Cadmium Telluride Quantum Dots as a Fluorescence Marker for Adipose Tissue Grafts

Abstract

Plastic and reconstructive surgeons increasingly apply adipose tissue grafting in a clinical setting, although the anticipation of graft survival is insecure. There are only few tools for tracking transplanted fat grafts in vivo. Murine adipose tissue clusters were incubated with negatively charged, mercaptoproprionic acid-coated cadmium telluride quantum dots (QDs) emitting in the dark red or near infrared. The intracellular localization of QDs was studied by confocal laser scanning microscopy. As a result, the adipose tissue clusters showed a proportional increase in fluorescence with increasing concentrations (1, 10, 16, 30, 50 nM) of cadmium telluride QDs. Laser scanning microscopy demonstrated a membrane bound localization of QDs. Vacuoles and cell nuclei of adipocytes were spared by QDs. We conclude that QDs were for the first time proven intracellular in adult adipocytes and demonstrate a strong fluorescence signal. Therefore, they may play an essential role for in vivo tracking of fat grafts.

Controlling Charge Transfer from Quantum Dots to Polyelectrolyte Layers Extends Prospective Applications of Magneto-Optical Microcapsules

“…The specimens analyzed should either possess the property of distinct, bright, and stable photoluminescence (PL) themselves or be labeled with such fluorophores. Semiconductor nanocrystals referred to as quantum dots (QDs) have been proved to be efficient fluorescent nanoprobes with many comparative advantages over organic dyes. − The unique photophysical properties of QDs, such as a wide absorption spectrum, a narrow, symmetrical, and size-tunable PL spectrum, a high quantum yield (QY), tremendous one- and two-photon extinction coefficients, and high photostability, make them attractive nanolabels for fluorescent tagging and optical encoding in drug delivery and cell detection systems. − Additionally, QDs are characterized by fluorescence lifetimes greatly exceeding those of conventional organic dyes, which provides the possibility of time gated in vitro and in vivo imaging. − However, the QD harmful chemical composition and unstable colloidal properties significantly limit their applicability as diagnostic, contrast, and drug delivery agents. , Encapsulation of the nanoparticles in micro- and nanocarriers reduces the potential QD toxicity due to the polymer coating restricting their direct contact with biological systems, in particular, at the cellular level. , …”

In vivo tracking of adipose tissue grafts with cadmium-telluride quantum dots

“…QDs were introduced as nanocrystals with unique luminescent properties and stable fluorescence emission [4,16]. There has been a tremendous increase in the use of semiconductor QDs as a fluorescent label for imaging, tracing and sensing in living tissues [5,17,18]. There have been attempts to couple QDs to specific ligands for target specificity [17][18][19].…”

“…Fat grafts weight between 0.05 and 0.10 g. Cadmium-telluride QDs (CdTe-QDs) were synthesized in water according to the previously published method [6]. The negatively charged CdTe-QDs 770 had a diameter of about 6.5 nm and showed a characteristic near infrared excitation profile with a peak at 770 nm with an excitation wavelength of 740 nm [5].…”

“…One of the major advantages lies in the wide absorption profile and an up to 10-fold greater molar extinction coefficient compared with organic dyes [ 4 ]. We have proven an intracellular uptake of QDs 675 in fat grafts before [ 5 ] and evaluated the use of the QDs as a new option for in vivo tracking in our current study.…”

Quantum Dot-labeled Tags Improve Minimal Detection Limit of CA125 in Ovarian Cancer Cells and Tissues

“…7,8 As with most cancers, the early detection of ovarian cancer by a sensitive diagnostic tool would have a significant impact on reducing its mortality and in this regard and based on their very high sensitive nature, QDs may aid precise determination of cancer biomarker over-expression at the early stage of the disease. [9][10][11] Here we quantitatively assessed sensitivity of CA125 profiling in an ovarian cancer cell line and cancer tissues using QD525-based detection system and compared it with the same system employing emission wavelength-matched fluorophore, FITC. Upon the results presented here, we concluded that QDs based detection systems profoundly decrease minimal detection level of CA125 expression and could be viewed as a reliable alternative to those systems that are being routinely employed for cancer biomarker detection.…”