SearcharxivSearch

arXiv subjects

Dawen Yu

Publications and source records attributed to Dawen Yu.

5 recordsLinked to original sources

An in situ self-adaptive hydrogel coating enables seamless neural interfaces via okra mucilage polysaccharide and {\alpha}-helical peptide amphiphiles co-assembly

Long-term stability of neural interfaces is frequently compromised by mechanical mismatch and chronic neuroinflammation, often leading to electrode detachment and signal failure. While hydrogel coatings offer a solution, conventional designs typically rely on exogenous conductive fillers that can sacrifice mechanical flexibility or induce toxicity. Here, we report on a soft neural interface based on the supramolecular co-assembly of a renewable natural polysaccharide, okra mucilage polysaccharide (OMP), and an {\alpha}-helical peptide amphiphiles (APA). The resulting OMP-APA hydrogel (OP gel) exhibits environment-responsive enhancements in bioadhesion and charge-transport capability triggered by physiological pH and electrical stimulation. These properties arise from intrinsic, stimulus-responsive alterations in fibre architecture and orientation, eliminating the need for conductive fillers. Leveraging interfacial liquid-liquid phase separation, we demonstrate the in situ coating of ultra-thin OP-gel coating onto carbon fibre electrodes (CFE). The OP-gel-coated electrodes (OP-CFE) significantly mitigate foreign body responses and glial scarring, enabling stable, high-quality neural recordings in a mouse cortical in vivo model. Our findings provide a versatile strategy for constructing seamless, multifunctional bio-interfaces through supramolecular co-assembly, with broad implications for advancing neural prosthetics and neuroscience research.

physics.bio-ph

A dispersal recolonisation 3D biofilm in vitro model based on co-assembled peptide amphiphiles and clinical wound fluid

Chronic wound infections are sustained by dynamic 3D biofilm cycles involving maturation, dispersal, and recolonisation, yet existing in vitro models fail to reproduce these temporal and structural complexities. Here, we report a strategy that co-assembles a designed protease-inhibitory peptide amphiphile (PA-GF) with patient-derived wound fluid (WF) to reconstruct the complete biofilm life cycle in vitro. The PA-GF sequence incorporates an HWGF motif capable of binding and inhibiting matrix metalloproteinase-9 (MMP-9), thereby preserving the integrity of recolonised biofilms under proteolytic stress. Co-assembling with WF generated a living material that faithfully mimicked the biochemical and mechanical microenvironment of chronic wounds, supporting the formation of stable 3D biofilms capable of dispersal and recolonisation. Furthermore, we established a controllable polymicrobial infection model and validated its translational relevance through antibiotic susceptibility profiling and spatial microbiological analyses. Notably, the antibiotic response patterns of the PA/WF-derived biofilms closely mirrored those observed in a rat wound infection in vivo model. Collectively, our findings demonstrate that co-assembling living materials can recapitulate the nutritional composition, 3D architecture, and recolonisation dynamics of in vivo infectious biofilms, offering a physiologically relevant and customisable platform for investigating chronic wound infections and accelerating anti-biofilm drug discovery.

physics.med-ph

De novo design of alpha-helical peptide amphiphiles repairing fragmented collagen type I via supramolecular co-assembly

The hierarchical triple-helix structure of collagen type I, Col I, is essential for extracellular matrix support and integrity. However, current reconstruction strategies face challenges such as chain mismatch, preventing proper fibril formation. Here, we report a supramolecular co-assembly strategy using a de novo-designed alpha-helical peptide amphiphile (APA) of just seven amino acids. The APA features a hydrophobic palmitic acid tail, which stabilizes the helical structure and promotes co-assembly upon interaction with complementary molecular structures. This minimal design enables selective recognition of fragmented collagen (FC), restoring triple-helix conformation and guiding fibre formation. We applied this mechanism to engineer FC-rich nanofat (NF) into a mechanically reinforced biomaterial. Integration of APA-NF with coaxial 3D printing enabled spatial control of structure and function. In a porcine model, this platform enhanced in situ vascularized adipose tissue regeneration. Our results demonstrate that hierarchical reconstruction of collagen via peptide-guided supramolecular assembly offers a promising strategy for soft tissue repair.

physics.chem-ph

A Novel Shape Guided Transformer Network for Instance Segmentation in Remote Sensing Images

Instance segmentation performance in remote sensing images (RSIs) is significantly affected by two issues: how to extract accurate boundaries of objects from remote imaging through the dynamic atmosphere, and how to integrate the mutual information of related object instances scattered over a vast spatial region. In this study, we propose a novel Shape Guided Transformer Network (SGTN) to accurately extract objects at the instance level. Inspired by the global contextual modeling capacity of the self-attention mechanism, we propose an effective transformer encoder termed LSwin, which incorporates vertical and horizontal 1D global self-attention mechanisms to obtain better global-perception capacity for RSIs than the popular local-shifted-window based Swin Transformer. To achieve accurate instance mask segmentation, we introduce a shape guidance module (SGM) to emphasize the object boundary and shape information. The combination of SGM, which emphasizes the local detail information, and LSwin, which focuses on the global context relationships, achieve excellent RSI instance segmentation. Their effectiveness was validated through comprehensive ablation experiments. Especially, LSwin is proved better than the popular ResNet and Swin transformer encoder at the same level of efficiency. Compared to other instance segmentation methods, our SGTN achieves the highest average precision (AP) scores on two single-class public datasets (WHU dataset and BITCC dataset) and a multi-class public dataset (NWPU VHR-10 dataset). Code will be available at http://gpcv.whu.edu.cn/data/.

cs.CV

Long-Range Correlation Supervision for Land-Cover Classification from Remote Sensing Images

Long-range dependency modeling has been widely considered in modern deep learning based semantic segmentation methods, especially those designed for large-size remote sensing images, to compensate the intrinsic locality of standard convolutions. However, in previous studies, the long-range dependency, modeled with an attention mechanism or transformer model, has been based on unsupervised learning, instead of explicit supervision from the objective ground truth. In this paper, we propose a novel supervised long-range correlation method for land-cover classification, called the supervised long-range correlation network (SLCNet), which is shown to be superior to the currently used unsupervised strategies. In SLCNet, pixels sharing the same category are considered highly correlated and those having different categories are less relevant, which can be easily supervised by the category consistency information available in the ground truth semantic segmentation map. Under such supervision, the recalibrated features are more consistent for pixels of the same category and more discriminative for pixels of other categories, regardless of their proximity. To complement the detailed information lacking in the global long-range correlation, we introduce an auxiliary adaptive receptive field feature extraction module, parallel to the long-range correlation module in the encoder, to capture finely detailed feature representations for multi-size objects in multi-scale remote sensing images. In addition, we apply multi-scale side-output supervision and a hybrid loss function as local and global constraints to further boost the segmentation accuracy. Experiments were conducted on three remote sensing datasets. Compared with the advanced segmentation methods from the computer vision, medicine, and remote sensing communities, the SLCNet achieved a state-of-the-art performance on all the datasets.

cs.CV