1.Neuroelectromagnetic Activities Across Temporal Scales
Zhuo-Qun SHEN ; Xiao-Fei XU ; Yan-Qing WANG ; Jing-Xin LI ; Lan TIAN ; Wei GUO ; Jing-Jing XU
Progress in Biochemistry and Biophysics 2026;53(6):1541-1560
Although global brain science research has progressed rapidly in recent decades, several fundamental questions in neuroscience remain unresolved. In particular, the physical mechanism underlying neural signal transmission remains controversial, and the carriers responsible for neural information storage and retrieval have not yet been fully clarified. These unresolved issues motivate us to re-examine the processes of neural information generation, transmission, integration, storage, and retrieval from multiple perspectives. A key observation is that neural electromagnetic activities are closely associated with time. Their duration, temporal structure, and dynamic evolution play crucial roles in neural information processing. In this work, we analyze neural electromagnetic activities from the perspective of temporal scales (referred to here as the “time course”). By reviewing and integrating findings from previous studies, we examine the characteristic time requirements and dynamic features of neural processes occurring at different stages of information processing. These stages include neural signal generation, signal transmission along axons, synaptic integration, synaptic plasticity, and memory formation and retrieval. Based on this temporal analysis, we outline a framework describing neural electromagnetic activities across a wide range of time scales, spanning from microseconds to minutes, hours, or even longer periods associated with long-term memory, which suggests that neural information processing involves multiple physical processes operating at different time levels. Rapid electromagnetic events may occur on microsecond scales, whereas electrophysiological phenomena such as action potentials typically last on the order of milliseconds. Longer time scales are associated with synaptic plasticity and memory-related processes. From this perspective, we propose that the physical carrier of neural information may be transient electromagnetic pulses with durations on the microsecond scale. In this framework, action potentials can be interpreted as the macroscopic electrophysiological manifestation of underlying electromagnetic processes triggered by ionic currents across neuronal membranes. Rather than being the fundamental neural signal itself, the action potential may represent a measurable membrane-level response associated with the successful activation of these electromagnetic events. Moreover, we discuss a possible mechanism for long-term memory storage. Considering the apparent temporal contradiction between the millisecond-scale excitation of neurons and the long-term persistence of memories, we believe that long-term memory information may be stored within neural network topologies formed by electrical synapse coupling. Such structures, referred to as electrically coupled memory networks (ECMNs), may enable neurons within the same network to respond rapidly and synchronously to stimuli, thereby facilitating efficient memory retrieval. Overall, this study emphasizes the importance of considering the temporal organization of neural electromagnetic activities when interpreting neural signaling mechanisms. It may provide new insights into the physical nature of neural information carriers and the mechanisms of memory storage and retrieval. Furthermore, highlighting the potential role of electromagnetic interactions in neural activity may contribute to the development of new theoretical frameworks and experimental approaches in neuroscience. Such perspectives may also offer valuable references for future research on neural coding, brain function mechanisms, and neuromodulation technologies.
2.Discussion on Pathogenesis and Treatment of Esophageal Precancerous Lesions from the Perspective of "Turbidity Damaging the Clear and Harmonious"
Cong HE ; Tingting XU ; Yi WANG ; Jing KONG ; Xiao WANG ; Xiaosu WANG ; Shumiao FAN ; Shengliang ZHU ; Bingduo ZHOU
Journal of Traditional Chinese Medicine 2026;67(13):1397-1402
It is considered that "turbid pathogen damaging the clear, and the loss of clarity and harmony regulation" is the core pathogenesis of esophageal precancerous lesions, with turbid pathogen persisting throughout the disease course. Turbid pathogen encompasses qi turbidity, phlegm turbidity, stasis turbidity, and toxin turbidity, closely related to dietary indiscretion, emotional disharmony, spleen-stomach deficiency, and kidney deficiency failing to consolidate. Turbid pathogen undergoes a dynamic evolution process of qi constraint generating turbid→ phlegm-stasis transforming into toxin→turbidity toxin harming the healthy qi, corresponding to the pathological alterations of hypoxia, inflammation and immunosuppression within the tumor microenvironment. The overall therapeutic principle is to remove turbidity and restore clarity. In the early stage, targeting the hypoxic tumor microenvironment, the suggested treatment method is opening constraint and dispersing the block, regulating qi and remove turbidity, with emphasis on soothing liver and regulating stomach, raising the clear and directing the turbid downward. In the middle stage, targeting inflammatory microenvironment, the treatment aims to clear toxin and dissipate nodules, resolve stasis and eliminate turbid, emphasizing phlegm-stasis elimination, turbid-toxin resolution, and concurrent stomach qi protection. In the late stage, corresponding to immunosuppressive microenvironment, the method of boosting qi, nourishing yin, reinforcing healthy qi, and eliminating turbidity can be used, with focus on spleen-stomach tonification, kidney essence replenishment, and healthy qi reinforcement to expel pathogenic factors.
3.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
4.Efficacy of Zishen Huoxue Formula in treatment of molecular-targeted therapy-associated proteinuria in patients with primary liver cancer
Jing JING ; Aozhe ZHANG ; Simiao YU ; Xin WANG ; Yongqiang SUN ; Yiling WANG ; Ruixin GAO ; Yinying LU ; Xiaohe XIAO ; Ruilin WANG
Journal of Clinical Hepatology 2026;42(4):874-881
ObjectiveTo investigate the effect of Zishen Huoxue Formula (ZSXHF) on molecular-targeted therapy-associated proteinuria in patients with primary liver cancer (PLC), to assess the efficacy of ZSXHF in the treatment of molecular-targeted therapy-associated proteinuria, and to provide a basis for clinical medication. MethodsA retrospective cohort study was conducted among the PLC patients with molecular-targeted therapy-associated proteinuria who were diagnosed and treated in The Department of Hepatology of Chinese PLA General Hospital, from January 1, 2022 to July 1, 2025. With ZSXHF treatment as the exposure factor, the patients with a cumulative treatment duration of ≥9 weeks were enrolled as traditional Chinese medicine (TCM) group, while those without TCM treatment were enrolled as control group. Propensity score matching was performed for the two groups at a ratio of 1∶1 based on sex, age, 24-hour urinary protein, blood urea nitrogen, and serum creatinine. The independent-samples t test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between groups. Univariate and multivariate Logistic regression analyses were used to investigate the influencing factors for promoting the improvement of targeted-therapy-associated proteinuria. ResultsA total of 137 PLC patients with targeted-therapy-associated proteinuria were enrolled, with 34 patients in the TCM group and 103 in the control group. After follow-up for 6 months, the TCM group had a significant improvement in urinary protein grade compared with the control group (χ2=9.261, P=0.016). There were 25 patients in each group after propensity score matching, and after follow-up for 6 months, there were significant differences between the two groups in urinary protein grade (χ2=15.689, P<0.001) and 24-hour urinary protein (Z=-3.075, P=0.002). After cumulative treatment with ZSXHF for ≥9 weeks, the TCM group had a significantly greater change in 24-hour urinary protein from baseline compared with the control group (t=-2.514, P=0.016), while there were no significant differences in the changes in liver and renal function after ZSXHF intervention between the two groups (all P>0.05). The multivariate Logistic regression analysis showed that ZSXHF treatment (odds ratio=2.901, 95% confidence interval: 1.135 — 7.417, P=0.026) was an independent influencing factor for improvement in molecular-targeted therapy-associated proteinuria. ConclusionZSHXF can effectively alleviate molecular-targeted therapy-associated proteinuria in PLC patients with a favorable safety profile, which provides a new reference for TCM prevention and treatment of molecular-targeted therapy-associated adverse reactions in PLC patients.
5.Constructing a rat animal model of pelvic organ prolapse:a comparison of three modeling methods
Jing YANG ; Houmei WANG ; Yi WANG ; Min SONG ; Jie REN ; Lujun DAI ; Ziwen XIAO
Chinese Journal of Tissue Engineering Research 2026;30(4):864-872
BACKGROUND:Currently,there are many modeling methods for pelvic organ prolapse animal models,and the commonly used methods are vaginal balloon dilatation,oophorectomy and the combination of the two.There is no study comparing the three modeling methods in detail.OBJECTIVE:To construct and validate a rat animal model of pelvic organ prolapse using three different methods and to identify the advantages and disadvantages of various models.METHODS:Seventy-two 8-week SPF-grade female Sprague-Dawley rats were selected and randomly divided into four groups,namely,vaginal balloon dilatation group,ovariectomy group,ovariectomy combined with vaginal balloon dilatation group(the combined group),and the sham-operated group(no ovariectomy and no vaginal dilatation).The vaginal wall tissues of rats were collected at 4,8 and 12 weeks after the operation for hematoxylin-eosin staining,Masson staining,EVG staining and immunohistochemical staining of α-smooth muscle actin,Vimentin and matrix metalloproteinase 9 detection,and the pelvic floor muscle tissues were taken at 4,8 and 12 weeks after the operation for hematoxylin-eosin staining,Masson staining and EVG staining.RESULTS AND CONCLUSION:(1)Hematoxylin-eosi staining showed that there was no significant difference in the decrease of vaginal epithelial layer thickness in the vaginal balloon dilatation group compared with the sham-operated group,(P>0.05),while the thickness of the vaginal epithelial layer was significantly reduced in the ovariectomy group and the ovariectomy combined with vaginal balloon dilation group(P<0.001),and the reduction was more significant in the ovariectomy combined with vaginal balloon dilation group,remained stable at 8 weeks after surgery and lasted until 12 weeks.(2)The changes in the content of collagen fibers and elastic fibers in the vaginal wall stained by Masson and EVG staining were the same as the changes in the thickness of the vaginal epithelial layer stained by hematoxylin-eosin,and there were no changes in collagen fibers and elastic fibers in the pelvic floor muscle tissues of the treatment groups.(3)At 4,8 and 12 weeks after treatment,there was no significant difference in the expression levels of α-smooth muscle actin,Vimentin and matrix metalloproteinase 9 in the vaginal wall tissue of the balloon dilation group compared with the control group(P>0.05),whereas the expression levels of α-smooth muscle actin and Vimentin were significantly decreased in the ovariectomy group and ovariectomy combined with vaginal balloon dilation group(P<0.01)and the expression of matrix metalloproteinase 9 showed a significant increase(P<0.01),with a more pronounced increase in the ovariectomy combined with vaginal balloon dilation group,and the increase reached a stable state at 8 weeks after surgery and could persist up to 12 weeks.To conclude,vaginal balloon dilatation could not maintain the degeneration of pelvic organ prolapse formed by the vaginal wall for a long period,and both ovariectomy and the combined method can be used.Ovariectomy combined with vaginal balloon dilatation can significantly accelerate and aggravate the formation of typical histological features of pelvic organ prolapse in vaginal wall tissues,effectively shorten the experimental period,and improve the efficiency.These effects reach a stable state at 8 weeks after surgery and can be sustained up to 12 weeks,which is practical and convenient for the study of pelvic organ prolapse animal models.
6.Biomechanical mechanism of sports-related patellar tendinitis
Caihong ZHONG ; Xiaoge XIAO ; Ming LI ; Jianhong LIN ; Jing HONG
Chinese Journal of Tissue Engineering Research 2026;30(6):1417-1423
BACKGROUND:Patellar tendonitis can present as tendon degeneration that fails to heal due to tissue overload and incomplete recovery.Patellar tendonitis is a predisposition to high jumping and its pathogenesis has not been clearly defined.OBJECTIVE:To explore the stress-strain relationship of patellar tendon in the take-off technique of high jump through the finite element model with accurate human anatomical structure,so as to provide ideas for the prevention and rehabilitation of patellar tendinitis.METHODS:Based on the CT and MRI imaging data of the lower extremity(including the knee and ankle)of one subject(22 years old,183 cm height,70 kg body mass),a three-dimensional finite element model of the lower extremity was reconstructed using medical imaging software,reverse engineering software and modeling software.The plantar pressure of the take-off leg was collected in eight subjects by gait testing system,and the technical action of high jump take-off was collected by motion capture system.The captured data were imported into human sports biomechanics software for analysis,and kinematic and kinetic data were obtained as the boundary conditions of finite element model for finite element simulation analysis.RESULTS AND CONCLUSION:The force borne by the patellar tendon reached 3.29 times of its own body mass when the subjects took off.In the take-off stage,the peak values of normal equivalent stress,strain and shear stress of the patellar tendon were 127.76 MPa,0.81 and 37.69 MPa,respectively,which were in the nonlinear region of the stress-strain curve,and the peak values were distributed in the proximal and posterior parts of patellar tendon.To conclude,the high patellar tendon force,strain and shear stress caused by the load of 3.29 times its own body mass during take-off are related to the induction of patellar tendinitis.
7.Construction of Organoid-on-a-chip and Its Applications in Biomedical Fields
Rui-Xia LIU ; Jing ZHANG ; Xiao LI ; Yi LIU ; Long HUANG ; Hong-Wei HOU
Progress in Biochemistry and Biophysics 2026;53(2):293-308
Organoid-on-a-chip technology represents a promising interdisciplinary advancement that merges two cutting-edge biomedical platforms: stem cell-derived organoids and microfluidics-based organ-on-a-chip systems. Organoids are self-organizing three-dimensional (3D) cell cultures that mimic the key structural and functional features of in vivo organs. However, traditional organoid culture systems are often static, lacking dynamic environmental cues and suffering from limitations such as batch-to-batch variability, low stability, and low throughput. Organ-on-a-chip platforms, by contrast, utilize microfluidic technologies to simulate the dynamic physiological microenvironment of human tissues and organs, enabling more controlled cell growth and differentiation. By integrating the advantages of organoids and organ-on-a-chip technologies, organoid-on-a-chip systems transcend the limitations of conventional 3D culture models, offering a more physiologically relevant and controllable in vitro platform. In organoid-on-a-chip systems, stem cells or pre-formed organoids are cultured in micro-engineered environments that mimic in vivo conditions, enabling precise control over fluid flow, mechanical forces, and biochemical cues. Specifically, these platforms employ advanced strategies including bio-inspired 3D scaffolds for structural support, precise spatial cell patterning via 3D bioprinting, and integrated biosensors for real-time monitoring of metabolic activities. These synergistic elements recreate complex extracellular matrix signals and ensure high structural fidelity. Based on structural complexity, organoid-on-a-chip systems are classified into single-organoid and multi-organoid types, forming a trajectory from unit biomimicry to systemic simulation. Single-organoid chips focus on highly biomimetic units by integrating vascular, immune, or neural functions. Multi-organoid chips simulate inter-organ crosstalk and systemic homeostasis, advancing complex disease modeling and PK/PD evaluation. This emerging technology has demonstrated broad application potential in multiple fields of biomedicine. Organoid-on-a-chip systems can recapitulate organ developmentin vitro, facilitating research in developmental biology. They mimic organ-specific physiological activities and mechanisms, showing promising applications in regenerative medicine for tissue repair or replacement. In disease modeling, they support the reconstruction of models for neurodegenerative, inflammatory, infectious, metabolic diseases, and cancers. These platforms also enable in vitro drug testing and pharmacokinetic studies (ADME). Patient-derived chips preserve genetic and pathological features, offering potential for precision medicine. Additionally, they reduce species differences in toxicology, providing human-relevant data for environmental, food, cosmetic, and drug safety assessments. Despite progress, organoid-on-a-chip systems face challenges in dynamic simulation, extracellular matrix (ECM) variability, and limited real-time 3D imaging, requiring improved materials and the integration of developmental signals. Current bottlenecks also include the high technical threshold for automation and the lack of standardized validation frameworks for regulatory adoption. Meanwhile, the concept of a “human-on-a-chip” has been proposed to mimic whole-body physiology by integrating multiple organoid modules. This approach enables systemic modeling of drug responses and toxicity, with the potential to reduce animal testing and revolutionize drug development. Future advancements in bio-responsive hydrogels and flexible biosensors will further empower these platforms to bridge the gap between bench-side research and personalized clinical interventions. In conclusion, organoid-on-a-chip technology offers a transformative in vitro model that closely recapitulates the complexity of human tissues and organ systems. It provides an unprecedented platform for advancing biomedical research, clinical translation, and pharmaceutical innovation. Continued development in biomaterials, microengineering, and analytical technologies will be essential to unlocking the full potential of this powerful tool.
8.Spatiotemporal Electrical Impedance Tomography for Speech Respiratory Assessment in Cleft Palate: an Interpretable Machine Learning Study
Yang WU ; Xiao-Jing ZHANG ; Hao YU ; Cheng-Hui JIANG ; Bo SUN ; Jia-Feng YAO
Progress in Biochemistry and Biophysics 2026;53(2):485-500
ObjectiveCleft palate (CP) is a common congenital deformity often associated with velopharyngeal insufficiency (VPI), which disrupts the physiological coupling between respiration and speech. Conventional clinical assessments, such as nasometry and spirometry, provide limited static data and fail to visualize the dynamic spatiotemporal distribution of lung ventilation during phonation. This study introduces spatiotemporal electrical impedance tomography (ST-EIT) to evaluate speech-respiratory functional features in CP patients compared to normal controls (NC). The aim is to characterize multi-domain respiratory patterns and to validate an interpretable machine learning framework for providing objective, quantitative evidence for clinical assessment. MethodsSeventy-five participants were enrolled in this study, comprising 37 patients with surgically repaired CP and 38 healthy volunteers matched for age, gender, and body mass index (BMI). All subjects performed standardized sustained phonation tasks while undergoing synchronous monitoring with a 16-electrode EIT system and a pneumotachograph. A comprehensive feature engineering pipeline was developed to extract physiological parameters across 3 complementary domains. (1) Temporal domain: including inspiratory/expiratory phase duration (tPhase), time constants (Tau), and inspiratory-to-expiratory time ratios (TI/TE); (2) airflow domain: comprising mean flow, peak flow, and instantaneous flow at 25%, 50%, and 75% of tidal volume; and (3) spatial domain: quantifying global and regional tidal impedance variation (TIV), global inhomogeneity (GI), and center of ventilation (CoV). Extreme Gradient Boosting (XGBoost) classifiers were trained using 5 distinct data sources (Spirometry, Nasometry, Inspiratory-EIT, Expiratory-EIT, and fused ST-EIT). Model performance was rigorously evaluated via stratified 5-fold cross-validation, and Shapley additive explanations (SHAP) were employed to quantify global and local feature contributions. ResultsThe CP group exhibited a distinct respiratory phenotype compared to controls. In the temporal domain, CP patients showed significantly shorter inspiratory (1.60 s vs.1.85 s, P<0.001) and expiratory phase durations (2.45 s vs. 3.95 s, P<0.001), indicating a rapid, shallow breathing rhythm. In the airflow domain, while inspiratory flows were comparable, the CP group demonstrated significantly elevated mean and peak flows during the expiratory phase (P<0.001), reflecting compensatory respiratory effort. Spatially, CP patients presented significant ventilation redistribution, characterized by higher regional TIV in the right-anterior (ROI1) and left-posterior (ROI4) quadrants, but lower TIV in the left-anterior (ROI2) quadrant. In terms of diagnostic accuracy, the multi-modal ST-EIT model achieved the highest performance (AUC: 0.915±0.012, Accuracy: 0.843±0.019, F1-score: 0.872±0.017), substantially outperforming models based on spirometry (AUC: 0.721) or nasometry (AUC: 0.625) alone. Interpretability analysis revealed that spatial domain features were the most critical, contributing 53.4% to the model’s decision-making, followed by temporal (25.0%) and airflow (21.6%) features. ConclusionST-EIT successfully captures the temporal, airflow, and spatial deviations in CP speech respiration that are undetectable by conventional methods—specifically, rapid phase transitions, hyperdynamic expiratory airflow, and regional ventilation heterogeneity. This study validates ST-EIT as a robust, non-invasive, and radiation-free tool for characterizing speech-respiratory dysfunction, offering high clinical value for bedside screening, rehabilitation planning, and longitudinal monitoring of patients with cleft palate.
9.Construction of Organoid-on-a-chip and Its Applications in Biomedical Fields
Rui-Xia LIU ; Jing ZHANG ; Xiao LI ; Yi LIU ; Long HUANG ; Hong-Wei HOU
Progress in Biochemistry and Biophysics 2026;53(2):293-308
Organoid-on-a-chip technology represents a promising interdisciplinary advancement that merges two cutting-edge biomedical platforms: stem cell-derived organoids and microfluidics-based organ-on-a-chip systems. Organoids are self-organizing three-dimensional (3D) cell cultures that mimic the key structural and functional features of in vivo organs. However, traditional organoid culture systems are often static, lacking dynamic environmental cues and suffering from limitations such as batch-to-batch variability, low stability, and low throughput. Organ-on-a-chip platforms, by contrast, utilize microfluidic technologies to simulate the dynamic physiological microenvironment of human tissues and organs, enabling more controlled cell growth and differentiation. By integrating the advantages of organoids and organ-on-a-chip technologies, organoid-on-a-chip systems transcend the limitations of conventional 3D culture models, offering a more physiologically relevant and controllable in vitro platform. In organoid-on-a-chip systems, stem cells or pre-formed organoids are cultured in micro-engineered environments that mimic in vivo conditions, enabling precise control over fluid flow, mechanical forces, and biochemical cues. Specifically, these platforms employ advanced strategies including bio-inspired 3D scaffolds for structural support, precise spatial cell patterning via 3D bioprinting, and integrated biosensors for real-time monitoring of metabolic activities. These synergistic elements recreate complex extracellular matrix signals and ensure high structural fidelity. Based on structural complexity, organoid-on-a-chip systems are classified into single-organoid and multi-organoid types, forming a trajectory from unit biomimicry to systemic simulation. Single-organoid chips focus on highly biomimetic units by integrating vascular, immune, or neural functions. Multi-organoid chips simulate inter-organ crosstalk and systemic homeostasis, advancing complex disease modeling and PK/PD evaluation. This emerging technology has demonstrated broad application potential in multiple fields of biomedicine. Organoid-on-a-chip systems can recapitulate organ developmentin vitro, facilitating research in developmental biology. They mimic organ-specific physiological activities and mechanisms, showing promising applications in regenerative medicine for tissue repair or replacement. In disease modeling, they support the reconstruction of models for neurodegenerative, inflammatory, infectious, metabolic diseases, and cancers. These platforms also enable in vitro drug testing and pharmacokinetic studies (ADME). Patient-derived chips preserve genetic and pathological features, offering potential for precision medicine. Additionally, they reduce species differences in toxicology, providing human-relevant data for environmental, food, cosmetic, and drug safety assessments. Despite progress, organoid-on-a-chip systems face challenges in dynamic simulation, extracellular matrix (ECM) variability, and limited real-time 3D imaging, requiring improved materials and the integration of developmental signals. Current bottlenecks also include the high technical threshold for automation and the lack of standardized validation frameworks for regulatory adoption. Meanwhile, the concept of a “human-on-a-chip” has been proposed to mimic whole-body physiology by integrating multiple organoid modules. This approach enables systemic modeling of drug responses and toxicity, with the potential to reduce animal testing and revolutionize drug development. Future advancements in bio-responsive hydrogels and flexible biosensors will further empower these platforms to bridge the gap between bench-side research and personalized clinical interventions. In conclusion, organoid-on-a-chip technology offers a transformative in vitro model that closely recapitulates the complexity of human tissues and organ systems. It provides an unprecedented platform for advancing biomedical research, clinical translation, and pharmaceutical innovation. Continued development in biomaterials, microengineering, and analytical technologies will be essential to unlocking the full potential of this powerful tool.
10.Spatiotemporal Electrical Impedance Tomography for Speech Respiratory Assessment in Cleft Palate: an Interpretable Machine Learning Study
Yang WU ; Xiao-Jing ZHANG ; Hao YU ; Cheng-Hui JIANG ; Bo SUN ; Jia-Feng YAO
Progress in Biochemistry and Biophysics 2026;53(2):485-500
ObjectiveCleft palate (CP) is a common congenital deformity often associated with velopharyngeal insufficiency (VPI), which disrupts the physiological coupling between respiration and speech. Conventional clinical assessments, such as nasometry and spirometry, provide limited static data and fail to visualize the dynamic spatiotemporal distribution of lung ventilation during phonation. This study introduces spatiotemporal electrical impedance tomography (ST-EIT) to evaluate speech-respiratory functional features in CP patients compared to normal controls (NC). The aim is to characterize multi-domain respiratory patterns and to validate an interpretable machine learning framework for providing objective, quantitative evidence for clinical assessment. MethodsSeventy-five participants were enrolled in this study, comprising 37 patients with surgically repaired CP and 38 healthy volunteers matched for age, gender, and body mass index (BMI). All subjects performed standardized sustained phonation tasks while undergoing synchronous monitoring with a 16-electrode EIT system and a pneumotachograph. A comprehensive feature engineering pipeline was developed to extract physiological parameters across 3 complementary domains. (1) Temporal domain: including inspiratory/expiratory phase duration (tPhase), time constants (Tau), and inspiratory-to-expiratory time ratios (TI/TE); (2) airflow domain: comprising mean flow, peak flow, and instantaneous flow at 25%, 50%, and 75% of tidal volume; and (3) spatial domain: quantifying global and regional tidal impedance variation (TIV), global inhomogeneity (GI), and center of ventilation (CoV). Extreme Gradient Boosting (XGBoost) classifiers were trained using 5 distinct data sources (Spirometry, Nasometry, Inspiratory-EIT, Expiratory-EIT, and fused ST-EIT). Model performance was rigorously evaluated via stratified 5-fold cross-validation, and Shapley additive explanations (SHAP) were employed to quantify global and local feature contributions. ResultsThe CP group exhibited a distinct respiratory phenotype compared to controls. In the temporal domain, CP patients showed significantly shorter inspiratory (1.60 s vs.1.85 s, P<0.001) and expiratory phase durations (2.45 s vs. 3.95 s, P<0.001), indicating a rapid, shallow breathing rhythm. In the airflow domain, while inspiratory flows were comparable, the CP group demonstrated significantly elevated mean and peak flows during the expiratory phase (P<0.001), reflecting compensatory respiratory effort. Spatially, CP patients presented significant ventilation redistribution, characterized by higher regional TIV in the right-anterior (ROI1) and left-posterior (ROI4) quadrants, but lower TIV in the left-anterior (ROI2) quadrant. In terms of diagnostic accuracy, the multi-modal ST-EIT model achieved the highest performance (AUC: 0.915±0.012, Accuracy: 0.843±0.019, F1-score: 0.872±0.017), substantially outperforming models based on spirometry (AUC: 0.721) or nasometry (AUC: 0.625) alone. Interpretability analysis revealed that spatial domain features were the most critical, contributing 53.4% to the model’s decision-making, followed by temporal (25.0%) and airflow (21.6%) features. ConclusionST-EIT successfully captures the temporal, airflow, and spatial deviations in CP speech respiration that are undetectable by conventional methods—specifically, rapid phase transitions, hyperdynamic expiratory airflow, and regional ventilation heterogeneity. This study validates ST-EIT as a robust, non-invasive, and radiation-free tool for characterizing speech-respiratory dysfunction, offering high clinical value for bedside screening, rehabilitation planning, and longitudinal monitoring of patients with cleft palate.

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