TABLE 2.

The delivery system of CRISPR-Cas9-based imaging.

Delivery vehicle	CRISPR-Cas9 format	Character	Efficiency	Advantage	Disadvantage	Application	Ref
SPPF-Dex nps	Plasmid	Photothermal regulation	12.8% indel mutation rate in HCT 116-GFP cells	Low toxicity, endolysosomal escape, payloads release	Less loading	In cell, in vivo	Li et al. (2019)
Au nanorod (APC)	Plasmid	Photothermal regulation	18.0% indel mutation rate in Hepa1-6 cells, 6.7% indel mutation in the liver tissue	Specific binding	Surface modification is needed to bind genes effectively	In cell, in vivo	Chen X. et al. (2020)
AR@PSS@PCM(ANP)	Plasmid	Photothermal regulation	39.7% indel mutation rate in B16F10 cells, 21.5% in tumor	Good biocompatibility, promote intracellular delivery	prone to negatively charge cells and proteins	In cell, in vivo	Tang et al. (2021)
Protamine–AuNCs	Plasmid	Cationic protamine facilitates release	27.5% indel mutation rate in HeLa cells	Cell-penetrating properties, nucleus-targeting	Reunion	In cell	Tao et al. (2021)
Photolabile semiconducting polymer nanotransducer	Plasmid	Photosensitive regulation	Indel 15- and 1.8-fold enhancements in cells and living mice	Efficient release of gene vectors	Low particle surface potential	In cell, in vivo	Lyu et al. (2019)
NTA-SS-PEG-PCL/Ce6 Complex	Cas9 RNP	Photosensitive regulation	42.6% indel mutation rate in CNE-2 cells, 31.2% indel mutation rate in tumor	Stability, low toxicity, tumor targeting	Cytotoxicity	In cell, in vivo	Deng et al. (2020)
UCNPs-Cas9@PEI	Cas9 RNP	Photosensitive regulation	Inhibited cancer cell proliferation and tumor growth	Endosomal escape	Low particle surface potential, less loading	In cell, in vivo	Pan et al. (2019)
Upconversion nanoparticles	Plasmid	Photosensitive regulation	Inhibited cancer cell proliferation and tumor growth	Light stability, low potential toxicity, no background light interference	Low particle surface potential	In cell, in vivo	Chi et al. (2021)
Au nanoparticles	Plasmid	Photothermal regulation	1.24% indel mutation rate inA375 cells, sustainable tumor inhibition	High loading efficiency, good stability, good repetition	Surface modification is needed to bind genes effectively	In cell, in vivo	Wang et al. (2018)
NIR light-triggered thermo-responsive copper sulfide (CuS)	Cas9 RNP	Photothermal regulation	37.3%indel mutation rate in A375 cells, 23.8% indel mutationin in tumor	Assist endosomal escape	Reunion, cytotoxicity	In cell, in vivo	Chen et al. (2021)
Electroporation	RNP, plasmid	Transient transfection, easy to cause damage to cell membranes	High transfection efficiency	Small dependence on cell types, equipment cost	Easy to cause damage to cell membranes	In cell	Chen S. et al. (2019)
Viral vector (AAV, LV, AdV)	Plasmid	Has been approved for human clinical trials, cause virus contamination	Stable, high transfection efficiency	High capacity	Introduce virus contamination, immune response	In cell, in vivo	Moreno et al. (2020)
Lipofectamine	RNP, plasmid	Simple preparation, good safety, low cost	High transfection efficiency	Simple preparation, good safety	Prone to immune response	In cell, in vivo	Liu et al. (2020)