Low pHs Research Articles

Decolorization of Crystal Violet from Aqueous Solution Using Electrofenton Process

In recent years, advance oxidation processes (AOPs) have been widely interested for treatment of industrial wastewater and organic matter. At among, Electrofenton has been proposed as a strong oxidative method. So, the aim of this work was purification of colored aqueous containing crystal violet by electrofenton process and steel mesh electrodes. All regents and methods were prepared from analytical grad and standard methods. The amounts of crystal violet were determined by colorimetric using a spectrophotometer at a maximum wavelength about 586 nm. The main parameters such as pH, applied current, dye concentration, reaction time and supporting electrolyte dose were investigated. Experimental data analysis was also performed using excel software. The results of this study showed that the better dye degradation is occurred in acidic pH (pH3), contact time of 5 minutes, initial concentration of crystal violet 50 mg/l, applied current 0.8 A and an electrolyte level about 0.1 g/L of NaCl. Higher electrical current and lower pHs were caused to generate the higher amount of oxidative radical and regeneration of Fe2+. Under optimal condition, crystal violet was removed around 99.72%. Referring to the results, it can be concluded that the electrofenton is a suitable in situ hydrogen peroxide generation technology for treatment of colored wastewater.

Dynamics of Strontium and geochemically correlated elements in soil during washing remediation with eco-complaint chelators

In the study, the dynamics of Sr2+ and geochemically correlated elements (Ca2+, Ba2+, and Y3+) in soil with chelators in the mix (soil to chelator ratio, 1:10; matrix, H2O) were assessed to understand chemical-induced washing remediation of radiogenic waste solids. Specifically, EDTA (2,2′,2″,2‴-(ethane-1,2-diyldinitrilo)tetraacetic acid), EDDS (2-[2-(1,2-dicarboxyethylamino)ethylamino]butanedioic acid), GLDA (2-[bis(carboxymethyl)amino]pentanedioic acid), and HIDS (2-(1,2-dicarboxyethylamino)-3-hydroxy-butanedioic acid) are chelators that are used as extractants. The effect of solution pH on chelator-induced extractions of the target elements (t-Es: Sr2+, Ca2+, Ba2+, or Y3+) from soil and stability constants of the t-Es complexes with chelators were used to explain the trends and magnitudes in interactions. Pre- and post-extractive solid-phase speciation was used to define the extent of the competence of each chelator in persuading dissolution of t-Es in the soil. The effects of ultrasonic energy, admixtures of biodegradable chelators, and excess chelators in solution (1:20) were also analyzed on the extractive removal of t-Es from soil. The results indicate that the Sr2+ removal with biodegradable chelators significantly exceeded (approximately 70%) when compared to that of environmentally-persistent EDTA at lower solution pHs and a higher soil to chelator ratio (GLDA > HIDS > EDDS ≈ EDTA). However, the extraction of the geochemically related element was significantly lower.

Removal of lead ion from aqueous solutions by adsorption onto phosphate-functionalized treated waste papers (PF-TWPs)

Waste papers, although known as a potential global concern, could be used as an adsorbent for removal of lead ions from the aqueous medium, following some degrees of modifications. The present study deals with the adsorption of Pb(II) ion from aqueous solution by using phosphate-functionalized treated waste papers (PF-TWPs). Batch adsorption study was performed based on contact time, pH, adsorbent dose, and temperature. There was logical coordination of experimental data with Freundlich and Langmuir isotherms. The results of this study showed that the percentage of Pb(II) adsorption on the PF-TWPs increased with increasing pH of approximately 5.5, higher or lower pHs showed no remarkable variation in adsorption capacity. The kinetics analysis showed a substantial correlation between the experimental adsorption data with the pseudo-second-order model. Besides, thermodynamic studies were conducted to explore the adsorption of Pb(II) onto PF-TWPs, regarding the influence of temperature on this process. The spontaneity and endothermicity of the Pb(II) adsorption process were identified based on the negative free energy value and positive enthalpy change. The result of the present study showed that the PF-TWPs could be used as a cost-effective adsorbent for Pb(II) removal from industrial effluent.

Comprehensive analysis of putative dihydroflavonol 4-reductase gene family in tea plant.

One identified dihydroflavonol 4-reductases (DFR) encoding gene (named as CsDFRa herein) and five putative DFRs (named as CsDFRb1, CsDFRb2, CsDFRb3, CsDFRc and CsDFRd) in tea (Camellia sinensis) have been widely discussed in recent papers concerning multi-omics data. However, except for CsDFRa, their function and biochemical characteristics are not clear. This study aims to compare all putative CsDFRs and preliminarily evaluate their function. We investigated the sequences of genes (coding and promoter regions) and predicted structures of proteins encoded, and determined the activities of heterologously expressed CsDFRs under various conditions. The results showed that the sequences of five putative CsDFRs were quite different from CsDFRa, and had lower expression levels as well. The five putative CsDFRs could not catalyze three dihydroflavonol substrates. The functional CsDFRa had the strongest affinity with dihydroquercetin, and performed best at pH around 7 and 35°C but was not stable at lower pHs or higher temperatures. Single amino acid mutation at position 141 modified the preference of CsDFRa for dihydroquercetin and dihydromyricetin, and also weakened its stability. These data suggest that only CsDFRa works in the pathway for generating anthocyanidins and catechins. This study provides new insights into the function of CsDFRs and may assist to develop new strategies to manipulate the composition of tea flavonoids in the future.

Identification of the tolerant capacity to aquatic environment factors (temperature, pH and dissolved oxygen) of Asian bumblebee catfish (Pseudomystus siamensis Regan, 1913)

Asian bumblebee catfish (Pseudomystus siamensis) belongs to Bagridae family and is an economic value ornamental species. However, biological characteristics of this fish species have been rarely reported in the literature. A study to identify tolerant capacity to aquatic environment factors (incipient lethal temperature (ILT) and incipient lethal pH (ILpH) and oxygen threshold) of Asian bumblebee catfish at three developmental stages namely embryo, hatchling and ten-day post hatching (dph) was carried out from July 2018 to January 2019 at the Experimental Farm for Aquaculture of Fisheries Faculty - Nong Lam University in HCM City. The results showed that the incipient upper and lower lethal temperatures (IULT and ILLT) were 32.5oC and 22.3oC for embryos, 36.7oC and 18.7oC for hatchlings, and 38.6oC and 15.9oC for 10 dph fish, respectively. The incipient upper and lower lethal pHs (IULpH and ILLpH) were 10.7 and 4.4 for embryos, 10.2 and 3.7 for hatchlings, and 10.2 and 3.8 for 10 dph fish, respectively. The oxygen thresholds of the catfish at the three stages were 4.7, 1.1 and 1.0 mg O2/L, respectively. The Asian bumblebee catfish at post hatching stages appears to tolerate to unfavorable environmental factors compared to embryonic one. The study results would be an important scientific base for researches on seed production and conservation of the fish in the future.

Improving the Stability of Oil Body Emulsions from Diverse Plant Seeds Using Sodium Alginate.

In this study, peanut, sesame, and rapeseed oil bodies (OBs) were extracted by the aqueous medium method. The surface protein composition, microstructure, average particle size , ζ-potential of the extracted OBs in aqueous emulsion were characterized. The stability of the OB emulsions was investigated. It was found that different OB emulsions contained different types and contents of endogenous and exogenous proteins. Aggregation at low pHs (<6) and creaming at high pHs (7 and 8) both occurred for all of three OB emulsions. Sodium alginate (ALG) was used to solve the instability of OB emulsions under different conditions—low concentration of ALG improved the stability of OB emulsions below and near the isoelectric point of the OBs, through electrostatic interaction. While a high concentration of ALG improved the OB emulsion stability through the viscosity effect at pH 7. The OB emulsions stabilized by ALG were salt-tolerant and freeze–thaw resistant.

Photoelectrocatalytic degradation of organics and formation of disinfection byproducts in reverse osmosis concentrate

The high content of organics in municipal reverse osmosis concentrate (ROC) requires proper treatment. Here, this study applied the photoelectrocatalysis (PEC) to reduce the concentration of organics in ROC. Meanwhile, the formation of disinfection byproducts (DBPs) was investigated. Participation of primary oxidants in organics removal and DBPs formation was revealed at different anodic potentials and pHs. The results showed that PEC process effectively oxidized the organics in ROC, achieving the highest mineralization rate of 63%. Increasing anodic potential from 0 to 1.0 V enhanced the oxidations of bulk organics (i.e., dissolved organic carbons (DOC), UV254, fluorescence, large molecular weight compounds) and trace-level pharmaceuticals. Raising anodic potential to higher than 1.0 V slightly benefited the oxidations of bulk organics, owing to the relatively stable formation of hydroxyl radicals (OH•) and radical reactive chlorine species (r-RCS). The continuously rising concentration of free chlorine (FC) accelerated the decompositions of pharmaceuticals at ≥ 1.0 V. However, the generated FC raised the concentration of DBPs up to 10.36 μmol/L at 3.0 V. Lowering initial pH from 7-9 to 4-6 improved the mineralization rates by around 20% due to the higher formation of OH• at pH 4-6. Further decreasing initial pH from 6 to 4 enhanced the breakdown of large molecular weight compounds as well as the decomposition of pharmaceuticals. This came from the strengthened formation of FC and r-RCS at lower pHs. The intense participation of FC and r-RCS resulted in a higher total DBP concentration at pH 4-6 than that at pH 7-9. However, the individual species of DBPs changed differently toward the pH shift. The results of this study show that PEC could be an alternative for organics oxidation in ROC with proper control of DBPs formation.

Characterizing highly fibrillated nanocellulose by modifying the gel point methodology

The characterization of nanocellulose fibres (NC) length is a difficult and indirect measurement which relies on aspect ratio calculation and fibre diameter analysis. The aspect ratio can be directly calculated from the gel point, a parameter obtained from sedimentation experiments. The gel point has been used with macroscopic fibres and microfibrillated cellulose, that easily sediment by gravity. However, this methodology has not yield consistent results with highly charged nanofibres nor with fibres with sediment layer difficult to observe. In this study, the gel point methodology is modified: 1) dying the fibres with Crystal Violet to enable the visualization of the fibrils sedimentation line without affecting the fibre network; and 2) by optimizing the sedimentation time to ensure complete settling. The two types of fibrils characterized -low and high fibrillated NC (LF-NC, HF-NC)- behave differently due to the slower sedimentation of HF-NC. The time to reach a stable sedimented layer increases with the level of fibre fibrillation, the charge and the decrease of fibre dimension. Reproducible gel point can be measured after 2 days for LF-NC; however, 8 days are required for HF-NC. The modified methodology was validated by quantifying the influence of pH and salt concentration. As expected, low pHs and the addition of CaCl2 coagulate HF-NC into flocs which increase the ratio: final over initial fibres height (Hs/Ho); this decreases significantly the gel point, as a lower amount of HF-NC are required to interconnect all fibres. This modified method is a valuable tool for the accurate dimensional characterisation of highly charged and low diameter cellulose nanofibres.

Pre-gelation assisted spray drying of whey protein isolates (WPI) for microencapsulation and controlled release

Pre-gelation of whey protein isolates (WPI), a milk protein, has been performed before spray drying to decrease the solubility of WPI. The heat-induced pre-gelation at 80 °C aims to produce the gelled WPI for microencapsulation and sustained releases. The gelation time has been studied for a good spray drying, since the feed solutions with higher viscosities cannot be spray dried. WPI solutions cannot be gelled at lower pHs. SEM images show that the spray-dried WPI-acetaminophen particles have wrinkled surfaces. With longer gelation, the spray-dried particles show larger particle sizes and greater changes in the protein structure. FTIR and DSC analysis suggest that the model ingredient (acetaminophen) is amorphous in the spray-dried particles. The release profiles of pre-gelled WPI tablets show good fittings to a first-order release model. Overall, the releases of acetaminophen have occurred over periods from 3 h to two days for different pre-gelation times. The first-order release constants have been determined.

Directed evolution of a 6-phosphogluconate dehydrogenase for operating an enzymatic fuel cell at lowered anodic pHs

Most enzymatic fuel cells (EFCs) are designed for operating at physiological conditions and cannot stand for low pHs due to the enzyme denaturation. Improving the acid tolerance of EFCs represents the increased robustness and diversity of their practical applications. In this study, we successfully constructed a three-enzyme pathway-catalyzed EFC consisting of two dehydrogenases and a diaphorase that can be operated at the anodic pH of 5.4. The acid-intolerance of one enzyme, 6-phosphogluconate dehydrogenase, was overcome by enzyme engineering. After the directed evolution including three rounds of error-prone PCR and a petri-dish-based double-layer screening method, the best 6-phosphogluconate dehydrogenase mutant (named as 3-3) exhibited a 42-fold increase in catalytic efficiency at pH 5.4 compared to the original enzyme. The electrochemical measurements revealed that the EFC equipped with this mutant achieved a maximum power density of 0.13 mW cm−2 at pH 5.4, more than 10-fold higher than that with the same enzyme unit loading but at pH 7.3. Under a high loading amount of enzymes, the EFC yielded a maximum power density of ∼0.5 mW cm−2, and that with the mutant also exhibited an improved stability. This study demonstrates that lowering anodic pH may be a useful strategy for constructing high-performance and robust EFCs and the concerns for enzyme deactivation can be addressed by enzyme engineering.

Impact of covalent or non-covalent bound epigallocatechin-3-gallate (EGCG) on assembly, physicochemical characteristics and digestion of ovotransferrin fibrils

The objectives of the present study were to investigate impact of covalent or non-covalent bound (−)-epigallocatechin-3-gallate (EGCG) on ovotransferrin (OVT) fibrils. Bound EGCG showed fibril-inhibitory activity in a concentration-dependent manner, and covalent bound EGCG inhibited OVT fibrillation more intensely than an equal amount of non-covalent bound EGCG. Bound EGCG resulted in larger fibril building blocks. Covalent bound EGCG shortened OVT fibrils significantly, and non-covalent bound EGCG induced smaller changes in length of OVT fibrils than covalent bound EGCG. A larger amount of covalent or non-covalent bound EGCG led to shorter OVT fibrils. Covalent bound EGCG did not change thickness of OVT fibrils, while newly emerged thicker fibrils were observed in the presence of non-covalent bound EGCG. Covalent bound EGCG shifted isoelectric point of OVT fibril to lower pHs than non-covalent bound EGCG. Bound EGCG decreased surface hydrophobicity, storage modulus and viscosity of OVT fibrils. OVT fibrils with bound EGCG possessed strong antioxidant capacity. The gastrointestinal digestion result demonstrated that covalent bound EGCG contributed to a higher increase in fibril digestibility than non-covalent bound EGCG.

Effects of pH on the simultaneous removal of hydrogen sulfide and ammonia in a combined absorption and electro-oxidation system

Biogas commonly contains both H2S and NH3, and these impurities need to be removed before use. In this study, a combined system consisting of an absorption column and an electro-oxidation reactor was developed to simultaneously treat H2S and NH3. In particular, the effect of the pH (6, 8, and 10) on the system performance was investigated. The mass transfer rate of H2S from the gas to liquid phases was sensitive to pH because of its relatively low solubility at low pHs, while more than 99% of the introduced NH3 was steadily absorbed. Therefore, a pH higher than 8 was favorable for the simultaneous removal of both gases. In the electro-oxidation reactor, H2S was primarily oxidized, while the NH3 oxidation started after H2S was completely eliminated. Furthermore, the oxidation rate and current efficiency of both H2S and NH3 increased with decreasing pH value. The results showed that a low pH was advantageous for the electro-oxidation. In conclusion, the mass transfer rate and oxidation kinetics should be balanced to increase the simultaneous removal of H2S and NH3. Therefore, among the tested pH values, the best performance in the combined system was achieved using a pH of 8.

Effects of potential climate change -induced environmental modifications on food intake and the expression of appetite regulators in goldfish

Climate changes due to global warming result in part from the release of gases such as carbon dioxide (CO2) and methane into the atmosphere and results in warming and acidification of water bodies, and changes precipitation and wind patterns, which might in turn affect water currents, turbulence and turbidity. These changes might affect feeding and its endocrine control. Feeding is regulated by central and peripheral hormones that either stimulate (e.g. orexin, ghrelin) or inhibit (e.g. irisin, cocaine and amphetamine regulated transcript – CART, cholecystokinin – CCK and peptide YY -PYY) food intake. In this study we examined the effects of four climate change-related environmental factors (i.e. temperature, pH, turbulence and turbidity) on food intake and the hypothalamic and intestinal expressions of appetite regulators in fish, using goldfish as a model. High temperatures increased food intake and the brain expression of orexin, and decrease brain CART 1 and intestinal CCK, PYY and ghrelin. Low pHs decreased feeding and increased the expressions of CART1 and CART2 in the hypothalamus and CCK and PYY in the intestine. Turbulence (waves) induced an increase in food intake and a decrease in mRNA expression levels of both CART1 and CART2 in the hypothalamus and both CCK and PYY in the intestine. Turbidity (low visibility) did not affect food intake but increased locomotion and the time taken to reach satiation, while increasing brain orexin and intestinal PYY expression levels and lowering CART1 hypothalamic expression. The results of this study suggest that environmental stress affects feeding physiology of goldfish and bring new insights on how fish might respond to climate changes.

Yield Optimization and Functionality of an Extract of Water-soluble Dietary Fiber and Solids from &lt;i&gt;Opuntia ficus-indica&lt;/i&gt; Stems

The purpose of this study is to optimize the extraction conditions (time, pH, and temperature) for water-soluble dietary fiber (SDF) and solids from Opuntia ficus-indica (OFI) stems and to evaluate the functionality of the optimized extract. The maximum extraction yield was obtained when 100% distilled water was used, indicating that ethanol hampered the extraction. The extraction yields were lower at higher temperatures and lower pHs. The maximum extraction of SDF (27.92%) and solids (5.6 g) was achieved with a 7-h extraction at 50oC and pH 7.0, with desirability being 0.958. The stem extract obtained under the optimum extraction conditions had an antioxidant capacity of 118.10 mg vitamin C equivalents (VCE) using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. In a medium containing 30% extract, the growth of E. coli was reduced by 34%, while that of B. cereus was reduced by 23%. These results suggest that OFI stems can be used as a functional resource.

Physiological, Structural, and Functional Analysis of the Paralogous Cation-Proton Antiporters of NhaP Type from Vibrio cholerae.

The transmembrane K+/H+ antiporters of NhaP type of Vibrio cholerae (Vc-NhaP1, 2, and 3) are critical for maintenance of K+ homeostasis in the cytoplasm. The entire functional NhaP group is indispensable for the survival of V. cholerae at low pHs suggesting their possible role in the acid tolerance response (ATR) of V. cholerae. Our findings suggest that the Vc-NhaP123 group, and especially its major component, Vc-NhaP2, might be a promising target for the development of novel antimicrobials by narrowly targeting V. cholerae and other NhaP-expressing pathogens. On the basis of Vc-NhaP2 in silico structure modeling, Molecular Dynamics Simulations, and extensive mutagenesis studies, we suggest that the ion-motive module of Vc-NhaP2 is comprised of two functional regions: (i) a putative cation-binding pocket that is formed by antiparallel unfolded regions of two transmembrane segments (TMSs V/XII) crossing each other in the middle of the membrane, known as the NhaA fold; and (ii) a cluster of amino acids determining the ion selectivity.

Mesoporous carbon xerogel material for the adsorption of model naphthenic acids: structure effect and kinetics modelling

ABSTRACT The study examined the preparation, characterization and the use of carbon xerogel (CX) material for the adsorption of three model naphthenic acids (NAs); such as, heptanoic acid (HPA), 5-cyclohexanepentanoic acid (CHPA), and 5-phenylvaleric acid (PVA). CX was synthesized by sol–gel method from resorcinol and formaldehyde. The characterization results showed that CX was a mesoporous material with large surface area (573 m2/g) and high pore volume (1.55 cm3/g), which was mainly composed of carbon (93.20%) and oxygen (6.71%). Adsorption studies revealed that PVA, the NA having an aromatic ring was adsorbed more easily by CX (87 mg/g) due to π–π interactions, followed by HPA (65 mg/g) and CHPA (61 mg/g). In addition, by studying the effect of solution pH, the result confirmed that repulsion greatly hindered the adsorption of HPA onto CX at pHs above that of the pHPZC and at lower pHs attractive electrostatic forces promoted adsorption. Adsorption kinetics fitted the pseudo-first-order model, which suggested that physisorption was most likely the means of adsorption. For the intraparticle diffusion model, the rate of film diffusion was higher than the rate of pore diffusion for each model compound regardless of their structure. Accordingly, this confirmed that pore diffusion was the rate-limiting step, although film diffusion still maintained a significant role in the rate of diffusion. In general, CX exhibited excellent adsorption performance due to its highly mesoporous character so it could be used as a passive treatment method in tailing ponds for removal of organic matters.

Effects of ocean acidification on life parameters and antioxidant system in the marine copepod Tigriopus japonicus

Ocean acidification (OA) is caused by alteration of global ocean carbon chemistry due to the increased pCO2 in the atmosphere and caused deleterious impacts on the marine ecosystem. Although various detrimental effects of OA were reported in marine organisms, the potential impact of OA on aquatic invertebrates still remains largely unknown. Here, we examined changes in life parameters and antioxidant system in response to low pH (7.5 and 7) in the marine copepod Tigriopus japonicus. Exposures to lower pHs (pH 7.5 and 7.0) of copepods resulted in lengthening of the developmental time with decreased fecundity and body length. Also, they showed increased reactive oxygen species contents with enhanced glutathione S-transferase and glutathione reductase activities but decreased glutathione peroxidase and superoxide dismutase activities in pH-dependent manner, indicating that OA exposure caused disturbance of the redox system in T. japonicus. Among several oxidative stress-related genes, GSTs2b was significantly up-regulated in response to OA. These findings will be helpful for a better understanding on the potential impact of OA on life parameters and antioxidant system in the marine copepod T. japonicus.

Multivalent assembly of a pyrene functionalized thio-N-acetylglucosamine: Synthesis, spectroscopic and WGA binding studies

We introduce here a new fluorescent derivative of 1-thio-β-N-acetylglucosamine linked to a pyrene system through a triazolylpentyl spacer, designed to self-assemble into a multivalent glycocluster. The synthesis was achieved by efficient CuAAC click reaction between a pyrene functionalized with an azide group and a suitable alkynyl thiomonosaccharide. Spectroscopic studies by fluorometry indicated that the self-assembly in aqueous medium is modulated by concentration and pH changes, the latter due to the presence of the amino group close to the π system. Circular dichroism experiments revealed a moderate positive signal, suggesting that the pyrene-thioGlcNAc conjugate can aggregate into a chiral supramolecular assembly. The sugar moiety showed to specifically and reversibly interact with the wheat germ agglutinin, a fact that was demonstrated by turbidity assay. SEM microscopy of a lyophilized solution at pH 10 revealed a fibrillar morphology compatible with the presence of tubular micelles, whereas crystalline and amorphous solids are formed at lower pHs.

Probiotic potential of Weissella strains isolated from horse feces

In this study, we isolated four Weissella confusa strains from the healthy horse feces to test their potential as equine probiotics. The identification and characteristics of these isolates were determined as per standard methods. Resistance and susceptibility of the isolated strains were tested to low pHs, different heat treatments, commonly used antibiotics and against the pathogenic strains of Salmonella, Pasteurella, Staphylococcus aureus, and Escherichia coli. After 3 h cultural in different pH medium, the 4 strains still had a certain amount of survival above pH 3.0. WH2 and WH4 were still viable at pH2.5. All the isolated strains showed proper growth at 60 °C while no strain survived at 80 °C. The inhibition of α-amylase, the scavenging ability of free radical DPPH· and hydroxyl free radical HO·were also investigated. The results showed that WH4 had highest inhibition rate of α-amylase activity and DPPH· free radical scavenging rate, and the inhibition rate of α-amylase activity was 24.09% and the DPPH· free radical scavenging rate was 35.78%. The inhibition rate ofα-amylase activity and DPPH· scavenging rate of free radicals in the other three strains were about 10%. The clearance rate of hydroxyl radical (HO·) in 4 strains was between 12% and 15%. The antibiotic susceptibilities varied for these four Weisella strains but all of them showed resistance against the frequently used equine antibiotics. All the four strains successfully suppressed the growth of standard strains in in vitro bacteriostasis experiment, which included Salmonella enteritidis (NTNC13349), Escherichia coli (C83902) and Staphylococcus aureus (BNCC186335). they also successfully suppressed the growth of state key laboratory isolating pathogens, which are Pasterurella multocida and Salmonella. Our findings suggest that the isolated strains of Weissella confusa can act as potential equine probiotics and should be explored further.

Antiproliferative effects of new magnetic pH-responsive drug delivery system composed of Fe3O4, CaAl layered double hydroxide and levodopa on melanoma cancer cells

In this study, an efficient drug delivery system composed of Fe3O4, CaAl layered double hydroxide (LDH) and l-Dopa has been synthesized through hydrogen bonds between l-Dopa and CaAl-LDH encapsulated Fe3O4 nanoparticles (Fe3O4@CaAl-LDH@l-Dopa). The structural features of Fe3O4@CaAl-LDH@l-Dopa were characterized using XRD, SEM, TEM, EDX, FT-IR, VSM, TGA, XPS, zeta potential analysis and BET. All of the characterization techniques show the uniform high surface area core-shell structure with about 120 nm in average size. Also, the obtained results clearly indicate that this drug delivery system possess high potent for adsorption of l-Dopa (52 wt%) and high drug encapsulation efficiency (71%). The amount of l-Dopa release in low pHs (53.8%) which simulates the environment of cancer cells is greater than higher pHs. The in vitro cytotoxic and anticancer activities of Fe3O4@CaAl-LDH@l-Dopa were investigated against Mel-Rm Cells Melanoma (NCIt: C3224) using LDH colorimetric assay and differential staining cell death assay. The results showed Fe3O4@CaAl-LDH@l-Dopa with a lower concentration of l-Dopa, illustrate a higher cytotoxicity and anticancer activity.