Material solutions for delivery of CRISPR/Cas-based genome editing tools: Current status and future outlook

Clustered regularly interspaced short palindromic repeat (CRISPR)/associated protein (CRISPR/Cas) system is an adaptable immune mechanism used by many bacteria to protect themselves from invading nucleic acids, and it has been recently exploited as an efficient tool for site-specific, programmable genome editing in both single cells and whole organisms with a precise manner. CRISPR/Cas system has been shown its great potentials for a wide range of biomedical applications, such as transcriptional control, epigenetic modification, genome-wide screening and chromosomal imaging, and treatment of genetic disorders. Despite these excitements, the shortage of delivery materials that can deliver genome editing tools (including plasmid DNA, mRNA, and ribonucleoprotein) represents one of the major challenges for successful CRISPR/Cas-based genome editing. This review seeks to provide a comprehensive overview of different types of carriers ranging from classic drug delivery materials to advanced drug delivery systems that can transport CRISPR/Cas systems and mediate genome editing at the targeted loci. The challenges and future prospects of the delivery materials for optimizing the CRISPR delivery system for clinical translations are also highlighted.