Bioluminescence and photoacoustic dual-modality imaging of apoptosis using a duramycin-immobilized gold nanorod probe

Phosphatidylethanolamine (PE) translocation is considered a hallmark event of cellular apoptosis. The development of non-invasive multi-modality probes targeting PE for apoptosis detection holds great promise. Here, we develop a dual-modality imaging probe, duramycin-Fluc-AuNRs (DFA), for detecting apoptosis in tumor cells. DFA is created by linking duramycin peptide and firefly luciferase (Fluc) recombinant protein to gold nanorods (AuNRs). Duramycin exhibits high affinity for PE, while Fluc produces a robust bioluminescence signal, and AuNRs enhance imaging resolution through photoacoustic conversion. The DFA probe demonstrates low toxicity in both cells and mice, showcasing its potential for in vivo applications. In A549 and 4T1 cell lines, the bioluminescence signal of the DFA probe increases with the degree of doxorubicin (Dox)-induced apoptosis. At the mouse level, mice with Dox-triggered apoptosis exhibit higher bioluminescence and photoacoustic imaging signals. Thus, this dual-modality bioluminescence/photoacoustic imaging platform holds significant potential for detecting cellular apoptosis and providing high-performance imaging information.