Microfluidic Production of Mangiferin-Loaded Liposomes Enables Gut–Joint Axis Modulation for Early Osteoarthritis Intervention

Microfluidic nanomanufacturing provides a controllable and scalable strategy for improving the oral delivery of poorly bioavailable natural compounds. Herein, mangiferin-loaded liposomes (Lip@MG) were fabricated using an in-house-developed continuous microfluidic platform integrated with a high-efficiency micromixer and evaluated as a gut-joint axis-oriented intervention for early knee osteoarthritis (KOA). Compared with the conventional batch method, microfluidic synthesis produced Lip@MG with a more uniform spherical morphology, a clearly defined bilayer structure, and a narrower particle size distribution. By adjusting the flow-rate ratio, Lip@MG with tunable particle sizes from 207.8 to 118.6 nm, reduced polydispersity, and stable negative zeta potentials of up to approximately -35 mV was obtained. In vitro, Lip@MG exhibited favorable cytocompatibility and enhanced chondrocyte viability. Transcriptomic analysis, qRT-PCR, and western blot further indicated that Lip@MG attenuated LPS-induced inflammatory responses in chondrocytes, at least partly by suppressing NF-κB signaling and inhibiting p65 phosphorylation. In an anterior cruciate ligament transection-induced KOA mouse model, oral Lip@MG administration alleviated cartilage degeneration, increased cartilage thickness from 132 to 215 μm, reduced the OARSI score from 2.5 to 1.5, increased subchondral bone mineral density by 27%, and restored colonic barrier integrity, as reflected by a 65% reduction in the colonic histopathological score. Full-length 16S rRNA gene sequencing revealed that Lip@MG reshaped KOA-associated gut dysbiosis by partially restoring the Firmicutes/Bacteroidetes balance and enriching potentially beneficial taxa. These findings demonstrate that microfluidically manufactured Lip@MG is a promising nutritional nanocarrier for microbiota-centered early KOA intervention through coordinated regulation of intestinal homeostasis and joint degeneration.