Cadmium-containing Quantum Dots: Current Perspectives on Their Application as Nanomedicine and Toxicity Concerns

With unique optical properties and versatile surface chemistry, cadmium-containing quantum dots (Cd-QDs) have attracted extensive attention for drug delivery in the field of biomedicine. However, Cd-QDs applications are currently restricted in cells and small animals due to their uncertain biological fate and potential toxicity. Consequently, the long-term fate of Cd-QDs and their interaction with biological systems need to be explored for the development of the clinical applications of Cd-QDs as nanomedicines. This review succinctly described recent progress in functionalized Cd-QDs for the design as multifunctional drug delivery system and advanced findings on the interactions of Cd-QDs with biological systems at the level of living systems, cells and biomacromolecules. This knowledge could provide suggestions to improve the delivery performance and biocompatibility of Cd-QDs as well as better understand the potential side effects of Cd-QDs in in vivo applications. In addition, attention was laid on exploring the similarities and discrepancy of their toxicological results at the three levels to comprehensively interpret the potential carcinogenicity of Cd-QDs and deeply understand the associated mechanism.