AUTHOR=Zhang Yuan , Zhang Ruiyang , Zhang Ti , Mu Yuhao , Juma Talante , Li Xu , Li Hao , Guo Quanyi , Cao Yongping TITLE=Restoration of tendon repair microenvironment by grapefruit exosome-loaded microneedle system for tendinopathy therapy JOURNAL=Frontiers in Bioengineering and Biotechnology VOLUME=Volume 13 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2025.1615650 DOI=10.3389/fbioe.2025.1615650 ISSN=2296-4185 ABSTRACT=Tendinitis repair remains challenging due to the limited self-renewal capacity of tenocytes and persistent inflammatory microenvironment. Conventional therapies remain limited by systemic drug toxicity and fail to coordinate immunomodulation with matrix remodeling. Plant-derived extracellular vesicles have demonstrated tissue repair potential owing to their unique bioactive components and exceptional cross-species compatibility. Nevertheless, their therapeutic role in tendon matrix regeneration remains underexplored. Here, we developed a grapefruit-derived exosome-loaded microneedle patch (MN@GF-Exos) to synergistically restored tendon structure and functions. Grapefruit-derived exosomes (GF-Exos) were loaded into dissolvable hyaluronic acid microneedles (MNs) for sustained release. GF-Exos reversed oxidative stress in tenocytes, enhancing cellular proliferation and migration, restoring collagen I synthesis, and polarizing macrophages toward M2-repair phenotypes. Transcriptomics revealed GF-Exos modulated cytokine-cytokine receptor interactions, suppressing inflammation-related pathways and activating ECM organization genes. In collagenase-induced tendinopathy mice, MN@GF-Exos enhanced gait recovery and extracellular matrix remodeling. Histology confirmed reduced fibrosis without ectopic ossification. Systemic safety was validated by unchanged organ histology and within-normal-limits serum biomarkers. This dual-functional system leverages plant exosomes’ multi-component synergy and MN’s spatiotemporal control, offering a translatable strategy for chronic tendon regeneration.