In vivo imaging of prostate tumor-targeted folic acid conjugated quantum dots Sulaxna Pandey, Prakash Choudhary, Virendra Gajbhiye, Sachin Jadhav, Dhananjay Bodas Cancer Nanotechnology, 2023 Cancer is a major threat to human health; thus, early detection is imperative for successful management. Rapid diagnosis can be achieved by imaging primary (subcutaneous) tumors using fluorophores conjugated with tumor markers. Here, the application of biocompatible, quantum efficient, monodisperse, and photostable polymer-coated quantum dots (PQDs) is demonstrated for targeted prostate tumor imaging in living SCID mice. Briefly, PQDs (blue) are conjugated to folic acid (FA-PQDs) using DCC-NHS chemistry. Initially, in vitro targeted imaging via FA-PQDs is evaluated in LNCaP cells. The confocal microscopic evaluation demonstrates the uptake of FA-PQDs. To understand the dispersion of PQDs in vivo, the biodistribution of PQDs is assessed at different time intervals (1- 180 min) using whole-body fluorescence imaging and computed tomography (CT) scan. PQDs are seen to accumulate in organs like the liver, kidneys, spleen, lungs, and urinary bladder within 60 min, however, PQDs are not observed at 180 min indicating renal clearance. Further, to target the prostate tumor (~ 200 mm3) in mice, FA-PQDs are injected intravenously, and whole-body fluorescence imaging along with a CT scan is recorded. FA-PQDs are seen at the tumor site as compared to PQDs. The results confirm that the FA-PQDs function as excellent nanoprobes for targeted tumor imaging in vivo.
Multiplexed bio-imaging using cadmium telluride quantum dots synthesized by mathematically derived process parameters in a continuous flow active microreactor S. Pandey, D. Mukherjee, P. Kshirsagar, C. Patra, D. Bodas Materials Today Bio, 2021 Quantum dots (QDs) are semiconductor nanocrystals with unique size-tunable emissions. To obtain a precise emission spectrum, monodispersity in size is imperative, which is achieved by controlling the reaction kinetics in a continuous flow of active microreactors. Further, a multivariate approach (dimensional analysis) is employed to impose stringent control on the reaction process resulting in monodispersed preparation of cadmium telluride (CdTe) quantum dots. Dimensional analysis knits multiple variables into a dimensionless mathematical form which not only predicts parameters precisely to obtain narrow size tunability but also guarantees reproducibility in synthesis. Analytical, structural, and optical characterization of the microreactor synthesized polydimethylsiloxane (PDMS) coated CdTe QDs reveal quantum efficient (61.5%), photostable (44%), and biocompatible nanocrystals of 5–15 nm. Further, PDMS-coated QDs (P-QDs) are conjugated with organelle-specific antibodies/biomarkers for in-vitro imaging in NIH 3T3 cells. Likewise, proliferating cell nuclear antigen (PCNA) and anti-myosin (MF20), cardiomyocytes antibodies are conjugated with P-QDs (red and green, respectively) to image the zebrafish's cardiac tissue. Antibodies tagged with quantum dots are imaged simultaneously using confocal microscopy. Thus, multiplexed bio-imaging of in-vitro and zebrafish tissue is demonstrated successfully. The results indicate the suitability of continuous flow active microreactor in conjunction with the mathematical prediction of process parameters to synthesize reproducibly monodispersed and quantum efficient QDs.
