Tendon injuries pose significant challenges due to limited intrinsic healing capacity. Biomimetic scaffolds that provide mechanical support, promote cell infiltration, and guide tenogenic differentiation are critical for effective tendon regeneration. This study aimed to fabricate and evaluate braided and non-braided electrospun nanofibrous scaffolds composed of polyurethane (PU), methacrylated alginate (ALMA), and decellularized tendon extracellular matrix (dECM) for supporting human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) and tendon repair. Aligned PU/ALMA nanofibers were fabricated and assembled into stacked (non-braided) or braided scaffolds. Scaffolds were characterized mechanically and biochemically before and after seeding with hUC-MSCs. Cell viability and proliferation were assessed via MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. In vitro degradation was evaluated over 30 days in PBS) phosphate-buffered saline) and collagenase type1 solutions. Scaffolds were implanted into 1-cm Achilles tendon defects in rabbits, and tendon regeneration was assessed histologically at 12 weeks post-surgery. Braided scaffolds exhibited higher ultimate tensile load (33.31 N) and elongation at failure (180.75
Electroactive biomaterials represent a novel branch of functional biomaterials, which can integrate electrical conductivity with mechanical strength or structural integrity in regenerative matrices. In this review, electroactive scaffolds are discussed within a structure–property–function paradigm with special emphasis on the influence of material composition, scaffold architecture, interfacial chemistry, conductivity, mechanical compliance, biodegradation behavior, and mode of stimulation on cell outcomes. Polymers on conducting, piezoelectric composites, iono-active hydrogels, carbon-based nanomaterials and hybrid systems are discussed about charge transport, biocompatibility, biodegradability, electrochemical stability and potential for translation limitations. Fabrication techniques such as electrospinning, additive manufacturing (3D printing), lithographic patterning and hydrogel hybridization have been assessed based on replication, scalability and tissue type specific design attribute. The review also addresses mechanistic correlations between scaffold features, cell adhesion, proliferation, lineage differentiation, ion-channel activity, cytoskeletal organization, and gene expression. In addition, the review includes preclinical evidence, the status of clinical trials, the regulatory classification, the constraints of manufacturing and the financial considerations. In conclusion, electroactive scaffolds present exciting opportunities for tissue regeneration; however, translation will be enhanced by more rigorous quantitative reporting, demonstration of long-term safety, establishment of standardized scaffold fabrication protocols, and realistic renditions of translation.
Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) have emerged as promising cell-free therapeutics because of their immunomodulatory and regenerative potential. Yet their clinical translation remains constrained by a persistent gap between functional optimization and manufacturing control. Low production yield, substantial heterogeneity, limited cargo control, and inadequate process standardization continue to compromise reproducibility, cross-study comparability, and scalable development. As a result, improvements in functional performance have not been matched by equivalent advances in product consistency and clinical manufacturability. This review discusses how exogenous conditioning, endogenous engineering, and bioprocess design can be leveraged to improve both MSC-EV function and translational feasibility. We assess current approaches to enhancing MSC-EV production and therapeutic activity, including priming strategies, genetic modification, and scalable culture systems, with emphasis on their benefits, limitations, and clinical relevance. We also examine critical translational barriers, including inconsistent isolation and quantification methods, the lack of standardized potency assays, and ill-defined critical quality attributes. Future progress in MSC-EV therapeutics will depend not simply on improving efficacy, but on establishing integrated development frameworks that align functional optimization with controllable risk, traceable quality, and affordable cost.
Electrical perceptual threshold (EPT) testing is a quantitative sensory assessment used to evaluate the level and severity of sensory impairment after spinal cord injury (SCI). However, conventional EPT procedures may involve variability in stimulus delivery, examiner-dependent response logging, and manual workflow requirements. These limitations reduce reproducibility and hinder broader clinical adoption. This study aimed to develop a multi-dermatome computer-controlled electrical perceptual threshold (multi-dermatome CCEPT) system for standardized sensory assessment. The multi-dermatome CCEPT system was designed to deliver a standardized stimulation protocol in randomized order across 28 dermatomes bilaterally. It programmatically controlled pulse width, pulse count, current amplitude, and current-step size, while synchronizing participant responses, examiner verification, and digital data logging. The system and selected protocol parameters were evaluated in five non-disabled participants as part of an engineering design and protocol-selection study. A preliminary electrode comparison showed no significant difference in EPTmin between the two electrode types. Pulse count and current-step size influenced measured thresholds: three pulses per step produced significantly lower EPTmin values than one pulse per step, while 0.1 mA increments produced significantly lower EPTmin values than 0.2 mA increments. Three pulses per step and a 0.2 mA current increment were selected for subsequent testing based on the observed EPTmin responses together with practical protocol considerations. A representative bilateral dermatomal profile showed generally lower thresholds in cervical and thoracic dermatomes and higher thresholds in lumbosacral dermatomes, consistent with previously reported rostrocaudal EPT patterns. This study demonstrates the technical feasibility of an integrated multi-dermatome CCEPT research prototype for standardized EPT testing. The system combines computer-controlled stimulus delivery, automated channel routing, synchronized response capture, and structured digital data acquisition within a single workflow. Further studies using the finalized protocol are required to establish test–retest reliability, healthy dermatomal reference profiles, and clinical feasibility and validity in individuals living with SCI.
Preterm neonates have a substantially higher risk of developing cerebral palsy than term neonates, and early identification of abnormal fidgety movement (FM) is clinically important for early risk screening. This pilot study investigated whether a combined metric-learning loss can improve FM/non-FM (nFM) representation learning in a neonatal multimodal dataset. Data were obtained from 11 preterm neonates at 3–5 months of corrected age and segmented into 1957 multimodal samples consisting of motion history image (MHI) features and inertial measurement unit (IMU) signals, with FM/nFM labels and segment metadata organized in a unified manifest. The proposed ImageBind-based framework was trained using MHI and IMU inputs, with FM/nFM labels used for supervised loss optimization, and final test-stage inference was likewise performed using only MHI and IMU data. To address the complementary limitations of triplet loss and tuned constellation loss, we designed a combined loss that jointly enforces local distance constraints and global embedding structure. Within this predefined internal sample-level evaluation setting, the combined-loss model outperformed single-loss baselines, achieving an accuracy of 0.838, F1-score of 0.828, AUROC of 0.909, and AUPRC of 0.894 on the internal test partition. These findings suggest that the combined loss mitigated the failure modes of single-loss training and improved class-wise balance under the present pilot methodological setting. Overall, this study provides foundational evidence that multimodal metric learning can support FM/nFM representation learning in preterm neonates and motivates further validation in larger subject-held-out cohorts.
