SERS and integrative imaging upon internalization of quantum dots into human oral epithelial cells

Abstract

CdTe quantum dots (QDs) are widely used in bio-applications due to their size and highly efficient optical properties. However internalization mechanisms thereof for the variety of freshly extracted, not cultivated human cells and their specific molecular interactions remains an open topic for discussion. In this study, we assess the internalization mechanism of CdTe quantum dots (3.3 nm) capped with thioglycolic acid using non cultivated oral epithelial cells obtained from healthy donors. Naked gold nanoparticles (40 nm) were successfully used as nanosensors for surface-enhanced Raman spectroscopy to efficiently identify characteristic Raman peaks, providing new evidence indicating that the first interactions of these QDs with epithelial cells occurred preferentially with aromatic rings and amine groups of amino acid residues and glycans from trans-membrane proteins and cytoskeleton. Using an integrative combination of advanced imaging techniques, including ultra-high resolution SEM, high resolution STEM coupled with EDX spectroscopy together with the results obtained by Raman spectroscopy, it was determined that thioglycolic acid capped CdTe QDs are efficiently internalized into freshly extracted oral epithelial cells only by facilitated diffusion, distributed into cytoplasm and even within the cell nucleus in three minutes.

Selenium-coated nanostructured lipid carriers used for oral delivery of berberine to accomplish a synergic hypoglycemic effect

“…Internalization of inflexible nanoparticles, such as quantum dots, silicon nanoparticles and mesoporous carbon, into various cells has been verified by researchers. [33][34][35] The excellent transcellular ability of SeNLCs confers them great suitability for oral delivery of berberine.…”

Fabrication by Laser Irradiation in a Continuous Flow Jet of Carbon Quantum Dots for Fluorescence Imaging

“…The samples were extracted from each subject by mechanical exfoliation accordingly to a variation of the protocol reported by Cepeda-Pérez. 44 The same protocol was followed to extract all the OECs; after the subject has rinsed the mouth using ultrapure Milli-Q water, an interdental brush was used to carefully scrape the inner area of each cheek. The scraped area was located between the first and the second molar on both sides of the jaw.…”

“…The samples extraction protocol is a variation of the Cepeda-Pérez. 44 The internalization of the CQDs into samples of OECs taken from 10 different subjects was analyzed by fluorescence images acquired with an inverted confocal microscope Leica TCS SP8 using a 405 nm diode as the excitation source and a PMT (photomultiplier tube) collecting light in the 420–637 nm region as the detector.…”

The conformation of bovine serum albumin adsorbed to the surface of single all‐dielectric nanoparticles following light‐induced heating

“…Basically, the globular protein BSA is commonly used to form a protein corona on plasmonic NPs as well as to bind to the surface of non‐metallic NPs . To coat our NPs, an aqueous solution of BSA (0.1 g/mL) was dropped (0.05 mL) onto these particles on the gold film, which was rotating at 100 Hz at room temperature in air.…”