Fully biodegradable and self-powered nerve guidance conduit based on zinc-molybdenum batteries for peripheral nerve repair.

Peripheral nerve injury (PNI) poses a significant public health issue, often leading to muscle atrophy and persistent neuropathic pain, which can drastically impact the quality of life for patients. Electrical stimulation represents an effective and non-pharmacological treatment to promote nerve regeneration. Yet, the postoperative application of electrical stimulation remains a challenge. Here, we propose a fully biodegradable, self-powered nerve guidance conduit (NGC) based on dissolvable zinc-molybdenum batteries. The conduit can offer topographic guidance for nerve regeneration and deliver sustained electrical cues between both ends of a transected nerve stump, extending beyond the surgical window. Schwann cell proliferation and adenosine triphosphate (ATP) production are enhanced by the introduction of the zinc-molybdenum batteries. In rodent models with 10-mm sciatic nerve damage, the device effectively enhances nerve regeneration and motor function recovery. This study offers innovative strategies for creating biodegradable and electroactive devices that hold important promise to optimize therapeutic outcomes for nerve regeneration.

Ferroelectric-assisted charge carrier separation over Bi2MoO6 nanosheets for photocatalytic dye degradation.

Low energy conversion efficiency from the absorbed photon to the catalytic species remains a major obstacle for the real application of photocatalysis. In recent years, the introduction of a built-in electric field has proved to be impactful in facilitating the photoinduced charge separation, among which, ferroelectric polarization is highly recommended by getting rid of mechanical stresses. Developing ferroelectrics directly as photoactive semiconductors is promising in view of the synergistic catalytic enhancement. Therefore, Bi2MoO6 nanosheets with ultrathin layered structure (<10 nm) and abundant oxygen vacancies were synthesized through the hydrothermal method. The two-dimensional nanostructure created more active sites and a convenient polarization condition. Subsequently, corona poling was applied on the Bi2MoO6 nanosheets, which can significantly accelerate the 100% degradation rate of RhB from 50 to 20 min, surpassing that of metal-free photocatalysts. The combined effect of semiconductor, ferroelectric polarization, oxygen vacancies, and nano-layered structure offers new strategies for designing multifield coupling catalysts, providing insights into the regulation of charge carrier dynamics.

Geometrical and Chemical-Dependent Hydrolysis Mechanisms of Silicon Nanomembranes for Biodegradable Electronics.

Biodegradable electronic devices that physically disappear in physiological or environmental solutions are of critical importance for widespread applications in healthcare management and environmental sustainability. The precise modulation of materials and devices dissolution with on-demand operational lifetime, however, remain a key challenge. Silicon nanomembranes (Si NMs) are one of the essential semiconductor components for high-performance biodegradable electronics at the system level. In this work, we discover unusual hydrolysis behaviors of Si NMs that are significantly dependent on the dimensions of devices as well as their surface chemistry statuses. The experiments show a pronounced increase in hydrolysis rates of p-type Si NMs with larger sizes, and mechanical stirring introduces a significant decrease in dissolution rates. The presence of phosphates and potassium ions in solutions, or lower dopant levels of Si NMs will facilitate the degradation of Si NMs and will also lead to a stronger size-dependent effect. Molecular dynamics simulations are performed to reveal ion adsorption mechanisms of Si NMs under different surface charge statuses and confirm our experimental observations. Through geometrical designs, Si NM-based electrode arrays with tunable dissolution lifetime are formed, and their electrochemical properties are analyzed in vitro. These results offer new controlling strategies to modulate the operational time frames of Si NMs through geometrical design and surface chemistry modification and provide crucial fundamental understandings for engineering high-performance biodegradable electronics.