Inhibition Capability Research Articles

Synergistic effect of essential oil distillates on the corrosion protection of GX4CrNiMo16-5-1 stainless in acid-chloride electrolyte

The inhibition capability of admixed rosemary oil with cinnamon cassia oil (RC), and grapefruit oil with lemongrass oil (GL) on GX4CrNiMo16-5-1 martensitic stainless steel (GX4ST) corrosion was studied in 6 M H2SO4/3.5% NaCl electrolyte by potentiodynamic polarization and optical microscopy characterization. Results show both admixed distillates performed effectively on GX4ST. The corrosion rate of GX4ST without the distillates at 2.82 mm/y significantly decreased to average value of 0.04 mm/y and 0.05 mm/y analogous to average inhibition efficiency of 98.64% and 98.23% for RC and GL compound. The oil distillates exhibit consistent anodic corrosion inhibition behavior at all concentrations studied. Corrosion thermodynamic calculations showed the distillates chemisorbed on the martensitic steel with Gibbs free energy values greater than -46.01 Kjmol−1 with respect to Langmuir isotherm equation which indicates negligible of lateral interaction effect among inhibitor molecules and surface coverage protection mechanism. Optical image representations of GX4ST after corrosion without the distillates showed severe surface degradation of general and localized corrosion. This contrast the images of the inhibited steel surface which were closely similar to the steel image before corrosion.

Poly(vinyl alcohol)-tannic Acid Cryogel Matrix as Antioxidant and Antibacterial Material.

The biocompatible, viscoelastic properties of poly(vinyl alcohol) (PVA) in combination with the antimicrobial and antioxidant natural polyphenolic, tannic acid (TA), and the natural flavonoid and antioxidant curcumin (Cur), were used in the preparation of PVA:TA and PVA:TA:Cur cryogel composites using cryotropic gelation to combine the individually beneficial properties. The effect of TA content on the antioxidant and antimicrobial activities of PVA:TA cryogel composites and the antioxidant activities of PVA:TA:Cur cryogel composites was determined using Trolox equivalent antioxidant capacity (TEAC) and total phenol content (TPC) assays, and were compared. The PVA:TA:Cur cryogel composite showed the highest antioxidant activity, with a TEAC value of 2.10 ± 0.24 and a TPC value of 293 ± 12.00. The antibacterial capacity of the PVA:TA and PVA:TA:Cur 1:1:0.1 cryogel composites was examined against two different species of bacteria, E. coli and S. aureus. It was found that the minimum inhibition concentration (MIC) value of the PVA:TA:Cur 1:1:0.1 cryogel composites varied between 5 and 10 mg/mL based on the type of microorganism, and the minimum bactericidal concentration (MBC) value was 20 mg/mL irrespective of the type of microorganism. Furthermore, the hemocompatibility of the PVA:TA cryogel composites was evaluated by examining their hemolytic and coagulation behaviors. PVA:TA 1:1 cryogels with a value of 95.7% revealed the highest blood clotting index value amongst all of the synthesized cryogels, signifying the potential for blood contacting applications. The release of TA and Cur from the cryogel composites was quantified at different pH conditions, i.e., 1.0, 7.4, and 9.0, and additionally in ethanol (EtOH) and an ethanol–water (EtOH:Wat) mixture. The solution released from the PVA:TA cryogels in PBS was tested for inhibition capability against α-glucosidase (E.C. 3.2.1.20). Concentration-dependent enzyme inhibition was observed, and 70 µL of 83 µg/mL PVA:TA (1:1) cryogel in PBS inhibited α-glucosidase enzyme solution of 0.03 unit/mL in 70 µL by 81.75 ± 0.96%.

Antagonistic activity and characterization of indigenous soil isolates of bacteria and fungi against onion wilt incited by Fusarium sp.

Tuber rot disease due to phytopathogen Fusarium oxysporum f. sp. cepae (Foc) infection is one of the main factors causing the decreasing global onions production. This study aims to find bacteria and fungi candidates with Foc antagonistic activity through in vitro tests using dual culture techniques. A total of three bacterial isolates and three fungal isolates isolated from the rhizosphere of healthy onion plants showed the ability to inhibit Fusarium oxysporum growth. LC648364 isolate had an average inhibitory capability of 65.93%. At the same time, LC648367 and LC648368 fungal isolates can inhibit the growth of F. oxysporum by as much as 74.82% and 67.76%, respectively. Molecular analysis based on 16S rRNA markers showed three isolates belonging to the Bacillus. The LC648364 isolates are closely related to species Bacillus sp. strain LLB-17, LC648365 is closely related to B. subtilis strain S11 and LC648366 is closely related to B. cereus strain EM6. For the fungi, based on internal transcribed spacer (ITS) gene markers, there are three isolates. The LC648367 isolate is closely related to Aspergillus tubingensis, LC648368 is closely related to Trichoderma asperellum and LC648369 is closely related to Issatchenkia orientalis. This study can be used to develop indigenous microbial consortiums as biological control agents for phytopathogenic fungi Fusarium tuber rot on onion.

Development and butyrylcholinesterase/monoamine oxidase inhibition potential of PVA-Moringa oleifera developed nanofibers

The objective of the current research was to study the effects of polyvinyl alcohol (PVA) electrospun nanofibers loaded with different concentrations of leaf extract of Moringa oleifera (MO) on butyrylcholinesterase (BuChE), monoamine oxidase A (MAO A) and monoamine oxidase B (MAO B) enzymes. The MO-loaded PVA nanofibers were investigated for their inhibitory effect on BuChE and MAO A & B enzymes. The characterization of the fabricated nanofibers was performed by using SEM, FTIR and XRD. The results showed that increasing the concentration of MO, the enzyme inhibition capability of electrospun nanofibers was greatly (p < 0.05) influenced. This study involved the fabrication of electrospun nanofibers of PVA containing four different concentrations of MO (0%, 0.1%, 0.2% and 0.4%). The SEM micrographs revealed that all the nanofibers were porous, beadless and smooth. At a high concentration of M. oleifera, uniform fibers were obtained. The FTIR results of the fabricated nanofibers revealed that chemical interaction did not take place between M. oleifera and polyvinyl alcohol. The results reveal that with an increase in the concentration of M. oleifera (MO), the enzymes inhibition capability of electrospun nanofibers is greatly influenced. Different concentrations of MO extract were successfully loaded to the MMT-reinforced, glutaraldehyde-cross-linked nanofibers.

Aqueous Dried Extract of Skytanthus acutus Meyen as Corrosion Inhibitor of Carbon Steel in Neutral Chloride Solutions

The implementation of corrosion engineering control methods and techniques is crucial to extend the life of urban and industrial infrastructure assets and industrial equipment affected by natural corrosion. Then, the search of stable and environmentally friendly corrosion inhibitors is an important pending task. Here, we provide experimental evidence on the corrosion inhibitory activity of aqueous extracts of Skytanthus acutus Meyen leaf, a native plant from the Atacama Desert in northern Chile. Skytanthus extracts as a powder should be prepared at 55 °C to avoid thermal decomposition and loss of corrosion inhibitory activity. Corrosion of carbon steel AISI1020 immersed in 0.5 M NaCl was evaluated in the presence of different doses of Skytanthus extract by complementary and simultaneous linear polarization, electrochemical impedance spectroscopy, and weight-loss technique under high hydrodynamic conditions. Mixed Potential Theory was applied to confirm the electrochemical activity of the extract inhibitory capabilities. The Skytanthus extracts reached a 90% corrosion inhibitory efficiency when tested at 100 to 1200 ppm in a time span of 48 h, through an electrochemical interaction between the extract inhibitor component and the carbon steel surface. The corrosion inhibition activity observed in Skytanthus dry extracts involves a protective film formation by a mechanism that includes an iron dissolution at the expense of either oxygen reduction and/or hydrogen evolution, followed by a ferrous-ferric iron cycling, the formation of an iron complex and adsorption to the metal surface, and, finally, desorption or degradation of the protecting film. The water-soluble plant extract was subjected to HPLC-MS analyses that rendered 14 major signals, with quinic acid, protocatechuic acid, chlorogenic acid isomers, vanillic acid hexoside, and patuletin 3-methoxy-7-glucoside as the most abundant components. Then, we propose that a phenolic derivative is responsible for the corrosion inhibitory activity found in Skytanthus extracts.

Self-healing dual biomimetic liquid-infused slippery surface in a partition matrix: Fabrication and anti-corrosion capability for magnesium alloy

Biomimetics affords versatile ways to develop new routes for protecting metals from corrosion. In this report, focusing on the inhibition of corrosion for magnesium alloy, different biomimetic strategies were studied. Using a facile immersion method followed by surface modification, a lotus leaf-inspired superhydrophobic surface (SHS) is achieved. However, in the water phase, the SHS is found to be vulnerable, and a hydrophilic defect spot can irreversibly deteriorate the corrosion inhibition capability. Based on the infusion of dimethyl silicone oil into a SHS matrix, a dual biomimetic slippery liquid-infused porous surface (SLIPS) in a partition matrix inspired by both Nepenthes pitcher and pomegranate fruit was prepared. In a 3.5 wt% NaCl solution, the corrosion resistance of the SLIPS is found to be four orders of magnitude larger than that of the untreated and superhydrophobic magnesium alloys. In comparison with the vulnerable SHS, the SLIPS can tolerate repeat mechanical damage, exhibiting prominent self-healing properties. A facile route leads to dual biomimetic slippery liquid-infused surface in partition matrix onto magnesium alloy. Slippery liquid-infused porous surface has long-term corrosion inhibition and good self-healing capability. • Immersion and surface modification leads to superhydrophobic AZ31B. • Durability of superhydrophobicity is short for corrosion inhibition. • Slippery liquid-infused porous surface protects AZ31B from corrosion.

Effect of addition of carbon dots to the frying oils on oxidative stabilities and quality changes of fried meatballs during refrigerated storage

Carbon dots (CDs) were prepared and noted to exhibit potent scavenging activities against DPPH·, ·OH, and O2·- radicals. Addition of CDs to frying oil as a means to improve oxidative stability and minimize quality changes of fried meatballs during refrigerated storage was investigated in comparison with the use of tert-butylhydroquinone (TBHQ) and carnosic acid (CA). Compared with the control sample, 0.05% CDs significantly reduced thiobarbituric acid reactive substances value, carbonyl and total volatile basic nitrogen contents of fried meatballs. Both lipid and protein oxidation inhibition capabilities of CDs were higher than those of 0.05% CA but lower than those of 0.02% TBHQ. Total sensory score of sample with CDs (7.1 ± 0.06) was significantly higher than those of the control (4.7 ± 0.03) and sample with TBHQ (6.4 ± 0.04). CDs could delay oxidation of fried meatballs during refrigerated storage and can well serve as an alternative antioxidant.

In vitro and in silico studies of chalcones derived from natural acetophenone inhibitors of NorA and MepA multidrug efflux pumps in Staphylococcus aureus

Bacterial resistance induced by efflux pumps is a frequent concern in clinical treatments involving multi-resistant bacteria. Staphylococcus aureus is a microorganism responsible for several types of infections and has several strains carrying efflux pumps, among them are the strain 1199B (NorA overexpresser), and the strain K2068 (MepA overexpresser). In this work, four chalcones derived from Croton anisodontus with modifications in the B ring in their structures were tested regarding their ability to inhibit NorA and MepA efflux pumps. The efflux pump inhibition mechanism was tested with the ethidium bromide substrate in the presence and absence of standard efflux pump inhibitors. The minimum inhibitory concentration values were also compared to those of strains that do not overexpress these efflux pumps. In order to gain some insights about the efflux pump mechanisms of these chalcones, two homology models were created (NorA and MepA) for a docking procedure. In addition, the ADME properties (absorption, distribution, metabolism and excretion) were also evaluated. The tested chalcones promoted synergism of the norfloxacin antibiotic by inhibiting associated efflux pumps. All four tested chalcones appear to bind to the binding sites of the efflux pump models in the same fashion as other chalcones with efflux pump inhibition capabilities. It was also verified that the chalcones 1–4 are well absorbed in the intestine, but with a decrease in their bioavailability, resulting in a low volume of distribution in the blood plasma, in addition to having a mild CNS activity. However, the chalcone 3 and 4 were not toxic due to metabolic activation. Whereas the chalcones 1 and 2 present a mutagenic risk, depending on the oral dose administered. The tested chalcones have not antibacterial activity; however, they are capable of inhibiting efflux pumps for the 1199B and K2068 strains. They promoted synergism of the norfloxacin antibiotic by inhibiting associated efflux pumps, as well as other associated mechanisms.

Phytochemical Analysis and Antibacterial Activities of Sidr Leaf Extract (Ziziphus spina-christi) against Pathogenic Bacteria in Aquaculture

The success rate of aquaculture is highly influenced by several factors, including optimum water quality, feed management, and microorganism control. Several microorganisms interfere with the quality of media and fish culture, i.e., fish growth. Aeromonas and Vibrio are the main pathogenic bacteria that disrupt fish growth and cause mortality. Sidr leaf (Ziziphus spina-christi) extract contains phytochemicals that have antibacterial properties. This study aimed to identify the phytochemical components and analyze the effect of Sidr leaf extract on the growth of aquaculture-based pathogenic bacteria. Sidr leaf extract was obtained using ethanol and tested via phytochemical analysis, chemical analysis, prediction of activity spectra for substances (PASS) examination, and inhibition capability against Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria, Pseudomonas putida, Pseudomonas aeruginosa, Streptococcus agalactiae, Vibrio vulnificus, Vibrio harveyi, Vibrio parahaemolyticus, and Vibrio alginolyticus. The results showed that Sidr leaf extract contained phytochemicals, namely, flavonoids, alkaloids, saponins, tannins, and steroids. Gas chromatography-mass spectrometry analyses showed that the Sidr leaf extract contained 30 compounds with antiseborrheic effects. PASS analysis demonstrated that 15 compounds (64.51% level) have potential as antibacterial, with a probability activity value of more than 0.300. The inhibition test showed that the Sidr leaf extract exhibited moderate-to-strong inhibition against pathogenic bacterial growth, except for V. vulnificus, for which it produced a weak inhibition. The results indicate that Sidr leaf extract can be used as a natural herb to control bacterial pathogens in fish cultivation.

Molecular structure, tautomer's, reactivity and inhibition studies on 6-Methyl-2-thiouracil for mild steel corrosion in aqueous HCl (1.00 M): Experimental and Theoretical Studies

• Raman, Infrared and NMR spectra were interpreted based on keto-thione tautomer of 6-Methyl-2-thiouracil molecule. • Polarization and impedance measurements were analyzed for corrosion inhibition efficiency of mild steel in HCl. • FMO and NBO calculations were to correlate the active sites with the inhibition efficiency. • Adsorption annealing simulations locate the best adhering geometry of the inhibitor to the metal surface. Raman (3500-100 cm −1 ) and FT-ATR (4000-360 cm −1 ) spectra of solid 6-Methyl-2-thiouracil (6M2TU) have been recorded in addition to 1 H and 13 C NMR along with Mass fragmentation patterns. Moreover, the hydroxy-thiole, keto-thiole, hydroxy-thione and keto-thione tautomer's stability were theoretically probed using (DFT) B3LYP/6-31G(d,p) calculations in favor of keto-thione in the gaseous phase by ~12-24.5 kcal/mol. Moreover, the monomer and dimer structures were verified by MS/MS spectral measurements owing to the recorded m/z peaks at 141.2 and 281.1, respectively. The inhibition efficiency of 6M2TU towards mild steel iron (MSFe) against 1.0 M HCl has been investigated with molar concentrations of 0.75-7.5 × 10 −3 at 30±2°C using potentiodynamic polarization, impedance measurements and electrochemical frequency modulation. The entitled compound shows a superior inhibition capability against corrosion ranged from 72-94% was obtained. The polarization curves suggest a mixed-type inhibitor for 6M2TU obeying the Langmuir adsorption model while the impedance data ensures an increase in the charge transfer resistance upon its adsorption on the surface of FeMS. Natural bond orbital (NBOs) showed an effective charge transfer from the inhibitor to d -orbitals of the metal in the following order; LP (S) > LP (O) > LP (N 1 ) > π (C=S) > LP (N 3 ) > π (C 5 =C 6 ) > π (C=O). The calculated low Δ E g a p (4.21 eV) predicts that 6M2TU have an efficient inhibition efficiency. Finally, The kinetic parameter F number (5.369673 cm −1 ) and the potential function (V 3 ) was estimated at 454±19 cm −1 (1.30±1.05 kcal/mol) implementing B3LYP/6-31G(d,p) optimized SPs and the calculated torsion frequency at 133 cm −1 . Raman, infrared and NMR spectra were used to study the molecular conformational/tautomeric structures of 6-Methyl-2-thiouracil. Vibrational interpretations were suggested for keto-thione tautomer based on normal coordinate analysis. The corrosion its inhibition effect on iron mild steel in HCl was investigated using potentiodynamic polarization and electrochemical impedance measurements favors a dominant/minor chemical/physical adsorption mechanism.

High-dose vitamin D metabolite delivery inhibits breast cancer metastasis.

Besides its well‐known benefits on human health, calcitriol, the hormonally active form of vitamin D3, has been being evaluated in clinical trials as an anticancer agent. However, currently available results are contradictory and not fundamentally deciphered. To the best of our knowledge, hypercalcemia caused by high‐dose calcitriol administration and its low bioavailability limit its anticancer investigations and translations. Here, we show that the one‐step self‐assembly of calcitriol and amphiphilic cholesterol‐based conjugates leads to the formation of a stable minimalist micellar nanosystem. When administered to mice, this nanosystem demonstrates high calcitriol doses in breast tumor cells, significant tumor growth inhibition and antimetastasis capability, as well as good biocompatibility. We further reveal that the underlying molecular antimetastatic mechanisms involve downregulation of proteins facilitating metastasis and upregulation of paxillin, the key protein of focal adhesion, in primary tumors.

Insight on the corrosion inhibition performance of psidium guajava linn leaves extract

This work multi-angle explored the anti-corrosion nature and mechanism of psidium guajava linn leaves extract for copper in H2SO4 environment.In this study, we used a simple and eco-friendly extraction way to acquire psidium guajava linn leaves extract (PGLLE). Fourier Transform infrared spectroscopy (FTIR) was executed to determine the active functional groups in PGLLE. Quantum chemical calculations effectively forecast the anti-corrosion characteristic of the four active substances in PGLLE. The results of molecular dynamics simulation predicted the stabilized adsorption configurations of the four substances in PGLLE on the Cu (111). Surface topography analysis can intuitively demonstrate that PGLLE effectually inhibits Cu corrosion. The data of electrochemical experiments show that the anti-corrosion capacity of PGLLE increases with the increase of the concentration in a certain interval. As the temperature hoists at definite temperature range, PGLLE can still be efficaciously adsorbed at the Cu surface, showing high-quality corrosion inhibition capabilities. Psidium guajava linn leaves can exist widely in nature, so it has great economic value as the inhibitor. Besides, PGLLE basically does not pollute the ecosystem when used as inhibitors.

Capillary Suction Timer and machine learning techniques as tools for evaluating the performance of different shale inhibitors used in drilling mud

Drilling through shales with higher clay content is highly challenging with water-based drilling fluids. Numerous shale swelling inhibitors such as salts, polymers, and other chemical additives are used in drilling muds to stabilize shale formations. The inspection of the swelling inhibition capabilities of these additives is of utmost importance before its field application. Capillary Suction Timer instrument has been used to evaluate the shale inhibition performance of three categories of shale stabilizers for water-based drilling fluids. Each category of additive contains three different types of chemicals: salts (Potassium Chloride, Potassium Formate, and Choline Chloride), polymers (polyN-[3-(dimethylamino)propyl]methacrylamide, poly[2-(acryloyloxy)ethyl]trimethylammonium chloride and Polyvinylpyrrolidone) and ionic liquids (1-Butyl-3-methylimidazolium chloride and two other deep eutectic solvents). Capillary Suction Time for each chemical additive has been determined for various concentrations at room temperature. This test helps assess the clay swelling capability of the drilling mud in the presence of different additives at various concentrations. The Capillary Suction Time is dependent on the type and concentrations of chemical additive exhibiting a relative change in clay water interaction inhibition. The ionic liquids area significant category for clay swelling inhibition showing a minimum increase in Capillary Suction Time after 24 h. This indicates shale inhibition durability of the additive by resisting the water intake by clay. In addition, Fourier Transform Infra-Red and X-ray Diffraction techniques helped in characterizing the clay under consideration. The present work focuses on modeling the capillary suction time using machine learning algorithms. This technique provides a robust model for assessing the swelling capabilities of the drilling mud based on the concentration and types of additives. Of the different algorithms used, the Gradient Boosting algorithm provides the best model for capillary suction time estimation with an accuracy of 98%.

Potential of tetradecyltrimethylammonium bromide in preventing fibrillation/aggregation of lysozyme: biophysical studies

A key step in the prevention of neurodegenerative disorders is to inhibit protein aggregation or fibrillation process. Functionality recognition is an essential strategy in developing effective therapeutics in addressing the treatment of amyloidosis. Here, we have focused on an approach based on structure–property energetics correlation associated with tetradecyltrimethylammonium bromide (TTAB), a cationic surfactant that acts as an inhibitor targeting different stages of hen egg-white lysozyme fibrillation. Characterization of amyloid fibrils and the inhibitory capability of 16 mM TTAB surfactant on fibrillation were investigated with the calorimetric, spectroscopic and microscopic techniques. ThT binding fluorescence studies inferred that micellar TTAB exerts its maximum inhibitory effect against amyloid fibrillation than monomer TTAB. The TEM measurements also confirmed complete absence of amyloid fibrils at micellar TTAB. At the same time, the transformation of β-sheet to α-helix under the action of TTAB was confirmed by the Far-UV CD spectroscopy. Although there have been some reports suggesting that cationic surfactants can induce aggregation in proteins, this work suggests that polar interactions between head groups of TTAB and amyloid fibrils are the predominant factors that cause retardation in fibrillation by interrupting/disturbing the intermolecular hydrogen bond of β-sheets. The present finding has explored the knowledge-based details in developing efficient potent inhibitors and provides a platform to treat diseases associated with protein misfolding. Communicated by Ramaswamy H. Sarma

Numerical investigation of anisotropic and time-dependent behaviors of tunnel invert structure in layered rock mass

In this paper, the bottom of the tunnel structure is uplifted with time under the condition of layered surrounding rock, and the influence of the change in slope angle on the bottom uplift is discussed. In addition, the finite difference method is used to simulate the limitation of the uplift deformation of the tunnel bottom structure by adjusting the rise span ratio of the inverted arch. The conclusions are as follows: (1) The “weak plane” in layered rock mass produces anisotropy of deformation. The creep speed of the surrounding rock is fast at the initial stage and then stabilizes after a certain period. (2) With different dip angles of the layered rock mass, the peak vertical displacement of the inverted arch filling layer is accordingly affected by the dip angle. (3) In engineering, the method of adjusting the rise span ratio to increase the depth of invert is usually applied to restrain the uplift deformation of invert structure. According to the numerical analysis results, with the increase in depth, the deformation inhibition capability does not become stronger. In addition, a similar situation occurs in the plastic zone of the filling layer. Thus, the rationality of deepening depth should be fully considered when adjusting the rise span ratio. This paper analyzes the numerical simulation of the tunnel substructure of a layered rock tunnel with time effect to provide a useful reference for the tunnel design under such surrounding rock conditions.

In silico identification of SARS-CoV-2 cell entry inhibitors from selected natural antivirals

The aim of this study is to identify potential drug-like molecules against SARS-CoV-2 virus among the natural antiviral compounds published in the Encyclopedia of Traditional Chinese Medicine. To test inhibition capability of these compounds first, we docked them with Spike protein, angiotensin-converting enzyme 2 (ACE2) (PDB ID: 6M0J) and neuropilin 1 (NRP1) (PDB ID: 7JJC) receptors, and found significant docking scores with extra precision up to −11 kcal/mol. Then, their stability in the binding pockets were further evaluated with molecular dynamics simulation. Eight natural antiviral compounds were identified as potential inhibitors against SARS-CoV-2 cell entry after 200 ns molecular dynamics simulations. We found CMP-3, CMP-4, CMP-5, CMP-6 and CMP-8 are strong binders for the spike protein, CMP-1, CMP-2, CMP-4, CMP-5 and CMP-7 are strong binders for the neuropilin receptor, and CMP-5 is a strong binder for the ACE2. Quercetin derivatives (CMP-4, CMP-5, CMP-6 and CMP-7) were found highly stable in the active domain of NRP1, ACE2 and Spike protein. Especially, CMP-5 showed an inhibitory activity for all targets. These natural antivirals may be potential drug candidates for the prevention of SARS-CoV-2 infection.

The expression, purification, and functional evaluation of the novel tumor suppressor fusion protein IL-24-CN.

Interleukin-24 (IL-24) can specifically induce apoptosis in a broad range of cancer cells without harming normal cells. The interaction of contortrostatin (CN) with integrins on angiogenic vascular endothelial and tumor cells is modulated by the RGD motifs that can significantly inhibit metastasis and angiogenesis. To achieve superior therapeutic efficacy by combining anti-metastasis with tumor-selective apoptosis activity, CN was fused at the C-terminus of IL-24 with a flexible linker (G4S)2, and the recombinant IL-24-CN was expressed in Escherichia coli as a Thioredoxin (Trx)/IL-24-CN fusion protein. The target protein was purified using nickel affinity chromatography. Furthermore, we simplified the purification process by purifying Trx-IL-24-CN and cleaving the Trx tag in one step. The final yield of IL-24-CN was 27.6mg/L based on flask fermentation. In vitro activity assay demonstrated that the recombinant IL-24-CN could more effectively suppress tumor growth and induce apoptosis of melanoma cells. Scratch and transwell assays suggested that IL-24-CN strongly reduced the migration and invasion behavior of melanoma cells. Immunofluorescence analysis and cell adhesion assay showed that CN could evidently improve the tumor inhibition capability of IL-24 by enhancing the affinity of recombinant protein toward cancer cells. In summary, a highly efficient strategy was developed for producing the bioactive IL-24-CN from prokaryotic cells, supporting IL-24-CN in melanoma therapy.Key points• Efficient heterologous production of recombinant IL-24-CN in E. coli using Trx fusion strategy.• Improved tumor growth suppression and apoptosis induction potency of IL-24-CN.• Enhanced cell adhesion ability of IL-24-CN in cancer cells.

The Impact of Bacteria of the Genus Bacillus upon the Biodamage/Biodegradation of Some Metals and Extensively Used Petroleum-Based Plastics

This paper tackles bacteria of the genus Bacillus as both biodamaging/biodegrading and biocontrolling agents. The article addresses the said bacteria’s ability to form biofilms and corrosive, antimicrobial and antibiofilm proactive compounds, primarily, siderophores. Their role depends on the species, microorganism strain, production of antimicrobial substances, biofilm formation, and the type of damaged material. The bacteria under analysis have demonstrated the ability to cause as well as inhibit biodamage. The involvement of bacteria of the genus Bacillus in microbiologically influenced corrosion processes is determined by the production of corrosive metabolites and the impact of certain bioelectrochemical mechanisms. Lipopeptides generated by Bacillus subtilis (surfactin, iturin and fengycin) are capable of modifying surfaces’ hydrophobic properties and impacting the microbes’ adhesion to surfaces. Produced by Bacillus velezensis, the siderophore bacillibactin at a high concentration is capable of inhibiting the formation of bacterial biofilms, thus slowing down the degradation of materials. Further study of siderophores as green inhibitors of microbiologically influenced corrosion may be promising as the said compounds possess antibiofilm-forming properties and high-intensity inhibitory capabilities.

Inhibition of hydroxylated polychlorinated biphenyls (OH-PCBs) on sulfotransferases (SULTs)

Polychlorinated biphenyls (PCBs) have been demonstrated as a kind of the persistent organic pollutants (POPs) that could exert complicated influences towards metabolism in human bodies. Since hydroxylated polychlorinated biphenyls (OH-PCBs) are important metabolites of PCBs, our study focuses on investigating the potential inhibitory capability of OH-PCBs on four human sulfotransferase (SULT) isoforms. P-nitrophenol (PNP) was utilized as nonselective probe substrate for this study, and recombinant SULT isoforms were utilized as the enzyme resources. Ultra-performance liquid chromatography (UPLC)-UV detecting system was used to analyze PNP and its metabolite PNP-sulfate. As result, 100 μM of most tested OH-PCBs significantly inhibited the activity of four SULT isoforms. Concentration-dependent inhibition of OH-PCBs towards SULTs was found, and half inhibition concentration values (IC50) of some inhibition processes were determined. Inhibition kinetics (inhibition kinetic type and parameters) were determined using 4′–OH–PCB106 as the representative OH-PCB, SULT1B1 and SULT1E1 as representative SULT isoforms. The inhibition kinetic parameters (Ki) were 1.73 μM and 1.81 μM for the inhibition of 4′–OH–PCB106 towards SULT1B1 and SULT1E1, respectively. In silico docking simulation was utilized to analyze the inhibition capability of 2′–OH–PCB5, 4′–OH–PCB9, 2′–OH–PCB12 towards SULT1A3.All these results obtained in this study are helpful for further understanding the toxicity of PCBs.

The comparative biological properties of Mg+ or Ca+ implanted Cu–TiN nanocomposite coatings on titanium alloys

In this paper, Cu–TiN nanocomposite coatings on titanium alloys were prepared by multi-target co-sputtering system. On this basis, Mg or Ca ions at the same doses were then implanted into the Cu–TiN coatings respectively via plasma immersion ion implantation system (PIII) to further improve their biological properties. The corrosion resistances, protein adhesion rates, in vitro cell proliferation and bacterial inhibition capabilities of Mg + implanted Cu–TiN and Ca+ implanted Cu–TiN were also compared. The results showed that the Mg+ implanted Cu–TiN showed (i) improved corrosion behavior, (ii) higher protein adsorption capacity, (iii) ideal cell proliferation and adhesion, (iv) better antimicrobial properties. The research results showed that compared with Ca, Mg and Cu–TiN combined better in osteogenetic and antibacterial activities, which could provide a good choice for the surface modification of medical materials.