Fabrication of Polymeric Hydrogels Containing Esomeprazole for Oral Delivery: In Vitro and In Vivo Pharmacokinetic Characterization.

Hydrogel is one of the most interesting and excellent candidates for oral drug delivery. The current study focuses on formulation development of hydrogels for controlled oral delivery of esomeprazole. The hydrogels were prepared by solution casting method by dissolving polymers in Polyvinyl alcohol (PVA) solution. Calcium alginate, Hydroxyl propyl methylcellulose (HPMC), acrylic acid and chondroitin sulfate were used in the preparation of hydrogels. Fourier transform infrared (FTIR) analysis showed no incompatibilities between drug and excipients used in the preparation of formulations. The hydrogels were characterized for size and surface morphology. Drug encapsulation efficiency was measured by Ultraviolet-visible (UV-VIS) spectroscopy. In vitro release studies were carried out using dissolution apparatus. The formulated hydrogels were then compared with the marketed product in vivo using rabbits. The result indicates that prepared hydrogels have a uniform size with a porous surface. The esomeprazole encapsulation efficiency of the prepared hydrogels was found to be 83.1 ± 2.16%. The esomeprazole-loaded hydrogel formulations showed optimum and Pharmacopeial acceptable range swelling behavior. The release of esomeprazole is controlled for 24 h (85.43 ± 0.32% in 24 h). The swelling and release of drug results make the prepared hydrogels a potential candidate for the controlled delivery of esomeprazole. The release of the drug from prepared hydrogel followed the super case transport-2 mechanism. The in vivo studies showed that prepared hydrogel formulations showed controlled and prolonged release of esomeprazole as compared to drug solution and marketed product. The formulations were kept for stability studies; there was no significant change observed in physical parameters, i.e., (appearance, color change and grittiness) at 40 °C ± 2/75% ± RH. There was a negligible difference in the drug content observed after the stability study suggested that all the formulations are stable under the given conditions for 60 days. The current study provides a valuable perspective on the controlled release profile of Hydroxyl propyl methylcellulose (HPMC) and calcium alginate-based esomeprazole hydrogels.

Recent advances in biodecolorization and biodegradation of environmental threatening textile finishing dyes.

Organic nature of dyes and their commercially made products are widely utilized in many industries including paper, cosmetics, pharmaceuticals, photography, petroleum as well as in textile manufacturing. The textile industry being the top most consumer of a large variety of dyes during various unit processes operation generates substantial amount of wastewater; hence, nominated as "Major Polluter of Potable Water". The direct discharge of such effluents into environment poses serious threats to the functioning of biotic communities of natural ecosystems. The detection of these synthetic dyes is considered as relatively easy, however, it is extremely difficult to completely eliminate them from wastewater and freshwater ecosystems. Aromatic chemical structure seems to be the main reason behind low biodegradability of these dyes. Currently, various physiochemical and biological methods are employed for their remediation. Among them, microbial degradation has attracted greater attention due to its sustainability, high efficiency, cost effectiveness, and eco-friendly nature. The current review presents recent advances in biodegradation of industrial dyes towards a sustainable and tangible technological innovative solutions as an alternative to existing conventional physicochemical treatment processes.

Bio-purification of domestic wastewater through constructed wetland planted with Paspalidium flavidum.

The current study was aimed to designed laboratory scale constructed wetland (CW) for the treatment of domestic wastewater under temperature range (18-38°C) and hydraulic retention times (24 and 48 h). Besides, the soil of vegetative unit of CW was assessed using conventional culturing techniques, and 13 different bacterial species (Escherichia coli, Micrococcus, Pseudomonas, Proteus, Klebsiella, Streptococcus, Alcaligenes, Salmonella, Bacillus, Enterobacter, Staphylococcus, Shigella and Corynebacterium spp.) were determined. The pathogenic microbial load was high in influent samples, but after treatment, about 73.1-99.7% and 43.5-86.7% reduction in CFU/ml and MPN/100 ml index, respectively, were observed. Moreover, the organic loads in terms of COD, TDS, TSS, and turbidity were high in all influent samples, but after treatment, average percentage removal in different physico-chemical parameters was observed during overall treatment operations, that is, COD (59.7-65.6%), TDS (59.6-76.8%), TSS (64.9-76.7%), and turbidity (72.7-91.6%), while pH of the effluent samples was observed in the prescribed limits. It was concluded that laboratory scale CW using natural flora Paspalidium flavidum and bacterial species was efficient in the reduction of different pollution indicators and hence a best option to be modified on pilot-scale for wastewater treatment in the rural regions of Peshawar. PRACTITIONER POINTS: Role of retention times on performance of CW were studied. The commonly existing vegetation was utilized to treat domestic waste water. Both vegetations and HRT are key ingredients in obtaining high treatment efficiency.

Thermally induced oxygen related defects in eco-friendly ZnFe2O4 nanoparticles for enhanced wastewater treatment efficiencies.

Herein, a simple but highly effective strategy of thermal annealing to modulate oxygen vacancies related defects in ZnFe2O4 (ZFO) nanoparticles for obtaining enhanced wastewater treatment efficiencies is reported. The as-prepared nanoparticles were thermally annealed at three different temperatures (500 °C, 600 °C and 700 °C) and their phase purity was confirmed by X-ray diffraction (XRD). All samples were found to exhibit pure phases of ZFO with different crystallite sizes ranging from 10 nm to 25 nm. The transmission electron microscope (TEM) images showed well dispersed nanoparticles and a strong correlation of grain size growth with annealing temperature was established. The optical absorption and emission characteristics were estimated through UV-visible and Photoluminescence (PL) spectroscopy. Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS) confirmed the variation of oxygen vacancies in the synthesized samples' lattice. The photocatalytic activities of all samples were investigated and the highest efficiencies were recorded for the ZFO samples annealed at 500 °C. Under high salinity condition, the organic dye degradation efficiency of the same sample remained the highest among all. The excellent dye degradation abilities in ZFO samples can be attributed to the abundance of oxygen vacancies in the crystal lattice that slow down the recombination rate during the photocatalysis process. Moreover, cytotoxicity tests revealed that all prepared ZFO samples showed insignificant cell structure effects on Picochlorum sp microalgae, as verified by Fourier-transform infrared (FTIR) spectroscopy. On the other hand, no significant changes were detected on the viable cell concentration and Chlorophyll a content. This work presents a systematic way to finely tune the crystal sizes and to modulate oxygen related defects in ZFO through a highly effective annealing approach to signify their potential in industrial wastewater and seawater treatment processes.

Environmental impact assessment of plastic waste during the outbreak of COVID-19 and integrated strategies for its control and mitigation.

During the COVID-19 pandemic, many positive shifts have been observed in the ecosystem, with a significant decrease in the greenhouse gas emissions and air pollution. On the other hand, there were unavoidable negative shifts due to a surge in demand for plastic products such as food and groceries' delivery packaging, single-use plastics, medical and personal protective equipment to prevent transmission of COVID-19. Plastic pollution can be considered as a key environmental issue in world due to the huge footprints of plastics on natural ecosystems and public health. Herein, we presented an overview on the rise of plastic pollution during the COVID-19 pandemic. The potential sources of plastic waste during COVID-19 with its negative effects on the environment such as marine ecosystems and the global economics are highlighted. We also suggested some strategies and recommendations to tackle plastic leakages by applying feedstock recycling, sterilization, and with the use of biodegradable plastics that have become a sustainable alternative to fossil fuel plastics. Also, the importance of elevating public awareness and some recommendations to mitigate plastic generated during the pandemic has been addressed as well.

Optimization of biosurfactant production from Pseudomonas sp. CQ2 and its application for remediation of heavy metal contaminated soil.

The present study was conducted to enhance the biosurfactant production yield of Pseudomonas sp. CQ2 isolated from the Chongqing oilfield (China). Besides, the capability of biosurfactant and underlying mechanism for remediation of heavy metal contaminated soil was also investigated. Our results suggested that maximum biosurfactant production (40.7 g/L) was attained at 35 °C by using soybean oil and ammonium nitrate as carbon and nitrogen sources with pH 7, rotational speed of 175 rpm and inoculation ratio of 3%). The removal efficiencies of 78.7, 65.7 and 56.9% for Cd, Cu and Pb respectively were achieved at optimized bioleaching conditions (pH: 11, soil/solution ratio: 30:1 and non-sterilized soil), comparative tests between common chemical surfactants (SDS, Tween-80) and biosurfactants demonstrated the larger removal capacity of biosurfactants. Through SEM-EDX, it was found that the granular material disappeared, the content of Cd, Cu and Pb decreased significantly, and the soil surface became smooth with hole formation after soil washing following bioleaching. ATR-FTIR results showed that the carboxyl functional groups in biosurfactants could chelate heavy metals. These results indicated that biosurfactants from Pseudomonas sp. CQ2 could effectively eliminate Cd, Cu, and Pb from soil.

Genome sequence of Epibacterium ulvae strain DSM 24752T, an indigoidine-producing, macroalga-associated member of the marine Roseobacter group.

Strain U95T (= DSM 24752T = LMG 26464T) is the type strain of Epibacterium ulvae, which is the type species of the genus Epibacterium. This genus belongs to the marine Roseobacter group. E. ulvae Strain U95T was isolated from the macroalga Ulva australis, is Gram-negative, rod-shaped and motile. Here we describe the permanent draft genome sequence and annotation of E. ulvae U95T with a focus on secondary metabolite production and interaction with its host. The genome contains 4,092,893 bp, 3977 protein-coding genes and 60 RNA genes. The genome encodes a gene cluster for synthesis of the blue-pigmented secondary metabolite indigoidine and contains several genes for adhesion mechanisms, putative bacteriocin, siderophores, a type VI secretion system, and enzymes that confer oxidative stress resistance. Combined, these features may aid in the successful colonization and persistence of E. ulvae on host surfaces and in competition with the surrounding microbial consortium.

Isolation of anticancer and antimicrobial metabolites from Epicoccum nigrum; endophyte of Ferula sumbul.

Owing to the importance of endophytes, current research was aimed to purify the secondary metabolites from targeted source. Ferula sumbul, a lipophilic extract of the endophyte was prepared in 10% methanol and partitioned with ethyl acetate and bioassay guided isolation was carried using standard protocols against bacterial, fungal and cancer cells. The active fractions consisted of three new metabolites (2-methyl-3-nonyl prodiginine, Bis (2-ethylhexyl) phthalate, and a meroterpenoid, Preaustinoid A). Their structures were confirmed with LCMS/MS. The purified metabolites showed valuable results against tested activities which concluded that these compounds have great potential and these may be applicable to textile (dyeing), pharmaceutical (drug, infectious agents) and food (preservatives) industries. This study reveals the potential of E. nigrum as an important source of bioactive compounds including 2-methyl-3-nonyl prodiginine, Bis (2-ethylhexyl) phthalate, and Preaustinoid A. This is first report of isolation of prodiginines as well as meroterpenoid and Bis (2-ethylhexyl) phthalate from Epicoccum nigrum.

Performance Evaluation of Integrated Constructed Wetland for Domestic Wastewater Treatment.

Simple, budget friendly, laboratory-scale integrated constructed wetland (ICW) was designed to assess domestic wastewater treatment performance at a loading rate of 75 mm/d, planted with native plant species: Veronica-angallis aquatica and compared with non-vegetative control system at various residence times of 4, 8, 12, 16, 20, 24, and 28 days. Results revealed that the vegetated ICW demonstrated superior performance over non-vegetated control: 69.12 vs 17.12%, 67.77 vs 16.04%, 68 vs 16.48%, 71.19 vs 6.56%, 71.54 vs 14.80%, and 72.04 vs 11.41% for total dissolved solids, total suspended solids, phosphates (PO4(-)), sulfate (SO4(-)), nitrate (NO3(-)), and nitrite (NO2(-)), respectively, at 20 days residence times. Reduction in bacterial counts (2.79 × 10(4) CFU/mL) and fecal pathogens (345.5 MPN index/100 mL) was observed in V. aquatica at 20 days residence time. Therefore, the present study highlights not only the presence of vegetation but also appropriate residence time in constructed wetlands for better performances.

Phenazine virulence factor binding to extracellular DNA is important for Pseudomonas aeruginosa biofilm formation.

Bacterial resistance to conventional antibiotics necessitates the identification of novel leads for infection control. Interference with extracellular phenomena, such as quorum sensing, extracellular DNA integrity and redox active metabolite release, represents a new frontier to control human pathogens such as Pseudomonas aeruginosa and hence reduce mortality. Here we reveal that the extracellular redox active virulence factor pyocyanin produced by P. aeruginosa binds directly to the deoxyribose-phosphate backbone of DNA and intercalates with DNA nitrogenous base pair regions. Binding results in local perturbations of the DNA double helix structure and enhanced electron transfer along the nucleic acid polymer. Pyocyanin binding to DNA also increases DNA solution viscosity. In contrast, antioxidants interacting with DNA and pyocyanin decrease DNA solution viscosity. Biofilms deficient in pyocyanin production and biofilms lacking extracellular DNA show similar architecture indicating the interaction is important in P. aeruginosa biofilm formation.

Influence of calcium in extracellular DNA mediated bacterial aggregation and biofilm formation.

Calcium (Ca(2+)) has an important structural role in guaranteeing the integrity of the outer lipopolysaccharide layer and cell walls of bacterial cells. Extracellular DNA (eDNA) being part of the slimy matrix produced by bacteria promotes biofilm formation through enhanced structural integrity of the matrix. Here, the concurrent role of Ca(2+) and eDNA in mediating bacterial aggregation and biofilm formation was studied for the first time using a variety of bacterial strains and the thermodynamics of DNA to Ca(2+) binding. It was found that the eDNA concentrations under both planktonic and biofilm growth conditions were different among bacterial strains. Whilst Ca(2+) had no influence on eDNA release, presence of eDNA by itself favours bacterial aggregation via attractive acid-base interactions in addition, its binding with Ca(2+) at biologically relevant concentrations was shown further increase in bacterial aggregation via cationic bridging. Negative Gibbs free energy (ΔG) values in iTC data confirmed that the interaction between DNA and Ca(2+) is thermodynamically favourable and that the binding process is spontaneous and exothermic owing to its highly negative enthalpy. Removal of eDNA through DNase I treatment revealed that Ca(2+) alone did not enhance cell aggregation and biofilm formation. This discovery signifies the importance of eDNA and concludes that existence of eDNA on bacterial cell surfaces is a key facilitator in binding of Ca(2+) to eDNA thereby mediating bacterial aggregation and biofilm formation.

Interface thermodynamic state-induced high-performance memristors.

A new class of memristors based on long-range-ordered CeO2 nanocubes with a controlled degree of self-assembly is presented, in which the regularity and range of the nanocubes can be greatly improved with a highly concentrated dispersed surfactant. The magnitudes of the hydrophobicity and surface energy components as functions of surfactant concentration were also investigated. The self-assembled nanostructure was found to demonstrate excellent degradation in device threshold voltage with excellent uniformity in resistive switching parameters, particularly a set voltage distribution of ∼ 0.2 V over 30 successive cycles and a fast response time for writing (0.2 µs) and erasing (1 µs) operations, thus offering great potential for nonvolatile memory applications with high performance at low cost.

The roles of extracellular DNA in the structural integrity of extracellular polymeric substance and bacterial biofilm development.

Bacteria adhere to natural and engineered surfaces and develop into mature biofilms encased in self-produced extracellular polymeric substances (EPSs). EPS consists of polysaccharides, proteins, metabolites and extracellular DNA (eDNA). Extracellular DNA release by bacteria is mediated by both quorum-sensing (QS)-dependent and -independent mechanisms. Quorum-sensing-independent mechanisms are responsible for basal levels of eDNA release, whereas QS-dependent mechanisms control the production of prophages, phenazines and proteins involved in cell lysis and subsequent release of elevated amounts of eDNA. Extracellular DNA binds with other biopolymers such as polysaccharides, proteins or metabolites like phenazines, thereby providing structural integrity to EPS. Extracellular DNA promotes attractive acid-base interactions between bacterial cells and between bacteria and surfaces. It therefore plays an essential structural role in stabilising biofilms and protecting bacterial cells from physical and chemical challenges. Accordingly, with current knowledge, it becomes clear that targeting and destroying eDNA in bacterial EPS is a promising strategy for treatment of bacterial-associated infections in a medical context and biofilm control on surfaces to prevent biocorrison in an engineering context. In contrast, the addition of DNA can be applied to engineering of biofilms for beneficial purposes such as remediation of environmental pollutants and electricity or fuel production in bioelectrochemical systems or bioreactors.

Reduction of Contaminants (Physical, Chemical, and Microbial) in Domestic Wastewater through Hybrid Constructed Wetland.

The current research was focused mainly on the designing and construction of efficient laboratory scale hybrid constructed wetland (HCW) for the treatment of domestic wastewater. Parameters like COD, BOD5, PO4, SO4, NO3, NO2, and pathogenic indicator microbes were monitored after hydraulic retention time (HRT) of 4, 8, 12, 16, and 20 days. Treatment efficiency of HCW kept on increasing with the increase in hydraulic retention time. Maximum efficiency of HCW was observed with a 20-day HRT, that is, 97.55, 97.5, 89.35, 80.75, 96.04, 91.52, and 98.6% reduction from the zero time value for COD, BOD5, PO4, SO4, NO3, NO2, and fecal coliforms, respectively. After 20 days' time, the treated water was free of almost all nutrients and microbial pollutants. Hence, increasing hydraulic retention time was found to ameliorate the operational competence of HCW. Thus HCW can serve as a promising technology for wastewater treatment and can be scaled up for small communities in the developing countries.

Analysis of elemental concentration using ICP-AES and pathogen indicator in drinking water of Qasim Abad, District Rawalpindi, Pakistan.

The present study was conducted to investigate drinking water quality (groundwater) from water samples taken from Qasim Abad, a locality of approximately 5,000 population, situated between twin cities Rawalpindi and Islamabad in Pakistan. The main sources of drinking water in this area are water bores which are dug upto the depth of 250-280 ft in almost every house. The study consists of the determination of physico-chemical properties, trace metals, heavy metals, rare earth elements and microbiological quality of drinking water. The data showed the variation of the investigated parameters in samples as follows: pH 6.75 to 8.70, electrical conductivity 540 to 855 µS/cm, total dissolved solids 325.46 to 515.23 ppm and dissolved oxygen 1.50 to 5.64 mg/L which are within the WHO guidelines for drinking water quality. The water samples were analysed for 30 elements (aluminium, iron, magnesium, manganese, silicon, zinc, molybdenum, titanium, chromium, nickel, tungsten, silver, arsenic, boron, barium, beryllium, cadmium, cobalt, copper, gallium, mercury, lanthanum, niobium, neodymium, lead, selenium, samarium, tin, vanadium and zirconium) by using inductively coupled plasma atomic emission spectroscopy. The organic contamination was detected in terms of most probable number (MPN) of faecal coliforms. Overall, elemental levels were lower than the recommended values but three water bores (B-1, B-6, B-7) had higher values of iron (1.6, 2.206, 0.65 ppm), two water bores (B-1, B-6) had higher values of aluminium (0.95, 1.92 ppm), respectively, and molybdenum was higher by 0.01 ppm only in one water bore (B-11). The total number of coliforms present in water samples was found to be within the prescribed limit of the WHO except for 5 out of 11 bore water samples (B-2, B-3, B-4, B-8, B-11), which were found in the range 5-35 MPN/100 mL, a consequence of infiltration of contaminated water (sewage) through cross connection, leakage points and back siphoning.