Dual-Functional Microneedles for In Situ Diagnosis and Biofilm-Targeted Therapy of Diabetic Periodontitis via Biomarker-Responsive Probes and Photothermal NO Nanomotors

Chronic periodontitis, a frequent complication of diabetes, is exacerbated by bacterial biofilms that drive progressive periodontal tissue destruction and systemic inflammation. Conventional treatments, utilizing mechanical debridement and systemic antibiotics, often fail to eradicate bacterial biofilms, promote antibiotic resistance, and lack real-time monitoring, leading to suboptimal therapeutic outcomes. Herein, we report a separable bilayer microneedle (MN) patch that enables localized, antibiotic-free, biofilm-targeted therapy and in situ biomarker-based monitoring for the integrated management of chronic periodontitis. Specifically, the swellable backing layer of the patch incorporates interleukin-6 and miRNA-223 responsive fluorescence probes, enabling visual, real-time assessment of periodontal inflammation and aiding in the diagnosis of chronic periodontitis. Simultaneously, the patch features a soluble MN tip embedded with indocyanine-green-modified asymmetrically gold-decorated hollow mesoporous silica nanoparticles, which are loaded with glucose oxidase and l-arginine, forming near-infrared (NIR-) driven nanomotors (JSGAs). Upon NIR irradiation, JSGAs generate local hyperthermia that enhances biofilm penetration and initiates a cascade catalytic reaction to release nitric oxide (NO). In rat models, the system significantly reduced local inflammation and bacterial infiltration while enabling longitudinal monitoring, offering a smart, closed-loop strategy for precise diagnosis and therapy of chronic periodontitis.