A Spatially Ordered Three-Input Logic Gate for Highly Specific and Sensitive Breast Tumor Imaging

Breast cancer poses a significant threat to the health of women globally. To date, clinically invasive needle biopsy may cause cancer metastasis, and noninvasive imaging methods exhibit suboptimal sensitivity. Therefore, developing a highly specific and sensitive diagnostic method for breast cancer detection continues to be a challenge. In this work, a spatially ordered three-input logic gate <b>KK(GGR)-Luc</b> is rationally designed to achieve precise and sensitive breast cancer <i>in vivo</i> imaging. The as-designed <b>KK(GGR)-Luc</b> can sequentially respond to urokinase-type plasminogen activator (uPA), cathepsin B (CTB), and luciferase (fLuc), and consequently, it generates highly specific bioluminescence (BL) signals in the 4T1 cells and tumors. Experimental results showed that the signal intensities of breast cancer treated with <b>KK(GGR)-Luc</b> exceeded those of all negative control groups by 3.5-fold in living cells and 5.0-fold <i>in vivo</i>, respectively. In addition, this spatially ordered three-input logic gate provided a long BL half-life (<i>t</i>_1/2 = 117.2 min) in cells, which showed great potential in breast cancer <i>in vivo</i> imaging. We hope that the proposed sequentially activated three-input logic gate will aid in achieving highly precise and sensitive diagnosis of breast cancer in clinic.