ObjectiveTo investigate the mechanism of Yangxin Tongmai Formula （养心通脉方， YTF） in trea-ting coronary heart disease with blood stasis syndrome based on DNA methylation. MethodsSeventy-two SD rats were randomly divided into a control group （n=12） and a modeling group （n=60）. The modeling group was subjected to a high-fat diet， intragastric administration of vitamin D3， and subcutaneous injection of isoprenaline to establish the rat model of coronary heart disease with blood stasis syndrome. Forty-one successfully modeled rats were then randomly allocated into model group， YTF low-， medium-， and high-dose groups， and the atorvastatin calcium group， with 8 rats in each group and 1 rat reserved. The YTF low-， medium-， and high-dose groups received YTF at 6， 12， and 18 g/（kg·d） by gavage， respectively. The atorvastatin calcium group received atorvastatin calcium tablets at 1.8 mg/（kg·d） by gavage. The control group and the model group received 0.9% sodium chloride injection at 4 ml/（kg·d） by gavage. All administrations were performed once daily for 3 weeks. Twenty-four hours after the last administration， serum lipid levels including total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein cholesterol （LDL-C）， and high-density lipoprotein cholesterol （HDL-C）， myocardial enzymes including cardiac troponin T （cTnT）， creatine kinase MB （CK-MB）， and lactate dehydrogenase （LDH）， and inflammatory factors including interleukin-1β （IL-1β） and interleukin-10 （IL-10） were detected by ELISA. Pathological changes in myocardial tissue were observed via HE staining. Whole blood DNA methylation sequencing was used to analyze differential methylation gene expression among the control group， model group， and YTF high-dose group. Western Blotting was used to verify the protein levels of the key genes and downstream signaling pathways. ResultsCompared to the control group， the model group showed increased levels of TC， TG， LDL-C， cTnT， CK-MB， LDH， and IL-1β， along with decreased levels of HDL-C and IL-10 （P＜0.05 or P＜0.01）. Compared to the model group， all treatment groups exhibited decreased levels of TC， LDL-C， CK-MB， and LDH， along with increased IL-10 levels. Among these， the high-dose YTF group demonstrated superior efficacy in reducing cTnT levels compared to the other TCM groups （P＜0.05 or P＜0.01）. HE staining indicated that the YTF high-dose group ameliorated myocardial cell swelling， disordered arrangement， pyknosis， and disappearance of nuclei， thereby reducing myocardial cell damage. Whole blood DNA methylation sequencing identified 240 differentially methylated genes shared by the control group， model group， and YTF high-dose group， including 109 hypermethylated and 131 hypomethylated genes； eif2ak3 was identified as a key differentially methylated gene. Compared to the control group， the model group exhibited increased protein levels of eukaryotic translation initiation factor 2 alpha kinase 3 （eIf2ak3）， phosphorylated protein kinase RNA-like endoplasmic reticulum kinase （p-PERK）， activating transcription factor 4 （ATF4）， C/EBP homologous protein （CHOP）， and Bax， along with a decreased level of B-cell lymphoma-2 （Bcl-2） protein （P＜0.05 or P＜0.01）. Compared to the model group， the YTF high-dose group showed decreased protein levels of eIf2ak3， p-PERK， ATF4， CHOP， and Bax， and an increased level of Bcl-2 protein （P＜0.05 or P＜0.01）. ConclusionYTF may regulate key differentially methylated genes such as eIf2ak3 and the PERK/ATF4/CHOP signaling pathway， thereby inhibiting endoplasmic reticulum stress， reducing myocardial cell apoptosis， and exerting therapeutic effects in coronary heart disease blood stasis syndrome.

ObjectiveTo investigate the ameliorative effect of Wendantang combined with Danshenyin and Dushentang （WDD） on mice with ischemic heart disease （IHD） presenting phlegm-stasis syndrome based on the inflammatory phenotype and differentiation of circulating monocytes. MethodsA model of IHD with phlegm-stasis syndrome was established using left anterior descending coronary artery ligation supplemented with a high-fat diet. Eighty model mice were randomly assigned to the model group， WDD low-dose group （WDD-L）， WDD medium-dose group （WDD-M）， WDD high-dose group （WDD-H）， and atorvastatin calcium tablet group， with 16 mice in each group. An additional 16 C57BL/6J mice were designated as the sham-operation group. The WDD groups received intragastric administration at doses of 8.91， 17.81， 35.62 g·kg^-1， and the atorvastatin calcium tablet group received the corresponding drug at 1.3 mg·kg^-1， twice daily. The sham-operation and model groups were given the same volume of pure water by gavage each day. After 5 consecutive weeks of administration， the cardiac index was calculated. Cardiac function was assessed by echocardiography. Myocardial histopathology was examined by hematoxylin-eosin （HE） staining. Serum N-terminal pro-B-type natriuretic peptide （pro-BNP） content was measured by enzyme-linked immunosorbent assay （ELISA）. Hemorheological parameters were analyzed using an automated hemorheology analyzer. Serum levels of total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein （LDL）， and high-density lipoprotein （HDL） were determined using an automated biochemical analyzer. Changes in circulating monocytes were detected by flow cytometry. Mouse bone marrow mononuclear cells were isolated in vitro and divided into blank group， model serum group， WDD-L drug-containing serum group， WDD-M drug-containing serum group， and WDD-H drug-containing serum group. CD36 expression and macrophage differentiation in each group were assessed by flow cytometry. The mechanism by which WDD mediates circulating monocyte differentiation was further explored using CD36 knockdown/overexpression RAW264.7 cell lines. ResultsCompared with the sham-operation group， the model group showed a significantly increased cardiac index （P0.01）， significantly decreased fractional shortening （FS） （P0.01）， and significantly increased left ventricular end-diastolic internal diameter （LVDD） and left ventricular end-systolic internal diameter （LVDS） （P0.01）. Cardiomyocytes exhibited marked deformation and necrosis with inflammatory cell infiltration. Serum pro-BNP levels were significantly elevated （P0.01）， and whole-blood viscosity （BV） at high， medium， and low shear rates was significantly increased （P0.01）. Compared with the model group， the WDD groups showed significantly reduced cardiac index （P0.05， P0.01）， significantly increased FS （P0.05， P0.01）， significantly decreased LVDD and LVDS （P0.01）， markedly improved cardiomyocyte morphology， significantly reduced inflammatory infiltration， significantly decreased serum pro-BNP levels （P0.01）， and significantly decreased BV at high， medium， and low shear rates （P0.01）， with the most pronounced improvement observed in the WDD-M group. Compared with the sham-operation group， TC， TG， and LDL levels were significantly increased in the model group （P0.05， P0.01）， while HDL levels were significantly decreased （P0.05）. After WDD-H treatment， TC， TG， and LDL levels were significantly reduced and HDL levels were significantly increased in mice （P0.05， P0.01）. Compared with the sham-operation group， classical monocytes in blood and bone marrow and intermediate monocytes in blood were significantly increased in the model group （P0.01）， whereas intermediate monocytes in bone marrow and non-classical monocytes in blood were significantly decreased （P0.01）. After WDD administration， all circulating monocyte subsets in blood and bone marrow were significantly alleviated （P0.05， P0.01）， with the WDD-M group showing the optimal effect. In vitro， compared with the blank group， CD36 expression on bone marrow monocytes and the proportion of differentiated macrophages were significantly increased in the model serum group （P0.01）， and CD36 expression was significantly upregulated on RAW264.7 cells （P0.01）. Compared with the model serum group， all drug-containing serum groups exhibited significantly reduced CD36 expression on bone marrow monocytes and significantly reduced macrophage differentiation （P0.01）. WDD downregulated CD36 expression in both CD36 knockdown and overexpression RAW264.7 cell lines （P0.05， P0.01）， with the strongest regulatory effect observed in the WDD-M drug-containing serum group. ConclusionWDD can significantly improve the manifestations of phlegm-stasis syndrome in IHD mice and reduce the proportion of classical circulating monocytes. Its mechanism may be related to the inhibition of CD36 expression on classical circulating monocytes.

ObjectiveTo investigate the ameliorative effect of Wendantang combined with Danshenyin and Dushentang （WDD） on mice with ischemic heart disease （IHD） presenting phlegm-stasis syndrome based on the inflammatory phenotype and differentiation of circulating monocytes. MethodsA model of IHD with phlegm-stasis syndrome was established using left anterior descending coronary artery ligation supplemented with a high-fat diet. Eighty model mice were randomly assigned to the model group， WDD low-dose group （WDD-L）， WDD medium-dose group （WDD-M）， WDD high-dose group （WDD-H）， and atorvastatin calcium tablet group， with 16 mice in each group. An additional 16 C57BL/6J mice were designated as the sham-operation group. The WDD groups received intragastric administration at doses of 8.91， 17.81， 35.62 g·kg^-1， and the atorvastatin calcium tablet group received the corresponding drug at 1.3 mg·kg^-1， twice daily. The sham-operation and model groups were given the same volume of pure water by gavage each day. After 5 consecutive weeks of administration， the cardiac index was calculated. Cardiac function was assessed by echocardiography. Myocardial histopathology was examined by hematoxylin-eosin （HE） staining. Serum N-terminal pro-B-type natriuretic peptide （pro-BNP） content was measured by enzyme-linked immunosorbent assay （ELISA）. Hemorheological parameters were analyzed using an automated hemorheology analyzer. Serum levels of total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein （LDL）， and high-density lipoprotein （HDL） were determined using an automated biochemical analyzer. Changes in circulating monocytes were detected by flow cytometry. Mouse bone marrow mononuclear cells were isolated in vitro and divided into blank group， model serum group， WDD-L drug-containing serum group， WDD-M drug-containing serum group， and WDD-H drug-containing serum group. CD36 expression and macrophage differentiation in each group were assessed by flow cytometry. The mechanism by which WDD mediates circulating monocyte differentiation was further explored using CD36 knockdown/overexpression RAW264.7 cell lines. ResultsCompared with the sham-operation group， the model group showed a significantly increased cardiac index （P<0.01）， significantly decreased fractional shortening （FS） （P<0.01）， and significantly increased left ventricular end-diastolic internal diameter （LVDD） and left ventricular end-systolic internal diameter （LVDS） （P<0.01）. Cardiomyocytes exhibited marked deformation and necrosis with inflammatory cell infiltration. Serum pro-BNP levels were significantly elevated （P<0.01）， and whole-blood viscosity （BV） at high， medium， and low shear rates was significantly increased （P<0.01）. Compared with the model group， the WDD groups showed significantly reduced cardiac index （P<0.05， P<0.01）， significantly increased FS （P<0.05， P<0.01）， significantly decreased LVDD and LVDS （P<0.01）， markedly improved cardiomyocyte morphology， significantly reduced inflammatory infiltration， significantly decreased serum pro-BNP levels （P<0.01）， and significantly decreased BV at high， medium， and low shear rates （P<0.01）， with the most pronounced improvement observed in the WDD-M group. Compared with the sham-operation group， TC， TG， and LDL levels were significantly increased in the model group （P<0.05， P<0.01）， while HDL levels were significantly decreased （P<0.05）. After WDD-H treatment， TC， TG， and LDL levels were significantly reduced and HDL levels were significantly increased in mice （P<0.05， P<0.01）. Compared with the sham-operation group， classical monocytes in blood and bone marrow and intermediate monocytes in blood were significantly increased in the model group （P<0.01）， whereas intermediate monocytes in bone marrow and non-classical monocytes in blood were significantly decreased （P<0.01）. After WDD administration， all circulating monocyte subsets in blood and bone marrow were significantly alleviated （P<0.05， P<0.01）， with the WDD-M group showing the optimal effect. In vitro， compared with the blank group， CD36 expression on bone marrow monocytes and the proportion of differentiated macrophages were significantly increased in the model serum group （P<0.01）， and CD36 expression was significantly upregulated on RAW264.7 cells （P<0.01）. Compared with the model serum group， all drug-containing serum groups exhibited significantly reduced CD36 expression on bone marrow monocytes and significantly reduced macrophage differentiation （P<0.01）. WDD downregulated CD36 expression in both CD36 knockdown and overexpression RAW264.7 cell lines （P<0.05， P<0.01）， with the strongest regulatory effect observed in the WDD-M drug-containing serum group. ConclusionWDD can significantly improve the manifestations of phlegm-stasis syndrome in IHD mice and reduce the proportion of classical circulating monocytes. Its mechanism may be related to the inhibition of CD36 expression on classical circulating monocytes.

Based on the "regulating the pivot and unblocking the stomach" theory， this article proposes that the core pathogenesis of bile reflux gastritis （BRG） is disharmony of the three pivots and imbalance between the gallbladder and the stomach. Specifically， the pivot of zang-fu （脏腑） organs （spleen and stomach） exhibits abnormal ascending and descending functions， while the pivot of opening and closing （shaoyang） shows impaired flow， and the pivot of mind （heart and brain） has disordered regulation. These three pivots interact， ultimately leading to bile reflux attacking the stomach， injuring the gastric mucosa， and causing symptoms such as epigastric distension， pain， acid regurgitation， and heartburn. Clinically， the treatment principle is unblocking and regulating the three pivots， harmonizing the gallbladder and descending stomach qi， which closely follows the different pathomechanisms of three-pivot dysregulation， applying treatment according to syndrome differentiation. The regulation of the pivot of zang-fu organs focuses on fortifying the spleen and harmonzing stomach， raising the clear and directing the turbid downward. The regulation of the opening-and-closing pivot emphasizes harmonizing shaoyang， promoting gallbladder function and bowel movement. The regulation of the mind pivot centers on calming the heart and the mind， and harmonizing the stomach to ensure smooth qi flow. "Unblocking and regulating three pivots" method aims to restore the physiological functions of the gallbladder and stomach， providing a conceptual framework for the clinical management of BRG.

Purpose: Non-operative management (NOM) has emerged as a promising organ-preserving strategy for patients with rectal cancer who achieve a clinical complete response (cCR) after neoadjuvant chemoradiotherapy (CRT). However, no standardized treatment protocol has been established for watch-and-wait strategies. Materials and Methods: This prospective study evaluated oncological outcomes of NOM combined with 4 months of adjuvant capecitabine. Patients with resectable rectal cancer (≤ 8 cm from the anal verge, cT2-4 or N+) underwent CRT (50-54 Gy in 25-27 fractions with capecitabine). Eight weeks post-CRT, a multidisciplinary team assessed cCR. Patients achieving cCR received six cycles of capecitabine (2 weeks on/1 week off) and were actively monitored. Results: Among 89 patients receiving CRT (2018-2023), 17 (19.1%) achieved cCR and were included. The median age was 65 years, and 64.7% were male. Eleven (64.7%) completed all six cycles of adjuvant therapy. After a median follow-up of 31.4 months, 11 patients (64.7%) remained disease-free. Local regrowth occurred in six patients (35.3%) with 2- and 4-year rates of 34.5% and 47.6%, respectively. Five underwent radical surgery, and one received transanal excision with systemic chemotherapy. At the time of assessment, 15 patients (88.2%) showed no evidence of disease, while two (11.8%) received palliative chemotherapy. All patients were alive. Conclusion NOM with adjuvant capecitabine showed promising oncological outcomes, offering an alternative to passive watch-and-wait approaches. Further refinement through multidisciplinary strategies is warranted.

Objectives: . Idiopathic sudden sensorineural hearing loss (ISSNHL) is a significant cause of hearing loss. Intratympanic steroid injection (ITSI) is commonly used as an initial or salvage treatment; however, the lack of a standardized treatment protocol has resulted in variability in clinical practice. In addition, no efficient prediction model currently exists to support personalized management. Therefore, this study aimed to develop tailored management strategies for ISSNHL using a machine-learning model. Methods: . This retrospective multicenter cohort study was conducted between January 2015 and December 2020, with data analysis performed between January 2021 and March 2024. Patients were selected based on the International Classification of Diseases, 10th Revision criteria for ISSNHL, along with relevant medication and procedure codes. Patients with pure-tone audiogram results not meeting ISSNHL criteria, better initial hearing in the affected ear, an identifiable etiology, no post-treatment audiogram, or delayed treatment (>6 weeks) were excluded. We included 770 patients diagnosed with ISSNHL who received ITSI. The primary outcome was the area under the receiver operating characteristic curve for prediction performance. Recovery status was determined using the last pure-tone audiogram. Modeling was conducted on the Quanta for Medical Care AI platform using five machine-learning algorithms and a nested cross-validation framework, in which feature selection and hyperparameter tuning were performed in the inner folds and model performance was evaluated in the outer folds. Results: . A random forest classifier outperformed the other models in predicting hearing outcomes, achieving an area under the receiver operating characteristic curve of 0.788. Time to ITSI was the most influential treatment-related factor, with ITSI administered within 10 days of hearing loss being associated with better outcomes. This model can be used to provide personalized prognostic estimates under different treatment protocols. Conclusion . The machine-learning-based prediction model facilitates personalized treatment strategies and timely treatment adjustments for ISSNHL, thereby optimizing the likelihood of complete recovery.

Processed electroencephalogram (EEG) indices, such as the Bispectral Index, have markedly influenced anesthesia practice as they translate brain activity into simple numerical indices. Nevertheless, as the manufacturing algorithms are not disclosed, the underlying neurophysiology remains obscured. Additionally, these indices are often affected by electromyographic contamination, pharmacological variability, and patient-specific EEG heterogeneity. In contrast, an EEG spectrogram, or density spectral array, preserves the frequency- and time-resolved structures of cortical oscillations. This information is presented in a form that is both physiologically meaningful and clinically interpretable. In this review, we trace the evolution of anesthesia from an index-based to a spectrogram-guided approach, and summarize the clinical rationale for adopting the latter. Key applications of this approach include the use of frontal alpha power as a biomarker of cortical stability and postoperative brain health, the identification of nociceptive arousal through alpha dropout and beta or delta arousal patterns, and individualized titration of multimodal or age-specific anesthetic management. Although current devices lack standardized quantitative alpha metrics and have limited sensitivity for low-frequency brain wave components, structured EEG education programs have proven to be effective in terms of fostering spectrogram literacy among anesthesiologists. By combining neurophysiological precision with bedside practicality, the EEG spectrogram represents a pivotal advance toward individualized, mechanism-based, and brain-protective anesthesia, transforming anesthetic monitoring from mere algorithmic abstraction to cortical insight.

Background: Type 2 diabetes mellitus (T2DM) is a complex, multifactorial disease with a significant global burden. Although genome-wide association studies (GWAS) have identified many T2DM-associated variants, most lie in non-coding regions, making it difficult to interpret their functional roles. Methods: We aimed to identify genetically regulated Cytosine–phosphate–Guanine (CpG) sites associated with T2DM by conducting a methylome-wide association study (MWAS), followed by Mendelian randomization (MR) and functional validation using human pancreatic cells and mouse models. MWAS was performed using summary statistics from large-scale GWAS and a DNA methylation (DNAm) prediction model to test associations between genetically predicted DNAm and T2DM. Results: We identified 111 CpG sites significantly associated with T2DM in Europeans, including 8 novel sites near genes not previously linked to T2DM. These findings were replicated in independent datasets. Many CpGs also showed associations with cardiometabolic traits, highlighting shared epigenetic mechanisms. Trans-ethnic MR analysis confirmed consistent effects for six CpGs in East Asians. Functional analysis revealed that several CpGs regulate gene expression in human pancreatic α- and β-cells. Among them, 2´-5´-oligoadenylate synthetase like (OASL) expression, regulated by a significant CpG, was differentially expressed in α-cells of T2DM cases compared to controls. Supporting evidence from mouse models suggests a role for OASL in glucose regulation. Conclusion Our study identifies novel genetically regulated CpG sites associated with T2DM risk and highlights OASL as a potential epigenetic regulator of glucose metabolism in α-cells. These findings provide mechanistic insights into the epigenetic architecture of T2DM and suggest potential targets for cross-ethnic biomarker development and therapeutic intervention.

Multidrug-resistant (MDR) bacterial infections have emerged as a serious challenge of global public health crisis. The overuse and misuse of conventional antibiotics have dramatically accelerated the emergence, evolution and worldwide spread of drug-resistant bacterial strains, necessitating urgent exploration of novel antibacterial strategies. Bacteriophages serve as natural bacterial predators offering distinct advantages including high host specificity, autonomous self-replication capabilities and cost-effective large-scale production. However, wild-type phages present significant clinical limitations due to their narrow host ranges, susceptibility to rapid immune clearance and poor penetration of bacterial biofilms, which severely restrict their therapeutic applications. The convergence of synthetic biology, nanotechnology and advanced gene editing technologies has accelerated the development of engineered bacteriophage platforms, providing programmable, scalable and clinically translatable pathways to overcome these inherent biological constraints. Here, we systematically delineate four fundamental strategies for engineered bacteriophage development. Chemical modification utilizes reactive functional groups such as amino, carboxyl and thiol moieties on capsid proteins through esterification, amidation or click chemistry reactions to achieve precise drug conjugation and surface functionalization. In vivo editing encompasses ultraviolet or chemical mutagenesis for random mutation induction, homologous recombination for targeted genetic alterations, recombineering methodologies including electroporation-mediated bacteriophage recombination engineering, and CRISPR-Cas systems for precise genome editing to enable exact genetic reconstruction and host range reprogramming. In vitro synthesis leverages genome engineering platforms where intact phage genomes are transferred into yeast or host bacteria to facilitate highly efficient homologous recombination, enabling large DNA fragment assembly and cross-gene host range expansion without bacterial toxicity constraints. Directed evolution combines artificial selection through mutation library screening with rational design approaches involving chimeric receptor binding protein construction or site-specific mutagenesis, effectively balancing the discovery of unknown adaptive pathways with targeted host specificity modification. Moreover, we comprehensively discuss therapeutic applications across diverse clinical scenarios. Engineered bacteriophage effectively disrupt bacterial biofilms through sophisticated functionalized delivery platforms including nanozyme-conjugated phages, phage-liposome nanoconjugates and bio-responsive hydrogels, demonstrating significantly enhanced bactericidal efficiency compared to unmodified free phages. These bioengineered vectors attenuate bacterial virulence and resensitize pathogens to antibiotics by delivering CRISPR-Cas systems or base editors to disrupt critical virulence factors such as pili, capsule synthesis machineries and quorum sensing systems, or by inactivating antibiotic resistance determinants including beta-lactamase genes. As an intelligent nanomedicine delivery platform, engineered bacteriophage enable precise pathogen elimination an through photocatalytic reactive oxygen species generation, immunomodulatory interventions, or controlled release of antibacterial drugs. Furthermore, oral administration of engineered bacteriophage facilitates microbiota modulation, which selectively eliminate intestinal pathogens while preserve beneficial commensal microbiota, thereby restoring microbial community balance and preventing complications associated with dysbiosis. Finally, we critically analyze persistent challenges including host strain matching complexity, evolution of bacterial resistance mechanisms, pharmacokinetic optimization requirements, optimal administration route selection, large-scale production quality control standards and clinical dosing determination protocols. Through multidisciplinary integration of synthetic biology, infectious disease medicine and immunology, future translational medicine studies of bacteriophage should establish comprehensive technical platforms encompassing rapid phage screening, intelligent rational design, rigorous in vivo evaluation and standardized clinical validation processes, ultimately advancing engineered bacteriophage from laboratory innovations to clinically approved therapeutics for effectively combating MDR bacterial infections.

ObjectiveCerebral ischemic injury triggers a complex pathological cascade characterized by excessive reactive oxygen species (ROS) accumulation, persistent oxidative stress, and sustained neuroinflammation in the injured brain microenvironment. These events collectively drive mitochondrial dysfunction, microglial overactivation, pro-inflammatory cytokine release, and progressive neuronal apoptosis, ultimately leading to severe and irreversible neurological deficits. However, conventional therapeutic strategies face critical limitations, including poor blood-brain barrier penetration, insufficient local drug concentration, uncontrolled drug release, and off-target systemic side effects. To address this pathological process, we rationally designed and fabricated an injectable ROS-responsive hydrogel loaded with polydopamine nanoparticles (PDA NPs) for spatiotemporally controlled antioxidation, anti-inflammation, and neuroprotection in the ischemic injury microenvironment. The present study aimed to systematically characterize the physicochemical properties, ROS-responsive drug release behavior, biocompatibility, and neuroprotective efficacy of this composite hydrogel system in vitro. MethodsPDA NPs were fabricated via oxidative self-polymerization. The ROS-responsive hydrogel was cross-linked using N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1,N1,N3,N3-tetramethylpropane-1, 3-diaminium (TSPBA) and polyvinyl alcohol (PVA). Morphology, particle size, Zeta potential, and structure of PDA NPs were characterized by dynamic light scattering (DLS), Zeta potential analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Microstructure, rheological properties, shear-thinning behavior, and ROS-triggered release profiles of the hydrogel were examined by SEM and rheometry. Biocompatibility was evaluated using HT22 mouse hippocampal neurons with CCK-8 and live/dead staining. An oxygen-glucose deprivation/reoxygenation (OGD/R) model was established to simulate ischemic injury in vitro. ROS levels and neuronal apoptosis were detected by DHE staining and TUNEL assay. Microglial polarization and pro-inflammatory cytokine expression were analyzed using immunofluorescence and RT-qPCR in BV-2 microglia. Transwell co-culture was used to verify the indirect neuroprotection mediated by modulated microglia. ResultsCharacterization results confirmed that the as-prepared PDA NPs were monodispersed spherical nanoparticles with uniform diameter and negative surface potential, demonstrating favorable dispersibility and robust ROS-scavenging activity. The TSPBA-PVA hydrogel exhibited a highly porous interconnected network, suitable mechanical strength, and obvious shear-thinning behavior, supporting its application as an injectable implant. More importantly, the hydrogel displayed typical ROS-responsive degradation and on-demand PDA NP release in a ROS-concentration-dependent manner. In vitro cellular experiments demonstrated that the PDA NP-loaded hydrogel possessed excellent biocompatibility with HT22 cells. In the OGD/R model, the hydrogel significantly reduced intracellular ROS accumulation and markedly suppressed neuronal apoptosis. Furthermore, the composite hydrogel effectively redirected BV-2 microglia from the pro-inflammatory M1 toward the anti-inflammatory M2 phenotypes, downregulated the expression of pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6, and reduced inflammatory damage. Transwell co-culture assays further validated that M2-polarized microglia mediated by the hydrogel significantly enhanced the survival of OGD/R-injured HT22 neurons and attenuated apoptosis. ConclusionIn this study, we successfully developed a novel injectable ROS-responsive hydrogel loaded with PDA NPs for synergistic antioxidative and anti-inflammatory neuroprotection. This intelligent hydrogel system enables ROS-triggered on-demand release of PDA NPs, efficiently scavenges excessive ROS, inhibits oxidative stress injury, modulates microglial polarization, and suppresses neuroinflammation, thereby exerting robust neuroprotective effects in vitro. This biomaterial platform provides a promising strategy for the targeted and controlled delivery of bioactive nanomaterials in the central nervous system diseases and establishes a solid experimental foundation for the development of in situ injectable therapies for ischemic brain injury.