Anti-EGFR indocyanine green-mitomycin C-loaded perfluorocarbon double nanoemulsion: A novel nanostructure for targeted photochemotherapy of bladder cancer cells

Abstract

The use of phototherapy as an adjuvant bladder cancer treatment has long been considered, but its application has been severely hampered due to a lack of tumor specificity, unpredicted cytotoxicity, and insufficient anticancer efficacy. In this study, we aim to manufacture anti-EGFR indocyanine green (ICG) mitomycin C (MMC) encapsulated perfluorocarbon double nanoemulsions (EIMPDNEs), and explore their photochemotherapeutic efficacy on EGFR-expressing bladder cancer cells in vitro. The EIMPDNEs were manufactured using a double emulsification technique followed by antibody conjugation on the particles’ surfaces. The EIMPDNE were 257 ± 19.4 nm in size, with a surface charge of −12.3 ± 2.33 mV. The EGFR targetability of the EIMPNDE was confirmed by its enhanced binding efficiency to T24 cells when compared with the performance of nanodroplets without EGFR conjugation (p < 0.05). In comparison with freely dissolved ICG, the EIMPDNEs with equal ICG content conferred an improved thermal stability to the encapsulated ICG, and were able to provide a comparable hyperthermia effect and significantly enhanced the production of singlet oxygen under 808 nm near infrared (NIR) exposure with an intensity of 6 W cm−2 for 5 min (p < 0.05). Based on viability analyses, our data showed that the EIMPDNEs were effective in bladder cancer cell eradication upon NIR exposure (808 nm; 6 W cm−2), and the resulting cell death rate was even higher than that caused by a five-fold higher amount of entrapped MMC alone. With the merits of improved ICG stability, EGFR binding specificity, and effective cancer cell eradication, the EIMPDNEs exhibit potential for use in EGFR-expressing bladder cancer therapy with lower chemotoxicity.