A sensitive and specific nano-vehicle based on self-amplified dual-input synthetic gene circuit for intracellular imaging and treatment.

Synthetic genetic circuits (SGCs) that sense multiple biomarkers and respond intelligently provide a powerful tool for intracellular biosensing. The SGC is usually loaded into the nanoscale liposomes to build functional intracellular nano-vehicles, widely applied in diagnosing and treating diseases. However, because the system needs to identify multiple targets to activate, the sensitivity will be inevitably reduced though the specificity is improved, leading to false-negative results in diagnosis and low killing dosage in treatment. Such compromise between specificity and sensitivity has been a bottleneck problem for the field. We innovatively invented the self-amplified dual-input (SADI) SGC@liposome nano-vehicle and broke the bottleneck problem above. It provides multiple sites for regulating sensitivity at both coarse and fine levels, allowing researchers to conveniently balance the sensitivity and specificity according to the application and instrumental setups. In recognizing ovarian cancer cells, the nano-vehicle could enhance the sensitivity by nearly 10-fold, and the specificity remained at high levels of 16-fold. We also changed the output fluorescent signal to output effectors such as apoptosis regulator (BAX) and proliferation-inhibiting protein (p21) and demonstrated the application range. Furthermore, we verified the generality of the system by applying it to target different cells. We believe it will provide a convenient and powerful tool for biosensors and targeted therapy.