The storage of dynamic information in hydrogels has aroused considerable interest regarding the multiple responsiveness of soft matter. Herein, we propose an electrical writing methodology to prepare dopamine (DA)-modified chitosan hydrogels with a dynamic information storage ability. A pH-responsive chitosan hydrogel medium was patterned by cathodic writing to in situ generate OH- in the writing area, at which dopamine underwent an auto-oxidation reaction in the locally alkaline environment to generate a dark color. The patterned information on the hydrogel can be encoded simply by electrical signals. The speed of information retrieval is positively correlated with the charge transfer during the electrical writing process, and the hiding of information is negatively correlated with the environmental stimulus (i.e., dopamine concentration, pH value, etc.). To showcase the versatility of this medium for information storage and the precision of the pattern, a quick response (QR) code is electronically written on dopamine-modified chitosan hydrogel and can be recognized programmably by a standard mobile phone. The results show that electrical regulation is a novel means to program the information storage process of hydrogels, which inspires future research on structural and functional information storage using stimulus-responsive hydrogels.

The management of diabetic wounds poses a substantial economic and medical burden for diabetic patients. Oxidative stress and persistent bacterial infections are considered to be the primary factors. Qiai essential oil (QEO) exhibits various pharmacological characteristics, including inflammatory-reducing, antibacterial, and antioxidant properties. Nevertheless, the hydrophobic nature and propensity for explosive release of this substance present constraints on its potential for future applications. Here, we developed a stimulus-responsive hydrogel to overcome the multiple limitations of QEO-based wound dressings. The QEO was encapsulated within graphene oxide (GO) through repeated extrusion using an extruder. Subsequently, QEO@GO nanoparticles were incorporated into a Gelatin-methacryloyl (GelMA) hydrogel. The QEO@GO-GelMA hydrogel demonstrated controlled release ablation, photothermal antibacterial effects, and contact ablation against two representative bacterial strains. It effectively reduced reactive oxygen species (ROS) generation, promoted angiogenesis, and decreased levels of the pro-inflammatory cytokine interleukin-6 (IL-6), thereby accelerating the healing process of diabetic wounds. In addition, in vitro and in vivo tests provided further evidence of the favorable biocompatibility of this multifunctional hydrogel dressing. Overall, the QEO@GO-GelMA hydrogel provides numerous benefits, encompassing antimicrobial properties, ROS-scavenging abilities, anti-inflammatory effects, and the capacity to expedite diabetic wound healing. These attributes make it an optimal choice for diabetic wound management.

BACKGROUND: The accurate detection of glucose and cholesterol plays a pivotal role in disease diagnosis and home care. To this end, biochemical analyzers have become extensively utilized tools for measuring disease biomarkers. Nonetheless, their poor portability and high cost have restricted their accessibility, limiting their use to laboratory settings and hindering the adoption of point-of-care testing (POCT). In contrast, the emergence of portable and affordable paper-based testing platform has revolutionized diagnostic testing by providing distance signals, enhancing intuitiveness and visual accessibility. Consequently, these platforms have become increasingly suitable for POCT.
RESULTS: We have developed a POCT platform that integrated AuNS@Ag, stimulus-responsive hydrogel and test strips, enabling visual distance reading of glucose. The silver-coated AuNS and enzyme were encapsulated within a temperature-responsive N-isopropylacrylamide-acrylamide (NIPAM-AcAm) hydrogel to act as target recognition and reaction units respectively. Glucose can diffuse freely within the hydrogel porous matrix, thereby instigating enzyme-catalyzed reaction that induce alterations in the photothermal effect of the system. This dynamic process ensures efficient and responsive modulation of the system\'s photothermal properties. By ingeniously capturing distance signals induced by the photothermal effect-mediated water release the visualization and quantification of target substances are achieved, with a linear range spanning from 0 to 30 mM. The consistency between distance-based POCT platform and commercial blood glucose meter demonstrates that the platform provides a portable, affordable and reliable method for visual reading biomarkers.
CONCLUSIONS: The proposed strategy enables direct, visual quantitative analysis of the target without the need for additional analytical instruments. Particularly, this method holds significant promise as an efficient platform for cholesterol and other disease markers measurement.