Provided herein are oligonucleotides, chimeric peptides, and peptide-oligonucleotide-conjugates. Also provided herein are methods of treating a muscle disease, a viral infection, or a bacterial infection in a subject in need thereof, comprising administering to the subject oligonucleotides, chimeric peptides, and peptide-oligonucleotide- conjugates described herein.本發明提供寡核苷酸、嵌合肽及肽-寡核苷酸共軛物。本文亦提供治療有需要個體之肌肉疾病、病毒感染或細菌感染之方法,其包含向該個體投與本文所描述之寡核苷酸、嵌合肽及肽-寡核苷酸共軛物。