CRISPR Genome Editing Technologies: From Cas9 Mechanism to Advanced Cas12/Cas13 Systems and Modern Delivery Strategies in Gene Therapy

Abstract

Gene therapy, which modifies genetic material inside cells, has become increasingly important for treating and preventing genetic and non-genetic illnesses. Recent advances in genome editing technologies, including the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated system, have significantly improved the accuracy and efficiency of targeted gene modifications. This review discusses the development of gene therapy and the emerging clinical relevance of CRISPR-based genome editing technologies, with particular emphasis on CRISPR-Cas9 and newer CRISPR-associated systems, namely Cas12 and Cas13. A major part of CRISPR-Cas9 functioning is the guidance provided by RNA, which directs nucleases to specific DNA sequences and enables the breaking of both DNA strands. The resulting break can be repaired by correcting the defective gene, disrupting the gene, or inserting an entirely new gene copy into the genome. Compared with previous genome-editing methods, CRISPR is simpler, faster, more accurate, and less expensive, making it highly attractive for therapeutic applications. Its use in treating genetic disorders, cancer, viral infections, and developing precision medicine continues to expand. The study also highlights delivery approaches for CRISPR therapeutics, including viral vectors, lipid nanoparticles, polymeric nanoparticles, and ribonucleoprotein complexes. Each strategy has specific advantages and limitations regarding safety, targeting ability, and clinical effectiveness. Recent developments in Cas12 and Cas13 systems have further broadened CRISPR applications by enabling improved DNA targeting and RNA editing without permanent genomic alterations. Although challenges such as off-target effects, immune responses, and delivery efficiency remain, continuous advances in genome editing and delivery technologies are rapidly moving CRISPR-based therapies toward clinical practice. Overall, CRISPR technology represents a major advancement in modern medicine and holds strong potential for developing safe, effective, and personalized therapeutic strategies.Although challenges such as off-target effects, immune responses, and delivery efficiency remain, continuous progress in genome editing and delivery technologies is rapidly advancing CRISPR-based therapies toward clinical practice. Overall, CRISPR technology represents a major advancement in modern medicine and holds strong potential for the future development of safe, effective, and personalized therapeutic strategies. Overall, CRISPR technology represents a major advancement in modern medicine and holds strong potential for the future development of safe, effective and personalized therapeutic strategies.