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.

Nano-scaled polyacrylonitrile for industrialization of nanofibers with photoluminescence and microbicide performance.

Nanofibers are investigated to be superiorly applicable in different purposes such as drug delivery systems, air filters, wound dressing, water filters, and tissue engineering. Herein, polyacrylonitrile (PAN) is thermally treated for autocatalytic cyclization, to give optically active PAN-nanopolymer, which is subsequently applicable for preparation of nanofibers through solution blow spinning. Whereas, solution blow spinning is identified as a process for production of nanofibers characterized with high porosity and large surface area from a minimum amounts of polymer solution. The as-prepared nanofibers were shown with excellent photoluminescence and microbicide performance. According to rheological properties, to obtain spinnable PAN-nanopolymer, PAN (12.5-15% wt/vol, honey like solution, 678-834 mPa s), thermal treatment for 2-4 h must be performed, whereas, time prolongation resulted in PAN-nanopolymer gelling or rubbering. Size distribution of PAN-nanopolymer (12.5% wt/vol) is estimated (68.8 ± 22.2 nm), to reflect its compatibility for the production of carbon nanofibers with size distribution of 300-400 nm. Spectral mapping data for the photoluminescent emission showed that, PAN-nanopolymer were exhibited with two intense peaks at 498 nm and 545 nm, to affirm their superiority for production of fluorescent nanofibers. The microbial reduction % was estimated for carbon nanofibers prepared from PAN-nanopolymer (12.5% wt/vol) to be 61.5%, 71.4% and 81.9%, against S. aureus, E. coli and C. albicans, respectively. So, the prepared florescent carbon nanofibers can be potentially applicable in anti-infective therapy.

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.

Involvement of silver and palladium with red peanuts skin extract for cotton functionalization.

A systematic study is currently demonstrated approach for approving the superior role of silver and palladium metallic particles in acting the role of mordant with acquiring the dyed cotton fabrics excellence in color fastness with additional functions of antimicrobial potentiality and UV-protection action. Whereas, samples were dyed with extract of red peanuts skin as natural textile colorant (RPN dye). The represented data revealed that, in absence of mordant, the samples treated with metal precursors prior to dyeing were exhibited with the excellent color strength, color fastness, antimicrobial action and UV-protection action. Color fastness (washing, rubbing and light fastness) was estimated to be in the range of very good-excellent. Sample pretreated with silver salt and dyed in the absence of mordant was graded with excellent UV-protection action (UPF 31.5, UVB T% 2.6% and UVB blocking percent 97.4%). Antimicrobial potency against E. coli, S. aureus and Candida albicans through inhibition zone and the reduction percent was approved to be in the range of excellence (93.01-99.51%) for the samples dyed in absence of mordant and pretreated with either silver or palladium precursors.

Selective separation of chlorophyll-a using recyclable hybrids based on Zn-MOF@cellulosic fibers.

Chlorophyll-a as pigments, exist in the green organelles for plants that act in photosynthesis. Different studies were considered with demonstration of an effective separation technique of Chlorophyll-a without decomposition; however, the reported methods were disadvantageous with expensiveness and low quantum yield. The current work uniquely represents an investigative method for the separation of Chlorophyll-a from spinach extract using cellulosic hybrids based on ZIF-8 @cellulosic fibers (Zn-zeolitic imidazolate frameworks@cellulosic fibers) as a cost effective and recyclable absorbents. To obtain hybrids, ZIF-8 was in-situ prepared over the cellulosic fibers (bamboo, modal and cotton). The untreated and treated fibers were well characterized via FTIR, SEM, EDX, XRD, in order to approve the successive impregnation of ZIF-8. Whereas, the microscopic images showed that, microcrystalline ZIF-8 rods with length of 1.3-4.4 µm were grown over the cellulosic fibers. The obtained hybrids and the untreated fibers were exploited in the separation of Chlorophyll-a via the adsorption/desorption process. The chlorophyll-adsorption was followed Langmuir isotherm and pseudo-second order model. The Langmuir maximum capacities of Chlorophyll-a onto hybrids were followed the order of ZIF-8@cotton (583.6 mg/g) > ZIF-8@modal (561.3 mg/g) > ZIF-8@bamboo (528.7 mg/g). After incorporation of ZIF-8, the maximum adsorption capacities of cellulosic fibers were enhanced by 1.4-1.9 times. Adsorption of chlorophyll onto the applied hybrids was lowered by 27-28%, after five repetitive washing cycles. The data summarized that; chlorophyll was effectively separated by the synthesized ZIF-8@cellulosic fibers hybrids, whereas, the prepared hybrids showed good reusability for application on wider scaled purposes.

Maillard reaction for nucleation of polymer quantum dots from chitosan-glucose conjugate: Antagonistic for cancer and viral diseases.

Polymer dots (PDs) ingrained from biopolymers are characterized by their biocompatibility & non-toxicity to be superiorly applicable for biomedicines. The point of novelty in the current study is to focus on the effect of Maillard reaction for conjugation of chitosan with glucose to enhance the affinity of chitosan as a biological resource of PDs. Chitosan-glucose conjugate was firstly prepared by Maillard reaction. PDs were nucleated from chitosan (C1 acidic, 10.6 nm & C2 basic, 11.4 nm) and chitosan-glucose conjugate (C3 acidic, 6.8 nm & C4 basic, 5.7 nm). The affinity of chitosan versus chitosan-glucose conjugate as molecular precursors for PDs as antiviral and anticancer laborers was studied. The synthesized PDs were tested against lung cancer (NSCLC, A549) and the estimated IC50 was 282.4 & 165.4 µg/mL for PDs (C3 & C4) ingrained from chitosan-glucose conjugate. The antiviral action of PDs against Coronavirus (229E) was estimated and the obtained IC50 for C3 & C4 was 43.6 and 19.3 mg/mL, respectively. PDs ingrained from chitosan-glucose conjugate showed higher anticancer and antiviral activities compared to that clustered from chitosan. Consequently, the modification of chitosan via Maillard reaction enhanced the biological affinity of the obtained PDs to be effectively applicable as antitumor and antiviral laborers.

Design of a dual pH and temperature responsive hydrogel based on esterified cellulose nanocrystals for potential drug release.

In this study, new stimuli - responsive hybrid hydrogels were achieved via succinylated cellulose nanocrystals (Su-CNC). The innovation was concerned with the inclusion of Su-CNC, at different degree of substitution (DS), into hydrogel network to render it pH and thermo-responsive characters through free radical polymerization reaction with poly(N-isopropylacrylamide) (PNIPAm). The prepared hydrogel was also examined for the in vitro release of Famotidine at different pH values. As clearly evident from the results, all the hydrogels prepared with different DS of Su-CNC, which were nominated as Su-CNC / PNIPAm (1-3), showed a high response to temperature change since their swelling behavior and hydrophilicity were decreased at 35 °C and upwards. This led to the more hydrophobicity character and thus the hydrogel shrinkage occurred. On the other hand, at pH 6, the hydrogels exhibited a significant Equilibrium Swelling Ratio (ESR) attaining 18.1, 17.3 and 16.8 (g/g) for Su-CNC / PNIPAm (1-3), respectively. However, Su-CNC / PNIPAm 2 hydrogel showed a significant response to the pH change from 8 to 2 which was advised to be selected as a potential pH responsive hydrogel for the in vitro Famotidine release.

Affinity of carbon quantum dots anchored within metal organic framework matrix as enhancer of plant nourishment.

Nano-fertilizers were ascribed to be significantly advantageous with minimizing the negative effects of requiring excessive contents in the soil and reducing the number of times for fertilization. Herein, the superior affinity of carbon quantum dots (CQDs) anchored within metal organic framework (Cu-BTC) matrix was investigated for the first time as a fertilizer for sunflower. CQDs were nucleated from alkali-hydrolyzed carboxymethyl cellulose (CMC) via the hydrothermal technique. The synthesized CQDs (6.8 ± 3.7 nm) were anchored within Cu-BTC (crystalline rod-like structure) matrix, to produce CQDs@Cu-BTC composite. The obtained CQDs and CQDs@Cu-BTC were applied as nutrients for the sunflower plant. The chlorophyll a and carotenoids contents were 0.465 & 0.497 and 0.350 & 0.364 mg/g after treatment with CQDs & CQDs@Cu-BTC, respectively. The shoot length of sunflower sample was increased after feeding with CQDs and CQDs@Cu-BTC to be 38.7 and 46.5 cm, respectively. The obtained results confirmed that, the synthesized CQDs@Cu-BTC showed superiority as nutrient material via enhancing the growth and physiological properties of sunflower and consequently could be used as fertilizer for plants instead of the commercial nutrient.

Controllable Release of Povidone-Iodine from Networked Pectin@Carboxymethyl Pullulan Hydrogel.

Povidone-iodine (PI) is a common antiseptic reagent which is used for skin infections and wound healing. The control release of PI is quite important to heal the deep and intense wounds. Herein, the preparation of biodegradable pectin@carboxymethyl pullulan (Pe@CMP) hydrogel was carried out and applied for controllable release of PI. CMP was synthesized by interaction of monochloroacetic acid with pullulan at different ratios. The Pe@CMP hydrogel was then prepared by crosslinking of pectin with CMP in presence of glutaraldehyde as cross linker. After carboxymethylation, COOH contents were enlarged to be 24.2-51.2 mmol/kg and degree of substitution was 0.44-0.93. The rheological properties of Pe@CMP hydrogel were enlarged by increment of pectin ratio. Swelling ratio in water (16.0-18.0%) was higher than that of artificial sweat (11.7-13.2%). Pe@CMP hydrogel containing 20% pectin, exhibited the lowest release and 57.7% from PI was released within 360 min. The biological activity of the released PI was monitored to be highly efficient. The kinetic of release was fitted well to the first ordered reaction and Higuchi models. The mechanism of release was explained by the swelling of hydrogel. The networked structure of hydrogel was opened by swelling and PI was released from the outer pores followed by inner pores, achieving the controllable release.

Technical textiles modified with immobilized carbon dots synthesized with infrared assistance.

Carbon quantum dots "CQDs" were investigated as photo-luminescent nanomaterials as it advantageous with nontoxicity to be alternative for metallic-nanomaterials in different purposes. Therefore, the presented report demonstrates an innovative strategy for industrialization of antimicrobial/fluorescent cotton textiles via exploitation of "CQDs". Unique/novel infrared-assisted technique was currently investigated for clustering "CQDs" form carboxymethyl cellulose. The successive nucleation of "CQDs" (8.0 nm) was affirmed via infra-red, Raman spectroscopy, NMR, TEM and Zeta-potential analysis. The clustered "CQDs" showed antimicrobial and fluorescent characters. The minimal inhibition concentration for "CQDs" (100 mg/mL) against E. coli and C. albicans showed pathogenic reduction of 96% and 82%, respectively. Fluorescent emission spectra for "CQDs" showed two intense peaks at 415-445 nm. "CQDs" were loaded upon pristine and cationized cotton to prepare CQDs@cotton and CQDs@cationized cotton. While, their physical/mechanical properties (air and water vapor permeabilities, tensile strength and elongation %) and thermal stability (TGA & DTG analysis) were studied. The CQDs@cationized cotton exhibited excellent antimicrobial activity with good durability as after ten repretitive washings, inhibition zone diameter against E. coli, was diminished from 21.0 mm to 14.0 mm. The fluorescent emmision intensity was diminished from 741 to 287 after 10 washing cycles. The produced cotton fabrics could be safely used in the medical and military textiles.

Melt intercalation technique for synthesis of hetero-metallic@chitin bio-composite as recyclable catalyst for prothiofos hydrolysis.

The compatibility of homo-metallic and hetero-metallic bio-composite was promisingly investigated as recyclable catalyst for prothiofos hydrolysis. Chitin as water insoluble biopolymer was functionalized as a template for generation of homo-metallic (Ag@chitin, Au@chitin and Pd@chitin) and hetero-metallic (Au@Ag@chitin, Pd@Ag@chitin and Pd@Au@Ag@chitin) composites, by using melt intercalation technique. Investigation of the compatibility of the synthesized homo-metallic and hetero-metallic bio-composites in hydrolysis of prothiofos was performed and affirmed via HPLC results. Immobilization of Pd in the composites showed perfection in the catalytic performance for prothiofos hydrolysis. Pd@Au@Ag@chitin exhibited the highest hydrolysis result of 99% for prothiofos was hydrolyzed within 150 min with rate constant (k1) of 24.48 min-1. After five recycles for Pd@Au@Ag@chitin, the hydrolysis of prothiofos was lowered from 346 mg/g to 269 mg/g with reduction percentage of 22%. The synthesized bio-composite was highly effective as recyclable catalyst and can be easily served in the remediation of pesticides.

Observable removal of pharmaceutical residues by highly porous photoactive cellulose acetate@MIL-MOF film.

Pharmaceutical products are used tremendously worldwide and subsequently released into wastewater even at very low concentration caused serious environmental problem due to their high activity. Therefore, the present work focuses on remarkable removal of paracetamol as one from the most used pharmaceutical intermediates, by using porous film based on cellulose acetate@metal organic framework (CA@Ti-MIL-NH2). The film was designed to achieve extreme removal of paracetamol by action of both of adsorption and degradation. Metal organic frame work was directly synthesized and inserted within the pre-prepared porous CA film to obtain porous CA@Ti-MIL-NH2 film. The synthesized films were applied in adsorption and photo-degradation of paracetamol separately and together. Due to the photocatalytic activity of Ti-MIL-NH2, the photo-degradation of paracetamol in visible-light was much effective and considerably high degradation of paracetamol was observed (k1 = 760.0 m-1) comparing to the adsorption (k1 = 160.0 m-1). The overall removal of paracetamol was significantly enlarged from 82.7 mg/g for CA film to 519.1 mg/g for porous CA@Ti-MIL-NH2 film. The used film exhibited quite good reusability and the removal of paracetamol was lowered from 96% to 85% after 5 regeneration cycles. Results of total organic carbon confirmed that paracetamol was fully degraded to CO2 and water.

Antitumor/antiviral carbon quantum dots based on carrageenan and pullulan.

Requirement for medication from pathogenic human viruses and cancer diseases are urgently considered, while, numerous reports were focused on investigating easily manufactured and excellently effective therapeutic reagents. Herein, CQDs were prepared with size of 2.1 nm from both of carrageenan and pullulan. CQDs nucleated from pullulan showed higher anti-proliferative effects against cancer cells, while, treatment with 100 µg/mL of CQDs colloids originated from pullulan and carrageenan separately resulted in diminishing of cancer cell viability percent to be 42.1 & 58.7%, respectively. Plaque reduction assay was also affirmed that, 2.5 µg/L of both of pullulan and carrageenan based CQDs exhibited viral inhibition with percent of 44.3& 59.5%, respectively. As a conclusion, pullulan showed seniority over carrageenan in nucleation of CQDs with higher anticancer activities. While, estimation of antiviral performance of the prepared CQDs confirmed the priority of carrageenan compared to pullulan in preparation of CQDs as antiviral laborer.

Employable metal (Ag & Pd)@MIL-125-NH2@cellulose acetate film for visible-light driven photocatalysis for reduction of nitro-aromatics.

The effective and reusable photocatalyst film based on metal @metal organic framework@cellulose acetate [metal (Ag & Pd)@MIL-125-NH2@CA] was systematically studied. Nano-silver was grown over the crystalline disc of MIL-125-NH2 within CA film, while, self-assembly of crystalline trees like the structure of Pd)@MIL-125-NH2 was observed inside CA matrix. The calculated band gap was diminished from 2.53 eV to 2.38-1.99 eV after doping of metal (Ag & Pd) within MIL-125-NH2@CA film. Compared to MIL-125-NH2@CA; metal (Ag & Pd)@MIL-125-NH2@CA film showed a considerably higher photocatalytic reduction of nitro-aromatics in visible light. After 60 min, 80.6-93.5 % of 2-nitrophenol was photoreduced when metal (Ag & Pd)@MIL-125-NH2@CA film was used. After 5 recycles, the photoreduction percentage of 2-nitrophenol was lowered to 54.4-62.0. The produced metal@MIL-125-NH2@CA films showed an effective photocatalytic reduction of nitro-aromatics in the visible light, reflecting their promising performance in preparation of intermediates useful in many industrial products.

Acacia gum versus pectin in fabrication of catalytically active palladium nanoparticles for dye discoloration.

Obedience to the aspects of green chemistry and due to its high catalytic potency, ecofriendly synthesis of palladium nanoparticles (PdNPs) was performed using pectin versus acacia gum as polysaccharides. The viscous solution of alkali solubilized polysaccharides acted superiorly in stabilization of MNPs by decreasing their Brownian motions and sequentially decreased their collision and coagulation. Production of PdNPs preliminary was confirmed via UV-visible spectra. Zetasizer and transmission electron microscopy data, the particle size of PdNPs were prepared by pectin (27.9 nm) is larger than that by acacia gum (5.3 nm). XRD and FT-IR data affirmed the redox reaction between biopolymers and metal ions to produce PdNPs. PdNPs synthesized by acacia gum were characterized by higher surface area (19.54 m2/g) compared to that prepared by pectin (3.67 m2/g). Additionally, PdNPs synthesized by acacia gum were exhibited by fastest rate of dye discoloration, resulting in complete reductive discoloration of dye after only 5 min and t1/2 was estimated to be 1.70 min, while, k1 was 408.8 × 10-3 min-1. The presented green technique could be successively applicable for synthesis of size regulated catalytically active PdNPs to be employable in various industrial purposes.

Environmentally exploitable biocide/fluorescent metal marker carbon quantum dots.

Carbon quantum dots are currently investigated to act as safe/potent alternatives for metal-based nanostructures to play the role of probes for environmental applications owing to their low toxicity, low cost, chemical inertness, biocompatibility and outstanding optical properties. The synthesis of biocide/fluorescent metal marker carbon quantum dots with hydrophilic character was performed via a quite simple and green technique. The natural biopolymer that was used in this study for the synthesis of carbon quantum dots is fragmented under strong alkaline conditions. Afterwards, under hydrothermal conditions, re-polymerization, aromatization and subsequent oxidation, the carbonic nanostructures were grown and clustered. Dialysis of the so-produced carbonic nanostructures was carried out to obtain highly purified/mono-dispersed carbon quantum dots with a size distribution of 1.5-6.5 nm. The fluorescence intensity of the synthesized carbon quantum dots under hydrothermal conditions for 3 h was affected by dialysis, however, the fluorescence intensity was significantly increased ca. 20 times. The synthesized carbon quantum dots were exploited as fluorescent markers in the detection of Zn2+ and Hg2+. The prepared carbon quantum dots also exhibited excellent antimicrobial potency against Bacillus cereus, Escherichia coli and Candida albicans. The detected minimal inhibitory concentration for the dialyzed CQDs towards the tested pathogens was 350-450 µL mL-1. The presented approach is a simple and green technique for the scaled-up synthesis of biocide/fluorescent marker carbon quantum dots instead of metal-based nanostructures for environmental applications, without using toxic chemicals or organic solvents.

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.