In Situ Investigation on the Protein Corona Formation of Quantum Dots by Using Fluorescence Resonance Energy Transfer

Abstract

nanomaterials and their application in the biomedicine. [7] Indeed, over the past decades, formation of protein corona onto surfaces of NPs has attracted great attentions in the nanotechnology and biology community, and impressive progress has been achieved. [8,9] Nevertheless, a quantitative analysis on the formation process of the protein corona is very difficult and complicated, owing to the highly dynamic NP-protein interaction process and too many influencing factors.Among various types of nanomaterials, ultrasmall NPs with sizes smaller than 10 nm (i.e., quantum dots, [10] metal nanoclusters, [11] and carbon dots) [12] show unique properties and great potential in molecular imaging for disease diagnosis and cancer treatment. Particularly, compared with large NPs, these ultrasmall NPs can more readily escape from macrophages, pass biological barriers, show longer blood circulation times, and be easily degraded or excreted in the living systems. [13,14] Thus, these ultrasmall NPs have been widely employed in various biomedical applications. However, a deep and comprehensive understanding of their biological behavior, i.e., NP-protein interactions, remains largely unclear yet mainly due to the lack of appropriate in situ characterization tools for these ultrasmall NPs. While researchers have developed several techniques such as fluorescence correlation spectroscopy, [15] dynamic light scattering, [16] synchrotron radiation-based techniques, [17] and nuclear magnetic resonance spectroscopy [18] enabling quantitative analysis of protein corona, it still requires the development of new approaches to monitor the protein-NP interactions in a highly sensitive and quantitative manner owing to the diversity of nanomaterials and complexity of biological systems. [19] Fluorescence resonance energy transfer (FRET) is the process of nonradiative transmission of excitation energy from an excited state donor to a ground state acceptor, resulting from the dipole-dipole interactions. [20] The efficiency of this energy transfer process is inversely proportional to the sixth power of the distance between donor and acceptor, making FRET extremely sensitive to small changes in distance. Therefore, FRET has been widely exploited as a "spectroscopic ruler" in many biological and biophysical researches. For example, FRET can be employed for monitoring conformational changes of biomolecules, [21] developing highly sensitive fluorescence A fundamental understanding of nanoparticle-protein corona and its interactions with biological systems is essential for future application of engineered nanomaterials. In this work, fluorescence resonance energy transfer (FRET) is employed for studying the protein adsorption behavior of nanoparticles. The adsorption of human serum albumin (HSA) onto the surface of InP@ZnS quantum dots (QDs) with different chirality (dand l-penicillamine) shows strong discernible differences in the binding behaviors including affinity and adsorption orientation that are obtained upon quantitative analysis of FRET data...

Ligand-induced chirality and optical activity in semiconductor nanocrystals: theory and applications

“…Kotov et al [40] reported that bovine serum albumin adsorbed one enantiomer of TGA-stabilized CdTe QDs with spontaneous chiral defects more effectively than the alternative, which allowed chiral separation of the CdTe QDs. Shang [147] has demonstrated that human serum albumin had different affinity and adsorption orientation onto the surface of D-and L-penicillamine capped InP/ZnS QDs, which was confirmed by CD and FRET data ( Figure 16).…”

Nano-Bio Interaction between Blood Plasma Proteins and Water-Soluble Silicon Quantum Dots with Enabled Cellular Uptake and Minimal Cytotoxicity

“…A detailed understanding of the secondary-or tertiary-structural changes of proteins upon binding with concentrated nanoparticles is necessary to appreciate the mutual interaction, realizing practical improvements in biocompatibility. Protein-nanoparticle interactions are common phenomena, which result in conformational changes or denaturation of the proteins adsorbed to the nanoparticles [ 56 ]. Investigations of such conformational changes have revealed that the protein can realize regular biological activity even after the interaction.…”

In vivo protein corona on nanoparticles: does the control of all material parameters orient the biological behavior?

“…Additionally, liposomes made of anionic or cationic lipids preferentially adsorb plasma proteins with isoelectric point (IEP), IEP > 5.5 or IEP < 5.5 respectively 65 . The chirality of the functionalized group may also be responsible for different protein binding behavior as observed by Qu et al 66 with InP@ZnS quantum dots. The adsorption of proteins (HSA) differs with the chirality (Dand L-penicillamine) of the functionalized group, impacting the binding affinity and conformation states.…”