Figure 2.

Cas9 RNP delivery strategy and chip performance. (A) Experimental scheme of Cas9/crRNA/tracrRNA ribonucleoprotein (Cas9 RNP) delivery for genome editing in hard-to-transfect cells via a microfluidic cell deformation chip. Scanning electron microscopy of deformable zones in the device is also shown. Scale bar, 10 µm. The red arrow indicates one curved tunnel with a depth of 15 µm and a width of 4–8 µm. (B) Cell deformation was shown by microscopy when SK-BR-3 cells passed through the micro construction: scale bar, 10 µm. (C) Microscopy of SK-BR-3 cells into which FITC-labeled 70 kDa dextran molecules were delivered through different chip designs. Arrays 1 and 2 show cell passage curved tunnels formed by different structural arrangements. Scale bar, 20 µm. (D) Delivery efficiency and cell viability 16 h after treatment were calculated for (C) at a fluid speed of 150 µL min⁻¹. Array 1 × 10 or array 2 × 10 indicates cells passing through a chip with 10 repeats of identical cell deformation zones. Error bars indicate SEM (n = 3). (Reproduced with permission from [95] Copyright 2020 Wiley.