Confocal laser scanning microscopy study of intercellular events in filopodia using 3-mercaptopropoinc acid capped CdSe/ZnS quantum dots

Luminescent ZnSe/ZnO Heterostructures for Photocatalytic Degradation of Azophloxine Dye and Bioimaging Applications

Herein, we demonstrate a simple hydrothermal route to synthesizing ZnSe/ZnO type II heterostructure using L-cysteine as a capping agent. The use of nanomaterials in bioimaging and photocatalysis towards the degradation of Azophloxine dye is of potential interest. The synthesized ZnSe/ZnO nanomaterials were characterized by UV-Vis absorption spectroscopy, fluorescence spectroscopy, IR spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It exhibits a strong sharp emission at 465 nm in fluorescence spectroscopy. The synthesized nanomaterials were used as an excellent fluorescence probe for imaging live-cell bacteria such as E. coli and S. aureus compared with the commercial staining dye PI (propidium iodide). The synthesized ZnSe/ZnO possess more photo-stability and showed excellent photocatalytic activity for the degradation of azophloxine dye under sunlight.

Synergistic anti-diabetic effect of phloroglucinol and total procyanidin dimer isolated from Vitisvinifera methanolic seed extract potentiates via suppressing oxidative stress: in-vitro evaluation studies

Diabetes is often associated with increased oxidative stress caused by an imbalance between detoxification and ROS production. Unfortunately, many commercial drugs available today for treating this disease have adverse side effects and ultimately fail to restore glucose homeostasis. Therefore, finding a dietary anti-diabetic remedy that is safe, effective, and economical is crucial. In this study, GC-MS analysis, subsequent HPLC-assisted fractionation, and SPE-based purification led to identifying and purifying of key components such as phloroglucinol and total procyanidin dimer (procyanidin dimer and procyanidin dimer gallate) from methanolic seed extract of Vitis vinifera. In-vitro anti-diabetic screening of various fractions derived from methanolic extract along with individual components and their combinations revealed the potential synergistic behaviour of phloroglucinol and total procyanidin dimer with the lowest IC50 of 48.21 ± 3.54 µg/mL for α-glucosidase and 63.06 ± 5.38 µg/mL for α-amylase inhibition which is found to be superior to the effect shown by the standard Epigallocatechin gallate. Later Glucose utilization studies demonstrated the concentration-dependent effect of Phloroglucinol and total procyanidin dimer, and that has raised the glucose uptake by approximately 36-57% in HepG2 cells and 35-58% in L6 myocytes over a concentration of 50-100 µg/mL. The superior anti-diabetic effect of Phloroglucinol and total procyanidin dimer was proved by the suppression of oxidative stress with an IC50 of 7.92 ± 0.36 µg/mL for DPPH scavenging and 16.87 ± 1.24 µg/mL for SOD scavenging which is competent with the standard ascorbic acid. According to this study, suppressing ROS levels by phloroglucinol and total procyanidin dimer would be the underlying mechanism for the synergistic anti-diabetic effect of this combination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03929-4.

Synthesis of CdSe and CdSe/ZnS Quantum Dots with Tunable Crystal Structure and Photoluminescent Properties

Mastery over the structure of nanocrystals is a powerful tool for the control of their fluorescence properties and to broaden the range of their applications. In this work, the crystalline structure of CdSe can be tuned by the precursor concentration and the dosage of tributyl phosphine, which is verified by XRD, photoluminescence and UV-vis spectra, TEM observations, and time-correlated single photon counting (TCSPC) technology. Using a TBP-assisted thermal-cycling technique coupled with the single precursor method, core-shell QDs with different shell thicknesses were then prepared. The addition of TBP improves the isotropic growth of the shell, resulting in a high QY value, up to 91.4%, and a single-channel decay characteristic of CdSe/ZnS quantum dots. This work not only provides a facile synthesis route to precisely control the core-shell structures and fluorescence properties of CdSe nanocrystals but also builds a link between ligand chemistry and crystal growth theory.

Active Aberration Correction with Adaptive Coefficient SPGD Algorithm for Laser Scanning Confocal Microscope

A laser scanning confocal microscope (LSCM) is an effective scientific instrument for studying sub-micron structures, and it has been widely used in the field of biological detection. However, the illumination depth of LSCMs is limited due to the optical aberrations introduced by living biological tissue, which acts as an optical medium with a non-uniform refractive index, resulting in a significant dispersion of the focus of LSCM illumination light and, hence, a loss in the resolution of the image. In this study, to minimize the effect of optical aberrations, an image-based adaptive optics technology using an optimized stochastic parallel gradient descent (SPGD) algorithm with an adaptive coefficient is applied to the optical path of an LSCM system. The effectiveness of the proposed aberration correction approach is experimentally evaluated in the LSCM system. The results illustrate that the proposed adaptive optics system with an adaptive coefficient SPGD algorithm can effectively reduce the interference caused by aberrations during depth imaging.