Cytotoxicity assessment of functionalized CdSe, CdTe and InP quantum dots in two human cancer cell models.
The toxicity of quantum dots (QDs) has been extensively studied over the past decade. Some common factors that originate the QD toxicity include releasing of heavy metal ions from degraded QDs and the generation of reactive oxygen species on the QD surface. In addition to these factors, we should also carefully examine other potential QD toxicity causes that will play crucial roles in impacting the overall biological system. In this contribution, we have performed cytotoxicity assessment of four types of QD formulations in two different human cancer cell models. The four types of QD formulations, namely, mercaptopropionic acid modified CdSe/CdS/ZnS QDs (CdSe-MPA), PEGylated phospholipid encapsulated CdSe/CdS/ZnS QDs (CdSe-Phos), PEGylated phospholipid encapsulated InP/ZnS QDs (InP-Phos) and Pluronic F127 encapsulated CdTe/ZnS QDs (CdTe-F127), are representatives for the commonly used QD formulations in biomedical applications. Both the core materials and the surface modifications have been taken into consideration as the key factors for the cytotoxicity assessment. Through side-by-side comparison and careful evaluations, we have found that the toxicity of QDs does not solely depend on a single factor in initiating the toxicity in biological system but rather it depends on a combination of elements from the particle formulations. More importantly, our toxicity assessment shows different cytotoxicity trend for all the prepared formulations tested on gastric adenocarcinoma (BGC-823) and neuroblastoma (SH-SY5Y) cell lines. We have further proposed that the cellular uptake of these nanocrystals plays an important role in determining the final faith of the toxicity impact of the formulation. The result here suggests that the toxicity of QDs is rather complex and it cannot be generalized under a few assumptions reported previously. We suggest that one have to evaluate the QD toxicity on a case to case basis and this indicates that standard procedures and comprehensive protocols are urgently needed to be developed and employed for fully assessing and understanding the origins of the toxicity arising from different QD formulations.
Institute of Gerontology and Geriatrics & Beijing Key Lab of Aging and Geriatrics, Chinese PLA General Hospital, Beijing 100853, PR China.
Jing
J
Liu
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Rui
R
Hu
Institute of Gerontology and Geriatrics & Beijing Key Lab of Aging and Geriatrics, Chinese PLA General Hospital, Beijing 100853, PR China.
Jianwei
J
Liu
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Butian
B
Zhang
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Yucheng
Y
Wang
Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
Xin
X
Liu
Department of Industrial and System Engineering, The Hang Kong Polytechnic University, Hung Hom, Hong Kong.
Wing-Cheung
WC
Law
School of Science, Changchun University of Science and Technology, Changchun 130022, PR China.
Liwei
L
Liu
Institute of Gerontology and Geriatrics & Beijing Key Lab of Aging and Geriatrics, Chinese PLA General Hospital, Beijing 100853, PR China. Electronic address: lye_301@163.com.
Ling
L
Ye
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. Electronic address: ktyong@ntu.edu.sg.
Ken-Tye
KT
Yong
D017209:Apoptosis / Q000187:drug effects; D019187:Cadmium Compounds / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007204:Indium / Q000633:toxicity*; D009374:Neoplasms, Experimental / Q000473:pathology / Q000503:physiopathology*; D010720:Phosphines / Q000633:toxicity*; D045663:Quantum Dots / Q000633:toxicity*; D018036:Selenium Compounds / Q000633:toxicity*; D013691:Tellurium / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods
D019187:Cadmium Compounds; D010720:Phosphines; D018036:Selenium Compounds; D007204:Indium; C058667:cadmium selenide; D013691:Tellurium; C090882:indium phosphide; C028337:cadmium telluride
Cancer cell; Cytotoxicity; Quantum dots