Research advance on cell imaging and cytotoxicity of different types of quantum Dots

Abstract

Quantum dots (QDs), as one of the emerging nanomaterials, have been widely studied by scientists due to their advantages and potential in bioimaging, especially cell imaging. Cadmium (Cd)‐based QDs, which have the best photoluminescence property, have received widespread attention. However, due to the obvious toxicity problem of these QDs, their cell imaging application is hindered. Recently, the emergence of Cd‐free‐metal and metal‐free QDs with lower toxicity makes people consider that Cd‐based QDs may be substituted by these QDs. However, problems of these QDs in cytotoxicity also cannot be ignored. Some reports claimed that their prepared emerging QDs for cell imaging were low toxicity, but there still exist up‐regulation of oxidative stress, inflammation, and apoptosis from other reports. And, up to now, few reports have separately summarized and discussed the issues of cell imaging and cytotoxicity of different types of QDs. Therefore, in this review, we classify QDs as following three types, Cd‐based, Cd‐free‐metal and metal‐free QDs, focus on the cell, the essential unit of life, discuss cell imaging application and cytotoxicity of QDs, and finally elucidate main mechanisms of cytotoxicity respectively. This review provides reference for the toxicity evaluation of QDs and highlights the potential cytotoxicity of Cd‐free QDs.

A Transcriptomic Analysis of T98G Human Glioblastoma Cells after Exposure to Cadmium-Selenium Quantum Dots Mainly Reveals Alterations in Neuroinflammation Processes and Hypothalamus Regulation

“…The batch of CdSe-QDs used in this work exhibited relatively low cytotoxicity, with an estimated concentration capable of reducing viability by 50% of around 250 µg/mL (Figure 3) and a maximum tolerable dose of 40 µg/mL (Table 1) after 72 h of exposure. However, Huang and Tang [18] reviewed the cytotoxicity of different cadmium-based QDs. They reported the need to apply doses between 20 and 160 µg/mL and exposures ranging from 4 h to 24 h for a 50% reduction in viability with a range of cellular lines.…”

Biocompatible Ni‐doped CdSe/ZnS semiconductor nanocrystals for cellular imaging and sorting

“…[43] Several reports have raised concerns about the toxicity of cadmium-based QDs in biological applications. [42,[44][45][46][47] The discovery of cadmium ion (Cd 2+ ) presence showed it to be the primary cause of cytotoxicity. To counteract the toxicity of QDs, a coating of inorganic material was utilized to coat the core QDs, preventing oxidation and photobleaching of the core cadmium.…”

Aminophosphate precursors for the synthesis of near‐unity emitting InP quantum dots and their application in liver cancer diagnosis

“…Quantum dots (QDs) are considered as a promising fluorescent probe for diagnostics and bioimaging applications owing to their unique optical features, including tunable emission wavelength, high photoluminescence quantum yield (PL QY), and excellent stability. [1][2][3][4][5] Since the heavy metal Cd ions in the state-of-the-art CdSe QDs are potentially harmful to the living organisms even if they are coated with nontoxic ZnS shell, [6][7][8] the development of alternative luminescent materials has received considerable research attention. [9,10] The optical properties of InP QDs are similar to those of the traditional CdSe QDs, which renders them an effective substitute material.…”