Smart Healthcare Photonic Nanomaterials and Devices

Over the last decade, significant progress has been made in the fundamental principles, design, and synthesis of photonic nanomaterials with diverse optical properties and functionalities.[1-3] Light-emitting and light-responsive nanomaterials – such as semiconductor quantum dots, plasmonic metal nanoparticles, organic carbon, and polymeric nanomaterials – have enabled effective diagnostic, therapeutic, and theranostic applications including fluorescence imaging, plasmon resonance-based sensing and imaging, photoacoustic imaging, photobiomodulation, photothermal therapy, photodynamic therapy, and optogenetic therapy.[3] Among them, gold nanomaterials, carbon nanomaterials, polymeric melanoidin, and upconversion nanoparticles (UCNPs) have attracted particular attention due to their unique photonic properties and biocompatibility. On top of that, with the development of advanced micro-light emitting diodes (μ-LEDs), stretchable and flexible electronics, and wireless communication systems, wearable and implantable photonic devices have been extensively investigated for a variety of biomedical applications.[3, 4] These photonic devices capable of emitting specific wavelengths and controlling the intensity or frequency of emitted light have been especially useful for multifunctional applications, including optogenetics, wound healing, and cancer therapy. Furthermore, the structural designs of photonic devices have enabled conformal contacts with a minimized mechanical modulus, facilitating efficient light transfer for electrotherapy, such as nerve and bone regeneration, wound therapy and pain management.[5] Recent work has begun to translate some of these promising photonic nanomaterials into the clinic, along with wearable and implantable devices. In this Special Issue, we provide an overview for the current state-of-the-art research on emerging photonic nanomaterials and devices for various smart healthcare applications (Figure 1). This Special Issue comprises 17 articles (9 Reviews, 7 Research Articles, and 1 Perspective), and the collection highlights photonic nanomaterials for 1) diagnostic and therapeutic applications, 2) wearable healthcare devices, 3) implantable healthcare devices, and 4) cross-cutting digital healthcare applications. Finally, we discuss the opportunities and challenges for advancing these technologies toward the future of photomedicine. Recent advances in photonic nanomaterials have revolutionized the field of biomedical diagnosis and therapy, providing unprecedented opportunities for non-invasive, high-precision, and multifunctional interventions. This section highlights two timely reviews on emerging trends and three recent research articles introducing biocompatible photonic nanomaterial platforms with excellent feasibility for clinical translation. L. N. Liu, J. Chao, and co-workers (article number 2500086) provide a comprehensive review illustrating the power of DNA-directed assembly to construct photonic nanostructures with programmable precision. By harnessing sequence-specific hybridization, diverse optical building blocks such as plasmonic nanoparticles, fluorescent probes, and photonic crystals can be spatially organized into highly ordered architectures. Such DNA-based assembly provides not only structural tunability but also functional adaptability for biosensing, imaging, and theranostic applications. S. Sánchez, D. Esporrín-Ubieto, and co-workers (article number 2502171) focus on engineered plasmonic and fluorescent nanomaterials, particularly gold nanoparticles (AuNPs) and gold nanoclusters (AuNCs). AuNPs provide localized surface plasmon resonance for enhanced biosensing and photothermal therapy, whereas ultrasmall AuNCs (< 2 nm) exhibit size-dependent fluorescence and reactive oxygen species modulation. This article highlights the versatility of gold-based nanomaterials as theranostic agents, which bridge the gap between molecular imaging and therapeutic functions. Together, these reviews outline emerging trends that define the current frontiers of photonic nanomaterials. A complementary set of recent research articles highlights distinct material systems that broaden the scope of photomedicine into metabolic regulation, multifunctional microrobots, and deep-tissue optical interrogation. Y.-K. Oh, J. Lee, H. S. Jung, and colleagues (article number 2418445) introduce the concept of photoactivated metabolic modulation, in which chaperone-mediated lipolysis is selectively triggered by light. This work expands the scope of photomedicine beyond cancer and infectious diseases into metabolic disorders, demonstrating the role of light as a precise switch for cellular energy regulation and highlighting the potential of photonics in treating obesity and related diseases. M. Sitti, D. Razansky, B. V. Lotsch, and colleagues (article number 2418425) report the development of upconversion nanoparticle – covalent organic framework (UCNP–COF) microrobots. These core–shell architectures couple the UCNP-based NIR-to-visible emission with the COF porosity for drug loading, while magnetic Janus configurations enable navigation in vivo. Such microrobots integrate real-time optoacoustic imaging, targeted delivery, and active locomotion, providing a blueprint for intelligent nanotheranostics. S. H. Yun and colleagues (article number 2418710) present indium phosphide (InP) laser particles with wideband tunability and deep-tissue detection capability. Operating in the near-infrared window (740–970 nm) with sub-nanometer linewidths, these laser probes enable multiplexed barcoding, high-fidelity spectral imaging, and deep-tissue interrogation far beyond the reach of conventional fluorophores. Their demonstration in live animal models confirms the great potential for clinical translation in disease monitoring and precision surgery. Wearable photonic devices are rapidly transforming healthcare by enabling continuous, non-invasive monitoring and personalized therapeutic interventions. The flexible integration of nanomaterials with skin, textiles, or contact lenses allows light to be harnessed in ways that are both patient-friendly and clinically meaningful. This section highlights five reviews to survey the emerging frontiers of wearable photonic systems and two research articles to demonstrate innovative material strategies for practical device implementation. Wei Gao, I. Park, and colleagues (article number 2419161) provide an overview of wearable photonic devices for precision healthcare. The article reviews recent advances in optical biosensing, wireless communication, and machine learning–assisted analytics, emphasizing how wearable platforms can continuously track physiological signals and biochemical markers. This work underscores the transformative role of photonic nanomaterials in driving the shift from centralized hospital diagnostics to decentralized, personalized medical systems. C. H. Lee, Y. L. Kim, and colleagues (article number 2418705) summarize the latest progress in photonic nanomaterials for wearable health solutions. Covering nanoparticles, nanofibers, and hydrogel-based systems, this review article highlights strategies to harness fluorescence, Raman scattering, and light absorption for biosensing and therapy. This review further discusses wearable patches, contact lenses, and textile-integrated platforms, pointing to a future where theranostic nanomaterials converge with daily life. N. Matsuhisa and colleagues (article number 2502727) discuss unperceivable designs for wearable electronics. They detail approaches to render devices imperceptible to the user by employing transparent electrodes, ultrathin substrates, and soft skin-like materials. By reducing mechanical and psychological barriers, these designs enhance patient comfort and compliance, thereby advancing wearable photonic systems toward long-term usability and social acceptance. M. Stevens and colleagues (article number 2502059) investigate the design of physical unclonable functions (PUFs) based on optically active materials. Leveraging AIEgens, photochromic compounds, and conjugated polymers, this review introduces new pathways for secure data management and counterfeit prevention in wearable devices. Beyond health monitoring, this work highlights the role of photonic nanomaterials in ensuring data security and authenticity in next-generation healthcare platforms. Y. S. Zhao, C. Zhang, and colleagues (article number 2415856) describe recent progress in flexible photonic materials and devices. They discuss polymers, hydrogels, and hybrid composites with tunable optical properties, and demonstrate their applications in optical waveguides, resonators, and filters for wearable sensing. By connecting synthetic strategies with device functionality, this review provides a roadmap for translating photonic materials into bio-integrated systems. Taken together, these reviews define the current state of wearable photonic devices. Additionally, two research articles highlight innovative materials that directly address practical challenges in device durability and responsiveness. T. Yokota, T. Someya, K. Fukuda, and colleagues (article number 2409649) demonstrate a robust full-surface bonding strategy between soft substrates and electrodes. By employing low-temperature plasma-assisted hybrid bonding, they achieve the stable integration of ultraflexible photoplethysmography (PPG) sensors without the need for adhesives. The resulting devices maintain optical and electrical performance even under extreme bending, underscoring the importance of interface engineering for reliable wearable photonic devices. S. Lin and colleagues (article number 2407925) report the development of fatigue-resistant mechanoresponsive color-changing hydrogels. These materials exhibit reversible and predictable optical responses to mechanical stress, maintaining their performance over 10000 cycles. Demonstrated as vision-based tactile sensors, the hydrogels enable robotic systems to visualize force distributions and also hold promise as wearable tactile sensors for healthcare monitoring. Collectively, these contributions showcase the rapid progress of wearable photonic nanomaterials, from optical sensing and therapeutic patches to imperceptible electronics, secure interfaces, and mechanoresponsive skins. By combining advanced material design with user-centered integration, wearable photonic devices are evolving into a clinically relevant and socially adoptable technology for smart digital healthcare. Implantable photonic devices are transforming healthcare by enabling deep-tissue interrogation, chronic neural modulation, and localized therapy with high spatial and temporal precision. Unlike wearable devices, implantable devices face unique challenges of biocompatibility, chronic stability, and integration with soft and dynamic tissues. In this Special Issue, two research articles highlight how photonic nanomaterials and device engineering can be leveraged to overcome these challenges and create platforms that bring light directly into the body for long-term clinical applications. P. Anikeeva and colleagues (article number 2408154) report the development of fiber-based probes for electrophysiology, photometry, and optogenetics. By employing flexible polymers and hybrid fibers, these probes integrate electrical recording, optical stimulation, and biochemical sensing into a single platform. This work emphasizes material innovations that reduce stiffness mismatches between device and tissue, thereby improving chronic stability and minimizing inflammation. Such multifunctional probes expand the scope of implantable photonic devices beyond fundamental neuroscience into potential applications to neuro-immune regulation and therapeutic neuromodulation. K. J. Lee, T.-H. Kwon and colleagues (article number 2411494) present deeply implantable, shape-morphing 3D micro light-emitting diode (3D microLED) devices for pancreatic cancer therapy. These microstructured light sources conform to the irregular surfaces of solid tumors and maintain stable tissue contact during tumor progression. By the metronomic photodynamic therapy via wireless power transfer, the devices achieve significant tumor reduction, suppression of stromal desmoplasia, and induction of immune-stimulatory tumor microenvironments in vivo. This work exemplifies how implantable photonic devices can overcome the limitations of fiber-based illumination, paving the way to minimally invasive, long-term light-based cancer therapy. Collectively, these contributions highlight how implantable photonic nanomaterials are evolving from neural interfacing probes to tumor-targeted therapeutic implants. By combining the advances in soft materials and structural designs, wireless energy delivery, and optical engineering, implantable photonic devices are paving the way for next-generation light-enabled futuristic therapies. Recent progress in photonic nanomaterials has not been confined to the single domain of diagnosis, wearable, or implantable systems. Instead, several works bridge these areas, offering integrative perspectives on how materials, devices, and system-level innovations can converge to advance multifunctional digital healthcare platforms. This section features a perspective and two reviews to exemplify such cross-cutting approaches, highlighting pathways to connect fundamental materials with translational devices. S. K. Hahn, J. A. Rogers, J. Kim, and colleagues (article number 2413189) present perspectives outlining multifunctional photonic nanomaterials and devices for smart digital photomedicine via neuro–immune cross-talks. This work highlights how photonic platforms, such as UCNPs, optogenetic actuators, and hybrid nanostructures, can be engineered to modulate neuro–immune interactions, thereby opening a big avenue in oncology, immunology, and regenerative medicine. By emphasizing the convergence of photonic nanomaterials with wearable and implantable platforms, this article proposes a roadmap toward next-generation digital photomedicine that leverages both systemic and localized optical control. Y. Lin and colleagues (article number 2418729) provide an extensive survey of printable photonic materials and devices for smart healthcare. This article explores printing technologies ranging from inkjet to 3D and screen printing, and how these approaches enable the scalable fabrication of wearable photonic patches, implantable light-emitting devices, and biodegradable photonic sensors. By bridging materials science with advanced manufacturing, this review underscores printing as a critical pathway to realize cost-effective, large-area, and personalized photonic healthcare devices, making the translation to clinical practice more feasible. W.-H. Yeo, K. J. Yu, and colleagues (article number 2416899) summarize the recent advances in photonic nanomaterials and integrated devices for smart digital healthcare. This comprehensive overview spans photosensitizers for phototherapy, flexible optical sensors for physiological monitoring, and integrated waveguides for implantable light delivery. This article also addresses system-level challenges, such as biocompatibility, mechanical durability, and data integration, framing the opportunities and limitations for deploying photonic technologies in clinical settings. By synthesizing insights from material innovation to device integration, this review provides a holistic perspective on the translational trajectory of photonic nanomedicine. Collectively, these cross-cutting contributions emphasize that the future of photonic nanomaterials lies in their integration across wearable and implantable materials and devices. By bridging material design, scalable manufacturing, and system-level integration, these works would chart a pathway toward multifunctional, translational, clinically relevant, and digitally connected photonic healthcare platforms. Photonic nanomaterials for smart healthcare have now reached a stage of rapid expansion and increasing maturity. Significant progress has been made not only in the design and optical engineering of nanomaterials for diagnosis and therapy but also in their integration into wearable and implantable platforms. Recent advances illustrate how photonic systems are evolving from fundamental optical innovations into multifunctional devices for continuous monitoring, targeted therapy, and digital connectivity. Cross-cutting approaches further highlight the convergence of materials, scalable fabrication, and system-level integration, pointing toward a new paradigm of digital photomedicine. However, there are several notable challenges as follows. Clinical translation is a crucial issue for commercial applications. Most photonic nanomaterials still face limitations in terms of biosafety and long-term stability with unclear pharmacokinetics. Biodegradability, immune compatibility, and consistent performance in complex tissue environments require further innovation. While the device integration poses difficulties, achieving mechanical durability, wireless operation, and seamless tissue interfaces is essential for further practical applications. For wearable systems, ensuring reliable adhesion, compliance, and data security remains as a challenge, whereas implantable devices must overcome several issues such as miniaturization, safe energy supply, wireless communication, foreign body response, and chronic stability. In parallel, there is a growing interest in clinical and industrial applications of photonic nanomaterials, including biosensing for continuous health management, photodynamic therapy, and photobiomodulation. These applications offer promising routes to translation, but demand even higher levels of biosafety, robustness, reproducibility, and regulatory clarity. In particular, it is strongly needed to thoroughly investigate the metabolic and immune responses of photonic nanomaterials and devices. In addition, the long-term stability under physiological conditions is increasingly critical, as devices and nanomaterials are continuously exposed to the dynamic biological environments with variable mechanical, thermal, and biochemical stresses. At this point, to achieve further progress, the focus should shift from demonstrating the proof-of-concept performance in controlled laboratory settings to ensuring long-term stability, clinical safety, and reliability under the real-world environments. Standard protocols must be well established for the biocompatibility testing, chronic implantation studies, and large-scale manufacturing. Furthermore, the reliability of high-yield nanomaterials for device fabrication must be ensured to guarantee the cost-effective production. At the same time, scalable and precise fabrication technologies, such as printable photonic systems, should be further investigated for uniform functionality and high-resolution integrations in both wearable and implantable devices. Additionally, the regulatory frameworks should be well adapted to accommodate hybrid technologies which combine nanomaterials, electronics, and optical components for clinical applications. Through this Special Issue, we aim to highlight the recent advances in photonic nanomaterials and devices for smart healthcare, offering perspectives on the key directions for further development. We hope this collection provides a valuable foundation for identifying practical strategies to overcome the current limitations and accelerate the clinical translation of photonic nanomedicine and devices into clinically viable, patient-centered healthcare solutions. The authors would like to thank Seong-Jong Kim and Tae Yeon Kim for their nice editing of this manuscript. This work was supported by the National Research Foundation of Korea (BRIDGE Research Program, RS-2022-NR067643) and KOBRA Project, RS - 2023 - 00260454 funded by the Ministry of Science and ICT, the Korea Medical Device Development Fund (RS-2023-00253749) and the B-IRC grant (RS-2023-00260454) funded by the Korean government, and the Korea Creative Content Agency grant (RS-2023-00223424) funded by the Ministry of Culture, Sports and Tourism of Korea. M.M.S. acknowledges support from the Engineering and Physical Sciences Research Council through a Frontier Research Guarantee grant (EP/Z000130/1) and from the Department of Science, Innovation and Technology (DSIT) and the Royal Academy of Engineering under the Chair in Emerging Technologies programme (CiET2021∖94). The authors declare no conflict of interest. Dame Molly Stevens DBE FRS FREng FMedSci is John Black Professor of Bionanoscience at the University of Oxford. Her multidisciplinary research spans diagnostics, advanced therapeutics, and regenerative medicine, influencing global healthcare innovation. As a serial entrepreneur, she has founded multiple biotech companies. She is a Fellow of the Royal Society, a Foreign Member of the National Academy of Engineering, and an International Honorary Member of the American Academy of Arts and Sciences. John A. Rogers is the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering, and Medicine at Northwestern University, with affiliate appointments in Mechanical Engineering, Electrical and Computer Engineering, and Chemistry, where he is also Director of the recently endowed Querrey Simpson Institute for Bioelectronics. He is a member of the National Academy of Engineering, the National Academy of Sciences, the National Academy of Medicine, the National Academy of Inventors, and the American Academy of Arts and Sciences. Sei Kwang Hahn is the Seok Cheon Endowed Chair Professor in the Department of Materials Science and Engineering at Pohang University of Science and Technology He has as the of of and of Reviews, and of and Member of He is a of and the Korean Academy of Science and and a member of the National Academy of Engineering, Korea.