Fluorescence sensing and imaging with carbon-based quantum dots for early diagnosis of cancer: A review.

This review discusses recent advances and the reported strategies over the last ten years on the use of carbon-based quantum dots (QDs), including carbon dots (CDs), graphene quantum dots (GQDs), and polymer dots (PDs) in the design of fluorescence imaging and biosensing system for early diagnosis of cancers. Besides, this study comprehensively reports the latest developments in these years in the fluorescence imaging (FI) area with special attention to carbon-based QDs that take advantage of the excellent properties offered by these zero-dimensional (0D) nanomaterials as fluorescent tags. The most remarkable advantages of these carbon nanomaterials in the development of fluorescence sensing and imaging strategies compared to the conventional dyes arise from sharp emission spectra, long photostability, low-cost synthesis, reliability, reproducibility, high fluorescent intensity, and high surface functional groups such as carboxyl and amide, which impart better solubility in many solvents and aqueous media and facilitate their easy functionalization with biological species. The final section discusses the main challenges to be met to take full advantage of these properties in fluorescence bio-sensing and imaging as well as the possible future trends in this field based on the great advances that have occurred in recent years.

Hybrid Microfluidic Device for High Throughput Isolation of Cells Using Aptamer Functionalized Diatom Frustules.

Circulating tumor cells (CTCs), secreted from primary and metastatic malignancies, hold a wealth of essential diagnostic and prognostic data for multiple cancers. Significantly, the information contained within these cells may hold the key to understanding cancer metastasis, both individually and fundamentally. Accordingly, developing ways to identify, isolate and interrogate CTCs plays an essential role in modern cancer research. Unfortunately, CTCs are typically present in the blood in vanishingly low titers and mixed with other blood components, making their isolation and analysis extremely challenging. Herein, we report the design, fabrication and optimization of a microfluidic device capable of automatically isolating CTCs from whole blood. This is achieved in two steps, via the passive viscoelastic separation of CTCs and white blood cells (WBCs) from red blood cells (RBCs), and subsequent active magnetophoretic separation of CTCs from WBCs. We detail the specific geometries required to balance the elastic and inertial forces required for successful passive separation of RBCs, and the use of computational fluid dynamics (CFD) to optimize active magnetophoretic separation. We subsequently describe the use of magnetic biosilica frustules, extracted from Chaetoceros sp. diatoms, to fluorescently tag CTCs and facilitate magnetic isolation. Finally, we use our microfluidic platform to separate HepG2-derived CTCs from whole blood, demonstrating exceptional CTC recovery (94.6%) and purity (89.7%).

Preparation, characterization, and in vivo evaluation of Rose damascene extract loaded solid lipid nanoparticles for targeted brain delivery.

According to a variety of experiments, Rose damascene may lead to memory enhancement and acetylcholine esterase inhibition. However, Rose damascene cannot pass through the blood-brain barrier due to its hydrophilic contents. Solid lipid nanoparticles (SLNs) are suitable carriers for brain drug delivery. Herein, SLNs were made by micro-emulsion method. Then, lactoferrin was covalently attached to the surface of the nanoparticles by amide bond interaction for targeted delivery. The nanoparticle properties and the amount of attached lactoferrin were calculated. The effect of the selected compounds on scopolamine-induced animals was also measured by Y-maze, passive avoidance test, elevated plus maze, and forced swim test. The results revealed that the size and zeta potential of nanoparticles were 52 nm and - 13 mV before conjugation, and 161 nm and - 16 mV after conjugation, respectively. The percentage of entrapment efficiency and drug loading before conjugation was 98 ,93.6 and, after conjugation, was 11.2, 15.9, respectively. According to Y-maze and passive avoidance test results, Rose damascene can enhance short-term memory and may also reduce anxiety and depression in scopolamine-induced animals.

In vitro antibacterial activity of poly (amidoamine)-G7 dendrimer.

BACKGROUND: Nano-scale dendrimers are synthetic macromolecules that frequently used in medical and health field. Traditional anibiotics are induce bacterial resistence so there is an urgent need for novel antibacterial drug invention. In the present study seventh generation poly (amidoamine) (PAMAM-G7) dendrimer was synthesized and its antibacterial activities were evaluated against representative Gram- negative and Gram-positive bacteria. METHODS: PAMAM-G7 was synthesized with divergent growth method. The structural and surface of PAMAM-G7 were investigated by transmission electron microscopy, scanning electron microscope and fourier transform infrared. Pseudomonas. aeruginosa (n = 15), E. coli (n = 15), Acinetobacter baumanni (n = 15), Shigella dysenteriae (n = 15), Klebsiella pneumoniae (n = 10), Proteus mirabilis (n = 15), Staphylococcus aureus (n = 15) and Bacillus subtilis (n = 10) have been used for antibacterial activity assay. Additionally, representative standard strains for each bacterium were included. Minimum Inhibitory Concentration (MIC) was determined using microdilution method. Subsequently, Minimum Bactericidal Concentration (MBC) was determined by sub-culturing each of the no growth wells onto Mueller Hinton agar medium. The cytotoxicity of PAMAM-G7 dendrimer were evaluated in HCT116 and NIH 3 T3 cells by MTT assay. RESULTS: The average size of each particle was approximately 20 nm. PAMAM-G7 was potentially to inhibit both Gram positive and gram negative growth. The MIC50 and MIC90 values were determined to be 2-4 µg/ml and 4-8 µg/ml, respectively. The MBC50 and MBC90 values were found to be 64-256 µg/ml and 128-256 µg/ml, respectively. The cytotoxity effect of dendrimer on HCT116 and NIH 3 T3 cells is dependent upon exposure time to and concentration of dendrimers. The most reduction (44.63 and 43%) in cell viability for HCT116 and NIH 3 T3 cells was observed at the highest concentration, 0.85 µM after 72 h treatmentm, respectively. CONCLUSIONS: This study we conclude that PAMAM-G7 dendrimer could be a potential candidate as a novel antibacterial agent.