ROS-responsive 3D biological scaffold delivers hypoxia-primed extracellular vesicles for targeted modulation of neuroinflammation in intracerebral hemorrhage.

BACKGROUND

Emerging evidence suggests that paracrine mechanisms may underlie the therapeutic effects of human umbilical cord mesenchymal stem cell-derived extracellular vesicles (EVs) (hUCMSC-exos) in mitigating neuroinflammation following intracerebral hemorrhage (ICH). Hypoxic preconditioning enhances the paracrine efficacy of hUCMSC-exos. Building on prior studies [1, 2], we developed a ROS-responsive three-dimensional (3D) biological scaffold encapsulating hypoxia-primed EVs (Hypo-Exos) for sustained release under reactive oxygen species (ROS)-rich conditions.

METHODS

The 3D biological scaffold was fabricated via a thermoresponsive crosslinking strategy using gelatin methacrylate (GelMA), silk fibroin, and brain-derived decellularized extracellular matrix (dECM), functionalized with phenylboronic acid (PBA)-modified polyvinyl alcohol (PVA). Hypo-Exos, enriched with miR-146b via hypoxia-inducible factor-1α (HIF-1α) activation, were incorporated into the scaffold using advanced 3D bioprinting. Dual-luciferase reporter assays validated miR-146b targeting of the 3'UTR of COP1 (an E3 ubiquitin ligase). In a rat ICH model, the scaffold was implanted in situ. Neurological function, angiogenesis, neuroinflammation, and synaptic plasticity were evaluated at days 1, 4, 7, and 14.

RESULTS

The 3D biological scaffold enabled sustained delivery of Hypo-Exos, shifting microglial polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotypes, thereby attenuating neuroinflammation and neuronal damage. Mechanistically, miR-146b suppressed COP1 expression via post-transcriptional silencing, thereby attenuating NF-κB p65 signaling and downregulating pro-inflammatory cytokines.

CONCLUSION

The ROS-responsive 3D biological scaffold -mediated delivery of Hypo-Exos modulates neuroinflammation through ubiquitination pathways, stabilizes the early-phase ICH microenvironment, and improves functional recovery. This platform represents a promising therapeutic strategy for ICH, offering dual advantages as a drug delivery system and a regenerative therapy.