KATRIN ZIRK*¹, ÜLO LANGEL^1,2
*Corresponding author
1. University of Tartu, Institute of Technology, Laboratory of Molecular Biotechnology, Nooruse 1, Tartu, Estonia
2. Stockholm University, Department of Neurochemistry, The Arrhenius Laboratories for Natural Sciences, SE-10691, Stockholm, Sweden

Abstract

Personalized medicine approaches based on different gene therapy settings have gained much attention lately. In order to enforce successful gene therapy, genetic material needs to be delivered into cells. Nucleic acids and their analogues are unable to do so and thus require assistance to reach their site of action residing in the cytoplasm or nucleus. Here we give a short review on recent advancements in cell-penetrating peptide mediated delivery of splice-correcting oligonucleotides. We report on different cell-penetrating peptides applied for vectorization of splice-correcting oligonucleotides using both covalent conjugation and non-covalent nanoparticle formation approach. While covalent conjugation has gained extensive interest, there have also been great advances in non-covalent complex formation.

Gene therapy is an approach that introduces nucleic acids into cells and aims to correct the gene function by altering the gene expression to prevent, halt, or reverse a pathological process (1). There are three main routes to gene therapy: restoring a lost gene function, silencing the disease-causing genes, or modifying a gene function. Achieving expression of a deficient gene product by therapeutic gene delivery is considered to be the classical gene therapy approach, but gene silencing and function modification have also gained quite an interest recently. 

RNA interference (RNAi) is a fundamental gene silencing pathway in eukaryotic cells, which is mediated by short interfering RNA (siRNAs) that can cleave complementary mRNA sequences with the help of the RNA-induced silencing complex (RISC) and argonaute 2. siRNA therapeutics target various diseases, including viral infection and cancer (2). Many genetic disorders, such as Duchenne muscular dystrophy (DMD), β-thalassemia, and spinal muscular atrophy, are associated with mutations that change the normal splicing patterns. Chemically altered antisense oligonucleotides, which modify gene function, have been developed ...