The present invention relates to chemical modification motifs for oligonucleotides. The oligonucleotides of the present invention, such as chemically modified antisense oligonucleotides, can have increased in vivo efficacy. The chemically modified oligonucleotides provide advantages in one or more of potency, efficiency of delivery, target specificity, toxicity, and/or stability. The chemically modified oligonucleotides have a specific chemical modification motif or pattern of locked nucleic acids (LNAs). The oligonucleotide (e.g. antisense oligonucleotide) can target RNA, such as miRNA or mRNA. Also provided herein are compositions comprising the chemically modified oligonucleotides and methods of using the chemically modified oligonucleotides as therapeutics for various disorders, including cardiovascular disorders.