ADVANCES OF CRISPR CAS9 TECHNOLOGY FOR GENOME AND EPIGENOME EDITING

The advent of CRISPR/Cas9 technology has revolutionized gene editing. Through diverse delivery methods, it has enabled effective gene editing across in vitro, ex vivo, and in vivo applications, thanks to ongoing advancements in the field. Viral vectors, despite their potential to trigger immune responses, limited cloning capacity, and risk of insertional mutagenesis, remain widely used in these systems. While chemical delivery methods still require extensive optimization to boost their efficiency for in vivo applications, physical delivery techniques are mostly confined to in vitro and ex vivo contexts. One of the most challenging aspects of gene editing remains developing a safe and effective in vivo delivery method for CRISPR/Cas9. CRISPR-Cas technology has also paved the way for a diverse range of molecular systems now widely used in research and increasingly in medical treatment. For instance, Cas proteins without nucleolytic activity—referred to as dead Cas proteins or dCas—can deliver functional cargo to specific, preselected genome locations. This review starts by examining the advantages and limitations of various physical methods for delivering Cas9. Next, it highlights key applications of CRISPR systems in epigenetic modifications. Finally, it explores the use of CRISPR-Cas9 technology in genome editing, with a particular focus on base editing and prime editing, along with its future prospects.