Gang Yang

Objective: Myocardial infarction (MI) triggers inflammation and fibrosis that drive the progressive impairment of cardiac function. Yet most pharmacological studies still depend on single-time-point histological or imaging endpoints and lack longitudinal, non-invasive assessments of treatment response. Electrocardiography (ECG) detects conduction and repolarization abnormalities tightly associated with myocardial injury and structural remodeling. However, ECG monitoring in mice is limited by rigid or invasive hardware, which restricts its use for longitudinal assessment of cardiac structure and function. Approach: Here, we propose an ECG-based non-invasive post-MI cardiac remodeling assessment approach and develop a flexible electrocardiographic monitoring microsystem (FECMS). Using the anti-remodeling drug (colchicine) therapy in an MI mouse model (Sham n = 4, MI n = 7 survivors, Col n = 7 survivors) for validation, we longitudinally track drug-induced changes in ECG parameters and systematically evaluate their concordance with functional, structural, and molecular indicators of cardiac injury and remodeling. Results: Colchicine treatment induced progressive shortening of the QRS and QT intervals and gradual stabilization of the PR interval. These interval changes were accompanied by increased EF and FS, decreased LVESV, reduced myocardial fibrosis and inflammatory infiltration, and lower plasma troponin I levels at the endpoint. Correlation analyses revealed strong relationships between drug-induced changes in ECG parameters and functional recovery and inhibited structural remodeling. Significance: The FECMS provides a new, non-invasive tool for longitudinal cardiovascular drug evaluation. This approach has the potential to complement or reduce reliance on terminal histological endpoints and to facilitate the optimization of dosing strategies in preclinical cardiovascular pharmacology.

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder among children and adolescents. Behavioral detection and analysis play a crucial role in ADHD diagnosis and assessment by objectively quantifying hyperactivity and impulsivity symptoms. Existing video-based action recognition algorithms focus on object or interpersonal interactions, they may overlook ADHD-specific behaviors. Current keypoints-based algorithms, although effective in attenuating environmental interference, struggle to accurately model the sudden and irregular movements characteristic of ADHD children. This work proposes a novel keypoints-based system, the Multi-cue Feature Fusion Network (MF-Net), for recognizing actions and behaviors of children with ADHD during the Test of Variables of Attention (TOVA). The system aims to assess ADHD symptoms as described in the DSM-V by extracting features from human body and facial keypoints. For human body keypoints, we introduce the Multi-scale Features and Frame-Attention Adaptive Graph Convolutional Network (MSF-AGCN) to extract irregular and impulsive motion features. For facial keypoints, we transform data into images and employ MobileVitv2 for transfer learning to capture facial and head movement features. Ultimately, a feature fusion module is designed to fuse the features from both branches, yielding the final action category prediction. The system, evaluated on 3801 video samples of ADHD children, achieves 90.6% top-1 accuracy and 97.6% top-2 accuracy across six action categories. Additional validation experiments on public datasets NW-UCLA, NTU-2D, and AFEW-VA verify the network’s performance.

Mouse models are extensively used in the study of Myocardial Infarction (MI) pathophysiology and drug discovery. Electrocardiogram (ECG), a cost-effective, rapid, and highly accurate method, is crucial for assessing mouse MI models. However, monitoring physiological characteristics in small animals like mice poses challenges given their diminutive size and soft skin. This study introduces a low-cost wireless ECG monitoring system (WEMS) for MI mice, by utilizing homemade flexible dry electrodes. The conductivity and physical property tests of the electrodes were performed. WEMS-collected ECG was verified for reliability through comparison with the reference instrument BL-420N. Mouse conscious ECG signal acquisition using WEMS was performed before and after surgery in control group and MI mice. To demonstrate that ECG acquired by WEMS is a viable means for evaluating MI in mice, two groups of mice were assessed for cardiac function, histology, and molecular biomarkers. The electrodes exhibit stable conductivity, and their physical properties are enhanced by varying material ratios. WEMS and HF-420N ECG waveforms are similar. In conscious ECG monitoring before and after surgery, control, and MI mice showed significant differences in waveforms and characteristic parameters. Mice with abnormal ECG waveforms exhibited characteristics of myocardial ischemia in cardiac function, histology, and biomolecular marker assessment. A WEMS was made and validated, providing a valuable means of assessment for research and drug development related to MI in mice.

Objective . Neonatal jaundice is a common condition in the early stages of newborns, and phototherapy is a fast, safe and effective method that is used to treat it. However, recent studies have shown that phototherapy may elicit side effects in infants, such as hypothermia, hyperthermia and dehydration. To improve the quality of phototherapy and the prognosis of patients, the changes in neonatal physiological parameters during phototherapy should be monitored to give better feedback to pediatricians or the phototherapy system. However, the current standard of clinical care during neonatal phototherapy with hard-wired devices limits this realization. Approach . Here, we developed a prototype of a neonatal wearable device, which can wirelessly potentially monitor the jaundice value, transepidermal water loss, skin wettedness factor and body orientation during phototherapy, and conducted prototype validation experiments. We also set up user-friendly interfaces and an analysis system on custom software, all designed to make the future addition of data interfaces for treatment feedback functions easier. Main results . The preliminary in vitro experiment demonstrated the effectiveness of simultaneous monitoring of the required physiological parameters. And further suggestions and specific operations are discussed in terms of optimization of the treatment of neonatal jaundice. Significance . It is believed that the established system has the potential to provide a basis for future phototherapy nursing guidelines and physiological monitoring standards.

Cardiomyocyte (CM) transplantation is a promising option for regenerating infarcted myocardium. However, poor cell survival and residence rates reduce the efficacy of cell transplantation. Gelatin (GA) hydrogel as a frequently-used cell carrier is a possible approach to increase the survival rate of CMs. In this study, microbial transglutaminase (mTG) and chemical crosslinkers glutaraldehyde, genipin, and 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide were employed to prepare GA hydrogels. The mechanical properties and degradation characteristics of these hydrogels were then evaluated. Neonatal rat CMs (NRCMs) were isolated and inoculated on the surface of these hydrogels or encapsulated in mTG-hydrogels. Cellular growth morphology and beating behavior were observed. Cellular viability and immunofluorescence were analyzed. Intracellular Ca ²⁺ transient and membrane potential propagation were detected using fluorescence dyes (Fluo-3 and di-4-ANEPPS, respectively). Results showed that the chemical crosslinkers exhibited high cytotoxicity and resulted in high rates of cell death. By contrast, mTG-hydrogels showed excellent cell compatibility. The CMs cultured in mTG-hydrogels for a week expressed CM maturation markers. The NRCMs begun independently beating on the third day of culture, and their beating synchronized after a week of culture. Furthermore, intracellular Ca ²⁺ transient events with periodicity were observed. In conclusion, the novel mTG-crosslinked GA hydrogel synthesized herein has good biocompatibility, and it supports CM adhesion, growth, and maturation.

Background: Tissue engineering, which involves the selection of scaffold materials, presents a new therapeutic strategy for damaged tissues or organs. Scaffold design based on blends of proteins and polysaccharides, as mimicry of the native extracellular matrix, has recently become a valuable strategy for tissue engineering. Objective: This study aimed to construct composite hydrogels based on natural polymers for tissue engineering. Methods: Composite hydrogels based on blends of gelatin with a polysaccharide component (chitosan or alginate) were produced and subsequently enzyme crosslinked. The other three hydrogels, chitosan hydrogel, sodium alginate hydrogel, and microbial transglutaminase-crosslinked gelatin (mTG/GA) hydrogel were also prepared. All hydrogels were evaluated for in vitro degradation property, swelling capacity, and mechanical property. Rat adipose-derived stromal stem cells (ADSCs) were isolated and seeded on (or embedded into) the above-mentioned hydrogels. The morphological features of ADSCs were observed and recorded. The effects of the hydrogels on ADSC survival and adhesion were investigated by immunofluorescence staining. Cell proliferation was tested by thiazolyl blue tetrazolium bromide (MTT) assay. Results: Cell viability assay results showed that the five hydrogels are not cytotoxic. The mTG/GA and its composite hydrogels showed higher compressive moduli than the single-component chitosan and alginate hydrogels. MTT assay results showed that ADSCs proliferated better on the composite hydrogels than on the chitosan and alginate hydrogels. Light microscope observation and cell cytoskeleton staining showed that hydrogel strength had obvious effects on cell growth and adhesion. The ADSCs seeded on chitosan and alginate hydrogels plunged into the hydrogels and could not stretch out due to the low strength of the hydrogel, whereas cells seeded on composite hydrogels with higher elastic modulus, could spread out, and grew in size. Conclusion: The gelatin-polysaccharide composite hydrogels could serve as attractive biomaterials for tissue engineering due to their easy preparation and favorable biophysical properties.

This comparative study aims to identify a biocompatible and effective crosslinker for preparing gelatin sponges. Glutaraldehyde (GTA), genipin (GP), 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide (EDC), and microbial transglutaminase (mTG) were used as crosslinking agents. The physical properties of the prepared samples were characterized, and material degradation was studiedin vitrowith various proteases andin vivothrough subcutaneous implantation of the sponges in rats. Adipose-derived stromal stem cells (ADSCs) were cultured and inoculated onto the scaffolds to compare the cellular biocompatibility of the sponges. Cellular seeding efficiency and digestion time of the sponges were also evaluated. Cellular viability and proliferation in scaffolds were analyzed by fluorescence staining and MTT assay. All the samples exhibited high porosity, good swelling ratio, and hydrolysis properties; however, material strength, hydrolysis, and enzymolytic properties varied among the samples. GTA–sponge and GP–sponge possessed high compressive moduli, and EDC–sponge exhibited fast degradation performance. GTA and GP sponge implants exerted strongin vivorejections, and the former showed poor cell growth. mTG–sponge exhibited the optimal comprehensive performance, with good porosity, compressive modulus, anti-degradation ability, and good biocompatibility. Hence, mTG–sponge can be used as a scaffold material for tissue engineering applications.

Microbial transglutaminase (mTG) was used as a crosslinking agent in the preparation of gelatin sponges. The physical properties of the materials were evaluated by measuring their material porosity, water absorption, and elastic modulus. The stability of the sponges were assessed via hydrolysis and enzymolysis. To study the material degradation in vivo, subcutaneous implantations of sponges were performed on rats for 1–3 months, and the implanted sponges were analyzed. To evaluate the cell compatibility of the mTG crosslinked gelatin sponges (mTG sponges), adipose-derived stromal stem cells were cultured and inoculated into the scaffold. Cell proliferation and viability were measured using alamarBlue assay and LIVE/DEAD fluorescence staining, respectively. Cell adhesion on the sponges was observed by scanning electron microscopy (SEM). Results show that mTG sponges have uniform pore size, high porosity and water absorption, and good mechanical properties. In subcutaneous implantation, the material was partially degraded in the first month and completely absorbed in the third month. Cell experiments showed evident cell proliferation and high viability. Results also showed that the cells grew vigorously and adhered tightly to the sponge. In conclusion, mTG sponge has good biocompatibility and can be used in tissue engineering and regenerative medicine.