(RXR)4XB

(RXR)4XB is a cell-penetrating peptide, that binds the phosphorodiamidate morpholino oligomers (PMOs), forms peptide-conjugated PMOs (PPMOs), and improves the delivery of PMO into bacterial cells. (RXR)4XB-PMO conjugate prevents the formation of biofilms, inhibits Pseudomonas aeruginosa with MIC50 of 0.5 to 16 μM, and reduces the bacterial burden in mouse acute pneumonia models.