A near infrared ratiometric platform based π-extended porphyrin metal-organic framework for O2 imaging and cancer therapy.

ABSTRACT Photodynamic therapy (PDT) is widely researched in tumor treatment, but its therapeutic effect is affected by oxygen (O2) concentration of tumor site. Here, we developed a Pd-coordinated π-conjugated extended porphyrin doped porphyrin metal-organic-framework (named as PTP). PTP can achieve near infrared (NIR) O2 concentration ratiometric imaging, solving the problems of short detection wavelengths and influence of self-concentrations. With the NIR excitation wavelength and the ability of higher singlet oxygen (1O2) generation, PTP can induce PDT more effectively. The efficient PDT also mediates cancer immunogenic cell death (ICD), which combines with the immune checkpoint inhibitor αPD-1 to achieve obviously cancer suppression and anti-metastasis effect. This theranostic NIR ratiometric nanoprobe can be used as a pre-evaluation on the outcome of PDT and high-efficient cancer combined treatment system, which will find great potential in tumor diagnosis and treatment.