Recent advances of CRISPR-based gene editing technologies and delivery strategies.

CRISPR technology is a powerful tool for gene editing, in which the efficient delivery of living target cells allows it to show great clinical potential. At present, the commonly used in vivo delivery strategies mainly include biological methods (AAV, VLP, SEND) and chemical methods (LNP), which subtly deliver gene editors to living target cells safely and efficiently from different ways. However, existing delivery systems have different extents of limitations in terms of editing efficiency, immunogenicity, half-life, etc., so developing optimized delivery systems is the key to fully realizing the potential of CRISPR-Cas system for intracellular gene editing. In order to fully understand the advantages of different delivery strategies to maximize the ability to help CRISPR systems choose delivery methods, we conducted a systematic review. In this paper, we introduce the types, principles and characteristics of gene editing systems in order to understand their requirements for delivery tools. We focus on describing the type, principle, load, immunogenicity, specificity, toxicity, etc. of the delivery system, so as to fully analyse its advantages and disadvantages for the selection of different editing environments. This review aims to provide new insights to facilitate appropriate delivery systems or improve the efficacy of existing systems.