A Folic Acid labelled Carbon Quantum Dot - Protoporphryin Ⅸ conjugate for use in folate receptor targeted Two-Photon excited Photodynamic Therapy

摘要

Folk acid (FA) has been used as a molecular targeting strategy to improve the specificity of a CQD-protoporphyrin Ⅸ (CQD-PPⅨ) conjugate to folate receptor positive (FR+) HeLa cells for use in two-photon excited Photodynamic Therapy (TPE-PDT). FA was covalently attached to the CQD-PPⅨ conjugate to form a FA-CQD-PPⅨ conjugate. The uptake of the FA-CQD-PPⅨ conjugate in FR+ HeLa cells was shown to be 7 times greater than the CQD-PPⅨ conjugate, while both conjugates showed a similar uptake in FR negative (FR-) HT-47 cells. TPE-PDT experiments, using HeLa cells as a target, revealed a 30% improved cytotoxicity for cells treated with the FA-CQD-PPⅨ conjugate and TPE compared to controls treated with the CQD-PPⅨ conjugate and TPE. Collectively, these results suggest the presence of FA can facilitate targeting of CQD-sensitiser conjugates to FR+ cells resulting in an improved PDT effect.