Excessive lighting is integral to dentists’ daily routines but can impair their vision, affecting personal and professional performance. Most studies focus on acute photodamage, neglecting chronic photo-injury from dental lighting and its impact on the blood-retinal barrier homeostasis. An epidemiological survey involving 14,523 individuals showed dentists had 3.6 times higher odds of vision-related issues compared to other occupations (OR = 3.639, 95% CI: 3.064–4.323). Subsequently, chronic photodamage models in rats were created to accurately simulate dental working conditions. Using systematic imaging and gene analysis, including OCT, tissue clearing technology and RNA-sequencing, dental lighting was found to disrupted both inner and outer blood-retinal barriers, reduced retinal blood vessels, and promoted perivascular macrophage recruitment. Among them, the number of capillary branches decreased sharply. Moreover, the activation of inflammatory-related pathways such as NF-κB signaling resulted in the damage of vision-related functional structures in the retina. Notably, among three dental light sources, low-intensity halogen caused minimal retinal damage, whereas blue and white LEDs significantly disrupted blood-retinal barrier homeostasis. This study explored the potential mechanism of dental lighting environment inducing the disruption of blood-retinal barrier homeostasis, and provided essential guidance for dental professionals in selecting light sources, which is conducive to reducing the risk of occupational ocular diseases among dentists.

This protocol describes a standardized and reproducible minimally invasive approach for establishing mouse models of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and osteoradionecrosis of the jaw (ORNJ). The method combines a unified low-trauma oral surgical procedure with disease-specific injury induction strategies to generate robust and clinically relevant models of jaw osteonecrosis. For BRONJ, systemic zoledronic acid administration is coupled with mandibular first molar extraction using tape-assisted mouth opening and customized bent micro-forceps, minimizing soft tissue damage and reducing procedural variability. For ORNJ, a customized lead-shielding platform enables precise, noninvasive mandible-targeted irradiation, producing reproducible bone injury while limiting off-target radiation exposure. Together, these complementary models provide a consistent and minimally invasive framework for investigating jaw osteonecrosis arising from distinct etiologies. The protocol supports comprehensive downstream analyses, including micro-computed tomography, histology, and immunofluorescence, and facilitates mechanistic studies of disease pathogenesis, bone regeneration, and therapeutic intervention.

Vascular and lymphatic vessel regeneration is crucial for tissue repair and organ function restoration. However, conventional biomaterials are often constrained by poor biocompatibility and unpredictable degradation behavior. Engineered short peptides, typically comprising 2-50 amino acids, offer a promising solution for vessel regeneration through direct receptor engagement independent of exogenous cargo delivery. These peptides regulate cellular behavior through four key principles: sequence engineering, structural control, functional integration, and dynamic responsiveness. In angiogenesis, short-peptide biomaterials have demonstrated notable progress by enabling receptor-specific activation, multifunctional synergy, and the precise recognition of pathological microenvironments. Although studies on lymphatic regeneration remain limited, advances in identifying targeting sequences and mechanisms of lymphangiogenesis provide a foundation for peptide-based therapeutic strategies. Preclinically, short-peptide systems have shown therapeutic potential in cardiovascular, metabolic, and lymphatic disorders including acute myocardial infarction and diabetic complications. Furthermore, integration with artificial intelligence and 3D bioprinting is expanding the functional versatility of peptide-based biomaterials. Despite these advances, critical challenges remain, including limited predictability of sequence-structure-function relationships, stability-activity trade-offs in peptide modification, the underdevelopment of lymphangiogenic peptides, and barriers to scalable manufacturing and regulation. This review analyzes the biological basis of vascular and lymphatic regeneration, along with the design principles and mechanisms of short-peptide materials, systematically compares their regenerative strategies, highlights current limitations in bioactive peptide design and translation, and summarizes key advances and challenges to guide future development in this emerging field.

The lymphatic system plays a crucial role in maintaining tissue fluid homeostasis, immune surveillance, and lipid transport. Dysfunction of the lymphatic system is associated with a variety of diseases, including lymphedema, cardiovascular disease, chronic inflammation, and metabolic disorders. Recent advances in biomaterials have highlighted hydrogels as promising platforms for promoting lymphatic regeneration, thanks to their unique biocompatibility and tunable physicochemical properties. This review provides a comprehensive overview of hydrogel-based approaches for lymphatic vessel regeneration (lymphangiogenesis). We first outline the anatomical and functional characteristics of lymphatic vessels and their involvement in disease pathogenesis. We then discuss the key biological mechanisms governing lymphangiogenesis, covering transcriptional control, growth factor signaling, extracellular matrix remodeling, mechanoregulation, immune cell interactions, and metabolic regulation. Based on these mechanistic insights, the discussion focuses on key hydrogel design principles, including biomimetic extracellular matrix engineering, optimization of mechanical properties, controllable degradation synchronized with tissue repair, and multifunctional platforms for delivery of growth factors, cells, and immunomodulatory agents. The preclinical evidence supporting these systems in treating lymphedema, repairing cardiac lymphatic injury, neurological disorders, skin wounds, and bone defects is also discussed. Finally, the review concludes by assessing the translational barriers that currently separate preclinical findings from clinical application, including the gap between acute injury models and chronic disease, manufacturing and regulatory challenges, and the need for more rigorous functional evaluation of therapeutic outcomes, providing valuable insights for the clinical translation of hydrogel-based lymphatic regeneration strategies.

Endothelial specialization is increasingly recognized as a fundamental regulator of tissue homeostasis, yet the cellular diversity of the skeletal vasculature remains incompletely resolved. Here, we integrate large-scale single-cell transcriptomics, cross-tissue comparisons, and imaging to comprehensively define endothelial heterogeneity across the skeleton. Our analyses demonstrate that the proposed post-arterial "type R" endothelial population is not a distinct endothelial subtype but instead comprises canonical venous endothelial cells and fatty acid-handling endothelial state. RNA velocity supports a venous continuum, while the proposed type R markers FMO2, and AQP7 lack both endothelial and skeletal specificity. The fatty acid-handling endothelial state, characterized by Lpl and Cd36 is conserved across multiple skeletal sites and non-skeletal tissues, indicating a general endothelial metabolic programme. Within bone, this endothelial state expands following high-fat diet and is suppressed during injury. Together, these findings redefine skeletal endothelial heterogeneity and establish the proposed type R population as part of a venous continuum.

High-resolution whole-organ imaging provides cellular and molecular insights into tissue and tumor microenvironments. Here, we present a protocol for processing whole soft tissue organs and human tissues for 3D imaging within 2-2.5 days. We describe steps for bleaching, antigen retrieval, and collagenase-based digestion, followed by whole-tissue immunolabeling. We then detail procedures for dehydration and optical clearing for imaging by light-sheet microscopy. For complete details on the use and execution of this protocol, please refer to Biswas et al.1.

The bone marrow niche (BMN) plays a central role in regulating hematopoietic stem-cell (HSC) maintenance, lineage commitment, and immune homeostasis, while also supporting osteogenesis and maintaining skeletal integrity. Once considered static, the BMN is now recognized as a dynamic and responsive microenvironment that integrates local signals and systemic cues to meet physiological demands and respond to stress. Aging causes profound and progressive changes to this niche, leading to functional decline across both hematopoietic and stromal compartments. Recent advances in high-resolution imaging, single-cell and spatial transcriptomics, and in vivo lineage tracing have revealed remarkable heterogeneity and plasticity within the vascular and mesenchymal elements of this niche. Yet, key questions remain unresolved, including the identity and hierarchy of mesenchymal and osteolineage cells, the specialization of subsets of endothelial cells, the integration of systemic regulation, and whether the aging bone marrow acts as a driver or a passenger in malignancy and chronic inflammation. This review revisits current models of the BMN, with a focus on the reciprocal interactions between osteogenic cells and specialized vasculature, and how their disruption during aging impairs hematopoietic output and skeletal remodeling. We also examine how systemic factors such as neural input, metabolic status, and inflammatory signaling influence the aging of the BMN. Finally, we highlight emerging translational platforms, including iPSC-derived bone marrow organoids, engineered niches/hydrogels, and vascularized organ-on-chip systems, that enable mechanistic testing of rejuvenation strategies. Together, these insights have the potential to pave the way toward targeted interventions that restore the function of the BMN and promote healthy aging of the bone and blood systems.

The visualization of tissue architecture has long been constrained by optical absorption and scattering phenomena. Recent advances in optical tissue clearing techniques have revolutionized deep tissue imaging by overcoming these fundamental limitations, enabling high-resolution microscopic examination of intact organ systems. In ophthalmic research, these methodologies provide transformative capabilities for macroscopic three-dimensional visualization, effectively addressing the spatial constraints inherent to conventional two-dimensional histological sections. This paradigm shift has opened new avenues for investigating complex spatial relationships in ocular biology, including vascular network organization, neural connectivity patterns, and dynamic cellular processes. This comprehensive review synthesizes the current literature on tissue clearing methodologies with specific emphasis on ocular applications, systematically examining (1) the unique structural considerations for eye tissue clearing, (2) the established protocols for ocular tissue clearing, (3) the new discoveries in ocular structures through tissue clearing, (4) the imaging acquisition and analysis for cleared eye tissue, and (5) the emerging directions for future technological development. By integrating diverse insights, this review establishes a foundation for the continued refinement of tissue clearing approaches in ocular research, promoting a deeper understanding of eye structure and pathology.

Lymphatic dysfunction, clinically presenting as secondary lymphedema and chronic inflammatory conditions, remains a significant clinical challenge following oncologic therapy and tissue trauma. Current therapeutic strategies offer limited long-term efficacy, and cell-based regenerative approaches are constrained by safety concerns and scalability limitations. Within this therapeutic landscape, exosomes have emerged as promising mediators of lymphatic vessel repair. However, their specific role in lymphatic regeneration has not yet been fully elucidated. These nanovesicles, derived from diverse cellular sources, carry diverse molecular constituents that precisely modulate cellular processes critical for lymphangiogenesis. Compelling evidence highlights the essential role of exosome-mediated networks in lymphangiogenic processes. Exosomes influence lymphatic endothelial cell behavior by engaging multiple canonical signaling pathways. Current reviews predominantly address exosome biology or lymphatic pathophysiology in isolation, lacking a systematic analysis of exosomal regulatory mechanisms. This review aims to delineate the multifunctional role of exosomes as modulators of the lymphatic regenerative niche. We further discuss current tissue engineering strategies that utilize exosomes to promote lymphatic vessel regeneration, identify persistent gaps, and seek to establish a theoretical foundation for exosome-based lymphatic regeneration.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe complication of antiresorptive therapy with poorly understood vascular mechanisms. Here, we integrate whole-organ tissue-clearing imaging, single-cell transcriptomics, and proteomics to construct a multimodal atlas of the mouse and human BRONJ mandibular microenvironment. We identify gross vascular and lymphatic rarefaction and four endothelial subtypes with aberrant Col2a1 upregulation. Fibroblasts and macrophages emerge as key endothelial interactors, highlighting dysregulation of the endothelium-matrix-immune axis. Unlike homeostatic Dmp1⁺/Tfap2a⁺ fibroblasts and Stab1⁺ macrophages, BRONJ lesions feature pathological Lrrc15⁺/Chad⁺ fibroblasts and Il6⁺ macrophages, driving ectopic chondrogenesis and inflammation. Mechanistically, the COL2A1-CD44 axis (EC-to-fibroblast/macrophage signaling) and COL2A1-SDC4 axis (EC-to-fibroblast signaling) are upregulated in BRONJ disease condition, while lineage tracing excludes EndoMT, implicating extracellular matrix remodeling. We functionally validate this axis via localized Col2a1 siRNA silencing and endothelial-specific genetic deletion. Cross-species validation in human mandibles confirms vascular-lymphatic dysregulation, inflammation, and chondrogenesis. Overall, we establish vascular and lymphatic dysregulation as a BRONJ hallmark and identify the COL2A1-CD44/SDC4 axis as a therapeutic target. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe complication of antiresorptive therapy with poorly understood vascular mechanisms. Here, the authors identify vascular and lymphatic drivers of BRONJ and show that genetic ablation or silencing of Col2a1 restores endothelial homeostasis and rescues osteonecrotic lesions.

Whole-organ 3-dimensional (3D) imaging of intact tissues provides high-resolution cellular and molecular insights into tissue and tumor microenvironments. However, immunolabeling and tissue clearing methods remain complex and time-consuming and often rely on toxic reagents and prolonged processing times. Here, we introduce a rapid 3D immunolabeling and light sheet microscopy platform for quantitative analysis of intact murine organs and human tissues within 2 to 2.5 d. This streamlined workflow integrates antigen retrieval, permeabilization, collagenase-based digestion, immunolabeling, dehydration, and tissue clearing into a single optimized pipeline for fast and reproducible processing of intact tissues. Notably, this ultrafast 3D imaging method is optimized for exogenous fluorescence labeling, overcoming limitations associated with endogenous fluorescence in conventional tissue clearing approaches. It enables robust quantitative analysis and detection of rare cell populations, including round α-smooth muscle actin (α-SMA)-positive cells in the thymus, while preserving overall tissue integrity and maintaining compatibility with downstream histology. Using this rapid whole-tissue imaging platform, we mapped lymphatic vessel networks across multiple organs and age groups, revealing age-associated expansion in specific endocrine tissues but not in other organs. Overall, this method provides a rapid, reproducible, and versatile approach for whole-organ and intact tissue imaging, enabling comprehensive mapping of complex tissue architectures and rare cells, and advancing quantitative light sheet-based tissue analysis and disease research.

Bone regeneration relies on specialized vascular niches, yet the contribution of lymphatic vessels across distinct skeletal sites remains poorly understood. Here, we identify bone lymphatics as an essential component of the regenerative microenvironment in the mandible and long bones. We demonstrate that bone lymphatic endothelial cells (LECs) constitute a specialized endothelial population that is transcriptionally and spatially distinct from periosteal LECs. During skeletal repair, bone LECs reactivate a regenerative transcriptional programme, and promote mandibular and fracture healing. In osteonecrosis of the jaw and periodontitis, bone lymphatic-associated signalling is disrupted, identifying impaired lymphatic function as a shared feature of mandibular disease. Therapeutic activation of VEGFC-FLT4 signalling during injury or mandibular disease restores lymphangiogenesis, enhances osteogenesis, and markedly improves bone regeneration. Together, our findings advance the paradigm-shifting role of bone lymphatics positive regulators of bone regeneration and identify lymphatic activation as a promising therapeutic strategy to enhance bone regeneration in mandibular diseases.

Although the coupled blood and lymphatic vascular systems are crucial for mammalian homeostasis, they remain understudied in skeletal contexts. The blood vessel system orchestrates oxygen delivery and waste clearance, while the lymphatic network dynamically regulates interstitial fluid balance and immune surveillance. Their embryonic codevelopment allows for synergistic microcirculatory control. Recently, increasing evidence has highlighted the critical role of the blood and lymphatic vascular networks in bone tissue repair. This network effectively promotes and accelerates bone regeneration by spatiotemporally regulating inflammation, bidirectional molecular trafficking, and the secretion of angiocrine/lymphangiocrine factors. Current reviews predominantly address the blood and lymphatic vascular systems in isolation, thereby failing to provide system-level insights into their coordinated regulation during osseous regeneration. This review systematically elaborates on the relationship of the blood and lymphatic vascular systems in bone repair. Furthermore, we describe current tissue engineering studies targeting the blood and lymphatic vascular networks to accelerate bone injury repair and identify critical gaps in this research field. Thus, we aimed to construct a theoretical framework for the coregulation of blood and lymphatic vascular systems in the context of bone injury repair.

Background The lymphatic vasculature maintains tissue fluid homeostasis, lipid transport, and immune surveillance. Beyond these classical roles, lymphatic vessels regulate tissue development and repair through lymphangiocrine signalling, whereby lymphatic endothelial cells (LECs) secrete mediators such as Reelin, R-spondin-3, and CCL21 that modulate stem cell niches, immune trafficking, and regeneration. Ageing-associated lymphatic dysfunction, driven by LEC senescence, impaired lymphangiogenesis, and lymph node stromal remodelling, leads to defective tissue repair, chronic low-grade inflammation, and increased susceptibility to diseases including cancer, cardiovascular disease, and neurodegeneration. Aim of the review This review summarizes lymphangiocrine signalling in regeneration, ageing, and cancer, proposing that age-related LEC dysfunction drives disease through impaired drainage, immune dysregulation, and loss of regenerative niches, and discusses emerging lymphatic-targeted therapies. Key scientific concepts Lymphatic vessels function as multicellular signalling hubs composed of LECs and associated stromal and immune cells that coordinate immune and regenerative responses. We summarize organ-specific lymphangiocrine mechanisms across multiple tissues and their roles in stem cell regulation and tissue repair. Age-related changes in lymphatic vessels and lymph node stroma impair drainage, drive immune dysregulation and inflammaging, and reduce regenerative capacity. Dysregulated lymphangiocrine signalling contributes to diseases including lymphedema, cardiovascular and metabolic disorders, neurodegeneration, and cancer. Finally, we discuss emerging strategies to restore lymphatic function in ageing tissues.

This protocol describes a standardized and reproducible minimally invasive method for establishing mouse models of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and osteoradionecrosis of the jaw (ORNJ) in adult male C57BL/6 mice. The procedure integrates a unified minimally traumatic oral surgical approach with distinct injury induction strategies for each condition. In BRONJ, systemic zoledronic acid administration is combined with mandibular first molar extraction using tape-assisted mouth opening and bent micro-forceps to reduce soft tissue injury and procedural variability. In ORNJ, a customized lead shielding system enables precise, noninvasive, mandible-targeted irradiation, ensuring reproducible bone injury with minimized off-target effects. Together, these models provide a consistent minimally invasive framework for studying jaw osteonecrosis across different etiologies, supporting downstream micro-CT, histological, and immunofluorescence analyses, and enabling investigations of disease mechanisms, bone repair, and therapeutic interventions.

The widespread presence of pathogenic microorganisms poses significant threats to human health. While antibiotics remain a powerful tool in combating bacterial infections, their overuse has accelerated the emergence of antibiotic-resistant strains, leading to a global health crisis. Antimicrobial peptides (AMPs), a class of bioactive molecules with potent antibacterial, antifungal, antiviral, and anti-inflammatory properties, have thus garnered increasing attention as a potential alternative to conventional antibiotics. However, AMPs are prone to enzymatic degradation in vivo, limiting their efficacy, and some exhibit inherent toxicity. Metal-Organic Frameworks (MOFs), characterized by their tunable pore size, excellent stability, and biocompatibility, have emerged as promising carriers for AMPs. This review examines the synergistic potential of AMPs@MOF drug-delivery systems, with a focus on their design, applications, and underlying antimicrobial mechanisms. MOFs can safeguard AMPs from degradation, enhance targeted delivery, and enable controlled, sustained release. These hybrid systems offer an effective strategy against drug-resistant pathogens by disrupting bacterial membranes, inhibiting protein synthesis, and modulating immune responses. This review provides a comprehensive overview of the AMPs@MOF system, highlighting its potential as a novel approach in the development of antimicrobial therapies.

Previous studies predominantly associated lymphatics with skeletal disease and bone loss. However, building on our work, bone lymphatics are emerging as a paradigm-shifting component of the skeletal microenvironment, illustrating their role as positive regulators of bone mass and repair. Here, we present a comprehensive analysis integrating spatial transcriptomics, single-cell RNA sequencing, and imaging across murine and human bones. Spatial transcriptomics identifies Prox1+ endothelial cells embedded within bone. Reanalysis of multiple scRNA-seq datasets confirms Prox1+ lymphatic endothelial cells (LECs) in bones, despite their underrepresentation in soft-tissue endothelial cell atlases. Periosteum is an insufficient source for bone lymphatics because it contains only sparse LECs. Our analyses further demonstrate that certain mouse models lack the sensitivity required to detect bone lymphatics and highlight the importance of high-resolution imaging. Collectively, convergent multimodal evidence substantiates LECs as an integral functional component of the skeletal microenvironment. This Matters Arising Response paper addresses the Meng et al. (2026) Matters Arising paper, published concurrently in this issue.

Chitosan (CS) based interpenetrating polymer network (IPN) is formed by cross-linking of CS with another polymer. It exhibits the ability of detecting environmental pollutants. In this work, the cross-linked CS was used as the network skeleton, the RAFT agent could produce an interpenetrating network with CS during the polymerization process, thereby forming a fluorescent hydrogel-type IPN (CS-Cy-PMAm and CS-Cy-PHD). The basic properties of CS-based hydrogels were analyzed by NMR, MS, FT-IR, SEM, TEM, AFM, and so on. This hydrogel prepared by in-situ synthesis technology not only has excellent film-forming properties but also EGME and toluene solvent molecules can significantly enhance the fluorescence of the hydrogel by infiltrating or squeezing the CS network. Due to the chelation of CN, CO, and thioester bonds with Hg+ to block the PET process, the hydrogel exhibited a highly sensitive 46-fold fluorescence enhancement up the Hg+ addition. The detection limit (LOD) of Hg+ was 13 nM, and the adsorption capacity was 84.0 mg·g-1. At the same time, the fluorescent film is made into a colorimetric card, which can realize real-time and portable detection of Hg+. This method expands the application of CS-based IPNs in environmental science and engineering.

Bone marrow health is central to transplantations, blood formation, and cancer progression. However, the bone marrow niche deteriorates with age, impairing haematopoietic stem cell function. Contrary to a recent report1 suggesting skull marrow resists ageing, our multi-laboratory investigation reveals the opposite: the skull marrow is among the vulnerable sites of age-related decline. Ageing skull niches consistently show loss of mesenchymal and osteoprogenitors, suppression of angiogenic and lymphatic programs, adipocyte accumulation, vascular senescence, DNA replication stress, mitochondrial dysfunction, cellular senescence, and heightened inflammation. Proteomic profiling further highlights this vulnerability, demonstrating that vertebral niches-unlike the skull-are relatively spared from these ageing hallmarks. Together, these convergent datasets overturn the notion of skull-specific resilience and instead establish the skull marrow as a fragile, degenerating environment. These findings redefine marrow ageing and highlight the skull as a critical, clinically relevant target for sustaining blood and immune health and reducing vulnerability to haematological disease.

Following damage to the skin and mucous membranes, bacterial infections, and excessive oxidative stress often lead to inflammatory responses and impaired wound healing, which can even be life-threatening. Surgical dressing combined with antimicrobial agent use is the major therapy. However, traditional gauze dressings are prone to causing secondary injuries, while systemic antibiotic therapy often fails to deliver sufficient drug concentrations at the wound site and carries the risk of systemic toxic side effects. Hydrogel dressing is a hot research field because of its breathability, biocompatibility, and easy access for modification. The healing of infected wounds is a complex process during which tough adhesion of the dressing to the wound and effective elimination of inflammation are both important for successful wound healing. To achieve this goal, we designed a "five-in-one" hydrogel wound dressing, CS/TA, using natural components including chitosan and tannic acid. Briefly, the CS/TA dressing was simultaneously characterized by five important capabilities, including tissue adhesion, self-healing property, extensibility, and antibacterial and antioxidant properties. The excellent adhesiveness, self-healing ability, and extensibility allowed the CS/TA dressing to conform to dynamic tissue changes and adhere closely to the wound. Moreover, the CS/TA dressing effectively eliminated bacteria and scavenged excess free radicals, thereby minimizing tissue inflammation. As a result, significantly accelerated wound healing was achieved in an infected wound model. To conclude, the study provided a novel perspective on hydrogel dressing design, and the five-in-one CS/TA dressing demonstrated great potential for infected wound treatment.