From mechanism to medicine: CRISPR‒Cas9 delivery strategies, therapeutic applications and translation challenges.

The advent of CRISPR‒Cas technology has revolutionized genome editing by providing unprecedented precision, efficiency, and versatility in genetic manipulation. This revolutionary system originated from bacterial adaptive immunity. It allows the programmed modification of DNA sequences in a highly specific way, as long as the desired modification site contains an enzyme-compatible protospacer adjacent motif (PAM) sequence. Recent innovations with CRISPR‒Cas systems have focused on optimizing delivery methods, addressing challenges and expanding their therapeutic applications. Delivery approaches, including viral vectors, lipid nanoparticles, and other nonviral vectors, have been improved to increase target specificity while minimizing off-target effects, ensuring safe and efficient In Vivo genome editing. The applications of CRISPR‒Cas technology include the correction of genetic disorders, engineering of immune cells for cancer therapy, and combating viral infections. However, significant challenges in the form of unintended edits, immune responses, and delivery to specific tissues or organs remain formidable barriers to clinical translation. New CRISPR variants, such as base editing, prime editing, and epigenome editing, provide solutions to improve accuracy and broaden intervention. This review covers recent progress in various CRISPR delivery methodologies, discusses broadening therapeutic applications, highlights ongoing challenges, and describes the future trajectory of this disruptive technology.