups were identified based on TyG levels. The relationship between TyG trajectory and the outcome of AF recurrence in patients was assessed through Kaplan-Meier survival curve analysis and multivariable Cox proportional hazards regression model. RESULTS: The study included 997 participants, with an average age of 63.21 ± 9.84 years, of whom 630 were males (63.19%). The mean follow-up period for the participants was 30.43 ± 17.75 months, during which 200 individuals experienced AF recurrence. Utilizing the minimum Bayesian Information Criterion (BIC) and the maximum Entropy principle, TyG levels post-AF RFCA were divided into three groups: Locus 1 low-low group (n = 791), Locus 2 low-high-low group (n = 14), and Locus 3 high-high group (n = 192). Significant differences in survival rates among the different trajectories were observed through the Kaplan-Meier curve (P < 0.001). Multivariate Cox regression analysis showed a significant association between baseline TyG level and AF recurrence outcomes (HR = 1.255, 95% CI: 1.087-1.448). Patients with TyG levels above 9.37 had a higher risk of adverse outcomes compared to those with levels below 8.67 (HR = 2.056, 95% CI: 1.335-3.166). Furthermore, individuals in Locus 3 had a higher incidence of outcomes compared to those in Locus 1 (HR = 1.580, 95% CI: 1.146-2). CONCLUSION: The TyG trajectories in patients with stage 3D AF are significantly linked to the outcomes of AF recurrence. Continuous monitoring of TyG levels during follow-up may help in identifying patients at high risk of AF recurrence, enabling the early application of effective interventions.

Shared genetic architecture and causal relationship between liver and heart disease.

This study investigates the relationship and genetic mechanisms of liver and heart diseases, focusing on the liver-heart axis (LHA) as a fundamental biological basis. Through genome-wide association study analysis, we explore shared genes and pathways related to LHA. Shared genetic factors are found in 8 out of 20 pairs, indicating genetic correlations. The analysis reveals 53 loci with pleiotropic effects, including 8 loci exhibiting shared causality across multiple traits. Based on SNP-p level tissue-specific multi-marker analysis of genomic annotation (MAGMA) analysis demonstrates significant enrichment of pleiotropy in liver and heart diseases within different cardiovascular tissues and female reproductive appendages. Gene-specific MAGMA analysis identifies 343 pleiotropic genes associated with various traits; these genes show tissue-specific enrichment primarily in the liver, cardiovascular system, and other tissues. Shared risk loci between immune cells and both liver and cardiovascular diseases are also discovered. Mendelian randomization analyses provide support for causal relationships among the investigated trait pairs.

Association of red blood cell distribution width and hemoglobin-to-RDW ratio with contrast-associated acute kidney injury in patients undergoing coronary angiography: A retrospective study.

BACKGROUND: Inflammation contributes to poor prognosis in cardiovascular diseases. A novel biomarker for systemic inflammation that has garnered attention is the red blood cell distribution width (RDW). This study is designed to explore potential associations between RDW and hemoglobin-to-RDW ratio (HRR) with contrast-associated acute kidney injury (CA-AKI). METHODS: This study retrospectively analyzed 4054 patients undergoing coronary angiography (CAG). Linear regression models were employed to assess the relationships between RDW or HRR and the elevation of serum creatinine (Scr). The associations between RDW or HRR and CA-AKI were explored using restricted cubic spline and log-binomial regression analyses taking into account specific cutoff values and quintiles. Exploratory analyses were also conducted to further investigate these associations. RESULTS: Among enrolled patients, the average age was 66.9 years and 34.3% were female. Notably, patients who developed CA-AKI tended to have higher RDW and lower HRR. Multivariable linear regression models demonstrated that RDW exhibited a positive association with Scr elevation (ß = 2.496, 95% confidence interval [CI] = 1.784-3.208), while HRR displayed a negative association (ß = -3.559, 95% CI = -4.243 to -2.875). Multivariable log-binomial regression models confirmed that both high RDW (RDW ≥ 13.8%) and low HRR (HRR < 8.9) were significantly associated with a higher risk of CA-AKI (RDW [≥13.8% vs. <13.8%]: relative risk [RR] = 1.540, 95% CI = 1.345-1.762; HRR [<8.9 vs. ≥8.9]: RR = 1.822, 95% CI = 1.584-2.096). Exploratory analysis determined that such associations still existed regardless of age, gender, estimated glomerular filtration rate, or anemia. CONCLUSIONS: Elevated preoperative RDW and decreased HRR were significantly associated with CA-AKI in patients undergoing CAG.

Cardiac remodeling on echocardiogram is related to contrast-associated acute kidney injury after coronary angiography: a cross-section study.

Background: Cardiac dysfunction is a well-established risk factor for contrast-associated acute kidney injury (CA-AKI). Nevertheless, the relationship between cardiac remodeling, as assessed by echocardiography, and CA-AKI remains uncertain. Method: A total of 3,241 patients undergoing coronary angiography (CAG) with/without percutaneous coronary intervention (PCI) were enrolled in this retrospective study. Collected echocardiographic parameters were normalized by body surface area (BSA) and divided according to quartile, including the left ventricular internal end-diastolic diameter index (LVIDDI), left ventricular internal end-systolic diameter index (LVIDSI), and left ventricular mass index (LVMI). Logistic regression analysis was conducted to ascertain the association between structural parameter changes and CA-AKI. Further investigation was performed in different subgroups. Results: The mean age of the participants was 66.6 years, and 16.3% suffered from CA-AKI. LVIDSI [≥22.9 mm/m2: OR = 1.953, 95%CI (1.459 to 2.615), P < 0.001], LVIDDI [≥33.2 mm/m2: OR = 1.443, 95%CI (1.087 to 1.914), P = 0.011], and LVMI [≥141.0 g/m2: OR = 1.530, 95%CI (1.146 to 2.044), P = 0.004] in quartile were positively associated with CA-AKI risk in general (all P for trend <0.05). These associations were consistent when stratified by age, left ventricular ejection fraction, estimated glomerular filtration rate, and N-terminal brain natriuretic peptide (all P for interaction >0.05). The presence of eccentric hypertrophy [OR = 1.400, 95%CI (1.093 to 1.793), P = 0.008] and the coexistence of hypertrophy and dilation [OR = 1.397, 95%CI (1.091 to 1.789), P = 0.008] carried a higher CA-AKI risk. Conclusion: The presence of cardiac remodeling, assessed by echocardiography, is associated with a higher risk of CA-AKI.

A nanometallic conductive composite-hydrogel core-shell microneedle skin patch for real-time monitoring of interstitial glucose levels.

A microneedle-based skin patch system allows the minimally invasive extraction of skin interstitial fluid, which offers hope for the realization of quantitative and non-invasive diagnosis/monitoring of biological/physiological signals (biomarkers) in the human body. This work describes a nanometallic conductive composite-hydrogel core-shell microneedle skin patch that can realize minimally invasive real-time monitoring of physiological signals. The microneedle sensing system contains an inner conductive silver paste core and an outer bioactive hydrogel layer. The inner core is coated with biomarker-specific enzymes while the outer hydrogel layer extracts the biomarkers from the skin interstitial fluid. This patch can be integrated with the commercial signal processing and transmission modules and enable real-time monitoring. Taking glucose as a model biomarker, we confirm the function and potential application of this core-shell microneedle patch for transdermal diagnosis. It is proven that the core-shell microneedle patch can quickly extract skin interstitial fluid within 30 seconds and has a fast and linear response to glucose concentrations from 0 to 21 mM with a correlation coefficient of 0.9970, which may pave the way for the future development of smart wearable devices with minimally invasive transdermal biosensors.

A skin patch integrating swellable microneedles and electrochemical test strips for glucose and alcohol measurement in skin interstitial fluid.

Microneedle (MN)-based diagnostic devices can efficiently access skin interstitial fluid (ISF) for accurate and minimally invasive detection of health-related biomarkers. This work reports a biomarker (i.e., glucose or alcohol) monitoring MN device that is composed of swellable MNs and electrochemical test strip. This device is constructed by adhering MN patch on the electrochemical strips using the chitosan as the connecting layer. The MNs penetrate the skin for extraction of ISF that flows to the backing layer of MNs and is analyzed by the test strip. In the in vitro skin models, this device accurately detects the glucose from 0 mM to 12 mM and alcohol from 0 mM to 20 mM. In vivo experiment shows this MN device is capable of minimally invasive sampling of ISF and analysis of glucose levels to determine the glycemic status of mice.

Liver enzymes mediate the association between aldehydes co-exposure and hypertriglyceridemia.

Aldehydes are recognized environmental toxicants that may affect lipid metabolism. For instance, acrolein has been found to increase serum triglyceride (TG) levels exclusively. However, it remains unclear whether other aldehydes are also associated with hypertriglyceridemia (HTG), and what mechanisms may be involved. This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey (NHANES, 2013-2014) to identify associations between serum aldehydes, liver enzymes, and HTG. Serum aldehydes included crotonaldehyde (CRAL), propanaldehyde (3AL), butyraldehyde (4AL), pentanaldehyde (5AL), isopentanaldehyde (I5AL), and heptanaldehyde (7AL). Liver enzymes included alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT). HTG was defined as fasting TG levels ≥ 1.7 mmol/L. Aldehyde co-exposure was quantified using weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR), while mediation analysis was performed to investigate the role of liver enzymes. Among 1474 participants (mean age 38.6 years, male 50.0%), 426 were diagnosed with HTG. 4AL, 5AL, I5AL, and 7AL were shown to be positively associated with HTG (all P values <0.05). Aldehydes co-exposure was also positively associated with HTG (OR 1.706, 95%CI 1.299-2.240), with 5AL contributing the highest weight (35.3%). Furthermore, aldehydes co-exposure showed positive associations with ALT, AST, and GGT (all P values <0.05), and all four liver enzymes were positively associated with HTG (all P values <0.05). Mediation analysis revealed that liver enzymes (ALT, AST, and GGT) may mediate the associations of 5AL and 7AL with HTG (all P values <0.05). This study identified a positive association between aldehyde co-exposure and HTG, which may be partially mediated by liver enzymes.

Luteolin intake is negatively associated with all-cause and cardiac mortality among patients with type 2 diabetes mellitus.

BACKGROUND: Luteolin, a common flavonoid in our daily diet, has potent anti-diabetic effects. However, its prognostic impact on type 2 diabetes mellitus (T2DM) is still uncertain. This study aimed to clarify this association. METHODS: In this prospective cohort study, 2,461 patients with T2DM were included from the National Health and Nutrition Examination Survey. Dietary luteolin intake was estimated by the type and amount of food consumed in a 24-hour dietary recall. All-cause and cardiac mortality were ascertained by National Death Index Mortality data (as of December 31, 2019). The association of luteolin intake with mortality risk was estimated by Cox proportional hazards model. RESULTS: The median (interquartile range) luteolin intake was 0.355 (0.130, 0.835) mg/day. During the follow-up (median, 8.4 years), 561 all-cause deaths (including 136 cardiac deaths) were documented. Per-unit increment of luteolin intake (natural logarithm transformed) was found to reduce all-cause mortality by 7.0% (P = 0.024) and cardiac mortality by 22.6% (P = 0.001) in patients with T2DM. An inverse dose-response association was identified between luteolin intake (range: 0.005-9.870 mg/day) and mortality risk. The consistent result was also shown when stratified by age, gender, race, body mass index, HbA1c level, and T2DM duration. Moreover, luteolin intake increment was also shown to be associated with a lower C-reactive protein level at baseline (ß =-0.332; 95% CI =-0.541, -0.122). CONCLUSION: The current study confirmed that the dietary luteolin intake increment reduced all-cause mortality (especially cardiac mortality) in patients with T2DM, which may be attributed to the anti-inflammatory property of luteolin.

Lightweight individual cow identification based on Ghost combined with attention mechanism.

Individual cow identification is a prerequisite for intelligent dairy farming management, and is important for achieving accurate and informative dairy farming. Computer vision-based approaches are widely considered because of their non-contact and practical advantages. In this study, a method based on the combination of Ghost and attention mechanism is proposed to improve ReNet50 to achieve non-contact individual recognition of cows. In the model, coarse-grained features of cows are extracted using a large sensory field of cavity convolution, while reducing the number of model parameters to some extent. ResNet50 consists of two Bottlenecks with different structures, and a plug-and-play Ghost module is inserted between the two Bottlenecks to reduce the number of parameters and computation of the model using common linear operations without reducing the feature map. In addition, the convolutional block attention module (CBAM) is introduced after each stage of the model to help the model to give different weights to each part of the input and extract the more critical and important information. In our experiments, a total of 13 cows' side view images were collected to train the model, and the final recognition accuracy of the model was 98.58%, which was 4.8 percentage points better than the recognition accuracy of the original ResNet50, the number of model parameters was reduced by 24.85 times, and the model size was only 3.61 MB. In addition, to verify the validity of the model, it is compared with other networks and the results show that our model has good robustness. This research overcomes the shortcomings of traditional recognition methods that require human extraction of features, and provides theoretical references for further animal recognition.

Transdermal delivery of dextran using conductive microneedles assisted by iontophoresis.

The combination of microneedles (MNs) and iontophoresis (ITP) can enhance the drug penetration in the skin. We previously demonstrated the enhanced delivery of small molecule lidocaine in dentistry by the conductive MNs assisted by ITP. However, the delivery of macromolecules is yet to be explored for this strategy. This study fabricates conductive MNs with polyaniline and hyaluronic acid, which is combined with ITP to deliver dextran macromolecules. This combination improves the penetration of dextran molecules (3-5 kDa, 150 kDa, and 500 kDa) to a depth of around 1536 µm in the agarose gel model. Compared to non-conductive MNs assisted by ITP or conductive MNs alone, conductive MNs assisted by ITP also improves dextran's penetration through the skin, fat, muscle, and cartilage.

Implantable Electronic Medicine Enabled by Bioresorbable Microneedles for Wireless Electrotherapy and Drug Delivery.

A combined treatment using medication and electrostimulation increases its effectiveness in comparison with one treatment alone. However, the organic integration of two strategies in one miniaturized system for practical usage has seldom been reported. This article reports an implantable electronic medicine based on bioresorbable microneedle devices that is activated wirelessly for electrostimulation and sustainable delivery of anti-inflammatory drugs. The electronic medicine is composed of a radio frequency wireless power transmission system and a drug-loaded microneedle structure, all fabricated with bioresorbable materials. In a rat skeletal muscle injury model, periodic electrostimulation regulates cell behaviors and tissue regeneration while the anti-inflammatory drugs prevent inflammation, which ultimately enhance the skeletal muscle regeneration. Finally, the electronic medicine is fully bioresorbable, excluding the second surgery for device removal.

Lightweight-Convolutional Neural Network for Apple Leaf Disease Identification.

As a widely consumed fruit worldwide, it is extremely important to prevent and control disease in apple trees. In this research, we designed convolutional neural networks (CNNs) for five diseases that affect apple tree leaves based on the AlexNet model. First, the coarse-grained features of the disease are extracted in the model using dilated convolution, which helps to maintain a large receptive field while reducing the number of parameters. The parallel convolution module is added to extract leaf disease features at multiple scales. Subsequently, the series 3 × 3 convolutions shortcut connection allows the model to deal with additional nonlinearities. Further, the attention mechanism is added to all aggregated output modules to better fit channel features and reduce the impact of a complex background on the model performance. Finally, the two fully connected layers are replaced by global pooling to reduce the number of model parameters, to ensure that the features are not lost. The final recognition accuracy of the model is 97.36%, and the size of the model is 5.87 MB. In comparison with five other models, our model design is reasonable and has good robustness; further, the results show that the proposed model is lightweight and can identify apple leaf diseases with high accuracy.

Micropatterned conductive elastomer patch based on poly (glycerol sebacate)-graphene for cardiac tissue repair.

Preparing a micropatterned elastomer film with characteristics that can simulate the mechanical properties, anisotropy, and electroactivity of natural myocardial tissues is crucial in cardiac tissue engineering after myocardial infarction (MI). Therefore, in this study, we developed several elastomeric films with a surface micropattern based on poly (glycerol sebacate) (PGS) and graphene (Gr). These films have sufficient mechanical strength (0.6 ± 0.1-3.2 ± 0.08 MPa) to withstand heartbeats, and the micropatterned structure also satisfies the natural myocardium anisotropy in the transverse and vertical. Moreover, Gr makes these films conductive (up to 5.80 × 10-7S m-1), which is necessary for the conduction of electrical signals between cardiomyocytes and the cardiac tissue. Furthermore, they have good cytocompatibility and can promote cell proliferation in H9c2 rat cardiomyocyte cell lines.In vivotest results indicate that these films have good biocompatibility. Notably, a film with 1 wt% Gr content (PGS-Gr1) significantly affects the recovery of myocardial function in rats after MI. This film effectively decreased the infarct size and degree of myocardial fibrosis and reduced collagen deposition. Echocardiographic evaluation showed that after treatment with this film, the left ventricular internal dimension (LVID) in systole and LVID in diastole of rats exhibited a significant downward trend, whereas the fractional shortening and ejection fraction were significantly increased compared with the control group. These data indicate that this electroactive micropatterned anisotropic elastomer film can be applied in cardiac tissue engineering.

Prognostic nomogram incorporating radiological features for predicting overall survival in patients with AIDS-related non-Hodgkin lymphoma.

BACKGROUND: Acquired immune deficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) is a high-risk factor for morbidity and mortality in patients with AIDS. This study aimed to determine the prognostic factors associated with overall survival (OS) and to develop a prognostic nomogram incorporating computed tomography imaging features in patients with acquired immune deficiency syndrome-related non-Hodgkin lymphoma (AR-NHL). METHODS: A total of 121 AR-NHL patients between July 2012 and November 2019 were retrospectively reviewed. Clinical and radiological independent predictors of OS were confirmed using multivariable Cox analysis. A prognostic nomogram was constructed based on the above clinical and radiological factors and then provided optimum accuracy in predicting OS. The predictive accuracy of the nomogram was determined by Harrell C-statistic. Kaplan-Meier survival analysis was used to determine median OS. The prognostic value of adjuvant therapy was evaluated in different subgroups. RESULTS: In the multivariate Cox regression analysis, involvement of mediastinal or hilar lymph nodes, liver, necrosis in the lesions, the treatment with chemotherapy, and the CD4 ≤100 cells/µL were independent risk factors for poor OS (all P < 0.050). The predictive nomogram based on Cox regression has good discrimination (Harrell C-index = 0.716) and good calibration (Hosmer-Lemeshow test, P = 0.620) in high- and low-risk groups. Only patients in the high-risk group who received adjuvant chemotherapy had a significantly better survival outcome. CONCLUSION: A survival-predicting nomogram was developed in this study, which was effective in assessing the survival outcomes of patients with AR-NHL. Notably, decision-making of chemotherapy regimens and more frequent follow-up should be considered in the high-risk group determined by this model.

DenseNet weed recognition model combining local variance preprocessing and attention mechanism.

Introduction: The purpose of this paper is to effectively and accurately identify weed species in crop fields in complex environments. There are many kinds of weeds in the detection area, which are densely distributed. Methods: The paper proposes the use of local variance pre-processing method for background segmentation and data enhancement, which effectively removes the complex background and redundant information from the data, and prevents the experiment from overfitting, which can improve the accuracy rate significantly. Then, based on the optimization improvement of DenseNet network, Efficient Channel Attention (ECA) mechanism is introduced after the convolutional layer to increase the weight of important features, strengthen the weed features and suppress the background features. Results: Using the processed images to train the model, the accuracy rate reaches 97.98%, which is a great improvement, and the comprehensive performance is higher than that of DenseNet, VGGNet-16, VGGNet-19, ResNet-50, DANet, DNANet, and U-Net models. Discussion: The experimental data show that the model and method we designed are well suited to solve the problem of accurate identification of crop and weed species in complex environments, laying a solid technical foundation for the development of intelligent weeding robots.

Enhanced Drug Permeation into Human Keloid Tissues by Sonophoresis-Assisted Microneedling.

Keloids are disfiguring pathological scars that could cause pain and pruritus. The conventional treatments, such as bolus injection of drugs or surgery, are invasive and require a personal visit to clinic. Microneedle (MN) technology has great potential to offer a self-administered and minimally invasive treatment of keloids. However, drugs delivered using MNs suffer from limited penetration in keloid tissue. This study demonstrates enhanced drug penetration in human keloid scar tissue by combining MN and sonophoresis.

Imaging and clinical features of patients with 2019 novel coronavirus SARS-CoV-2.

BACKGROUND: The pneumonia caused by the 2019 novel coronavirus (SARS-CoV-2, also called 2019-nCoV) recently break out in Wuhan, China, and was named as COVID-19. With the spread of the disease, similar cases have also been confirmed in other regions of China. We aimed to report the imaging and clinical characteristics of these patients infected with SARS-CoV-2 in Guangzhou, China. METHODS: All patients with laboratory-identified SARS-CoV-2 infection by real-time polymerase chain reaction (PCR) were collected between January 23, 2020, and February 4, 2020, in a designated hospital (Guangzhou Eighth People's Hospital). This analysis included 90 patients (39 men and 51 women; median age, 50 years (age range, 18-86 years). All the included SARS-CoV-2-infected patients underwent non-contrast enhanced chest computed tomography (CT). We analyzed the clinical characteristics of the patients, as well as the distribution characteristics, pattern, morphology, and accompanying manifestations of lung lesions. In addition, after 1-6 days (mean 3.5 days), follow-up chest CT images were evaluated to assess radiological evolution. FINDINGS: The majority of infected patients had a history of exposure in Wuhan or to infected patients and mostly presented with fever and cough. More than half of the patients presented bilateral, multifocal lung lesions, with peripheral distribution, and 53 (59%) patients had more than two lobes involved. Of all included patients, COVID-19 pneumonia presented with ground glass opacities in 65 (72%), consolidation in 12 (13%), crazy paving pattern in 11 (12%), interlobular thickening in 33 (37%), adjacent pleura thickening in 50 (56%), and linear opacities combined in 55 (61%). Pleural effusion, pericardial effusion, and lymphadenopathy were uncommon findings. In addition, baseline chest CT did not show any abnormalities in 21 patients (23%), but 3 patients presented bilateral ground glass opacities on the second CT after 3-4 days. CONCLUSION: SARS-CoV-2 infection can be confirmed based on the patient's history, clinical manifestations, imaging characteristics, and laboratory tests. Chest CT examination plays an important role in the initial diagnosis of the novel coronavirus pneumonia. Multiple patchy ground glass opacities in bilateral multiple lobular with periphery distribution are typical chest CT imaging features of the COVID-19 pneumonia.

Mussel-inspired, antibacterial, conductive, antioxidant, injectable composite hydrogel wound dressing to promote the regeneration of infected skin.

Infection is a major obstacle to wound healing. To enhance the healing of infected wounds, dressings with antibacterial activities and multifunctional properties to promote wound healing are highly desirable. Herein, gelatin-grafted-dopamine (GT-DA) and polydopamine-coated carbon nanotubes (CNT-PDA) were used to engineer antibacterial, adhesive, antioxidant and conductive GT-DA/chitosan/CNT composite hydrogels through the oxidative coupling of catechol groups using a H2O2/HRP (horseradish peroxidase) catalytic system. The addition of the antibiotic doxycycline endowed the hydrogels with antimicrobial activity to treat infected full-thickness defect wounds. Additionally, CNT-PDA endowed these hydrogels with an excellent photothermal effect, leading to good in vitro and in vivo antibacterial activities against Gram-positive and Gram-negative bacteria. The catechol group and polydopamine imparted tissue adhesiveness, and the hemostatic and antioxidant abilities of these hydrogels were also investigated. The porosity, degradability, swelling, rheological, mechanical, and conductive behaviors of these hydrogels were finely regulated by changing the concentration of CNT-PDA. Hemolysis and cytocompatibility tests using L929 fibroblast cells confirmed the good biocompatibility of these hydrogels. The wound closure, collagen deposition, histomorphological examination and immunofluorescence staining results demonstrated the excellent effects of these hydrogels in an infected full-thickness mouse skin defect wound. In summary, the adhesive antibacterial and conductive GT-DA/chitosan/CNT hydrogels showed great potential as multifunctional bioactive dressings for the treatment of infected wounds.

Aligned conductive core-shell biomimetic scaffolds based on nanofiber yarns/hydrogel for enhanced 3D neurite outgrowth alignment and elongation.

Aligned topographical cue has been demonstrated as a critical role in neuronal guidance, and it is highly beneficial to develop a scaffold with aligned structure for peripheral nerve tissue regeneration. Although considerable efforts have been devoted to guiding neurite alignment and extension, it remains a remarkable challenge for developing a biomimetic scaffold for enhancing 3D aligned neuronal outgrowth. Herein, we present a core-shell scaffold based on aligned conductive nanofiber yarns (NFYs) within the hydrogel to mimic the 3D hierarchically aligned structure of the native nerve tissue. The aligned NFYs assembled by a bundle of aligned nanofibers composed of polycaprolactone (PCL), silk fibroin (SF), and carbon nanotubes (CNTs) are prepared by a developed dry-wet electrospinning method, which has the ability to induce neurite alignment and elongation when PC12 cells and dorsal root ganglia (DRG) cells are cultured on their 3D peripheral surface. Particularly, such an aligned nanofibrous structure also induces aligned neurite extension and cell migration from DRG explants along the direction of nanofibers. 3D core-shell scaffolds are fabricated by encapsulating NFYs within the hydrogel shell after photocrosslinking, and these 3D aligned scaffolds are able to control cellular alignment and elongation of nerve cells in this 3D environment. Our results suggest that such 3D hierarchically aligned core-shell scaffold consists of NFYs that mimic the aligned nerve fiber structure to induce neurite alignment and extension and a hydrogel shell that mimics the epineurium layer to protect nerve cell organization within a 3D environment, which is largely promising for the design of biomimetic scaffolds in nerve tissue engineering. STATEMENT OF SIGNIFICANCE: Designing scaffolds with 3D aligned structure has been paid more attention for peripheral nerve tissue regeneration, because the aligned topographical cue is able to induce neurites alignment and extension. However, developing scaffolds mimicking the hierarchically aligned structure of native nerve tissue for directing 3D aligned neuronal outgrowth without external stimulation remains challenging. This work presented a simple and efficient strategy to prepare a 3D biomimetic core-shell scaffold based on electrospun aligned conductive nanofiber yarns within photocurable hydrogel shell to mimic the hierarchically aligned structure of native nerve tissue. These 3D aligned composite scaffolds performed the ability to direct 3D cellular alignment and elongation of nerve cells along with the nanofiber yarn direction, and the hydrogel shell mimicking the epineurium layer was able to protect nerve cells organization within the 3D environment, which indicated their great potential in peripheral nerve tissue engineering applications.

Adhesive Hemostatic Conducting Injectable Composite Hydrogels with Sustained Drug Release and Photothermal Antibacterial Activity to Promote Full-Thickness Skin Regeneration During Wound Healing.

Developing injectable nanocomposite conductive hydrogel dressings with multifunctions including adhesiveness, antibacterial, and radical scavenging ability and good mechanical property to enhance full-thickness skin wound regeneration is highly desirable in clinical application. Herein, a series of adhesive hemostatic antioxidant conductive photothermal antibacterial hydrogels based on hyaluronic acid-graft-dopamine and reduced graphene oxide (rGO) using a H2 O2 /HPR (horseradish peroxidase) system are prepared for wound dressing. These hydrogels exhibit high swelling, degradability, tunable rheological property, and similar or superior mechanical properties to human skin. The polydopamine endowed antioxidant activity, tissue adhesiveness and hemostatic ability, self-healing ability, conductivity, and NIR irradiation enhanced in vivo antibacterial behavior of the hydrogels are investigated. Moreover, drug release and zone of inhibition tests confirm sustained drug release capacity of the hydrogels. Furthermore, the hydrogel dressings significantly enhance vascularization by upregulating growth factor expression of CD31 and improve the granulation tissue thickness and collagen deposition, all of which promote wound closure and contribute to a better therapeutic effect than the commercial Tegaderm films group in a mouse full-thickness wounds model. In summary, these adhesive hemostatic antioxidative conductive hydrogels with sustained drug release property to promote complete skin regeneration are an excellent wound dressing for full-thickness skin repair.