A non-peptide chymotrypsin activatable probe for 3D-photoacoustic and NIR fluorogenic imaging of deep tumor

Dual-modality organic imaging agents hold great potential for comprehensive disease diagnosis by taking advantage of each mode. However, so far, there have been rarely reported on the design of alpha-CT triggered PA/ NIRF bioagents for precision clinical diagnosis of deep tumor, as it is indeed challenging to develop a molecular guideline to enable and boost every optical imaging efficacy simultaneously. Herein, we first proposed a 3D-PA/ NIRF dual-modality strategy triggered by alpha-CT to image deep tumor with high spatial resolution and deep penetration. The non-peptide probe HDC was established with hemicyanine as dual signal platform and 4-bro-mobutyryl as reaction site of alpha-CT. The probe HDC showed good sensitivity, selectivity, and affinity in response to alpha-CT in vitro. Significantly, the probe HDC enabled 3D-PA imaging of alpha-CT activated deep tumor with high spatial resolution and deep penetration. Meanwhile, owing to the NIR fluorescence in tumor site is strong with higher contrast than that of surrounding healthy tissue, it is convenient to depict tumor margin for anatomical analysis. Thus, alpha-CT activated 3D-PA/NIRF dual-modality imaging strategy in vivo is expected to be used to further guide the clinical treatment and clinical therapy effect.