A non-viral CRISPR/Cas9 delivery system for therapeutically targeting HBV DNA and pcsk9 in vivo

Cpf1, a type-V CRISPR–Cas effector endonuclease, exhibits gene-editing activity in human cells through a single RNA-guided approach. Here, we report the design and assessment of an array of 42 types of engineered Acidaminococcus sp. Cpf1 (AsCpf1) CRISPR RNA (crRNA) and 5 types of AsCpf1 mRNA in human cell lines. We show that the top-performing modified crRNA (cr3′5F, containing five 2′-fluoro ribose at the 3′ terminus) and AsCpf1 mRNA (full ψ-modification) improved gene-cutting efficiency by, respectively, 127% and 177%, with respect to unmodified crRNA and plasmid-encoding AsCpf1. We also show that the combination of cr3′5F and ψ-modified AsCpf1 or Lachnospiraceae bacterium Cpf1 (LbCpf1) mRNA augmented gene-cutting efficiency by over 300% with respect to the same control, and discovered that 11 out of 16 crRNAs from Cpf1 orthologues enabled genome editing in the presence of AsCpf1. Engineered CRISPR–Cpf1 systems should facilitate a broad range of genome editing applications.

Hypochlorous acid (HClO) is a promising diagnostic marker for inflammation and relevant diseases. Although many probes were previously developed for HClO imaging, the development of organ targeting probes is still lacking. Herein, we designed and synthesized a series of cyanine derivatives as ratiometric fluorescent probes to detect endogenous HClO in the lungs with inflammation. By installing diverse lipid chains and amino groups on cyanine, we identified that ClO1, with one n-octadecane chain and two 2-[[2-(dimethylamino)ethyl]methylamino]-ethyl groups, is a superior probe to target the lungs over other major organs in mice. ClO1 was able to sense both exogenous and endogenous HClO in A549 (human lung epithelial) cells through fluorescence ratiometric imaging. In a lipopolysaccharide (LPS)-induced lung inflammation mouse model, ClO1 effectively captured endogenous HClO in the lungs after intravenous administration. Overall, these cyanine-derived probes merit further development as organ targeting HClO sensors.