Peptide functionalized upconversion/NIR II luminescent nanoparticles for targeted imaging and therapy of oral squamous cell carcinoma.

Early diagnosis is critical and challenging for tongue squamous cell carcinoma (TSCC), which is a kind of tumor with high malignancy, poor prognosis, and a high incidence of invasion and metastasis. In this research, dual-modal optical imaging rare earth nanoparticle (RENP) probes with peptide functionalization are designed for targeted TSCC imaging and therapy. RENP@C@Au (UCA) with enhanced red upconversion luminescence (UCL) and near infrared II (NIR II) imaging intensity is designed by metal and codopant modulation, and the two peaks at about 650 nm and 1064 nm of Nd ions are relatively stable with less quenching and suitable for luminescence bioimaging. Then, the cMBP peptide targeted to Cal 27 TSCC cells with highly expressed c-MET proteins is combined with UCA. Compared with human's normal cells of MCF-10A, other tumor cell lines such as A549 and HeLa, together with mice tumor cells of 4T1, the designed probe has targeted imaging and therapy to Cal 27. The final in vivo experiment shows that the probe with high NIR II luminescence signals is not easy to retain when injected into the tail vein, indicating its potential precise clinical application for the diagnosis and therapy of TSCC.