Surface Passivation of Carbon Dots for Tunable Biological Performance.

Recent investigations were shifted this trend toward exploring the biomedical applicability of CDs, relevant to chronic diseases. Herein, a systematic approach is demonstrated for studying the effect of variation in the surface passivation of CDs for tuning its optical character and biological performance. Alginate and pectin were successfully clustered oxygen-surface passivated CDs, while, chitin was used to nucleate nitrogen-surface passivated CDs. Pectin-treated with base (4.1 ± 1.8 nm) and chitin-treated acid (3.5 ± 1.7 nm) were ingrained the smallest O-surface passivated CDs and N-surface passivated CDs, respectively. However, N-surface passivated CDs were shown with the highest optical activity. CDs colloids prepared from alginate, pectin & chitin, resulted in reduction of tumor cell viability percentage to be 80.8%, 74.0% & 69.0% respectively. O-surface passivated CDs nucleated from alginate showed the highest anti-proliferative effects. Moreover, O-surface passivated CDs (from alginate) showed the supremacy in inhibition of inflammation, while, increasing of its concentration ten times resulted in significant increment in inhibition percent to be 28% & 42%, using 1 µg/mL & 10 µg/mL, respectively. In summarization, it could be decided that, compared to N-surface passivated CDs (from chitin), O-surface passivated CDs (from alginate) showed excellency in application as a concurrent anti-inflammatory/antitumor drug, to be applied as a potential therapeutical reagent for treatment of inflammation, in production of vaccines, immune-therapeutics, and immune-suppressive drugs.

Pyrimidine-5-carbonitrile derivatives as sprout for CQDs proveniences: Antitumor and anti-inflammatory potentiality.

A comparative study is proposed to show the effect of variation in the heteroatoms in the main skeleton of CQDs proveniences, on their affinity for nucleation of CQDs, as anti-inflammatory and anticancer drugs. Heterocyclic-based CQDs sprout was successfully exploited for preparation of three CQDs proveniences, named as; 2-(2,5-dimethoxyphenyl)-4,6-dioxo-6,11-dihydro-4H-pyrimido[2,1-b] quinazoline-3-carbonitrile (compound A), 2-(2,5-dimethoxyphenyl)-4,6-dioxo-4H,6H-benzo[e]pyrimido[2,1-b][1,3]oxazine-3-carbonitrile (compound S) and 2-(2,5-dimethoxyphenyl)-4,6-dioxo-4H,6H-benzo[e]pyrimido[2,1-b][1,3] thiazine-3-carbonitrile (compound T). Chemical formulas of CQDs proveniences & CQDs were verified via FTIR, 1HNMR, 13CNMR & XRD. Particle size of TM-CQDs, A-CQDs, S-CQDs & T-CQDs were estimated to be 3.7 ± 1.4, 4.6 ± 1.6, 5.9 ± 1.6 nm and 3.0 ± 1.3 nm, respectively. All of CQDs proveniences & CQDs were examined for their affinity as anti-inflammatory drugs via Griess assay. CQDs ingrained from TM (TM-CQDs) were detected with the highest NO inhibition% by increasing its concentration from 10 up to 100 µM to be 40 % to 89 %, respectively. Moreover, their anti-tumor performance against MCF-7: breast Adenocarcinoma cell line was approved via sulforhodamine B assay, whereas, IC50 was evaluated for TM-CQDs, A-CQDs, S-CQDs and T-CQDs to be 38.16, 36.09, 100 and 100 µg/ml, respectively.

pH responsive intelligent nano-engineer of nanostructures applicable for discoloration of reactive dyes.

Multifunctional polymers were commonly ascribed as intelligent materials due to the presence of different functional groups on the polymeric skeleton which causes the high sensitivity to the interchanging of physicochemical conditions. Herein, under different temperatures, monitoring the pH response of lignin as intelligent nano-engineer (reducer and stabilizer) for synthesis of size and shape regulated silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) & palladium nanoparticles (PdNPs) is systematically studied. The regulation of the particle size and stability of NPs were remarkably affected by acidity and basicity of the reaction medium at which they were prepared. TEM and zetasizer data showed that, highly size and shape regulated AgNPs & AuNPs is successively produced under acidic conditions with particle size of 13.8 and 5.7 nm, respectively. While basic conditions is more advisable in case of PdNPs to be produced with particle size of 4.5 nm. Catalytic performance of biphasic NPs in reductive discoloration of azo dye (reactive yellow dye 145) was followed the order of PdNPs > AuNPs > AgNPs. The half time for discoloration of dye with basic prepared NPs was dramatically decreased from 21.87 min for AgNPs and 18.34 for AuNPs to 1.45 min for PdNPs.

Metal-dependent nano-catalysis in reduction of aromatic pollutants.

Nanostructures have great potential in catalysis and their compositions may cause some interferences in the reactivity. Therefore, the present study focuses on comparison between three metallic nanoparticle-based Ag, Au, and Pd as nano-catalyst in reduction of aromatic pollutants. To neglect any interpenetration in their catalytic reactivity, the metallic nanoparticles were prepared via a consistent and reproducible one-step method with alkali-activated dextran. Interestingly, small sized/spherical AgNPs, AuNPs, and PdNPs were successively prepared with particle size of 3.4, 8.3, and 17.1 nm, respectively. The catalytic performance of the synthesized NPs was estimated for the reduction of p-nitroaniline and methyl red dye as different aromatic pollutants. Regardless of the particle size, there was a strong relation between catalytic action and the type of metal which followed the order of PdNP > AuNPs > AgNPs. Graphical Abstract.