Quantum dot-based theranostics

Abstract

Luminescent semiconductor nanocrystals, also known as quantum dots (QDs), have advanced the fields of molecular diagnostics and nanotherapeutics. Much of the initial progress for QDs in biology and medicine has focused on developing new biosensing formats to push the limit of detection sensitivity. Nevertheless, QDs can be more than passive bio-probes or labels for biological imaging and cellular studies. The high surface-to-volume ratio of QDs enables the construction of a "smart" multifunctional nanoplatform, where the QDs serve not only as an imaging agent but also a nanoscaffold catering for therapeutic and diagnostic (theranostic) modalities. This mini review highlights the emerging applications of functionalized QDs as fluorescence contrast agents for imaging or as nanoscale vehicles for delivery of therapeutics, with special attention paid to the promise and challenges towards QD-based theranostics.

Silicon Oxide (SiOx, 0&ltx&lt2): a Challenging Material for Optoelectronics

“…Of great interest it is now the surface passivation of the waterdispersed Si-nc with organic compounds; in this way the luminescence is stabilized and their function as markers is more accurate. Moreover, considering the high surface-tovolume ratio of these nanocrystals, another function for them is foreseen: as therapeutic and diagnostic (theranostic) agent (Ho and Leong, 2010). There many conditions that an inorganic nanocrystal must accomplish for a complete compatibility with the in vivo organic material.…”

Intracellular distribution of nontargeted quantum dots after natural uptake and microinjection

“…27 There is still a lot to learn about cellular uptake and intracellular transport of nanoparticles in order to interpret data from in vitro studies unambiguously, to improve their in vivo use, and to facilitate the rational design of functionalized quantum dots. 28 Therefore, this study was dedicated to expanding the understanding of natural quantum dot uptake by analysis of differences in accumulation between several cell lines, over wide time intervals. The focus was on intracellular localization and transportation of one type of nonfunctionalized quantum dot bearing a negatively charged coating, observing its fate after incubation in complete medium or serum-free medium, and after microinjection.…”

Multi-dimensional correlative imaging of subcellular events: combining the strengths of light and electron microscopy

“…Because QDs are not able to permeate cell membranes in the same way as standard organic dyes, various methods have been implemented to introduce them into cells, including injection or microinjection (Dubertret et al 2002;Larson et al 2003), the use of transfection agents (Chang et al 2008), liposome-or electroporation-mediated incorporation (Derfus et al 2004) or peptide-based and/or aptamer-mediated delivery (Chang et al 2008;Mattheakis et al 2004;Zhang et al 2006). In the final approach, exciting developments in the delivery of large molecules by aptamers and carrier peptide conjugates have been reported (Ho and Leong 2010;Walther et al 2008). The distance that QDs can penetrate into tissue should also be considered.…”