siHIF-1α-loaded micellar nanoparticles inhibit M1 macrophage activation to ameliorate chronic rhinosinusitis

To investigate the molecular mechanisms by which micellar nanoparticles loaded with small interfering RNA targeting hypoxia-inducible factor 1-alpha (MNP_siHIF-1α) modulate macrophage polarization and ferroptosis in chronic rhinosinusitis (CRS), offering a novel therapeutic approach to ameliorate chronic inflammation and immune dysregulation in CRS.

Transcriptomic analysis of the GSE10406 dataset identified 3821 differentially expressed genes (DEGs) in CRS, with functional enrichment via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Single-cell RNA sequencing (scRNA-seq) using the Seurat package characterized cellular heterogeneity in nasal mucosal tissues of CRS mice. In vitro, Raw264.7 macrophages were transfected with lentiviral sh-HIF-1α or oe-TFRC constructs, followed by RT-qPCR, chromatin immunoprecipitation (ChIP), dual-luciferase assays, and flow cytometry to assess HIF-1α-TFRC interactions, ROS accumulation, and M1 polarization. MNP_siHIF-1α, prepared using PCL-PEG/PPEEA diblock copolymers, was characterized via dynamic light scattering (DLS) and gel retardation assays. In vivo, CRS mice received intranasal MNP_siHIF-1α (10 mg/mL, 20 μL, thrice weekly for 4 weeks), with histopathological and inflammatory outcomes evaluated by H&E staining, immunohistochemistry, and ELISA.

HIF-1α was significantly upregulated in CRS tissues (p < 0.05) and activated TFRC transcription by binding its promoter, driving M1 macrophage polarization (↑NOS2, IL-6, IL-1β; p < 0.05) and ferroptosis (↑MDA, Fe²⁺; p < 0.05). Silencing HIF-1α reduced TFRC expression (↓42 %, p < 0.05), suppressed ROS levels (↓35 %, p < 0.05), and inhibited M1 polarization (↓50 % IL-6, p < 0.05). MNP_siHIF-1α (51.0 ± 2.3 nm, ζ-potential: +27.9 mV) achieved 95 % siRNA loading at N/P 5:1 and reduced nasal mucosal thickening (↓60 %, p < 0.01) and inflammatory cytokines (TNF-α: ↓45 %, p < 0.05) in CRS mice. Ferroptosis markers (GPX4: ↑2.1-fold, MDA: ↓55 %) confirmed therapeutic efficacy.

MNP_siHIF-1α suppresses the HIF-1α/TFRC-ROS axis, mitigates M1 macrophage-driven inflammation, and inhibits ferroptosis, significantly alleviating CRS progression. This study underscores the potential of nanotechnology-based siRNA delivery as a precision therapy for CRS, though further validation of long-term safety and clinical translation is warranted.