CO enhances agomir transfection under pathological conditions to inhibit MMP overexpression

Cellular uptake of exogenous nucleic acids is inhibited in pathological tissues accompanied by excessive expression of matrix metalloproteinases (MMPs). We show that CO, as a regulator of membrane function, can reactivate uptake of agomir (Ago) in pathological condition via RAB5-mediated endocytic pathway. Herein, a responsive nanoparticle-crosslinked injectable hydrogel (CO-Ago gel) was engineered as a prototype for co-delivering CO and Ago to inhibit MMP overexpression in accordance with the disease severity. Compared to a typical matrix-enhanced gene therapy (Ago gel), CO-Ago gel significantly promoted Ago uptake, achieving an order of magnitude improvement of targeted gene expression under pathological conditions (11.2-fold for cardiomyocyte and 15.3-fold for primary fibroblasts). The therapeutic effect of CO-Ago gel on MMP overexpression was assessed in rat models of myocardial ischemia reperfusion and diabetic skin wound healing. The results suggest CO-enhanced transfection could contribute to the development of next-generation adjuvants for gene-based therapies and vaccines in vivo.