Green Fluorescent Protein Nanovessel Serves as a Nucleolus Targeting Material and Molecule Carrier in Living Cells

The nucleolus is responsible for RNA transcription, processing, and ribosome assembly, the dysfunction of which is associated with a number of diseases. In this report, a new member of fluorescent protein nanovessels (FPNs), constructed using thioflavin-T (ThT) and bovine serum albumin (BSA) as building blocks, is described. As a popular amyloid specific dye, ThT is nonfluorescent by itself, while its fluorescence can be lighted up upon interacting with amyloid proteins. Herein, ThT is coassembled with the BSA scaffold at high temperature to form T(hT)-FPNs. These green fluorescence emissive bio-abiotic hybrid materials can serve as a novel probe for real-time nucleolus imaging of living cells. Besides, T-FPNs show potential in delivering insoluble and/or impenetrable drugs into living cells, suggesting another role as a molecule carrier.

Synthesis, characterization and antitumor properties of selenium nanoparticles coupling with ferulic acid

Selenium nanoparticles (Se NPs) attract a lot of attention as potential cancer therapeutic agents. However, the antitumor activities of pure Se NPs are poor, and some modifiers are needed to enhance the activities. In the present study, we prepared Ferulic Acid (FA)-modified selenium nanoparticles in a facile synthetic approach. The obtained FA-Se NPs were characterized using transmission electron microscope (TEM), dynamic light scattering (DLS), ultraviolet-visible spectrophotometer (UV-VIS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Energy dispersive X-ray (EDX) spectroscopy. In vitro antitumor effects of FA, Se NPs and FA-Se NPs in HepG-2 cells were examined by methyl thiazolyl tetrazolium (MTT) assay. It showed that FA-Se NPs effectively inhibited the growth of HepG-2 cells with IC₅₀ value of 11.57 ± 3.6 μg/ml, while the value of Se NPs was >100 μg/ml. In addition, FA behaves no obvious antitumor effects at high concentrations up to 100 μg/ml. In order to investigate the antitumor mechanism of FA-Se NPs, fluorescence morphological examination and Annexin V-FITC/PI staining analysis were performed to observe the apoptosis of HepG-2 cells induced by FA-Se NPs. Meanwhile, mitochondrial membrane potential (MMP), intracellular reactive oxygen species (ROS) levels and caspase-3 and -9 activities were detected. The results revealed that FA-Se NPs induced intracellular ROS generation and MMP disruption by finally activating caspase-3/9 to trigger HepG-2 cells apoptosis through mitochondrial pathway. Further investigation on the interactions of FA-Se NPs with calf thymus DNA (ctDNA) indicated that the antitumor activities may be associated with the DNA-binding properties of FA-Se NPs.

Comparative study on toxicity of extracellularly biosynthesized and laboratory synthesized CdTe quantum dots

Nanobiosynthesis belongs to the most recent methods for synthesis of nanoparticles. This type of synthesis provides many advantages including the uniformity in particle shape and size. The biosynthesis has also a significant advantage regarding chemical properties of the obtained particles. In this study, we characterized the basic properties and composition of quantum dots (QDs), obtained by the extracellular biosynthesis by Escherichia coli. Furthermore, the toxicity of the biosynthesized QDs was compared to QDs prepared by microwave synthesis. The obtained results revealed the presence of cyan CdTe QDs after removal of substantial amounts of organic compounds, which stabilized the nanoparticle surface. QDs toxicity was evaluated using three cell lines Human Foreskin Fibroblast (HFF), Human Prostate Cancer cells (PC-3) and Breast Cancer cells (MCF-7) and the MTT assay. The test revealed differences in the toxicity between variants of QDs, varying about 10% in the HFF and 30% in the MCF-7 cell lines. The toxicity of the biosynthesized QDs to the PC-3 cell lines was about 35% lower in comparison with the QDs prepared by microwave synthesis.

Protein-gold hybrid nanocubes for cell imaging and drug delivery

Multifunctional biocompatible nanomaterials containing both fluorescent and vehicle functions are highly favored in bioimaging, therapeutic, and drug delivery applications. Nevertheless, the rational design and synthesis of highly biocompatible multifunctional materials remain challenging. We present here the development of novel protein-gold hybrid nanocubes (PGHNs), which were assembled using gold nanoclusters, bovine serum albumin, and tryptophan as building blocks. The green-synthesized PGHNs in this study are blue-emitting under UV exposure and cube-shaped with a size of approximately 100 nm. These hybrid nanomaterials are highly biocompatible as shown by cytotoxicity experiments and can be readily internalized by different types of cells. Moreover, PGHNs can act as nanovehicles that successfully deliver dyes or drugs into the cells. The protein-metal hybrid nanocubes can serve as a new type of dual-purpose tool: a blue-emitting cell marker in bioimaging investigation and a nanocarrier in drug delivery studies.