Multifunctional materials for implantable and wearable photonic healthcare devices

Flexible, surface-lighting MicroLED skin patch for multiple human skincare

As the global population ages, concerns regarding aesthetic appearance have increased. Wearable light-emitting diode (LED) devices have received significant attention in the cosmetic fields due to their non-invasive, non-thermal, home-use characteristics. However, conventional bulk LED chips have limitations in flexibility and uniform irradiation, hindering efficient light penetration into the skin. Here, we introduce a flexible, surface-lighting microLED (FSLED) patch with uniform light-emission for various skincare applications. The FSLED was fabricated using a pick-and-place transfer technique, which allows for high-density irradiation over the large area, while maintaining outstanding mechanical flexibility. In addition, the FSLED was designed to deliver light efficiently and emit light evenly by conforming to the skin. Finally, we prove the effect of the FSLED for pore tightening and skin rejuvenation through clinical trials.

Albumins constrainting the conformation of mitochondria-targeted photosensitizers for tumor-specific photodynamic therapy

Tumor ablation Preclinical organelle-targeted phototherapies have effectively achieved tumor photoablation for regenerative biomedical applications in cancer therapies. However, engineering effective phototherapy drugs with precise tumor-localization targeting and organelle direction remains challenging. Herein, we report a albumins constrainting mitochondrial-targeted photosensitizer nanoparticles (PSs@BSAs) for tumor-specific photodynamic therapy. X-ray crystallography elucidates the two-stage assembly mechanism of PSs@BSAs. Femtosecond transient absorption spectroscopy and quantum mechanical calculations reveal the implications of conformational dynamics at the excited state. PSs@BSAs can efficiently disable mitochondrial activity, and further disrupt tumor angiogenesis based on the photodynamic effect. This triggers a metabolic and oxidative stress crisis to facilitate photoablation of solid tumor and antitumor metastasis. The study fully elucidates the interdisciplinary issues of chemistry, physics, and biological interfaces, thereby opening new horizons to inspire the engineering of organelle-targeted tumor-specific photosensitizers for biomedical applications.

Smart theranostic contact lenses

Although smart contact lenses have demonstrated great potential in theranostics, there remain critical challenges and opportunities in their commercial development. In this Perspective, the current status and capability of smart theranostic contact lenses are highlighted, focusing on their application as sensing systems for detecting biomarkers such as glucose, intraocular pressure (IOP), and inflammatory cytokines, and as drug delivery systems (DDS) for precise and controlled therapy. Additionally, key challenges associated with clinical development and commercialization of smart theranostic contact lenses are discussed, to optimize diagnostic and therapeutic interventions. Considering the rapid evolution of the field, we finally also discuss the need for systematic studies on safety, efficacy, and mass-production, and we spark new ideas for advancing smart theranostic contact lenses into versatile platforms for personalized medicine.

Imine-Based Polymeric Mixed Ionic-Electronic Conductors Featuring Degradability and Biocompatibility for Transient Bioinspired Electronics

Degradable features are highly desirable to advance next-generation organic mixed ionic-electronic conductors (OMIECs) for transient bioinspired artificial intelligence devices. It is highly challenging that OMIECs exhibit excellent mixed ionic-electronic behavior and show degradability simultaneously. Specially, in OMIECs, doping is often a tradeoff between structural disorder and charge carrier mobilities. Here, we describe a regiochemistry-driven backbone curvature approach to prepare OMIECs, enabling doped state ordered within efficient ionic-electronic conduction in organic electrochemical transistors (OECTs) and presenting degradable characteristics. Significantly, i-3gTIT shows an outstanding mobility (1.99 cm2 V-1 s-1) and μC* (302 F V-1 cm-1 s-1), and presents higher disorder-tolerance upon doping and faster degradation behavior than its regioisomer, o-3gTIT. Especially, the resulting OECT-based inverter shows a high voltage gain of 31.6 V V-1 at a low driving voltage of 0.6 V. Moreover, we demonstrate an application of transient OECT, i. e., biodegradable solid-state electrolyte of OECT-based artificial synapses. Remarkably, the regiochemistry-driven film crystallinity modulation enables the conversion from volatile to non-volatile operation in such synapses. The transient synapse based on i-3gTIT achieves over 90 % recognition accuracy for small digit handwritten images, showing potential in security neuromorphic computing. Our work is the first presentation enabling excellent mixed conduction of OMIECs with degradable features for transient bioinspired electronics.

Biomaterials for reliable wearable health monitoring: Applications in skin and eye integration

Recent advancements in biomaterials have significantly impacted wearable health monitoring, creating opportunities for personalized and non-invasive health assessments. These developments address the growing demand for customized healthcare solutions. Durability is a critical factor for biomaterials in wearable applications, as they must withstand diverse wearing conditions effectively. Therefore, there is a heightened focus on developing biomaterials that maintain robust and stable functionalities, essential for advancing wearable sensing technologies. This review examines the biomaterials used in wearable sensors, specifically those interfaced with human skin and eyes, highlighting essential strategies for achieving long-lasting and stable performance. We specifically discuss three main categories of biomaterials-hydrogels, fibers, and hybrid materials-each offering distinct properties ideal for use in durable wearable health monitoring systems. Moreover, we delve into the latest advancements in biomaterial-based sensors, which hold the potential to facilitate early disease detection, preventative interventions, and tailored healthcare approaches. We also address ongoing challenges and suggest future directions for research on material-based wearable sensors to encourage continuous innovation in this dynamic field.

Wearable blood pressure sensors for cardiovascular monitoring and machine learning algorithms for blood pressure estimation

With advances in materials science and medical technology, wearable sensors have become crucial tools for the early diagnosis and continuous monitoring of numerous cardiovascular diseases, including arrhythmias, hypertension and coronary artery disease. These devices employ various sensing mechanisms, such as mechanoelectric, optoelectronic, ultrasonic and electrophysiological methods, to measure vital biosignals, including pulse rate, blood pressure and changes in heart rhythm. In this Review, we provide a comprehensive overview of the current state of wearable cardiovascular sensors, focusing particularly on those that measure blood pressure. We explore biosignal sensing principles, discuss blood pressure estimation methods (including machine learning algorithms) and summarize the latest advances in cuffless wearable blood pressure sensors. Finally, we highlight the challenges of and offer insights into potential pathways for the practical application of cuffless wearable blood pressure sensors in the medical field from both technical and clinical perspectives.

Advances in Photonic Materials and Integrated Devices for Smart and Digital Healthcare: Bridging the Gap Between Materials and Systems

Recent advances in developing photonic technologies using various materials offer enhanced biosensing, therapeutic intervention, and non-invasive imaging in healthcare. Here, this article summarizes significant technological advancements in materials, photonic devices, and bio-interfaced systems, which demonstrate successful applications for impacting human healthcare via improved therapies, advanced diagnostics, and on-skin health monitoring. The details of required materials, necessary properties, and device configurations are described for next-generation healthcare systems, followed by an explanation of the working principles of light-based therapeutics and diagnostics. Next, this paper shares the recent examples of integrated photonic systems focusing on translation and immediate applications for clinical studies. In addition, the limitations of existing materials and devices and future directions for smart photonic systems are discussed. Collectively, this review article summarizes the recent focus and trends of technological advancements in developing new nanomaterials, light delivery methods, system designs, mechanical structures, material functionalization, and integrated photonic systems to advance human healthcare and digital healthcare.

Photonic Nanomaterials for Wearable Health Solutions

This review underscores the transformative potential of photonic nanomaterials in wearable health technologies, driven by increasing demands for personalized health monitoring. Their unique optical and physical properties enable rapid, precise, and sensitive real-time monitoring, outperforming conventional electrical-based sensors. Integrated into ultra-thin, flexible, and stretchable formats, these materials enhance compatibility with the human body, enabling prolonged wear, improved efficiency, and reduced power consumption. A comprehensive exploration is provided of the integration of photonic nanomaterials into wearable devices, addressing material selection, light-matter interaction principles, and device assembly strategies. The review highlights critical elements such as device form factors, sensing modalities, and power and data communication, with representative examples in skin patches and contact lenses. These devices enable precise monitoring and management of biomarkers of diseases or biological responses. Furthermore, advancements in materials and integration approaches have paved the way for continuum of care systems combining multifunctional sensors with therapeutic drug delivery mechanisms. To overcome existing barriers, this review outlines strategies of material design, device engineering, system integration, and machine learning to inspire innovation and accelerate the adoption of photonic nanomaterials for next-generation of wearable health, showcasing their versatility and transformative potential for digital health applications.

Single-Cell Multi-omics Assessment of Spinal Cord Injury Blocking via Cerium-doped Upconversion Antioxidant Nanoenzymes

Spinal cord injury (SCI) impairs the central nervous system and induces the myelin-sheath-deterioration because of reactive oxygen species (ROS), further hindering the recovery of function. Herein, the simultaneously emergency treatment and dynamic luminescence severity assessment (SETLSA) strategy is designed for SCI based on cerium (Ce)-doped upconversion antioxidant nanoenzymes (Ce@UCNP-BCH). Ce@UCNP-BCH can not only efficiently eliminate the SCI localized ROS, but dynamically monitor the oxidative state in the SCI repair process using a ratiometric luminescence signal. Moreover, the classic basso mouse scale score and immunofluorescence analysis together exhibit that Ce@UCNP-BCH effectively facilitates the regeneration of spinal cord including myelin sheath, and promotes the functional recovery of SCI mice. Particularly, the study combines snATAC-eq and snRNA-seq to reveal the heterogeneity of spinal cord tissue following Ce@UCNP-BCH treatment. The findings reveal a significant increase in myelinating oligodendrocytes, as well as higher expression of myelination-related genes, and the study also reveals the gene regulatory dynamics of remyelination after treatment. Besides, the ETLSA strategy synergistically boosts ROS consumption through the superoxide dismutase (SOD)-related pathways after SOD-siRNA treatment. In conclusion, this SETLSA strategy with simultaneously blocking and dynamic monitoring oxidative stress has enriched the toolkit for promoting SCI repair.

Stretchable Multimodal Photonic Sensor for Wearable Multiparameter Health Monitoring

Stretchable sensors that can conformally interface with the skins for wearable and real-time monitoring of skin deformations, temperature, and sweat biomarkers offer critical insights for early disease prediction and diagnosis. Integration of multiple modalities in a single stretchable sensor to simultaneously detect these stimuli would provide a more comprehensive understanding of human physiology, which, however, has yet to be achieved. Here, this work reports, for the first time, a stretchable multimodal photonic sensor capable of simultaneously detecting and discriminating strain deformations, temperature, and sweat pH. The multimodal sensing abilities are enabled by realization of multiple sensing mechanisms in a hydrogel-coated polydimethylsiloxane (PDMS) optical fiber (HPOF), featured with high flexibility, stretchability, and biocompatibility. The integrated mechanisms are designed to operate at distinct wavelengths to facilitate stimuli decoupling and employ a ratiometric detection strategy for improved robustness and accuracy. To simplify sensor interrogation, spectrally-resolved multiband emissions are generated upon the excitation of a single-wavelength laser, utilizing upconversion luminescence (UCL) and radiative energy transfer (RET) processes. As proof of concept, this work demonstrates the feasibility of simultaneous monitoring of the heartbeat, respiration, body temperature, and sweat pH of a person in real-time, with only a single sensor.

Inverse design of nanophotonic devices enabled by optimization algorithms and deep learning: recent achievements and future prospects

Nanophotonics, which explores significant light-matter interactions at the nanoscale, has facilitated significant advancements across numerous research fields. A key objective in this area is the design of ultra-compact, high-performance nanophotonic devices to pave the way for next-generation photonics. While conventional brute-force, intuition-based forward design methods have produced successful nanophotonic solutions over the past several decades, recent developments in optimization methods and artificial intelligence offer new potential to expand these capabilities. In this review, we delve into the latest progress in the inverse design of nanophotonic devices, where AI and optimization methods are leveraged to automate and enhance the design process. We discuss representative methods commonly employed in nanophotonic design, including various meta-heuristic algorithms such as trajectory-based, evolutionary, and swarm-based approaches, in addition to adjoint-based optimization. Furthermore, we explore state-of-the-art deep learning techniques, involving discriminative models, generative models, and reinforcement learning. We also introduce and categorize several notable inverse-designed nanophotonic devices and their respective design methodologies. Additionally, we summarize the open-source inverse design tools and commercial foundries. Finally, we provide our perspectives on the current challenges of inverse design, while offering insights into future directions that could further advance this rapidly evolving field.

TiOx-Based Implantable Memristor for Biomedical Engineering

Implantable memristors are considered an emerging electronic technology that can simulate brain memory function and demonstrate some promising applications in the biomedical field. However, it remains a critical challenge to enhance their long-term stability and biocompatibility in implantation environments. In this work, an implantable memristor has been successfully fabricated based on TiOx using magnetron sputtering. The device demonstrated excellent thermal stability and recoverability at elevated temperatures, providing important experimental evidence for its applications under high-temperature environments. More importantly, after long-term testing under biological mimicking environments, such as fresh pork and bullfrog tissues, the memristor maintained excellent bipolar resistive switching (RS) characteristics and stable memory performance, indicating its potential for use in medical fields. Further analysis revealed that the RS behaviors of the device are mainly controlled by space charge limited currents (SCLC), Ohmic conduction, and Schottky emission conduction mechanisms. Therefore, the long-term stability of the implantable memristor is validated under real biological environments, promoting the transition of implantable memristor from theory to practical applications and laying the foundation for further biomedical applications.

Molecular-scale in-operando reconfigurable electronic hardware

It is challenging to reconfigure devices at molecular length scales. Here we report molecular junctions based on molecular switches that toggle stably and reliably between multiple operations to reconfigure electronic devices at molecular length scales. Rather than static on/off switches that always revert to the same state, our voltage-driven molecular device dynamically switches between high and low conduction states during six consecutive proton-coupled electron transfer steps. By changing the applied voltage, different states are accessed resulting in in operando reconfigurable electronic functionalities of variable resistor, diode, memory, and NDR (negative differential conductance). The switching behavior is voltage driven but also has time-dependent features making it possible to access different memory states. This multi-functional switch represents molecular scale hardware operable in solid-state devices (in the form of electrode-monolayer-electrode junctions) that are interesting for areas of research where it is important to have access to time-dependent changes such as brain-inspired (or neuromorphic) electronics.

Lighting the Path to Precision Healthcare: Advances and Applications of Wearable Photonic Sensors

Recent advancements in wearable photonic sensors have marked a transformative era in healthcare, enabling non-invasive, real-time, portable, and personalized medical monitoring. These sensors leverage the unique properties of light toward high-performance sensing in form factors optimized for real-world use. Their ability to offer solutions to a broad spectrum of medical challenges - from routine health monitoring to managing chronic conditions, inspires a rapidly growing translational market. This review explores the design and development of wearable photonic sensors toward various healthcare applications. The photonic sensing strategies that power these technologies are first presented, alongside a discussion of the factors that define optimal use-cases for each approach. The means by which these mechanisms are integrated into wearable formats are then discussed, with considerations toward material selection for comfort and functionality, component fabrication, and power management. Recent developments in the space are detailed, accounting for both physical and chemical stimuli detection through various non-invasive biofluids. Finally, a comprehensive situational overview identifies critical challenges toward translation, alongside promising solutions. Associated future outlooks detail emerging trends and mechanisms that stand to enable the integration of these technologies into mainstream healthcare practice, toward advancing personalized medicine and improving patient outcomes.

Liquid-based encapsulation for implantable bioelectronics across broad pH environments

Wearable and implantable bioelectronics that can interface for extended periods with highly mobile organs and tissues across a broad pH range would be useful for various applications in basic biomedical research and clinical medicine. The encapsulation of these systems, however, presents a major challenge, as such devices require superior barrier performance against water and ion penetration in challenging pH environments while also maintaining flexibility and stretchability to match the physical properties of the surrounding tissue. Current encapsulation materials are often limited to near-neutral pH conditions, restricting their application range. In this work, we report a liquid-based encapsulation approach for bioelectronics under extreme pH environments. This approach achieves high optical transparency, stretchability, and mechanical durability. When applied to implantable wireless optoelectronic devices, our encapsulation method demonstrates outstanding water resistance in vitro, ranging from extremely acidic environments (pH = 1.5 and 4.5) to alkaline conditions (pH = 9). We also demonstrate the in vivo biocompatibility of our encapsulation approach and show that encapsulated wireless optoelectronics maintain robust operation throughout 3 months of implantation in freely moving mice. These results indicate that our encapsulation strategy has the potential to protect implantable bioelectronic devices in a wide range of research and clinical applications.

Stretchable Primary-Blue Color-Conversion Layer: In Situ Crystallization of Phase-Engineered Perovskite Nanocrystals in an Organic Matrix

Although the use of ultraviolet (UV) light-emitting diode backlight with red, green, and blue color-conversion layers (CCLs) in displays simplifies the manufacturing process and improves display uniformity, research on blue CCLs remains limited and has been mostly reported in the sky-blue region (> 470 nm), which is insufficient to satisfy the Rec. 2020 color standard. As halide perovskites offer a high extinction coefficient, color purity, and photoluminescence quantum yield (PLQY), they become highly competitive color-converting materials for CCLs. This work presents a simple method for the in situ fabrication of perovskite nanocrystal (NC) films for primary-blue CCL and additionally proposes a set of scientific guidance rules regarding significant factors that affect the nucleation and in situ crystallization kinetics of perovskite NCs. The fabricated films are highly stretchable, emit bright primary-blue light (∼460 nm), and have PL that is tolerant to UV irradiation. By introducing fluorinated arylammonium salts, the quantum and dielectric confinement effects are desirably adjusted, which induces efficient energy transfer processes for primary-blue emission. This strategy yields phase-engineered perovskite NCs embedded in an organic matrix, which enables spectrally stable and robust PL under high tensile strain (> 250%) and after prolonged UV irradiation (> 40 d). Consequently, this work demonstrates that the in situ fabricated stretchable blue CCLs achieve 100% agreement with Rec. 2020.

Integration of Functional Materials in Photonic and Optoelectronic Technologies for Advanced Medical Diagnostics

Integrating functional materials with photonic and optoelectronic technologies has revolutionized medical diagnostics, enhancing imaging and sensing capabilities. This review provides a comprehensive overview of recent innovations in functional materials, such as quantum dots, perovskites, plasmonic nanomaterials, and organic semiconductors, which have been instrumental in the development of diagnostic devices characterized by high sensitivity, specificity, and resolution. Their unique optical properties enable real-time monitoring of biological processes, advancing early disease detection and personalized treatment. However, challenges such as material stability, reproducibility, scalability, and environmental sustainability remain critical barriers to their clinical translation. Breakthroughs such as green synthesis, continuous flow production, and advanced surface engineering are addressing these limitations, paving the way for next-generation diagnostic tools. This article highlights the transformative potential of interdisciplinary research in overcoming these challenges and emphasizes the importance of sustainable and scalable strategies for harnessing functional materials in medical diagnostics. The ultimate goal is to inspire further innovation in the field, enabling the creation of practical, cost-effective, and environmentally friendly diagnostic solutions.

In situ fabrication of self-filtered near-infrared Ti3C2Tx/n-Si Schottky-barrier photodiodes for a continuous non-invasive photoplethysmographic system

Two-dimensional (2D) MXenes have emerged as promising candidates to serve as Schottky contact electrodes for the development of high-performance photodiodes owing to their extraordinary electronic properties. However, it remains a formidable challenge to fabricate a large-area, uniform MXene layer for practical device application. Here, we develop a facile route to produce a large-area Ti3C2Tx layer by post-etching treatment of a pulsed laser-deposited Ti3AlC2 film, enabling the in situ construction of a back-illuminated Ti3C2Tx/n-Si Schottky-barrier photodiode. Significantly, the device exhibits excellent performance with a distinctive self-filtered near-infrared (NIR) photoresponse behavior in the range of 700-1100 nm. By avoiding disturbances caused by ambient light, the NIR photodiode-based transmission-type photoplethysmographic (PPG) measurement system is capable of more reliable detection of PPG waveforms than the commercial PPG sensors for continuously monitoring heart rate. This enables the accurate extraction of blood pressures using a PPG-only method. Our findings not only pave the way for fabrication of a high-quality large-area 2D MXene layer, but also provide a general design principle for developing high-performance MXene/Si photodiodes for health monitoring systems.

Zwitterion Interlocked Diarylethene Molecules Order, Unconnected Diarylethene Molecules Disorder

A diarylethene-based zwitterionic molecule (DZM) is newly synthesized for the development of smart films exhibiting reversible color change and switchable ionic conductivity in response to external light stimuli. This dual molecular building block is constructed through zwitterionic interlocking and strong phase separation between the dendron-shaped aliphatic tails and the diarylethene head. Uniaxial shear coating and molecular self-assembly result in anisotropically oriented nanostructures, which are further solidified through photopolymerization. In the absence of zwitterionic interlocking, DZM fails to form ordered structures and remains disordered. The anisotropically oriented nanostructures of DZM exhibit polarization-dependent photochromic properties despite the inherent low anisotropy of a single diarylethene chromophore. Structural analysis reveals that the zwitterion-interlocked molecular building block self-assemble into nanocolumns that align uniaxially during the shear coating process. Alternating ultraviolet and visible light reversibly switches the ionic conductivity of the DZM thin film and a change in color is observed due to the photoisomerization of the diarylethene chromophore. Utilizing the polarization-dependent photochromic properties, light-sensitive smart thin films are demonstrated with potential applications in anti-counterfeiting labels and sensors.

Recent progress of flexible rechargeable batteries

The rapid popularization of wearable electronics, soft robots and implanted medical devices has stimulated extensive research in flexible batteries, which are bendable, foldable, knittable, wearable, and/or stretchable. Benefiting from these distinct characteristics, flexible batteries can be seamlessly integrated into various wearable/implantable devices, such as smart home systems, flexible displays, and implantable sensors. In contrast to conventional lithium-ion batteries necessitating the incorporation of stringent current collectors and packaging layers that are typically rigid, flexible batteries require the flexibility of each component to accommodate diverse shapes or sizes. Accordingly, significant advancements have been achieved in the development of flexible electrodes, current collectors, electrolytes, and flexible structures to uphold superior electrochemical performance and exceptional flexibility. In this review, typical structures of flexible batteries are firstly introduced and classified into mono-dimensional, two-dimensional, and three-dimensional structures according to their configurations. Subsequently, five distinct types of flexible batteries, including flexible lithium-ion batteries, flexible sodium-ion batteries, flexible zinc-ion batteries, flexible lithium/sodium-air batteries, and flexible zinc/magnesium-air batteries, are discussed in detail according to their configurations, respectively. Meanwhile, related comprehensive analysis is introduced to delve into the fundamental design principles pertaining to electrodes, electrolytes, current collectors, and integrated structures for various flexible batteries. Finally, the developments and challenges of flexible batteries are summarized, offering viable guidelines to promote the practical applications in the future.

An AI-Cyborg System for Adaptive Intelligent Modulation of Organoid Maturation

Recent advancements in flexible bioelectronics have enabled continuous, long-term stable interrogation and intervention of biological systems. However, effectively utilizing the interrogated data to modulate biological systems to achieve specific biomedical and biological goals remains a challenge. In this study, we introduce an AI-driven bioelectronics system that integrates tissue-like, flexible bioelectronics with cyber learning algorithms to create a long-term, real-time bidirectional b ioelectronic interface with o ptimized a daptive intelligent m odulation (BIO-AIM). When integrated with biological systems as an AI-cyborg system, BIO-AIM continuously adapts and optimizes stimulation parameters based on stable cell state mapping, allowing for real-time, closed-loop feedback through tissue-embedded flexible electrode arrays. Applied to human pluripotent stem cell-derived cardiac organoids, BIO-AIM identifies optimized stimulation conditions that accelerate functional maturation. The effectiveness of this approach is validated through enhanced extracellular spike waveforms, increased conduction velocity, and improved sarcomere organization, outperforming both fixed and no stimulation conditions.

Switchable 3D Photonic Crystals Based on the Insulator-to-Metal Transition in VO2

Photonic crystals (PhCs) are optical structures characterized by the spatial modulation of the dielectric function, which results in the formation of a photonic band gap (PBG) in the frequency spectrum. This PBG blocks the propagation of light, enabling filtering, confinement, and manipulation of light. Most of the research in this field has concentrated on static PhCs, which have fixed structural and material parameters, leading to a constant PBG. However, the growing demand for adaptive photonic devices has led to an increased interest in switchable PhCs, where the PBG can be reversibly activated or shifted. Vanadium dioxide (VO2) is particularly notable for its near-room-temperature insulator-to-metal transition (IMT), which is accompanied by significant changes in its optical properties. Here, we demonstrate a fabrication strategy for switchable three-dimensional (3D) PhCs, involving sacrificial templates and a VO2 atomic layer deposition (ALD) process in combination with an accurately controlled annealing procedure. The resulting VO2 inverse opal (IO) PhC achieves substantial control over PBG in the near-infrared (NIR) region. Specifically, the synthesized VO2 IO PhC exhibits PBGs near 1.49 and 1.03 μm in the dielectric and metallic states of the VO2 material, respectively, which can be reversibly switched by adjusting the external temperature. Furthermore, a temperature-dependent switch from a narrow-band NIR reflector to a broad-band absorber is revealed. This work highlights the potential of integrating VO2 into 3D templates in the development of switchable photonics with complex 3D structures, offering a promising avenue for the advancement of photonic devices with adaptable functionalities.

Flexible bioelectronic systems with large-scale temperature sensor arrays for monitoring and treatments of localized wound inflammation

Continuous monitoring and closed-loop therapy of soft wound tissues is of particular interest in biomedical research and clinical practices. An important focus is on the development of implantable bioelectronics that can measure time-dependent temperature distribution related to localized inflammation over large areas of wound and offer in situ treatment. Existing approaches such as thermometers/thermocouples provide limited spatial resolution, inapplicable to a wearable/implantable format. Here, we report a conformal, scalable device package that integrates a flexible amorphous silicon-based temperature sensor array and drug-loaded hydrogel for the healing process. This system can enable the spatial temperature mapping at submillimeter resolution and high sensitivity of 0.1 °C, for dynamically localizing the inflammation regions associated with temperature change, automatically followed with heat-triggered drug delivery from hydrogel triggered by wearable infrared light-emitting-diodes. We establish the operational principles experimentally and computationally and evaluate system functionalities with a wide range of targets including live animal models and human subjects. As an example of medical utility, this system can yield closed-loop monitoring/treatments by tracking of temperature distribution over wound areas of live rats, in designs that can be integrated with automated wireless control. These findings create broad utilities of these platforms for clinical diagnosis and advanced therapy for wound healthcare.

Clinical Validation of Face-Fit Surface-Lighting Micro Light-Emitting Diode Mask for Skin Anti-Aging Treatment

Photobiomodulation therapy based on micro light-emitting diodes (µLEDs) holds remarkable potential for the beauty industry. Here, a cosmetically effective face-fit surface-lighting µLED mask for skin anti-aging is introduced. The face-conformable mask enables deep tissue treatment through proximal light irradiation, with a 3D origami structure capable of adapting to complex facial contours with closed adherence. A blister-assisted laser transfer achieves rapid and accurate µLEDs transfer at a high throughput of 50 chips per second, facilitating a mass-producible and large-area process. Finally, clinical trials demonstrate significant improvements in elasticity, sagging, and wrinkles across six facial areas, with a maximum enhancement of 340% in deep skin elasticity of the perioral area compared to the conventional LED mask group.

Functional Semi-Interpenetrating Polymer Networks

Semi-interpenetrating polymer networks (SIPNs) have garnered significant interest due to their potential applications in self-healing materials, drug delivery systems, electrolytes, functional membranes, smart gels and, toughing. SIPNs combine the characteristics of physical cross-linking with advantageous chemical properties, offering broad application prospects in materials science and engineering. This perspective introduces the history of semi-interpenetrating polymer networks and their diverse applications. Additionally, the ongoing challenges associated with traditional semi-interpenetrating polymer materials are discussed and provide an outlook on future advancements in novel functional SIPNs.

Material design of biodegradable primary batteries: boosting operating voltage by substituting the hydrogen evolution reaction at the cathode

Transient primary batteries (TPBs) degrade after use without leaving harmful toxic substances, providing power sources for developing low-invasive and environmentally benign sensing platforms. Magnesium and zinc, both abundant on Earth, possess low anodic potentials and good biodegradability, making them useful as anode materials. However, molybdenum, a biodegradable metal, causes the hydrogen evolution reaction (HER) at the cathode, reducing the operating voltage of cells because of its low cathodic potential. In this review, we examine recent material designs to increase the operating voltage by introducing alternative electrochemical reactions at the cathode, including the oxygen reduction reaction, metal-ion intercalation into transition metal oxides, and halogen ionization, all of which have higher cathodic potentials than the HER. After discussing the characteristics, constituents, and demonstration of TPBs, we conclude by exploring their potential as power sources for implants, wearables, and environmental sensing applications.

A wearable and stretchable dual-wavelength LED device for home care of chronic infected wounds

Phototherapy can offer a safe and non-invasive solution against infections, while promoting wound healing. Conventional phototherapeutic devices are bulky and limited to hospital use. To overcome these challenges, we developed a wearable, flexible red and blue LED (r&bLED) patch controlled by a mobile-connected system, enabling safe self-application at home. The patch exhibits excellent skin compatibility, flexibility, and comfort, with high safety under system supervision. Additionally, we synthesized a sprayable fibrin gel (F-gel) containing blue light-sensitive thymoquinone and red light-synergistic NADH. Combined with bLED, thymoquinone eradicated microbes and biofilms within minutes, regardless of antibiotic resistance. Furthermore, NADH and rLED synergistically improved macrophage and endothelial cell mitochondrial function, promoting wound healing, reducing inflammation, and enhancing angiogenesis, as validated in infected diabetic wounds in mice and minipigs. This innovative technology holds great promise for revolutionizing at-home phototherapy for chronic infected wounds.

Advances in Biointegrated Wearable and Implantable Optoelectronic Devices for Cardiac Healthcare

With the prevalence of cardiovascular disease, it is imperative that medical monitoring and treatment become more instantaneous and comfortable for patients. Recently, wearable and implantable optoelectronic devices can be seamlessly integrated into human body to enable physiological monitoring and treatment in an imperceptible and spatiotemporally unconstrained manner, opening countless possibilities for the intelligent healthcare paradigm. To achieve biointegrated cardiac healthcare, researchers have focused on novel strategies for the construction of flexible/stretchable optoelectronic devices and systems. Here, we overview the progress of biointegrated flexible and stretchable optoelectronics for wearable and implantable cardiac healthcare devices. Firstly, the device design is addressed, including the mechanical design, interface adhesion, and encapsulation strategies. Next, the practical applications of optoelectronic devices for cardiac physiological monitoring, cardiac optogenetics, and nongenetic stimulation are presented. Finally, an outlook on biointegrated flexible and stretchable optoelectronic devices and systems for intelligent cardiac healthcare is discussed.

Multifunctional nanomaterials for smart wearable diabetic healthcare devices

Wearable diabetic healthcare devices have attracted great attention for real-time continuous glucose monitoring (CGM) using biofluids such as tears, sweat, saliva, and interstitial fluid via noninvasive ways. In response to the escalating global demand for CGM, these devices enable proactive management and intervention of diabetic patients with incorporated drug delivery systems (DDSs). In this context, multifunctional nanomaterials can trigger the development of innovative sensing and management platforms to facilitate real-time selective glucose monitoring with remarkable sensitivity, on-demand drug delivery, and wireless power and data transmission. The seamless integration into wearable devices ensures patient's compliance. This comprehensive review evaluates the multifaceted roles of these materials in wearable diabetic healthcare devices, comparing their glucose sensing capabilities with conventionally available glucometers and CGM devices, and finally outlines the merits, limitations, and prospects of these devices. This review would serve as a valuable resource, elucidating the intricate functions of nanomaterials for the successful development of advanced wearable devices in diabetes management.

Engineered Janus hydrogels: biomimetic surface engineering and biomedical applications

Hydrogel bioadhesives, when applied to dysfunctional tissues substituting the epidermis or endothelium, exhibit compelling characteristics that enable revolutionary diagnostic and therapeutic procedures. Despite their demonstrated efficacy, these hydrogels as soft implants are still limited by improper symmetric surface functions, leading to postoperative complications and disorders. Janus hydrogel bioadhesives with unique asymmetric surface designs have thus been proposed as a reliable and biocompatible hydrogel interface, mimicking the structural characteristics of natural biological barriers. In this comprehensive review, we provide guidelines for the rational design of Janus hydrogel bioadhesives, covering methods for hydrogel surface chemistry and microstructure engineering. The engineering of Janus hydrogels is highlighted, specifically in tuning the basal surface to facilitate instant and robust hydrogel-tissue integration and modulating the apical surface as the anti-adhesion, anti-fouling, and anti-wear barrier. These asymmetric designs hold great potential in clinical translation, supporting applications including hemostasis/tissue sealing, chronic wound management, and regenerative medicine. By shedding light on the potential of Janus hydrogels as bioactive interfaces, this review paper aims to inspire further research and overcome current obstacles for advancing soft matter in next-generation healthcare.

Stiffness and Interface Engineered Soft Electronics with Large-Scale Robust Deformability

Skin-like stretchable electronics emerge as promising human-machine interfaces but are challenged by the paradox between superior electronic property and reliable mechanical deformability. Here, a general strategy is reported for establishing robust large-scale deformable electronics by effectively isolating strains and strengthening interfaces. A copolymer substrate is designed to consist of mosaic stiff and elastic areas with nearly four orders of magnitudes modulus contrast and cross-linked interfaces. Electronic functional devices and stretchable liquid metal (LM) interconnects are conformally attached at the stiff and elastic areas, respectively, through hydrogen bonds. As a result, functional devices are completely isolated from strains, and resistances of LM conductors change by less than one time when the substrate is deformed by up to 550%. By this strategy, solar cells, wireless charging antenna, supercapacitors, and light-emitting diodes are integrated into a self-powered electronic skin that can laminate on the human body and exhibit stable performances during repeated multimode deformations, demonstrating an efficient path for realizing highly deformable energy autonomous soft electronics.

Graphene-enabled laser lift-off for ultrathin displays

Laser lift-off (LLO) of ultrathin polyimide (PI) films is important in the manufacturing of ultrathin displays. However, conventional LLO technologies face challenges in separating the ultrathin PI films without causing mechanical and electrical damage to integrated devices. Here, we propose a graphene-enabled laser lift-off (GLLO) method to address the challenges. The GLLO method is developed by integrating chemical vapor deposition (CVD)-grown graphene at the interface between a transparent carrier and an ultrathin PI film, exhibiting improved processability and lift-off quality. In particular, the GLLO method significantly mitigates plastic deformation of the PI film and minimizes carbonaceous residues remaining on the carrier. The role of graphene is attributed to three factors: enhancement of interfacial UV absorption, lateral heat diffusion, and adhesion reduction, and experimentations and numerical simulations verify the mechanism. Finally, it is demonstrated that the GLLO method separates ultrathin organic light-emitting diode (OLED) devices without compromising performance. We believe that this work will pave the way for utilizing CVD graphene in various laser-based manufacturing applications.

Soft Bioelectronics for Heart Monitoring

Cardiovascular diseases (CVDs) are a predominant global health concern, accounting for over 17.9 million deaths in 2019, representing approximately 32% of all global fatalities. In North America and Europe, over a million adults undergo cardiac surgeries annually. Despite the benefits, such surgeries pose risks and require precise postsurgery monitoring. However, during the postdischarge period, where monitoring infrastructures are limited, continuous monitoring of vital signals is hindered. In this area, the introduction of implantable electronics is altering medical practices by enabling real-time and out-of-hospital monitoring of physiological signals and biological information postsurgery. The multimodal implantable bioelectronic platforms have the capability of continuous heart sensing and stimulation, in both postsurgery and out-of-hospital settings. Furthermore, with the emergence of machine learning algorithms into healthcare devices, next-generation implantables will benefit artificial intelligence (AI) and connectivity with skin-interfaced electronics to provide more precise and user-specific results. This Review outlines recent advancements in implantable bioelectronics and their utilization in cardiovascular health monitoring, highlighting their transformative deployment in sensing and stimulation to the heart toward reaching truly personalized healthcare platforms compatible with the Sustainable Development Goal 3.4 of the WHO 2030 observatory roadmap. This Review also discusses the challenges and future prospects of these devices.

Exploring role of microbatteries in enhancing sustainability and functionality of implantable biosensors and bioelectronics

Microbatteries are emerging as a sustainable, miniaturized power source, crucial for implantable biomedical devices. Their significance lies in offering high energy density, longevity, and rechargeability, facilitating uninterrupted health monitoring and treatment within the body. The review delves into the development of microbatteries, emphasizing their miniaturization and biocompatibility, crucial for long-term, safe in-vivo use. It examines cutting-edge manufacturing techniques like physical and chemical vapor deposition, and atomic layer deposition, essential for the precision manufacture of the microbatteries. The paper contrasts primary and secondary batteries, highlighting the advantages of zinc-ion and magnesium-ion batteries for enhanced stability and reduced reactivity. It also explores biodegradable batteries, potentially obviating the need for surgical extraction post-use. The integration of microbatteries into diagnostic and therapeutic devices is also discussed, illustrating how they enhance the efficacy and sustainability of implantable biosensors and bioelectronics.

Biomaterials with cancer cell-specific cytotoxicity: challenges and perspectives

Significant advances have been made in materials for biomedical applications, including tissue engineering, bioimaging, cancer treatment, etc. In the past few decades, nanostructure-mediated therapeutic strategies have been developed to improve drug delivery, targeted therapy, and diagnosis, maximizing therapeutic effectiveness while reducing systemic toxicity and side effects by exploiting the complicated interactions between the materials and the cell and tissue microenvironments. This review briefly introduces the differences between the cells and tissues of tumour or normal cells. We summarize recent advances in tumour microenvironment-mediated therapeutic strategies using nanostructured materials. We then comprehensively discuss strategies for fabricating nanostructures with cancer cell-specific cytotoxicity by precisely controlling their composition, particle size, shape, structure, surface functionalization, and external energy stimulation. Finally, we present perspectives on the challenges and future opportunities of nanotechnology-based toxicity strategies in tumour therapy.

Printable, stretchable metal-vapor-desorption layers for high-fidelity patterning in soft, freeform electronics

High-fidelity patterning of thin metal films on arbitrary soft substrates promises integrated circuits and devices that can significantly augment the morphological functionalities of freeform electronics. However, existing patterning methods that decisively rely on prefabricated rigid masks are severely incompatible with myriad surfaces. Here, we report printable, stretchable metal-vapor-desorption layers (s-MVDLs) that can enable high-fidelity patterning of thin metal films on freeform polymeric surfaces. The printed rubbery matrix with highly mobile chains effectively repels various metal vapors from the surface and inhibits their condensation, thereby allowing selective metal deposition. The s-MVDLs are printed by direct ink writing techniques, enabling customizable and scalable thin metal patterns ranging from the micrometer to millimeter scale with high fidelity. Furthermore, the superior stretchability and mechanical robustness of the s-MVDLs allow highly compliant deformation along the substrates, enabling the construction of unconventional circuits and devices on multi-curvature, non-developable, and stretchable surfaces.

Sonosynthetic Cyanobacteria Oxygenation for Self-Enhanced Tumor-Specific Treatment

Photosynthesis, essential for life on earth, sustains diverse processes by providing nutrition in plants and microorganisms. Especially, photosynthesis is increasingly applied in disease treatments, but its efficacy is substantially limited by the well-known low penetration depth of external light. Here, ultrasound-mediated photosynthesis is reported for enhanced sonodynamic tumor therapy using organic sonoafterglow (ultrasound-induced afterglow) nanoparticles combined with cyanobacteria, demonstrating the proof-of-concept sonosynthesis (sonoafterglow-induced photosynthesis) in cancer therapy. Chlorin e6, a typical small-molecule chlorine, is formulated into nanoparticles to stimulate cyanobacteria for sonosynthesis, which serves three roles, i.e., overcoming the tissue-penetration limitations of external light sources, reducing hypoxia, and acting as a sonosensitizer for in vivo tumor suppression. Furthermore, sonosynthetic oxygenation suppresses the expression of hypoxia-inducible factor 1α, leading to reduced stability of downstream SLC7A11 mRNA, which results in glutathione depletion and inactivation of glutathione peroxidase 4, thereby inducing ferroptosis of cancer cells. This study not only broadens the scope of microbial nanomedicine but also offers a distinct direction for sonosynthesis.

Flexible self-powered bioelectronics enables personalized health management from diagnosis to therapy

Flexible self-powered bioelectronics (FSPBs), incorporating flexible electronic features in biomedical applications, have revolutionized the human-machine interface since they hold the potential to offer natural and seamless human interactions while overcoming the limitations of battery-dependent power sources. Furthermore, as biosensors or actuators, FSPBs can dynamically monitor physiological signals to reveal real-time health abnormalities and provide timely and precise treatments. Therefore, FSPBs are increasingly shaping the landscape of health monitoring and disease treatment, weaving a sophisticated and personalized bond between humans and health management. Here, we examine the recent advanced progress of FSPBs in developing working mechanisms, design strategies, and structural configurations toward personalized health management, emphasizing its role in clinical medical scenarios from biophysical/biochemical sensors for sensing diagnosis to robust/biodegradable actuators for intervention therapy. Future perspectives on the challenges and opportunities in emerging multifunctional FSPBs for the next-generation health management systems are also forecasted.

A water-resistant, ultrathin, conformable organic photodetector for vital sign monitoring

Ultrathin flexible photodetectors can be conformably integrated with the human body, offering promising advancements for emerging skin-interfaced sensors. However, the susceptibility to degradation in ambient and particularly in aqueous environments hinders their practical application. Here, we report a 3.2-micrometer-thick water-resistant organic photodetector capable of reliably monitoring vital sign while submerged underwater. Embedding the organic photoactive layer in an adhesive elastomer matrix induces multidimensional hybrid phase separation, enabling high adhesiveness of the photoactive layer on both the top and bottom surfaces with maintained charge transport. This improves the water-immersion stability of the photoactive layer and ensures the robust sealing of interfaces within the device, notably suppressing fluid ingression in aqueous environments. Consequently, our fabricated ultrathin organic photodetector demonstrates stability in deionized water or cell nutrient media over extended periods, high detectivity, and resilience to cyclic mechanical deformation. We also showcase its potential for vital sign monitoring while submerged underwater.

Advances in Multifunctional Electronic Catheters for Precise and Intelligent Diagnosis and Therapy in Minimally Invasive Surgery

The advent of catheter-based minimally invasive surgical instruments has provided an effective means of diagnosing and treating human disease. However, conventional medical catheter devices are limited in functionalities, hindering their ability to gather tissue information or perform precise treatment during surgery. Recently, electronic catheters have integrated various sensing and therapeutic technologies through micro/nanoelectronics, expanding their capabilities. As micro/nanoelectronic devices become more miniaturized, flexible, and stable, electronic surgical catheters are evolving from simple tools to multiplexed sensing and theranostics for surgical applications. The review on multifunctional electronic surgical catheters is lacking and thus is not conducive to the reader's comprehensive understanding of the development trend in this field. This review covers the advances in multifunctional electronic catheters for precise and intelligent diagnosis and therapy in minimally invasive surgery. It starts with the summary of clinical minimally invasive surgical instruments, followed by the background of current clinical catheter devices for sensing and therapeutic applications. Next, intelligent electronic catheters with integrated electronic components are reviewed in terms of electronic catheters for diagnosis, therapy, and multifunctional applications. It highlights the present status and development potential of catheter-based minimally invasive surgical devices, while also illustrating several significant challenges that remain to be overcome.

Wearable biosensors in cardiovascular disease

This review provides a comprehensive overview of the latest advancements in wearable biosensors, emphasizing their applications in cardiovascular disease monitoring. Initially, the key sensing signals and biomarkers crucial for cardiovascular health, such as electrocardiogram, phonocardiography, pulse wave velocity, blood pressure, and specific biomarkers, are highlighted. Following this, advanced sensing techniques for cardiovascular disease monitoring are examined, including wearable electrophysiology devices, optical fibers, electrochemical sensors, and implantable cardiac devices. The review also delves into hydrogel-based wearable electrochemical biosensors, which detect biomarkers in sweat, interstitial fluids, saliva, and tears. Further attention is given to flexible electronics-based biosensors, including resistive, capacitive, and piezoelectric force sensors, as well as resistive and pyroelectric temperature sensors, flexible biochemical sensors, and sensor arrays. Moreover, the discussion extends to polymer-based wearable sensors, focusing on innovations in contact lens, textile-type, patch-type, and tattoo-type sensors. Finally, the review addresses the challenges associated with recent wearable biosensing technologies and explores future perspectives, highlighting potential groundbreaking avenues for transforming wearable sensing devices into advanced diagnostic tools with multifunctional capabilities for cardiovascular disease monitoring and other healthcare applications.

Glucose-based biofuel cells and their applications in medical implants: A review

In glucose biofuel cells (G-BFCs), glucose oxidation at the anode and oxygen reduction at the cathode yield electrons, which generate electric energy that can power a wide range of electronic devices. Research associated with the development of G-BFCs has increased in popularity among researchers because of the eco-friendly nature of G-BFCs (as related to their construction) and their evolution from inexpensive bio-based materials. In addition, their excellent specificity towards glucose as an energy source, and other properties, such as small size and weight, make them attractive within various demanding applied environments. For example, G-BFCs have received much attention as implanted devices, especially for uses related to cardiac activities. Envisioned pacemakers and defibrillators powered by G-BFCs would not be required to have conventional lithium batteries exchanged every 5-10 years. However, future research is needed to develop G-BFCs demonstrating more stable power consistency and improved lifespan, as well as solving the challenges in converting laboratory-made implantable G-BFCs into implanted devices in the human body. The categorization of G-BFCs as a subcategory of different biofuel cells and their performance is reviewed in this article.

Bioluminescent Systems for Theranostic Applications

Bioluminescence, the light produced by biochemical reactions involving luciferases in living organisms, has been extensively investigated for various applications. It has attracted particular interest as an internal light source for theranostic applications due to its safe and efficient characteristics that overcome the limited penetration of conventional external light sources. Recent advancements in protein engineering technologies and protein delivery platforms have expanded the application of bioluminescence to a wide range of theranostic areas, including bioimaging, biosensing, photodynamic therapy, and optogenetics. This comprehensive review presents the fundamental concepts of bioluminescence and explores its recent applications across diverse fields. Moreover, it discusses future research directions based on the current status of bioluminescent systems for further expansion of their potential.

Simultaneous Circular Dichroism and Wavefront Manipulation with Generalized Pancharatnam-Berry Phase Metasurfaces

Simultaneous circular dichroism and wavefront manipulation have gained considerable attention in various applications, such as chiroptical spectroscopy, chiral imaging, sorting and detection of enantiomers, and quantum optics, which can improve the miniaturization and integration of the optical system. Typically, structures with n-fold rotational symmetry (n ≥ 3) are used to improve circular dichroism, as they induce stronger interactions between the electric and magnetic fields. However, manipulating the wavefront with these structures remains challenging because they are commonly considered isotropic and lack a geometric phase response in linear optics. Here, we propose and experimentally demonstrate an approach to achieve simultaneous circular dichroism (with a maximum value of ∼0.62) and wavefront manipulation using a plasmonic metasurface made up of C3 Archimedes spiral nanostructures. The circular dichroism arises from the magnetic dipole-dipole resonance and strong interactions between adjacent meta-atoms. As a proof of concept, two metadevices are fabricated and characterized in the near-infrared regime. This configuration possesses the potential for future applications in photodetection, chiroptical spectroscopy, and the customization of linear and nonlinear optical responses.

Evolution of Musculoskeletal Electronics

The musculoskeletal system, constituting the largest human physiological system, plays a critical role in providing structural support to the body, facilitating intricate movements, and safeguarding internal organs. By virtue of advancements in revolutionized materials and devices, particularly in the realms of motion capture, health monitoring, and postoperative rehabilitation, "musculoskeletal electronics" has actually emerged as an infancy area, but has not yet been explicitly proposed. In this review, the concept of musculoskeletal electronics is elucidated, and the evolution history, representative progress, and key strategies of the involved materials and state-of-the-art devices are summarized. Therefore, the fundamentals of musculoskeletal electronics and key functionality categories are introduced. Subsequently, recent advances in musculoskeletal electronics are presented from the perspectives of "in vitro" to "in vivo" signal detection, interactive modulation, and therapeutic interventions for healing and recovery. Additionally, nine strategy avenues for the development of advanced musculoskeletal electronic materials and devices are proposed. Finally, concise summaries and perspectives are proposed to highlight the directions that deserve focused attention in this booming field.

Insertable Biosensors: Combining Implanted Sensing Materials with Wearable Monitors

Insertable biosensor systems are medical diagnostic devices with two primary components: an implantable biosensor within the body and a wearable monitor that can remotely interrogate the biosensor from outside the body. Because the biosensor does not require a physical connection to the electronic monitor, insertable biosensor systems promise improved patient comfort, reduced inflammation and infection risk, and extended operational lifetimes relative to established percutaneous biosensor systems. However, the lack of physical connection also presents technical challenges that have necessitated new innovations in developing sensing chemistries, transduction methods, and communication modalities. In this review, we discuss the key developments that have made insertables a promising option for longitudinal biometric monitoring and highlight the essential needs and existing development challenges to realizing the next generation of insertables for extended-use diagnostic and prognostic devices.

Biodegradable MoNx@Mo-foil electrodes for human-friendly supercapacitors

With the advancement in the field of biomedical research, there is a growing demand for biodegradable electronic devices. Biodegradable supercapacitors (SCs) have emerged as an ideal solution for mitigating the risks associated with secondary surgeries, reducing patient discomfort, and promoting environmental sustainability. In this study, MoNx@Mo-foil was prepared as an active material for biodegradable supercapacitors through high-temperature and nitridation processes. The composite electrode exhibited superior electrochemical performance in both aqueous and solid-state electrolytes. In the case of the solid-state electrolyte, the MoNx@Mo-foil composite electrode-based device demonstrated excellent cycling stability and electrochemical performance. Additionally, the composite electrode exhibited rapid and complete biodegradability in a 3% H2O2 solution. Through detailed experimental analysis and performance testing, we verified the potential application of the MoNx@Mo-foil composite electrode in biodegradable supercapacitors. This work provides a new choice of degradable material for developing biomedical electronic devices.

Metainterface Heterostructure Enhances Sonodynamic Therapy for Disrupting Secondary Biofilms

Implant-related secondary infections are a challenging clinical problem. Sonodynamic therapy (SDT) strategies are promising for secondary biofilm infections by nonsurgical therapy. However, the inefficiency of SDT in existing acoustic sensitization systems limits its application. Therefore, we take inspiration from popular metamaterials and propose the design idea of a metainterface heterostructure to improve SDT efficiency. The metainterfacial heterostructure is defined as a periodic arrangement of heterointerface monoclonal cells that amplify the intrinsic properties of the heterointerface. Herein, we develop a TiO2/Ti2O3/vertical graphene metainterface heterostructure film on titanium implants. This metainterface heterostructure exhibits extraordinary sonodynamic and acoustic-to-thermal conversion effects under low-intensity ultrasound. The modulation mechanisms of the metainterface for electron accumulation and separation are revealed. The synergistic sonodynamic/mild sonothermal therapy disrupts biofilm infections (antibacterial rates: 99.99% for Staphylococcus aureus, 99.54% for Escherichia coli), and the osseointegration ability of implants is significantly improved in in vivo tests. Such a metainterface heterostructure film lays the foundation for the metainterface of manipulating electron transport to enhance the catalytic performance and holding promise for addressing secondary biofilm infections.

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

Reconfiguring hydrogel assemblies using a photocontrolled metallopolymer adhesive for multiple customized functions

Stimuli-responsive hydrogels with programmable shape changes are promising materials for soft robots, four-dimensional printing, biomedical devices and artificial intelligence systems. However, these applications require the fabrication of hydrogels with complex, heterogeneous and reconfigurable structures and customizable functions. Here we report the fabrication of hydrogel assemblies with these features by reversibly gluing hydrogel units using a photocontrolled metallopolymer adhesive. The metallopolymer adhesive firmly attached individual hydrogel units via metal-ligand coordination and polymer chain entanglement. Hydrogel assemblies containing temperature- and pH-responsive hydrogel units showed controllable shape changes and motions in response to these external stimuli. To reconfigure their structures, the hydrogel assemblies were disassembled by irradiating the metallopolymer adhesive with light; the disassembled hydrogel units were then reassembled using the metallopolymer adhesive with heating. The shape change and structure reconfiguration abilities allow us to reprogramme the functions of hydrogel assemblies. The development of reconfigurable hydrogel assemblies using reversible adhesives provides a strategy for designing intelligent materials and soft robots with user-defined functions.