Biscarbamate cross-linked low molecular weight PEI for delivering IL-1 receptor antagonist gene to synoviocytes for arthritis therapy.

Cytoxicity is an essential concern for polyethyleneimine 25 kDa (PEI 25 kDa), a widely reported, highly effective transfection agent used in gene delivery. In our recent experiments, Small molecular weight cross-linked poly(ethylene imine) by biscarbamate linkage (PEI-Bu) (Mn: 3278, Mw: 4289) can reduce target cell apoptosis induced by polycationic transfection, and has almost the same DNA condensation capability as PEI 25 kDa. PEI-Bu showed significantly higher activity and lower cytotoxicity than PEI 25 kDa in transfecting the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1Ra) gene to rat synoviocytes, an optimal target for arthritis treatment. The expression of IL-1Ra in synoviocytes then suppresses the expression of metalloproteases 13 (MMP13) gene, which is responsible for cartilage destruction regulated by IL-1β in arthritis. In conclusion, PEI-Bu is a promising tool for delivering IL-1Ra gene to synoviocytes for arthritis therapy.