The ameliorative role of Aloe vera-loaded chitosan nanoparticles on Staphylococcus aureus induced acute lung injury: Targeting TLR/NF-κB signaling pathways.

Background: Acute lung injury (ALI) is a severe condition distinguished by inflammation and impaired gas exchange in the lungs. Staphylococcus aureus, a common bacterium, can cause ALI through its virulence factors. Aloe vera is a medicinal plant that has been traditionally used to treat a variety of illnesses due to its anti-inflammatory properties. Chitosan nanoparticles are biocompatible and totally biodegradable materials that have shown potential in drug delivery systems. Aim: To explore the antibacterial activity of Aloe vera-loaded chitosan nanoparticles (AV-CS-NPs) against S. aureus in vitro and in vivo with advanced techniques. Methods: The antibacterial efficacy of AV-CS-NPs was evaluated through a broth microdilution assay. In addition, the impact of AV-CS-NPs on S. aureus-induced ALI in rats was examined by analyzing the expression of genes linked to inflammation, oxidative stress, and apoptosis. Furthermore, rat lung tissue was scanned histologically. The rats were divided into three groups: control, ALI, and treatment with AV-CS-NPs. Results: The AV-CS-NPs that were prepared exhibited clustered semispherical and spherical forms, having an average particle size of approximately 60 nm. These nanoparticles displayed a diverse structure with an uneven distribution of particle sizes. The maximum entrapment efficiency of 95.5% ± 1.25% was achieved. The obtained findings revealed that The minimum inhibitory concentration and minimum bactericidal concentration values were determined to be 5 and 10 ug/ml, respectively, indicating the potent bactericidal effect of the NPs. Also, S. aureus infected rats explored upregulation in the mRNA expression of TLR2 and TLR4 compared to healthy control groups. AV-CS-NP treatment reverses the case where there was repression in mRNA expression of TLR2 and TLR4 compared to S. aureus-treated rats. Conclusion: These NPs can serve as potential candidates for the development of alternative antimicrobial agents.

Predicting Atmospheric Water-Soluble Organic Mass Reversibly Partitioned to Aerosol Liquid Water in the Eastern United States.

Water-soluble organic matter (WSOM) formed through aqueous processes contributes substantially to total atmospheric aerosol, however, the impact of water evaporation on particle concentrations is highly uncertain. Herein, we present a novel approach to predict the amount of evaporated organic mass induced by sample drying using multivariate polynomial regression and random forest (RF) machine learning models. The impact of particle drying on fine WSOM was monitored during three consecutive summers in Baltimore, MD (2015, 2016, and 2017). The amount of evaporated organic mass was dependent on relative humidity (RH), WSOM concentrations, isoprene concentrations, and NOx/isoprene ratios. Different models corresponding to each class were fitted (trained and tested) to data from the summers of 2015 and 2016 while model validation was performed using summer 2017 data. Using the coefficient of determination (R2) and the root-mean-square error (RMSE), it was concluded that an RF model with 100 decision trees had the best performance (R2 of 0.81) and the lowest normalized mean error (NME < 1%) leading to low model uncertainties. The relative feature importance for the RF model was calculated to be 0.55, 0.2, 0.15, and 0.1 for WSOM concentrations, RH levels, isoprene concentrations, and NOx/isoprene ratios, respectively. The machine learning model was thus used to predict summertime concentrations of evaporated organics in Yorkville, Georgia, and Centerville, Alabama in 2016 and 2013, respectively. Results presented herein have implications for measurements that rely on sample drying using a machine learning approach for the analysis and interpretation of atmospheric data sets to elucidate their complex behavior.

Employing of Curcumin-Silver Nanoparticle-Incorporated Sodium Alginate-Co-Acacia Gum Film Hydrogels for Wound Dressing.

Skin wound healing is time-consuming and frequently accompanied by bacterial infections and the development of scars. The rise of antibiotic-resistant bacterial strains has sparked a growing interest in naturally occurring bioactive substances, like curcumin, that possess wound-healing capabilities. Silver is a natural antimicrobial agent, and finds extensive use in specialized wound dressings. Silver nanoparticles (AgNPs) were synthesized using an eco-friendly approach, employing curcumin. The prepared nanoparticles have been characterized using TEM, DLS, and zeta potential. The prepared AgNPs were loaded on sodium alginate-co-gum arabic hydrogel. Two hydrogel samples (with and without AgNPs) have been applied for wound healing. The developed silver nanoparticles that were created exhibited effective action against both types of bacteria, namely Gram-negative and Gram-positive. Alg-co-AG-AgNPs demonstrated faster wound healing rates compared to using the control hydrogel sample. The novel dressings of curcumin-silver nanoparticle-incorporated sodium alginate-co-gum arabic hydrogels (Alg-co-AG-AgNPs) exhibited exceptional biocompatibility and have the potential to serve as a wound dressing that possesses antibacterial properties and reduces scarring.

Green Synthesized Silver Nanoparticles Loaded in Polysaccharide Hydrogel Applied to Chronic Wound Healing in Mice Models.

The prevalence of chronic wounds is increasing owing to the expanding population and the growing number of individuals suffering from diabetes. Such a chronic wound continues to be a significant healthcare burden for diabetic patients because it frequently carries a high chance of limb loss due to amputation and reduces survival as a result. Development of innovative wound dressing materials with the potential to stop bacterial infections and accelerate the process of tissue regeneration is needed to increase the effectiveness of diabetic wound healing. In the current study, a co-polymerization process based on a free radical reaction was used to create a hydrogel of polysaccharides blend graft acrylamide (PsB-g-Am). Starch, chitosan, and alginate make up the polysaccharides blend (PsB). The produced hydrogel's structure was characterized using FTIR spectroscopy. The antibacterial activities of silver nanoparticles synthesized through the green method using garlic bulb (Allium sativum) is reported. The silver nanoparticles' physical characteristics were examined using scanning electron microscopy, transmission electron microscopy analysis, and UV-visible spectroscopy and they were found to range in size from 50 to 100 nm. The agar well diffusion technique is used to investigate the antibacterial characteristics. Inclusion of silver nanoparticles in the hydrogels demonstrated concentration-dependent antibacterial behavior against Gram-negative Klebsiella pneumoniae and Gram-positive Staphylococcus aureus during antimicrobial testing of the hydrogels. When hydrogels were applied to diabetic mice, the system was examined for its healing abilities, and positive therapeutic results were obtained in as little as 14 days. Thus, it can be inferred that graft copolymer of chitosan-AgNPs hydrogels can promote healing in chronic wounds over time and can be utilized as an alternative to conventional therapies for chronic wounds (such as those brought on by diabetes) in mouse models.

Silver Nanoparticles Loaded on Chitosan-g-PVA Hydrogel for the Wound-Healing Applications.

Silver nanoparticle composites have abundant biomedical applications due to their unique antibacterial properties. In the current work, green tea leaf extract was used as a natural reducing agent to synthesize AgNPs (AgNPs) using microwave irradiation technology. Furthermore, microwave irradiation has been used for the preparation of AgNPs/chitosan (Ch) grafted polyvinyl alcohol (PVA) hydrogel samples. To approve the accomplishment of AgNPs hydrogel polymer, UV-spectrum, TEM, and FT-IR spectrum analyses and the release of silver ions, actions were taken. The wound-healing ability of the prepared hydrogel samples was measured via both the in vitro (fibroblast cells) and the in vivo using rat models. It was found that chitosan-grafted polyvinyl alcohol, including AgNPs, exhibited excellent antibacterial activity against E. coli and S. aureus using the agar diffusion method. It can be said that microwave irradiation was successful in creating a hydrogel that contained silver nanoparticles. A wound that was still open was successfully treated with these composites.

Aqueous processing of water-soluble organic compounds in the eastern United States during winter.

Aqueous multi-phase processes are significant contributors to organic aerosol (OA) mass in the atmosphere. This study characterizes the formation of water-soluble organic matter during the winter in the eastern United States through simultaneous measurements of water-soluble organic carbon in the gas and particle phases (WSOCg and WSOCp, respectively). The formation of secondary WSOCp occurred primarily through two pathways: (1) absorptive partitioning of oxygenated organics to the bulk OA and (2) aqueous phase processes. WSOCp formation through the former pathway was evident through the relationship between the fraction of total WSOC in the particle phase (Fp) and the total OA concentration. Conversely, evidence for nighttime aqueous WSOCp formation was based upon the strong enhancement in Fp with increasing relative humidity, indicating the uptake of WSOCg to aerosol liquid water (ALW). The Fp-RH relationship was only observed for temperatures between 0-10 °C, suggesting conditions for aqueous multi-phase processes were enhanced during these times. Temperature exhibited an inverse relationship with ALW and a proportional relationship with aerosol potassium. ALW and biomass burning precursors were both abundant in the 0-10 °C temperature range, facilitating aqueous WSOCp formation. To assess the impact of particle drying on the WSOCp concentrations, the particle measurements alternated between ambient and dried channels. No change was observed in the concentration of particles before and after drying, indicating that the WSOCp formed through the uptake of WSOCg into OA and ALW remained in the condensed phase upon particle drying at all temperature ranges. This work contributes to our understanding of sources, pathways, and factors affecting aqueous aerosol formation in the winter.

Reverse Osmosis Membrane Zero Liquid Discharge for Agriculture Drainage Water Desalination: Technical, Economic, and Environmental Assessment.

Agricultural drainage water (ADW) represents a potential source for fresh water after receiving appropriate treatments to satisfy the water quality requirements. Desalination of ADW with medium salinity and moderate contamination with organic and inorganic chemical pollutants could provide a techno-economically feasible approach for facing water scarcity in arid areas. The current work presents a conceptual zero liquid discharge ADW desalination system proposed to treat 300,000 m3/d. The system is based on pretreatment to remove impurities harmful to desalination by staged reverse osmosis (RO) membrane. The brine from the last RO stage is treated via thermal vapor compression followed by evaporation in solar ponds to recover more fresh water and salts of economic value. The essential technical features of the proposed system components are formulated. The proposed system components and its technical and economic indicators are deduced using available software for water pretreatment, RO membrane, desalination, thermal desalination, and solar evaporation ponds. The system provides total distilled water recovery of about 98% viz. 294,000 m3/d in addition to recovered salts of 245,000 t/y. The net cost of water production amounts to USD 0.46 /m3. The environmental considerations of the system are addressed and advantages of applying zero liquid discharge system are elucidated.

The breathing human infrastructure: Integrating air quality, traffic, and social media indicators.

Outdoor air pollution is a complex system that is responsible for the deaths of millions of people annually, yet the integration of interdisciplinary data necessary to assess air quality's multiple metrics is still lacking. This case study integrates atmospheric indicators (concentrations of criteria pollutants including particulate matter and gaseous pollutants), traffic indicators (permanent traffic monitoring station data), and social indicators (community responses in Twitter archives) representing the interplay of the three critical pillars of the United Nations' Triple Bottom Line: environment, economy, and society. During the watershed moment of the COVID-19 pandemic lockdowns in Florida, urban centers demonstrated the gaps and opportunities for understanding the relationships, through correlations rather than causations, between urban air quality, traffic emissions, and public perceptions. The relationship between the perception and the traffic variables were strongly correlated, however no correlation was observed between the perception and actual air quality indicators, except for NO2. These observations might consequently infer that traffic serves as people's proxy for air quality, regardless of actual air quality, suggesting that social media messaging around asthma may be a way to monitor traffic patterns in areas where no infrastructure currently exists or is prohibited to build. It also indicates that people are less likely to be reliable sensors to accurately measure air quality due to bias in their observations of traffic volume and/or confirmation biases in broader social discourse. Results presented herein are of significance in demonstrating the capacity for interdisciplinary studies to consider the predictive capacities of social media and air pollution, its use as both lever and indicator of public support for air quality legislation and clean-air transitions, and its ability to overcome limitations of surface monitoring stations.

A mouse model for studying the effect of blood anti-PEG IgMs levels on the in vivo fate of PEGylated liposomes.

The presence of anti-polyethylene glycol (PEG) antibodies in the systemic circulation might have potential implications for the therapeutic activity of PEGylated products in vivo in the clinic. In order to study the effect of pre-existing anti-PEG antibodies on the in vivo fate and the therapeutic efficiency of PEGylated therapeutics, we developed a BALB/c mouse model by virtue of the intraperitoneal (i.p.) inoculation of hybridoma cells (HIK-M09 and HIK-M11), secreting monoclonal anti-PEG IgM, mimicking the presence of pre-existing anti-PEG antibodies in the blood. In the model, the titers of anti-PEG IgM in the blood increased as a function of hybridoma cells numbers and time after i.p. inoculation. The in vivo levels of anti-PEG IgM decreased in a dose-dependent manner, following i.v. administration of empty PEGylated liposomes. C26 tumor-bearing mice with measurable levels of anti-PEG IgM, receiving i.v. injection of DiR-labeled empty PEGylated liposomes, showed lower levels of liposomal tumor accumulation and higher levels of liver and spleen accumulation, compared to C26 tumor-bearing mice without measurable anti-PEG IgM. This specifies that the presence of anti-PEG IgM in the murine circulation induced accelerated blood clearance of PEGylated liposomes and reduced their tumor accumulation. The biodistribution and antitumor efficacy of commercially available doxorubicin (DXR)-containing PEGylated liposomes, Doxil®, were scrutinized in the anti-PEG IgM mouse model. In C26 tumor-bearing mice having circulating anti-PEG IgM, at 24 h after injection almost no DXR was observed in blood and tumor, and increased DXR accumulation was observed in spleen and liver, compared to tumor-bearing mice with no circulating anti-PEG IgM. The antitumor efficacy of Doxil® was significantly compromised in the C26 tumor-bearing mice in the presence of anti-PEG IgM. These results demonstrate that the anti-PEG IgM mouse model could be a useful prognostic indicator for the therapeutic effectiveness of different formulations of PEGylated therapeutics in pre-clinical studies.

On the impact of the COVID-19 pandemic on air quality in Florida.

Since early 2020, the world has faced an unprecedented pandemic caused by the novel COVID-19 virus. In this study, we characterize the impact of the lockdown associated with the pandemic on air quality in six major cities across the state of Florida, namely: Jacksonville, Tallahassee, Gainesville, Orlando, Tampa, and Miami. Hourly measurements of PM2.5, ozone, NO2, SO2, and CO were provided by the US EPA at thirty sites operated by the Florida Department of Environmental Protection during mid-February to mid-April from 2015 through 2020. To analyze the effect of the pandemic, atmospheric pollutant concentrations in 2020 were compared to historic data at these cities during the same period from 2015 to 2019. Reductions in NO2 and CO levels were observed across the state in most cities and were attributed to restrictions in mobility and the decrease in vehicle usage amid the lockdown. Likewise, decreases in O3 concentrations were observed and were related to the prevailing NOx-limited regime during this time period. Changes in concentrations of SO2 exhibited spatial variations, concentrations decreased in northern cities, however an increase was observed in central and southern cities, likely due to increased power generation at facilities primarily in the central and southern regions of the state. PM2.5 levels varied temporally during the study and were positively correlated with SO2 concentrations during the lockdown. In March, reductions in PM2.5 levels were observed, however elevations in PM2.5 concentrations in April were attributed to long-range transport of pollutants rather than local emissions. This study provides further insight into the impacts of the COVID-19 pandemic on anthropogenic sources from vehicular emissions and power generation in Florida. This work has implications for policies and regulations of vehicular emissions as well as consequences on the use of sustainable energy sources in the state.

Flurbiprofen-loaded niosomes-in-gel system improves the ocular bioavailability of flurbiprofen in the aqueous humor.

The present work aimed to prolong the contact time of flurbiprofen (FBP) in the ocular tissue to improve the drug anti-inflammatory activity. Different niosome systems were fabricated adopting thin-film hydration technique and using the nonionic surfactant Span 60. The morphology of the prepared niosomes was characterized by scanning electron microscopy (SEM). Physical characterization by differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy were conducted for the optimized formula (F5) that was selected on the basis of percent entrapment efficiency, vesicular size and total lipid content. F5 was formulated as 1% w/w Carpobol 934 gel. Pharmacokinetic parameters of FBP were investigated following ocular administration of F5-loaded gel system, F5 niosome dispersion or the corresponding FBP ocular drops to albino rabbits dispersion. Anti-inflamatory effect of F5-loaded carbopol gel was investigated by histopathological examination of the corneal tissue before and after the treatment of inflamed rabbit eye with the system. Results showed that cholesterol content, surfactant type. and total lipid contents had an apparent impact on the vesicle size of the formulated niosomes. Physical characterization revealed reduced drug crystallinity and incidence of interaction with other niosome contents. F5-loaded gel showed higher Cmax, area under the curve (AUC0-12), and thus higher ocular bioavailability than those of the corresponding FBP ocular solution. F5-loaded gel showed a promising rapid anti-inflammatory effect in the inflamed rabbit eye. These findings will eradicate the necessity for frequent ocular drug instillation and thus, improve patient compliance.

Drying-Induced Evaporation of Secondary Organic Aerosol during Summer.

This study characterized the effect of drying on the concentration of atmospheric secondary organic aerosol (SOA). Simultaneous measurements of water-soluble organic carbon in the gas (WSOCg) and particle (WSOCp) phases were carried out in Baltimore, MD during the summertime. To investigate the effect of drying on SOA, the WSOCp measurement was alternated through an ambient channel (WSOCp) and a "dried" channel (WSOCp,dry) maintained at ∼35% relative humidity (RH). The average mass ratio between WSOCp,dry and WSOCp was 0.85, showing that significant evaporation of the organic aerosol occurred due to drying. The average amount of evaporated water-soluble organic matter (WSOM = WSOC × 1.95) was 0.6 µg m(-3); however, the maximum evaporated WSOM concentration exceeded 5 µg m(-3), demonstrating the importance of this phenomenon. The systematic difference between ambient and dry channels indicates a significant and persistent source of aqueous SOA formed through reversible uptake processes. The wide-ranging implications of the work are discussed, and include: new insight into atmospheric SOA formation; impacts on particle measurement techniques; a newly identified bias in PM2.5 measurements using the EPA's Federal Reference and Equivalent Methods (FRM and FEM); atmospheric model evaluations; and the challenge in relating ground-based measurements to remote sensing of aerosol properties.