Quantum dots: synthesis, bioapplications, and toxicity

Abstract

This review introduces quantum dots (QDs) and explores their properties, synthesis, applications, delivery systems in biology, and their toxicity. QDs are one of the first nanotechnologies to be integrated with the biological sciences and are widely anticipated to eventually find application in a number of commercial consumer and clinical products. They exhibit unique luminescence characteristics and electronic properties such as wide and continuous absorption spectra, narrow emission spectra, and high light stability. The application of QDs, as a new technology for biosystems, has been typically studied on mammalian cells. Due to the small structures of QDs, some physical properties such as optical and electron transport characteristics are quite different from those of the bulk materials.

Layer-by-layer assembled fluorescent probes in the second near-infrared window for systemic delivery and detection of ovarian cancer

“…S4C). Hepato-renal toxicity is a well-known issue preventing the approval of QDs for biomedical applications, and the observed damage is likely attributed to the leakage of the QDs out of the LbL shell (34,35). To our knowledge, this is the first report of the head-to-head comparison of toxicities of NIR-II probes in an identical LbL platform.…”

Biosynthesis of cadmium sulphide quantum dots by usingPleurotus ostreatus(Jacq.) P. Kumm

“…Some data suggest that QDs have very low toxicity, whereas other reports demonstrate that QDs may exert negative influence on cell viability, growth and development. [25] It was also found that biosynthesized CdS possess lower toxicity on plant, insect (our unpublished data) and non-human primate [26] cells. However, the toxicity of CdS semiconductor nanoparticles is associated with their physicochemical properties.…”

“…Surface modification can increase the hydrophilicity of QDs and at the same time, reduce their toxicity. [25] It is the extracellular biosynthesis of nanoparticles by means of living organisms that can result in the production of water-soluble, stable and low-toxic luminescent nanoscale crystals because of their additional surface coating with biomolecules. Hence, the growing opinion that extracellular biosynthesis of nanoparticles could prove the most promising approach in nanobiotechnology.…”

Physicochemical Characteristics of Fe3O4Magnetic Nanocomposites Based on Poly(N-isopropylacrylamide) for Anti-cancer Drug Delivery

“…Doxorubicin was encapsulated within this system with the floating and swelling method. Poly (NIPAAm-MAA-VP) magnetic nanocomposite loaded with Dox was characterized in terms of size and in-vitro release of doxorubicin (Valizadeh et al, 2012;Akbarzadeh et al, 2012a;2012b;2012c;2012d).…”