Chronological-Programmed Black Phosphorus Hydrogel for Responsive Modulation of the Pathological Microenvironment in Myocardial Infarction.

Electroactive hydrogels have garnered extensive interest as a promising approach to myocardial tissue engineering. However, the challenges of spatiotemporal-specific modulation of individual pathological processes and achieving nontoxic bioresorption still remain. Herein, inspired by the entire postinfarct pathological processes, an injectable conductive bioresorbable black phosphorus nanosheets (BPNSs)-loaded hydrogel (BHGD) was developed via reactive oxide species (ROS)-sensitive disulfide-bridge and photomediated cross-linking reaction. Significantly, the chronologically programmed BHGD hydrogel can achieve graded modulation during the inflammatory, proliferative, and maturation phases of myocardial infarction (MI). More details, during early infarction, the BHGD hydrogel can effectively reduce ROS levels in the MI area, inhibit cellular oxidative stress damage, and promote macrophage M2 polarization, creating a favorable environment for damaged myocardium repair. Meanwhile, the ROS-responsive structure can protect BPNSs from degradation and maintain good conductivity under MI microenvironments. Therefore, the BHGD hydrogel possesses tissue-matched modulus and conductivity in the MI area, facilitating cardiomyocyte maturation and electrical signal exchange, compensating for impaired electrical signaling, and promoting vascularization in infarcted areas in the maturation phase. More importantly, all components of the hydrogel degrade into nontoxic substances without adverse effects on vital organs. Overall, the presented BPNS-loaded hydrogel offers an expandable and safe option for clinical treatment of MI.

Large-Scale Fabrication of Freestanding Polymer Ultrathin Porous Membranes for Transparent Transwell Coculture Systems.

Advancements in cell coculture systems with porous membranes have facilitated the simulation of human-like in vitro microenvironments for diverse biomedical applications. However, conventional Transwell membranes face limitations in low porosity (ca. 6%) and optical opacity due to their large thickness (ca. 10 µm). In this study, we demonstrated a one-step, large-scale fabrication of freestanding polymer ultrathin porous (PUP) membranes with thicknesses of hundreds of nanometers. PUP membranes were produced by using a gap-controlled bar-coating process combined with polymer blend phase separation. They are 20 times thinner than Transwell membranes, possessing 3-fold higher porosity and exhibiting high transparency. These membranes demonstrate outstanding molecular permeability and significantly reduce the cell-cell distance, thereby facilitating efficient signal exchange pathways between cells. This research enables the establishment of a cutting-edge in vitro cell coculture system, enhancing optical transparency, and streamlining the large-scale manufacturing of porous membranes.

First-Principles Studies on Transition Metal Doped Mo2B2 as Anode Material for Li-Ion Batteries.

New two-dimensional (2D) transition-metal borides have attracted considerable interest in research on electrode materials for Li-ion batteries (LIBs) owing to their promising properties. In this study, 2D molybdenum boride (Mo2 B2 ) with and without transition metal (TM, TM=Mn, Fe, Co, Ni, Ru, and Pt) atom doping was investigated. Our results indicated that all TM-doped Mo2 B2 samples exhibited excellent electronic conductivity, similar to the intrinsic 2D Mo2 B2 metal behavior, which is highly beneficial for application in LIBs. Moreover, we found that the diffusion energy barriers of Li along paths 1 and 2 for all TM-doped Mo2 B2 samples are smaller than 0.30 and 0.24 eV of the pristine Mo2 B2 . In particular, for 2D Co-doped Mo2 B2 , the diffusion energy barriers of Li along paths 1 and 2 are reduced to 0.14 and 0.11 eV, respectively, making them the lowest Li diffusion barriers in both paths 1 and 2. This indicates that TM doping can improve the electrochemical performance of 2D Mo2 B2 and that Co-doped Mo2 B2 is a promising electrode material for LIBs. Our work not only identifies electrode materials with promising electrochemical performance but also provides guidance for the design of high-performance electrode materials for LIBs.

Injectable Asymmetric Adhesive-Antifouling Bifunctional Hydrogel for Peritoneal Adhesion Prevention.

Peritoneal adhesion is a common problem after abdominal surgery and can lead to various medical problems. In response to the lack of in situ retention and pro-wound healing properties of existing anti-adhesion barriers, this work reports an injectable adhesive-antifouling bifunctional hydrogel (AAB-hydrogel). This AAB-hydrogel can be constructed by "two-step" injection. The tissue adhesive hydrogel based on gallic acid-modified chitosan and aldehyde-modified dextran is prepared as the bottom hydrogel (B-hydrogel) by Schiff base reaction. The aldehyde-modified zwitterionic dextran/carboxymethyl chitosan-based hydrogel is formed on the B-hydrogel surface as the antifouling top hydrogel (T-hydrogel). The AAB-hydrogel exhibits good bilayer binding and asymmetric properties, including tissue adhesive, antifouling, and antimicrobial properties. To evaluate the anti-adhesion effect in vivo, the prepared hydrogels are injected onto the wound surface of a mouse abdominal wall abrasion-cecum defect model. Results suggest that the AAB-hydrogel has antioxidant capacity and can reduce the postoperative inflammatory response by modulating the macrophage phenotype. Moreover, the AAB-hydrogel could effectively inhibit the formation of postoperative adhesions by reducing protein deposition, and resisting fibroblast adhesions and bacteria attacking. Therefore, AAB-hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions.

An Important Role in Novel Immune Mechanism and Diagnostic Model of Ankylosing Spondylitis: The CeRNA-ADRB2 Network.

Objective: The mechanism of ankylosing spondylitis (AS) remains unclear, and clinical diagnosis still pose challenges. This study aims to explore potential regulatory mechanisms underlying AS and develop a novel diagnostic model. Methods: Interspinous ligament (ISL) tissues were collected from control samples and ankylosing spondylitis with kyphotic deformity (AS-KD) samples during surgery, followed by high-throughput sequencing. By integrating gene expression profiles from publicly available AS peripheral blood (PB) samples, differentially expressed immune genes (DEIRGs) were identified. Through gene set enrichment analysis(GSEA), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, the regulatory mechanisms of the immune gene family in AS were explored. A diagnostic model for AS were constructed and validated it externally. Additionally, a competing endogenous RNA(ceRNA)-protein regulatory network was built for key immune genes. Results: Adrenergic receptor beta 2 (ADRB2) was downregulated in both ISL and PB samples. It was enriched in common pathways, including natural killer cell-mediated cytotoxicity, B cell receptor signaling pathway, Th1 and Th2 cell differentiation. Using the LASSO algorithm, 12 DEIRGs were identified, including the downregulated ADRB2. Based on the DEIRGs family, a novel diagnostic model was constructed with an AUC of 0.87 for the validation set and 0.7 for the test set. The AUC for ADRB2 alone was 0.75. Subgrouping AS based on these immune genes revealed a close association with neutrophils. GSEA and KEGG analysis of ISL, PB, and subgrouping of AS showed that ADRB2 may be involved in regulating the T cell receptor signaling pathway. Immune infiltration analysis indicated a decrease in CD8+ T cell infiltration, which was positively correlated with ADRB2. ADRB2 in AS-KD was regulated by multiple ceRNA-protein (lncRNA-[hsa-miR-513a-5p]-mRNA-protein). Conclusion: The immune gene family, especially ADRB2, participates in the mechanism and contributes to the diagnosis of AS.

Injectable spontaneously formed asymmetric adhesive hydrogel with controllable removal for wound healing.

Healing large-scale wounds has been a long-standing challenge in the field of biomedicine. Herein, we propose an injectable oxidated sodium alginate/gelatin/3,3'-dithiobis(propionic hydrazide)-aurum (Alg-CHO/gelatin/DTPH-Au) hydrogel filler with asymmetric adhesion ability and removability, which is formed by the Schiff-base reaction between aldehyde-based sodium alginate and multi-amino crosslinkers (gelatin and DTPH), combined with the coordination interaction between Au nanoparticles and disulfide bond of DTPH. Consequently, the prepared Alg-CHO/gelatin/DTPH-Au hydrogel exhibits high mechanical properties and injectable behaviors owing to its multiple-crosslinked interactions. Moreover, because various types of interaction bonding form on the contact side with the tissue, denser crosslinking of the upper layer relative to the lower layer occurs. Combined with the temperature difference between the upper and lower surfaces, this results in asymmetric adhesive properties. Owing to the photothermal effect, the reversible coordination interaction between Au nanoparticles and DTPH and the change in the triple helix structure of gelatin to a coil structure impart the filler-phased removability and antibacterial ability. The choice of all natural polymers also allows for favorable degradability of the wound filler and outstanding biocompatibility. Based on these features, this versatile wound filler can achieve a wide range of applications in the field of all-skin wound repair.

Chronological adhesive cardiac patch for synchronous mechanophysiological monitoring and electrocoupling therapy.

With advances in tissue engineering and bioelectronics, flexible electronic hydrogels that allow conformal tissue integration, online precision diagnosis, and simultaneous tissue regeneration are expected to be the next-generation platform for the treatment of myocardial infarction. Here, we report a functionalized polyaniline-based chronological adhesive hydrogel patch (CAHP) that achieves spatiotemporally selective and conformal embedded integration with a moist and dynamic epicardium surface. Significantly, CAHP has high adhesion toughness, rapid self-healing ability, and enhanced electrochemical performance, facilitating sensitive sensing of cardiac mechanophysiology-mediated microdeformations and simultaneous improvement of myocardial fibrosis-induced electrophysiology. As a result, the flexible CAHP platform monitors diastolic-systolic amplitude and rhythm in the infarcted myocardium online while effectively inhibiting ventricular remodeling, promoting vascular regeneration, and improving electrophysiological function through electrocoupling therapy. Therefore, this diagnostic and therapeutic integration provides a promising monitorable treatment protocol for cardiac disease.

A Zwitterionic Hydrogel with Anti-Oxidative and Anti-Inflammatory Properties for the Prevention of Peritoneal Adhesion by Inhibiting Mesothelial-Mesenchymal Transition.

Postoperative peritoneal adhesion is a serious clinical complication. Various hydrogel barriers have been developed to prevent peritoneal adhesion. However, it remains a challenge to design a hydrogel with desirable physicochemical properties and bioactivities. In this study, a zwitterionic polysaccharide-based multifunctional hydrogel is developed using epigallocatechin-3-gallate (EGCG) to prevent postoperative abdominal adhesion. This hydrogel is simple to use and has desirable properties, such as excellent injectability, self-healing, and non-swelling properties. The hydrogel also has ultralow fouling capabilities, such as superior bactericidal performance, cell and protein adhesion, and low immunogenicity resistance. Moreover, the hydrogel exhibits good antioxidant activity, which is attributed to the integration of EGCG. Furthermore, the detailed mechanism from in vivo and in vitro experimental studies illustrates that hydrogel compositions can synergistically prevent adhesion formation through multiple pathways, including anti-inflammatory and antioxidant capabilities and inhibition effects on the mesothelial-mesenchymal transition (MMT) process induced by transforming growth factor (TGF-ß). In summary, this zwitterionic multifunctional hydrogel has great potential to prevent postoperative adhesion formation in the clinical setting.

Development and validation of a machine learning-based nomogram for predicting HLA-B27 expression.

BACKGROUND: HLA-B27 positivity is normal in patients undergoing rheumatic diseases. The diagnosis of many diseases requires an HLA-B27 examination. METHODS: This study screened totally 1503 patients who underwent HLA-B27 examination, liver/kidney function tests, and complete blood routine examination in First Affiliated Hospital of Guangxi Medical University. The training cohort included 509 cases with HLA-B27 positivity whereas 611 with HLA-B27 negativity. In addition, validation cohort included 147 cases with HLA-B27 positivity whereas 236 with HLA-B27 negativity. In this study, 3 ML approaches, namely, LASSO, support vector machine (SVM) recursive feature elimination and random forest, were adopted for screening feature variables. Subsequently, to acquire the prediction model, the intersection was selected. Finally, differences among 148 cases with HLA-B27 positivity and negativity suffering from ankylosing spondylitis (AS) were investigated. RESULTS: Six factors, namely red blood cell count, human major compatibility complex, mean platelet volume, albumin/globulin ratio (ALB/GLB), prealbumin, and bicarbonate radical, were chosen with the aim of constructing the diagnostic nomogram using ML methods. For training queue, nomogram curve exhibited the value of area under the curve (AUC) of 0.8254496, and C-value of the model was 0.825. Moreover, nomogram C-value of the validation queue was 0.853, and the AUC value was 0.852675. Furthermore, a significant decrease in the ALB/GLB was noted among cases with HLA-B27 positivity and AS cases. CONCLUSION: To conclude, the proposed ML model can effectively predict HLA-B27 and help doctors in the diagnosis of various immune diseases.

To infer the probability of cervical ossification of the posterior longitudinal ligament and explore its impact on cervical surgery.

The ossification of the posterior longitudinal ligament (OPLL) in the cervical spine is commonly observed in degenerative changes of the cervical spine. Early detection of cervical OPLL and prevention of postoperative complications are of utmost importance. We gathered data from 775 patients who underwent cervical spine surgery at the First Affiliated Hospital of Guangxi Medical University, collecting a total of 84 variables. Among these patients, 144 had cervical OPLL, while 631 did not. They were randomly divided into a training cohort and a validation cohort. Multiple machine learning (ML) methods were employed to screen the variables and ultimately develop a diagnostic model. Subsequently, we compared the postoperative outcomes of patients with positive and negative cervical OPLL. Initially, we compared the advantages and disadvantages of various ML methods. Seven variables, namely Age, Gender, OPLL, AST, UA, BMI, and CHD, exhibited significant differences and were used to construct a diagnostic nomogram model. The area under the curve (AUC) values of this model in the training and validation groups were 0.76 and 0.728, respectively. Our findings revealed that 69.2% of patients who underwent cervical OPLL surgery eventually required elective anterior surgery, in contrast to 86.8% of patients who did not have cervical OPLL. Patients with cervical OPLL had significantly longer operation times and higher postoperative drainage volumes compared to those without cervical OPLL. Interestingly, preoperative cervical OPLL patients demonstrated significant increases in mean UA, age, and BMI. Furthermore, 27.1% of patients with cervical anterior longitudinal ligament ossification (OALL) also exhibited cervical OPLL, whereas this occurrence was only observed in 6.9% of patients without cervical OALL. We developed a diagnostic model for cervical OPLL using the ML method. Our findings indicate that patients with cervical OPLL are more likely to undergo posterior cervical surgery, and they exhibit elevated UA levels, higher BMI, and increased age. The prevalence of cervical anterior longitudinal ligament ossification was also significantly higher among patients with cervical OPLL.

Clinical model of pulmonary metastasis in patients with osteosarcoma: A new multiple machine learning-based risk prediction.

BACKGROUND: Metastasis is one of the most significant prognostic factors in osteosarcoma (OS). The goal of this study was to construct a clinical prediction model for OS patients in a population cohort and to evaluate the factors influencing the occurrence of pulmonary metastasis. METHODS: We collected data from 612 patients with osteosarcoma (OS), and 103 clinical indicators were collected. After the data were filtered, the patients were randomly divided into training and validation cohorts by using random sampling. The training cohort included 191 patients with pulmonary metastasis in OS and 126 patients with non-pulmonary metastasis, and the validation cohort included 50 patients with pulmonary metastasis in OS and 57 patients with non-pulmonary metastasis. Univariate logistics regression analysis, LASSO regression analysis and multivariate logistic regression analysis were performed to identify potential risk factors for pulmonary metastasis in patients with osteosarcoma. A nomogram was developed that included risk influencing variables selected by multivariable analysis, and used the concordance index (C-index) and calibration curve to validate the model. Receiver operating characteristic curve (ROC), decision analysis curve (DCA) and clinical impact curve (CIC) were employed to assess the model. In addition, we used a predictive model on the validation cohort. RESULTS: Logistic regression analysis was used to identify independent predictors [N Stage + Alkaline phosphatase (ALP)+Thyroid stimulating hormone (TSH)+Free triiodothyronine (FT3)]. A nomogram was constructed to predict the risk of pulmonary metastasis in patients with osteosarcoma. The performance was evaluated by the concordance index (C-index) and calibration curve. The ROC curve provides the predictive power of the nomogram (AUC = 0.701 in the training cohort, AUC = 0.786 in the training cohort). Decision curve analysis (DCA) and clinical impact curve (CIC) demonstrated the clinical value of the nomogram and higher overall net benefits. CONCLUSIONS: Our study can help clinicians effectively predict the risk of lung metastases in osteosarcoma with more readily available clinical indicators, provide more personalized diagnosis and treatment guidance, and improve the prognosis of patients. MINI ABSTRACT: A new risk model was constructed to predict the pulmonary metastasis in patients with osteosarcoma based on multiple machine learning.

Strongly adhesive zwitterionic composite hydrogel paints for surgical sutures and blood-contacting devices.

Hydrogels show eminent advantages in biomedical and pharmaceutical fields. However, their application as coating materials for biomedical devices is limited by several key challenges, such as lack of universality, weak mechanical strength, and low adhesion to the substrate. Here we report versatile and tough adhesion composite hydrogel paints (CHPs), which consist of zwitterionic copolymers and microgels, both with reactive groups. The CHPs exhibit tunable rheology and thickness, hydrophilicity, biofouling resistance, durability, and convenient fabrication on metal, polymer, and inorganic surfaces with arbitrary shapes. As a proof-of-concept, the CHP-surgical sutures demonstrate exceptional lubrication, drug delivery, anti-infection, and anti-fibrous capsule properties. Moreover, the CHP-PVC tubing effectively prevents thrombus formation in vitro and ex vivo rabbit blood circulation without anticoagulants. This work provides valuable insights for enhancing and developing integrated hydrogel technologies for biomedical devices. STATEMENT OF SIGNIFICANCE: The combination of hydrogel and biomedical devices can enable numerous existing applications in medicine. In this study, inspired by the principle of microgel reinforcement in industrial paints, we propose a simple and versatile zwitterionic composite hydrogel paints (CHPs) strategy, which can be easily applied to diverse substrates with arbitrary shapes by covalent grafting between complementary groups by brush, dip, or spray. The CHPs integrated universality, tough adhesion, mechanical durability, and anti-biofouling properties because of their unique chemical composition and coating structure design. This strategy provides a simple and versatile route for surface modification of biomedical devices.

Application of machine learning in prediction of bone cement leakage during single-level thoracolumbar percutaneous vertebroplasty.

BACKGROUND: In the elderly, osteoporotic vertebral compression fractures (OVCFs) of the thoracolumbar vertebra are common, and percutaneous vertebroplasty (PVP) is a common surgical method after fracture. Machine learning (ML) was used in this study to assist clinicians in preventing bone cement leakage during PVP surgery. METHODS: The clinical data of 374 patients with thoracolumbar OVCFs who underwent single-level PVP at The First People's Hospital of Chenzhou were chosen. It included 150 patients with bone cement leakage and 224 patients without it. We screened the feature variables using four ML methods and used the intersection to generate the prediction model. In addition, predictive models were used in the validation cohort. RESULTS: The ML method was used to select five factors to create a Nomogram diagnostic model. The nomogram model's AUC was 0.646667, and its C value was 0.647. The calibration curves revealed a consistent relationship between nomogram predictions and actual probabilities. In 91 randomized samples, the AUC of this nomogram model was 0.7555116. CONCLUSION: In this study, we invented a prediction model for bone cement leakage in single-segment PVP surgery, which can help doctors in performing better surgery with reduced risk.

Comprehensive AI-assisted tool for ankylosing spondylitis based on multicenter research outperforms human experts.

Introduction: The diagnosis and treatment of ankylosing spondylitis (AS) is a difficult task, especially in less developed countries without access to experts. To address this issue, a comprehensive artificial intelligence (AI) tool was created to help diagnose and predict the course of AS. Methods: In this retrospective study, a dataset of 5389 pelvic radiographs (PXRs) from patients treated at a single medical center between March 2014 and April 2022 was used to create an ensemble deep learning (DL) model for diagnosing AS. The model was then tested on an additional 583 images from three other medical centers, and its performance was evaluated using the area under the receiver operating characteristic curve analysis, accuracy, precision, recall, and F1 scores. Furthermore, clinical prediction models for identifying high-risk patients and triaging patients were developed and validated using clinical data from 356 patients. Results: The ensemble DL model demonstrated impressive performance in a multicenter external test set, with precision, recall, and area under the receiver operating characteristic curve values of 0.90, 0.89, and 0.96, respectively. This performance surpassed that of human experts, and the model also significantly improved the experts' diagnostic accuracy. Furthermore, the model's diagnosis results based on smartphone-captured images were comparable to those of human experts. Additionally, a clinical prediction model was established that accurately categorizes patients with AS into high-and low-risk groups with distinct clinical trajectories. This provides a strong foundation for individualized care. Discussion: In this study, an exceptionally comprehensive AI tool was developed for the diagnosis and management of AS in complex clinical scenarios, especially in underdeveloped or rural areas that lack access to experts. This tool is highly beneficial in providing an efficient and effective system of diagnosis and management.

A biocompatible cell cryoprotectant based on sulfoxide-containing amino acids: mechanism and application.

The preservation of cells at cryogenic temperatures requires the presence of cryoprotectants (CPAs). Dimethyl sulfoxide (DMSO), as a state-of-the-art CPA, is widely used for the storage of many types of cells. However, its intrinsic toxicity is still an obstacle for its applications in clinical practice. Herein, we report a DMSO analogue, L-methionine sulfoxide (Met(O)-OH), as a CPA for cell cryopreservation. The molecular-level cryopreservation roles of Met(O)-OH were investigated by experiments and molecular dynamics simulations. The results also found that Met(O)-OH showed high ice recrystallization inhibition (IRI) activity and the ice crystals in Met(O)-OH solution tend to be relatively round and smooth; moreover, the ice size was significantly reduced to 30.26 µm compared with pure water (135.87 µm) or DMSO solution (45.08 µm). At the molecular level, Met(O)-OH could stably bind the surface of the ice crystals and form more stable hydrogen bonds with ice compared with L-methionine. Moreover, Met(O)-OH could significantly reduce the damage to cells caused by osmotic shock and did not change the cell viability even at high concentration (4%). Based on these results, nucleated L929 cells and anuclear sheep red blood cells (SRBCs) were used as cell models to investigate the cryopreservation activity of Met(O)-OH. The results suggested that, under the optimum protocol, Met(O)-OH showed an effective post-thaw survival efficiency with ultrarapid freezing, and the post-thaw survival efficiency of L929 cells reached 84.0%. This work opens up the possibility for an alternative to traditional toxic CPA DMSO, and provides insights for the development of DMSO analogues with non-toxic/low toxicity for cell cryoprotection applications.

A self-gelling powder based on polyacrylic acid/polyacrylamide/quaternate chitosan for rapid hemostasis.

In order to improve the hemostatic effect of the hemostatic dressing for non-compressible wounds, unknown bleeding points and irregularly shaped wounds, a self-gelling hemostasis powder based on polyacrylic acid/polyacrylamide/quaternate chitosan (PAA/PAM/QCS) is prepared in this study. When in contact with water, the PAA/PAM/QCS can fuse and rapidly form a stable hydrogel in a short time (< 0.25 min). The PAA/PAM ratio is the main parameter that modulates the formation of the self-gel. The PAA/PAM self-gel can be formed only when the PAA/PAM ratio is 5:5, and the introduction of QCS does not influence the self-gelling behaviors and hydrogel stability. Moreover, the PAA/PAM/QCS self-gel shows good adhesive properties on wet tissue surfaces. In addition, the introduction of QCS improves the antibacterial activity of the self-gelling hemostasis powder. Furthermore, the prepared PAA/PAM/QCS powder can rapidly adsorb lots of blood, aggregate blood cells and platelets. The hemostatic results in vivo show that PAA/PAM/QCS powder is superior to the control group and commercial product groups (chitosan powder) with performance similar to hemostatic zeolite in terms of the amount of bleeding and hemostatic time. Therefore, the PAA/PAM/QCS self-gelling powder shows great application prospects for rapid hemostasis.

Zwitterionic Polysaccharide-Based Hydrogel Dressing as a Stem Cell Carrier to Accelerate Burn Wound Healing.

Stem cell therapy integrated with hydrogels has shown promising potential in wound healing. However, the existing hydrogels usually cannot reach the desired therapeutic efficacy for burn wounds due to the inadaptability to wound shape and weak anti-infection ability. Moreover, it is difficult to improve the environment for the survival and function of stem cells under complicated wound microenvironments. In this study, an injectable and self-healing hydrogel (DSC), comprising sulfobetaine-derived dextran and carboxymethyl chitosan, is fabricated through a Schiff-base reaction. Meanwhile, the DSC hydrogel shows high nonfouling properties, including resistance to bacteria and nonspecific proteins; moreover, the prepared hydrogel can provide a biomimetic microenvironment for cell proliferation whilst maintaining the stemness of adipose-derived stem cells (ADSCs) regardless of complex microenvironments. In burnt murine animal models, the ADSCs-laden hydrogel can significantly accelerate wound healing rate and scarless skin tissue regeneration through multiple pathways. Specifically, the ADSCs-laden DSC hydrogel can avoid immune system recognition and activation and thus reduce the inflammatory response. Moreover, the ADSCs-laden DSC hydrogel can promote collagen deposition, angiogenesis, and enhance macrophage M2 polarization in the wound area. In summary, sulfobetaine-derived polysaccharide hydrogel can serve as a versatile platform for stem cell delivery to promote burn wound healing.

An Intrapericardial Injectable Hydrogel Patch for Mechanical-Electrical Coupling with Infarcted Myocardium.

Although hydrogel-based patches have shown promising therapeutic efficacy in myocardial infarction (MI), synergistic mechanical, electrical, and biological cues are required to restore cardiac electrical conduction and diastolic-systolic function. Here, an injectable mechanical-electrical coupling hydrogel patch (MEHP) is developed via dynamic covalent/noncovalent cross-linking, appropriate for cell encapsulation and minimally invasive implantation into the pericardial cavity. Pericardial fixation and hydrogel self-adhesiveness properties enable the MEHP to highly compliant interfacial coupling with cyclically deformed myocardium. The self-adaptive MEHP inhibits ventricular dilation while assisting cardiac pulsatile function. The MEHP with the electrical conductivity and sensitivity to match myocardial tissue improves electrical connectivity between healthy and infarcted areas and increases electrical conduction velocity and synchronization. Overall, the MEHP combined with cell therapy effectively prevents ventricular fibrosis and remodeling, promotes neovascularization, and restores electrical propagation and synchronized pulsation, facilitating the clinical translation of cardiac tissue engineering.

Microgel reinforced zwitterionic hydrogel coating for blood-contacting biomedical devices.

Zwitterionic hydrogels exhibit eminent nonfouling and hemocompatibility. Several key challenges hinder their application as coating materials for blood-contacting biomedical devices, including weak mechanical strength and low adhesion to the substrate. Here, we report a poly(carboxybetaine) microgel reinforced poly(sulfobetaine) (pCBM/pSB) pure zwitterionic hydrogel with excellent mechanical robustness and anti-swelling properties. The pCBM/pSB hydrogel coating was bonded to the PVC substrate via the entanglement network between the pSB and PVC chain. Moreover, the pCBM/pSB hydrogel coating can maintain favorable stability even after 21 d PBS shearing, 0.5 h strong water flushing, 1000 underwater bends, and 100 sandpaper abrasions. Notably, the pCBM/pSB hydrogel coated PVC tubing can not only mitigate the foreign body response but also prevent thrombus formation ex vivo in rats and rabbits blood circulation without anticoagulants. This work provides new insights to guide the design of pure zwitterionic hydrogel coatings for biomedical devices.