Chlorin e6 (Synonyms: Ce6)

Chlorin e6(Ce6) is a second-generation photosensitizer. Compared to the first-generation photosensitizers, Chlorin e6 has the advantage of efficiently absorbing longer light wavelengths, which is favorable for deeper tissue penetration^[1] .Chlorin e6-based photosensitizers are widely used in antitumor photodynamic therapy(PDT) due to high quantum output of single oxygen and a strong absorption band in a red region^[2]

Chlorin e6-mediated PDT inhibits adipocyte differentiation and lipogenesis via regulating AMPK in 3T3-L1 cells, indicated that Chlorin e6-mediated PDT might serve as a potential therapy for the treatment of obesity and obesity-associated diseases^[2]. Chlorin e6-Fu/AL@GG hydrogel can be a feasible nanocarrier for Chlorin e6-assisted PDT that possesses an excellent capability to selectively kill colon cancer cells^[3]

Chlorin e6-loaded PEG-PCL nanoemulsions (Ce6-PCL-NEs) showed efficient cellular uptake and, upon laser irradiation, generated singlet oxygen to kill tumor cells. Particularly, Chlorin e6-PCL-NEs showed prolonged blood circulation and about 60% increased tumor accumulation compared to free Chlorin e6 after intravenous injection to 4T1 tumor-bearing mice(2.5mg/kg), indicated the promising potential of Chlorin e6-PCL-NEs for efficient PDT and in vivo drug delivery to tumor tissue^[4]. Chlorin e6 nano-precipitations (Chlorin e6 NPs) can be prepared by a one-pot method for effective photodynamic therapy of colorectal cancer. The HT-29 tumour-bearing mice were randomly divided into three groups and were administered intravenously with saline, free Chlorin e6 and Chlorin e6 NPs (5mg/kg Chlorin e6) once every 2 days for 2 weeks. The laser was applied three times 24h post injection (680 nm, 0.5 W/cm² for 5 min). Chlorin e6 NPs showed significantly enhanced anticancer benefits compared to free Chlorin e6, which almost obtained full ablation of tumours at the end of the study^[5]

References:
[1].Ryu AR, Kim YW, et al. Chlorin e6-mediated photodynamic therapy modulates adipocyte differentiation and lipogenesis in 3T3-L1 cells. Photodiagnosis Photodyn Ther. 2020;31:101917.
[2].Papayan G.V., Akopov А.L. Photodynamic theranostics of central lung cancer: capabilities of early diagnosis and minimally invasive therapy (review). Sovremennye tehnologii v medicine 2021; 13(6): 78
[3].Karuppusamy S, Hyejin K, et al. Nanoengineered chlorin e6 conjugated with hydrogel for photodynamic therapy on cancer. Colloids Surf B Biointerfaces. 2019;181:778-788.
[4].Park C, Yoo J, et al. Chlorin e6-Loaded PEG-PCL Nanoemulsion for Photodynamic Therapy and In Vivo Drug Delivery. Int J Mol Sci. 2019;20(16):3958. Published 2019 Aug 14.
[5].Miao Z, Wang Y, et al. One-pot synthesis chlorin e6 nano-precipitation for colorectal cancer treatment Ce6 NPs for colorectal cancer treatment. IET Nanobiotechnol. 2021;15(8):680-685.