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More than 90% of surgical patients develop postoperative adhesions, and the incidence of hospital re-admissions can be as high as 20%. Current adhesion barriers present limited efficacy due to difficulties in application and incompatibility with minimally invasive interventions. To solve this clinical limitation, we developed an injectable and sprayable shear-thinning hydrogel barrier (STHB) composed of silicate nanoplatelets and poly(ethylene oxide). We optimized this technology to recover mechanical integrity after stress, enabling its delivery though injectable and sprayable methods. We also demonstrated limited cell adhesion and cytotoxicity to STHB compositions in vitro. The STHB was then tested in a rodent model of peritoneal injury to determine its efficacy preventing the formation of postoperative adhesions. After two weeks, the peritoneal adhesion index was used as a scoring method to determine the formation of postoperative adhesions, and STHB formulations presented superior efficacy compared to a commercially available adhesion barrier. Histological and immunohistochemical examination showed reduced adhesion formation and minimal immune infiltration in STHB formulations. Our technology demonstrated increased efficacy, ease of use in complex anatomies, and compatibility with different delivery methods, providing a robust universal platform to prevent postoperative adhesions in a wide range of surgical interventions.

Dermal tattoo biosensors are promising platforms for real‐time monitoring of biomarkers, with skin used as a diagnostic interface. Traditional tattoo sensors have utilized small molecules as biosensing elements. However, the rise of synthetic biology has enabled the potential employment of engineered bacteria as living analytical tools. Exploiting engineered bacterial sensors will allow for potentially more sensitive detection across a broad biomarker range, with advanced processing and sense/response functionalities using genetic circuits. Here, the interfacing of bacterial biosensors as living analytics in tattoos is shown. Engineered bacteria are encapsulated into micron‐scale hydrogel beads prepared through scalable microfluidics. These biosensors can sense both biochemical cues (model biomarkers) and biophysical cues (temperature changes, using RNA thermometers), with fluorescent readouts. By tattooing beads into skin models and confirming sensor activity post‐tattooing, our study establishes a foundation for integrating bacteria as living biosensing entities in tattoos. [ABSTRACT FROM AUTHOR]

Early and accurate diagnosis of glaucoma is crucial to prevent the progressive deterioration that leads to irreversible vision loss. It is imperative to develop an effective screening tool for glaucoma. Ciliary neurotrophic factor (CNTF) is a tear biomarker implicated in glaucoma pathogenesis. Lateral flow assay (LFA) provides an ideal platform for detection of glaucoma in tear fluid. A quantum dot‐based fluorescence LFA, integrated with a 3D printed readout box, is developed for fast (30 min), sensitive, and quantitative CNTF detection in tears. A standard curve is firstly generated for the quantitative detection of CNTF. The limit of detection (LOD) of the obtained LFA strip at 6.45 pg·mL−1 is comparable to that of the enzyme‐linked immunosorbent assay (ELISA) at 6.42 pg·mL−1. This enables the identification of low CNTF levels (25.7 ± 14.9 pg·mL−1) reported in tear fluid from glaucoma patients. This LFA is found to be highly selective for CNTF and maintained consistent results in different pH condition. The strip remaines stablewhen stored in the darkat room temperature. A smartphone app is developed to simplify analysis and enable prompt and easily obtainable results. This method shows great potential to be a powerful tool for point‐of‐care glaucoma screening. [ABSTRACT FROM AUTHOR]

Photonic technologies have made enormous impacts on modern medicine, advancing disease diagnostics and treatments as well as health monitoring. A long‐standing challenge in the use of light and its widespread effects in photomedicine is the finite penetration of light in tissues. However, judiciously engineered optical fibers helped overcome this challenge and advance light delivery to deep tissues with spatial precision and desired accessibility. In recent years, the development of photonic technologies including optical biomaterials, fiber functionalization, and biomedical device innovations has greatly expanded the scope of light‐based healthcare. Here, the fundamentals and materials of fiber optics to endow themselves with biocompatibility, flexibility, and diverse functionalities required for long‐term implantation are overviewed. The design strategies of lab‐on‐fiber techniques, operation requirements to construct fiber optic sensors, and their health monitoring applications as wearable and implantable devices are presented. The use of fiber optics in major light‐based therapeutic modalities including optogenetics, photodynamic therapy, photobiomodulation, photochemical cross–linking, and photothermal therapy is illustrated to enhance their effectiveness, specificity, and feasibility. In short, a comprehensive review is provided on the fiber optic techniques and the latest photonic devices, which are envisioned to evolve photomedicine in clinical and point‐of‐care practices. [ABSTRACT FROM AUTHOR]

Delivery of drugs with controlled temporal profiles is essential for wound treatment and regenerative medicine applications. For example, bacterial infection is a key challenge in the treatment of chronic and deep wounds. Current treatment strategies are based on systemic administration of high doses of antibiotics, which result in side effects and drug resistance. On-demand delivery of drugs with controlled temporal profile is highly desirable. Here, we have developed thermally controllable, antibiotic-releasing nanofibrous sheets. Poly(glycerol sebacate)- poly(caprolactone) (PGS-PCL) blends were electrospun to form elastic polymeric sheets with fiber diameters ranging from 350 to 1100 nm and substrates with a tensile modulus of approximately 4-8 MPa. A bioresorbable metallic heater was patterned directly on the nanofibrous substrate for applying thermal stimulation to release antibiotics on-demand. In vitro studies confirmed the platform's biocompatibility and biodegradability. The released antibiotics were potent against tested bacterial strains. These results may pave the path toward developing electronically controllable wound dressings that can deliver drugs with desired temporal patterns.

Hydrogel optical fibers are utilized for continuous glucose sensing in real time. The hydrogel fibers consist of poly(acrylamide-co-poly(ethylene glycol) diacrylate) cores functionalized with phenylboronic acid. The complexation of the phenylboronic acid and cis-diol groups of glucose enables reversible changes of the hydrogel fiber diameter. The analyses of light propagation loss allow for quantitative glucose measurements within the physiological range.

Safe, accurate, and reliable analysis of urinary biomarkers is clinically important for early detection and monitoring of the progression of chronic kidney disease (CKD), as it has become one of the world's most prevalent non-communicable diseases. However, current technologies for measuring urinary biomarkers are either time-consuming and limited to well-equipped hospitals or lack the necessary sensitivity for quantitative analysis and post a health risk to frontline practitioners. Here we report a robust paper-based dual functional biosensor, which is integrated with the clinical urine sampling vial, for the simultaneous and quantitative analysis of pH and glucose in urine. The pH sensor was fabricated by electrochemically depositing IrOx onto a paper substrate using optimised parameters, which enabled an ultrahigh sensitivity of 71.58 mV pH-1. Glucose oxidase (GOx) was used in combination with an electrochemically deposited Prussian blue layer for the detection of glucose, and its performance was enhanced by gold nanoparticles (AuNPs), chitosan, and graphite composites, achieving a sensitivity of 1.5 μA mM-1. This dual function biosensor was validated using clinical urine samples, where a correlation coefficient of 0.96 for pH and 0.98 for glucose detection was achieved with commercial methods as references. More importantly, the urine sampling vial was kept sealed throughout the sample-to-result process, which minimised the health risk to frontline practitioners and simplified the diagnostic procedures. This diagnostic platform, therefore, holds high promise as a rapid, accurate, safe, and user-friendly point-of-care (POC) technology for the analysis of urinary biomarkers in frontline clinical settings. [ABSTRACT FROM AUTHOR]

The detection of gas concentrations in harsh environments with high performance is an emerging research area. Ensuring that external factors do not affect the detection and that it is immune to electromagnetic interference are key factors in guaranteeing reliable gas detection in a variety of tough environments. Among all types of gas-sensing methods, photoacoustic (PA) methods based on optical interferometers offer high sensitivity, anti-electromagnetic interference capability, and non-magnetic saturation. This article first presents the basic principles and characteristics of the main optical interferometers, the PA effect, and the core technologies of PA gas-sensing methods. It then reviews advanced optical interferometer-based methods for PA gas sensing and summarizes their characteristics, including the heterodyne-based Mach-Zehnder interferometer (MZI), optical fiber-based MZI, Sagnac interferometer (SI)-based, diaphragm-based extrinsic Fabry-Perot (F-P) interferometer (EFPI), cantilever-based EFPI, cantilever-based Michelson interferometer (MI), difference-based MI, and membrane-less optical microphone–photoacoustic spectroscopy (MeoM–PAS) sensing methods. In particular, the MeoM–PAS methods for gas sensing are discussed in detail, as they offer a completely static measurement system and the separation of a PA gas cell from the measuring system for applications in complicated and adverse circumstances. This review also outlines the advantages and limitations of these PA gas-sensing technologies. [ABSTRACT FROM AUTHOR]

Ultra‐thin atomic crystals are promising for fabricating next‐generation photonic and optoelectronic devices. Wafer‐scale characterization techniques are highly desired for efficient and accurate thickness identification of these crystals and their heterostructures. Optical contrast between atomic crystals and substrates based on Fresnel theory is a key technique for the identification of thicknesses. Both RGB color information and spectroscopic information have been explored for layer number counting and implemented with machine learning algorithms based on large amounts of data for feature extraction. In this work, a multispectral microscopic method combining the hardware design and deep‐learning algorithms is developed. Multispectral image restoration during large‐area scanning caused by optical imaging modality drifts and automated layer number identification based on multispectral grayscale images are studied using deep learning models: generative adversarial network (GAN) and 3D U‐Net. These models are trained using custom‐built multispectral data sets and evaluated quantitatively with indicators (Dice coefficient, confusion matrix, structural similarity). After these models are trained and tested, they are integrated into a graphic user interface for on‐site identification use. The developed method provides a framework using multispectral images for 3D data reconstruction and segmentation and can be implemented for wafer‐scale characterization of heterostructures containing different species of ultra‐thin atomic crystals. [ABSTRACT FROM AUTHOR]

Laser ablation has been utilized for locally and selectively modifying the surface wettability of materials in situ and enabling on‐demand microfabrication. The anisotropic wettability has been observed on chemical and/or topographical patterns, such as an array of laser‐inscribed strips with spacings, created on surfaces during the fabrication process. Herein, the effectiveness of the femtosecond laser ablation is evaluated in selectively modifying surface wettability. The areas processed by laser ablation exhibit anisotropic wetting behavior, even after the laser strips are overlapped. The laser‐induced anisotropic surface wettability is present in space governed by laser scanning speed, scan/strip overlap, laser fluence, scan repetition, and bidirectional scanning angle. Moreover, the femtosecond laser ablation process is optimized to enhance the conventional laser inscription, leading to a modified and consistent methodology to achieve cost‐effective fabrication. [ABSTRACT FROM AUTHOR]

Optical technologies are essential for the rapid and efficient delivery of health care to patients. Efforts have begun to implement these technologies in miniature devices that are implantable in patients for continuous or chronic uses. In this review, we discuss guidelines for biomaterials suitable for use in vivo. Basic optical functions such as focusing, reflection, and diffraction have been realized with biopolymers. Biocompatible optical fibers can deliver sensing or therapeutic-inducing light into tissues and enable optical communications with implanted photonic devices. Wirelessly powered, light-emitting diodes (LEDs) and miniature lasers made of biocompatible materials may offer new approaches in optical sensing and therapy. Advances in biotechnologies, such as optogenetics, enable more sophisticated photonic devices with a high level of integration with neurological or physiological circuits. With further innovations and translational development, implantable photonic devices offer a pathway to improve health monitoring, diagnostics, and light-activated therapies.