Real-Time Functional Assay of Volumetric Muscle Loss Injured Mouse Masseter Muscles via Nanomembrane Electronics

All-in-one wearable drug efficacy assessment systems for bulbar muscle function using amyotrophic lateral sclerosis animal models

Preclinical studies are crucial for developing amyotrophic lateral sclerosis drugs. Current FDA-approved drugs have been created by monitoring limb muscle function and histological analysis of amyotrophic lateral sclerosis model animals. Drug candidates for this disease have yet to be tested for bulbar-onset type due to the limitations of traditional preclinical tools: excessive animal use and discrete detection of disease progress. Here, our study introduces an all-in-one, wireless, integrated wearable system for facilitating continuous drug efficacy assessment of dysphagia-related muscles in animals during natural eating behaviors. By incorporating a kirigami-based strain-isolation mechanism, this device mounted on the skin of animals mitigates electromyography signal contamination caused by unpredictable animal movements. Our findings indicate this system, measuring the progression of motor neuron denervation, offers high precision in monitoring drug effects on dysphagia-responsible bulbar muscles. This study paves the way for more humane and efficient approaches to developing treatment solutions for degenerative neuromuscular diseases.

A critical size volumetric muscle loss model in mouse masseter with impaired mastication on nutrition

Orofacial muscle defect due to congenital anomalies, tumour ablation or traumatic accident that exceeds endogenous regeneration capacity may lead to sustained deficits in masticatory function and nutrition intake. Functional recovery has always been the goal of muscle tissue repair, but currently, there is no suitable model for quantitative analyses of either functional consequences or treatment efficacy of orofacial muscle defect. This study proposed a critical size volumetric muscle loss (VML) model in mouse masseter with impaired mastication on nutrition. Full-thickness VML defects in diameter of 1.0, 1.5, 2.0 and 3.0 mm were generated in the centre of the mouse masseter using a biopsy punch to determine the critical size for functional impairment. In the VML region, myogenesis was dampened but fibrogenesis was activated, as long with a reduction in the density of the neuromuscular junction and an increase in vascular density. Accordingly, persistent fibrosis was observed in the centre region of VML in all diameters. The 2.0 mm diameter was the critical threshold to masticatory function impairment after VML in the masseter. VML of 3.0 mm diameter led to a significant impact on nutrition intake and body weight gain. Autologous muscle graft effectively relieved the fibrosis and functional deficit after VML injury in the masseter. This model serves as a reliable tool in studying functional recovery strategies for orofacial muscle defects.

Acrylated Hyaluronic-Acid Based Hydrogel for the Treatment of Craniofacial Volumetric Muscle Loss

Current treatment options for craniofacial volumetric muscle loss (VML) have disadvantages and cannot fully restore normal function. Bio-inspired semisynthetic acrylated hyaluronic acid (AcHyA) hydrogel, which fills irregularly shaped defects, resembles an extracellular matrix, and induces a minimal inflammatory response, has shown promise in experimental studies of extremity VML. We therefore sought to study AcHyA hydrogel in the treatment of craniofacial VML. For this, we used a novel model of masseter VML in the rat. Following the creation of a 5 mm × 5 mm injury to the superficial masseter and administration of AcHyA to the wound, masseters were explanted between 2 and 16 weeks postoperatively and were analyzed for evidence of muscle regeneration including fibrosis, defect size, and fiber cross-sectional area (FCSA). At 8 and 16 weeks, masseters treated with AcHyA showed significantly less fibrosis than nonrepaired controls and a smaller decrease in defect size. The mean FCSA among fibers near the defect was significantly greater among hydrogel-repaired than control masseters at 8 weeks, 12 weeks, and 16 weeks. These results show that the hydrogel mitigates the fibrotic healing response and wound contracture. Our findings also suggest that hydrogel-based treatments have potential use as a treatment for the regeneration of craniofacial VML and demonstrate a system for evaluating subsequent iterations of materials in VML injuries.

A fabric-based wearable sensor for continuous monitoring of decubitus ulcer of subjects lying on a bed

For multifunctional wearable sensing systems, problems related to wireless and continuous communication and soft, noninvasive, and disposable functionality issues should be solved for precise physiological signal detection. To measure the critical transitions of pressure, temperature, and skin impedance when continuous pressure is applied on skin and tissue, we developed a sensor for decubitus ulcers using conventional analog circuitry for wireless and continuous communication in a disposable, breathable fabric-based multifunctional sensing system capable of conformal contact. By integrating the designed wireless communication module into a multifunctional sensor, we obtained sensing data that were sent sequentially and continuously to a customized mobile phone app. With a small-sized and lightweight module, our sensing system operated over 24 h with a coin-cell battery consuming minimum energy for intermittent sensing and transmission. We conducted a pilot test on healthy subjects to evaluate the adequate wireless operation of the multifunctional sensing system when applied to the body. By solving the aforementioned practical problems, including those related to wireless and continuous communication and soft, noninvasive, and disposable functionality issues, our fabric-based multifunctional decubitus ulcer sensor successfully measured applied pressure, skin temperature, and electrical skin impedance.

The era of nano-bionic: 2D materials for wearable and implantable body sensors

Nano-bionics have the potential of revolutionizing modern medicine. Among nano-bionic devices, body sensors allow to monitor in real-time the health of patients, to achieve personalized medicine, and even to restore or enhance human functions. The advent of two-dimensional (2D) materials is facilitating the manufacturing of miniaturized and ultrathin bioelectronics, that can be easily integrated in the human body. Their unique electronic properties allow to efficiently transduce physical and chemical stimuli into electric current. Their flexibility and nanometric thickness facilitate the adaption and adhesion to human body. The low opacity permits to obtain transparent devices. The good cellular adhesion and reduced cytotoxicity are advantageous for the integration of the devices in vivo. Herein we review the latest and more significant examples of 2D material-based sensors for health monitoring, describing their architectures, sensing mechanisms, advantages and, as well, the challenges and drawbacks that hampers their translation into commercial clinical devices.

Highly-integrated, miniaturized, stretchable electronic systems based on stacked multilayer network materials

Elastic stretchability and function density represent two key figures of merits for stretchable inorganic electronics. Various design strategies have been reported to provide both high levels of stretchability and function density, but the function densities are mostly below 80%. While the stacked device layout can overcome this limitation, the soft elastomers used in previous studies could highly restrict the deformation of stretchable interconnects. Here, we introduce stacked multilayer network materials as a general platform to incorporate individual components and stretchable interconnects, without posing any essential constraint to their deformations. Quantitative analyses show a substantial enhancement (e.g., by ~7.5 times) of elastic stretchability of serpentine interconnects as compared to that based on stacked soft elastomers. The proposed strategy allows demonstration of a miniaturized electronic system (11 mm by 10 mm), with a moderate elastic stretchability (~20%) and an unprecedented areal coverage (~110%), which can serve as compass display, somatosensory mouse, and physiological-signal monitor.