Diabetes and its complications, including impaired wound healing, present a critical clinical challenge and burden for the U.S. healthcare system, with costs of over USD 13 billion annually. Hyperglycemia and chronic inflammation in diabetic wounds increase reactive oxygen species (ROS) production, inducing oxidative stress and perpetuating inflammation, which delays healing. This study investigates inflammation, oxidative stress, and the roles of cellular populations in a diabetic wound healing mouse model (db/db). Given that diabetes leads to persistent inflammation and impaired fibroblast function, we also examined how diabetes influences superoxide production in dermal fibroblasts. Blood, dermal fibroblasts, and wound tissue were collected from 12-week-old female diabetic (Db) and heterozygous (Hz) mice. Electron paramagnetic resonance (EPR) spectroscopy revealed higher superoxide levels in diabetic blood, dermal fibroblasts, and wounds compared to controls. In diabetic wounds, immunohistochemistry and flow cytometry showed increased leukocyte infiltration and reduced macrophage presence, with a higher proportion of pro-inflammatory Ly6C^hi macrophages. These results suggest that elevated superoxide production and persistent inflammation contribute to impaired fibroblast function and delayed wound healing in diabetes. By identifying the contributions of ROS and Ly6C^hi macrophages to oxidative stress and chronic inflammation, this study offers insights into therapeutic strategies. These findings highlight the importance of addressing systemic oxidative stress alongside localized inflammation to improve wound healing outcomes in diabetic patients and advance diabetic wound care strategies.

Acute respiratory distress syndrome (ARDS) has approximately 40% in-hospital mortality, and treatment is limited to supportive care. Pneumonia is the underlying etiology in many cases with unrestrained inflammation central to the pathophysiology. We have previously shown that CNP-miR146a, a radical scavenging cerium oxide nanoparticle (CNP) conjugated to the anti-inflammatory microRNA(miR)-146a, reduces bleomycin- and endotoxin-induced acute lung injury (ALI) by decreasing inflammation. We therefore hypothesized that CNP-miR146a would decrease inflammation in murine infectious ALI. Mice were injured with intratracheal (IT) MRSA or saline followed by treatment with IT CNP-miR146a or saline control. Twenty-four hours post-infection, bronchoalveolar lavage fluid (BALF) and whole lungs were analyzed for various markers of inflammation. Compared to controls, MRSA infection significantly increased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1β; p < 0.05), BALF proinflammatory cytokines (IL-6, IL-8, TNFα, IL-1β; p < 0.01), and inflammatory cell infiltrate (p = 0.03). CNP-miR146a treatment significantly decreased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1β; p < 0.05), bronchoalveolar proinflammatory protein leak (IL-6, IL-8, TNFα; p < 0.05), and inflammatory infiltrate (p = 0.01). CNP-miR146a decreases inflammation and improves alveolar–capillary barrier integrity in the MRSA-infected lung and has significant promise as a potential therapeutic for ARDS.