Acute and chronic cadmium telluride quantum dots-exposed human bronchial epithelial cells: The effects of particle sizes on their cytotoxicity and carcinogenicity

• Published in: Biochemical and biophysical research communications 2018-01, Vol.495 (1), p.899-903
• Main Authors: Zheng, Wei, Xu, Yan-Ming, Wu, Dan-Dan, Yao, Yue, Liang, Zhan-Ling, Tan, Heng Wee, Lau, Andy T.Y.
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; ACUTE EXPOSURE; AGAR; BEAS-2B; Cadmium telluride quantum dots; CADMIUM TELLURIDES; Cell transformation; CELL TRANSFORMATIONS; CHRONIC EXPOSURE; Cytotoxicity; Human lung cells; LUNGS; OPTICAL PROPERTIES; PARTICLE SIZE; RESPIRATORY TRACT CELLS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2017.11.074

Quantum dots (QDs) are semiconducting nanocrystals with unique optical properties. When coated with shell/capping, QDs are not deleterious to cells and organisms. However, when QDs are retained in the cellular environment for a certain period of time, their coatings may be degraded, yielding “naked” QDs. Although some studies have documented the acute effects of cadmium telluride (CdTe) QDs in various cell lines, however, to our knowledge, there are no published studies on the chronic effects of CdTe QDs in normal lung cells. In this study, we therefore sought to study the effects of CdTe QDs of various particle sizes on their cytotoxicity and carcinogenicity in normal human bronchial epithelial cells (BEAS-2B). A total of three particle sizes of CdTe QD with emission maximum at 520, 580, and 730 nm were employed (abbreviated as 520Q, 580Q, and 730Q, respectively). Our results indicated that acute exposure to 520Q (∼2.04 nm in diameter) and 580Q (∼3.24 nm in diameter) elicited dose-dependent cytotoxicity; while acute exposure to 730Q (∼5.40 nm in diameter) elicited negligible cytotoxicity in BEAS-2B cells. Notably, chronic exposure to CdTe QD of all three tested particle sizes induced BEAS-2B cell transformation as evidenced by enhanced cell migration and anchorage-independent growth on soft agar. Taken together, our findings suggest that CdTe QDs are potent human lung carcinogens. •Human bronchial epithelial cells (BEAS-2B) were dosed with CdTe quantum dots (QDs).•Acute exposure to CdTe QD with 5 nm diameter elicited negligible cytotoxicity.•Notably, chronic exposure to CdTe QDs of all tested sizes induced cell transformation.•CdTe QDs of various particle sizes exert similar carcinogenicity in human lung cells.