Estimating Moisture Content of Sausages with Different Types of Casings via Hyperspectral Imaging in Tandem with Multivariate

The moisture levels in sausages that were stored for 16 days and added with different concentrations of orange extracts to a modification solution were assessed using response surface methodology (RSM). Among the 32 treatment matrixes, treatment 10 presented a higher moisture content than that of treatment 19. Spectral pre-treatments were employed to enhance the model's robustness. The raw and pre-processed spectral data, as well as moisture content, were fitted to a regression model. The RSM outcomes showed that the interactive effects of [soy lecithin concentration] × [soy oil concentration] and [soy oil concentration] × [orange extract addition] on moisture were significant (p < 0.05), resulting in an R2 value of 78.28% derived from a second-order polynomial model. Hesperidin was identified as the primary component of the orange extracts using high-performance liquid chromatography (HPLC). The PLSR model developed from reflectance data after normalization and 1st derivation pre-treatment showed a higher coefficient of determination in the calibration set (0.7157) than the untreated data (0.2602). Furthermore, the selection of nine key wavelengths (405, 445, 425, 455, 585, 630, 1000, 1075, and 1095 nm) could render the model simpler and allow for easy industrial applications.

Quaternary Ammonium Compounds: A Chemical Class of Emerging Concern.

Quaternary ammonium compounds (QACs), a large class of chemicals that includes high production volume substances, have been used for decades as antimicrobials, preservatives, and antistatic agents and for other functions in cleaning, disinfecting, personal care products, and durable consumer goods. QAC use has accelerated in response to the COVID-19 pandemic and the banning of 19 antimicrobials from several personal care products by the US Food and Drug Administration in 2016. Studies conducted before and after the onset of the pandemic indicate increased human exposure to QACs. Environmental releases of these chemicals have also increased. Emerging information on adverse environmental and human health impacts of QACs is motivating a reconsideration of the risks and benefits across the life cycle of their production, use, and disposal. This work presents a critical review of the literature and scientific perspective developed by a multidisciplinary, multi-institutional team of authors from academia, governmental, and nonprofit organizations. The review evaluates currently available information on the ecological and human health profile of QACs and identifies multiple areas of potential concern. Adverse ecological effects include acute and chronic toxicity to susceptible aquatic organisms, with concentrations of some QACs approaching levels of concern. Suspected or known adverse health outcomes include dermal and respiratory effects, developmental and reproductive toxicity, disruption of metabolic function such as lipid homeostasis, and impairment of mitochondrial function. QACs' role in antimicrobial resistance has also been demonstrated. In the US regulatory system, how a QAC is managed depends on how it is used, for example in pesticides or personal care products. This can result in the same QACs receiving different degrees of scrutiny depending on the use and the agency regulating it. Further, the US Environmental Protection Agency's current method of grouping QACs based on structure, first proposed in 1988, is insufficient to address the wide range of QAC chemistries, potential toxicities, and exposure scenarios. Consequently, exposures to common mixtures of QACs and from multiple sources remain largely unassessed. Some restrictions on the use of QACs have been implemented in the US and elsewhere, primarily focused on personal care products. Assessing the risks posed by QACs is hampered by their vast structural diversity and a lack of quantitative data on exposure and toxicity for the majority of these compounds. This review identifies important data gaps and provides research and policy recommendations for preserving the utility of QAC chemistries while also seeking to limit adverse environmental and human health effects.

The possibility of using perfluorocarbon compounds for virus-associated pneumonia treatment

The issues of practicality in using perfluorocarbon gas transport emulsions (or pure perfluorocarbons) in severe virus-associated pneumonia treatment were considered, including those caused by coronavirus infection. Perfluorocarbons are fully fluorinated carbon compounds, on the basis of which artificial blood substitutes have been developed - gas transport perfluorocarbon emulsions for medical purposes. Perfluorocarbon emulsions were widely used in the treatment of patients in critical conditions of various genesis at the end of the last-the beginning of this century, accompanied by hypoxia, disorders of rheological properties and microcirculation of blood, perfusion of organs and tissues, intoxication, and inflammation. Large-scale clinical trials have shown a domestic plasma substitute advantage based on perfluorocarbons (perfluoroan) over foreign analogues. It is quite obvious that the inclusion of perfluorocarbon emulsions in the treatment regimens of severe virus-associated pneumonia can significantly improve this category's treatment results after analyzing the accumulated experience. A potentially useful area of therapy for acute respiratory distress syndrome is partial fluid ventilation with the use of perfluorocarbons as respiratory fluids as shown in the result of many studies on animal models and existing clinical experience. There is no gas-liquid boundary in the alveoli, as a result of which, there is an improvement in gas exchange in the lungs and a decrease in pressure in the respiratory tract when using this technique, due to the unique physicochemical properties of liquid perfluorocarbons. A promising strategy for improving liquid ventilation effectiveness using perfluorocarbon compounds is a combination with other therapeutic methods, particularly with moderate hypothermia. Antibiotics, anesthetics, vasoactive substances, or exogenous surfactant can be delivered to the lungs during liquid ventilation with perfluorocarbons, including to the affected areas, which will enhance the drugs accumulation in the lung tissues and minimize their systemic effects. However, the indications and the optimal technique for conducting liquid ventilation of the lungs in patients with acute respiratory distress syndrome have not been determined currently. Further research is needed to clarify the indications, select devices, and determine the optimal dosage regimens for perfluorocarbons, as well as search for new technical solutions for this technique.

Monitoring of the Surfactants in Surface Waters in Slovakia and the Possible Impact of COVID-19 Pandemic on Their Presence

In order to keep the home and occupational environment clean and non-infectious, the consumption of cleaners and disinfectants, including cosmetics, is increasing. Excessive use of these products results in their accumulation in the aquatic environment. Conventional wastewater treatment plants are unable to effectively remove the emergent pollutants, including personal care products. This article is focused on the monitoring of the presence of personal care products in surface waters in two river basins in the Slovak Republic, in terms of the surfactant content. Ecotoxicological evaluation of the selected samples from the monitored river basins was performed by an acute toxicity test using the test organism Daphnia magna. The monitoring results indicate the presence of personal care products in the aquatic environment which poses an ecological and environmental risk. Monitoring in the Hron and Nitra river basins confirmed contamination with the surfactants, to which the measures related to the COVID-19 pandemic contributed. The content of the surfactants in personal care products is significant, and their impact on the aquatic environment is not sufficiently monitored.

Chemico-Physical Properties of Some 1,1'-Bis-alkyl-2,2'-hexane-1,6-diyl-bispyridinium Chlorides Hydrogenated and Partially Fluorinated for Gene Delivery.

The development of very efficient and safe non-viral vectors, constituted mainly by cationic lipids bearing multiple charges, is a landmark for in vivo gene-based medicine. To understand the effect of the hydrophobic chain's length, we here report the synthesis, and the chemico-physical and biological characterization, of a new term of the homologous series of hydrogenated gemini bispyridinium surfactants, the 1,1'-bis-dodecyl-2,2'-hexane-1,6-diyl-bispyridinium chloride (GP12_6). Moreover, we have collected and compared the thermodynamic micellization parameters (cmc, changes in enthalpy, free energy, and entropy of micellization) obtained by isothermal titration calorimetry (ITC) experiments for hydrogenated surfactants GP12_6 and GP16_6, and for the partially fluorinated ones, FGPn (where n is the spacer length). The data obtained for GP12_6 by EMSA, MTT, transient transfection assays, and AFM imaging show that in this class of compounds, the gene delivery ability strictly depends on the spacer length but barely on the hydrophobic tail length. CD spectra have been shown to be a useful tool to verify the formation of lipoplexes due to the presence of a "tail" in the 288-320 nm region attributed to a chiroptical feature named ψ-phase. Ellipsometric measurements suggest that FGP6 and FGP8 (showing a very interesting gene delivery activity, when formulated with DOPE) act in a very similar way, and dissimilar from FGP4, exactly as in the case of transfection, and confirm the hypothesis suggested by previously obtained thermodynamic data about the requirement of a proper length of the spacer to allow the molecule to form a sort of molecular tong able to intercalate DNA.

SG-APSIC1050: Personal care formulations prove effective against evolving variants of SARS-CoV-2: Implications for public health and hygiene

Objectives: Early in the COVID-19 pandemic, global health authorities identified and emphasized the importance of practicing proper hand hygiene to reduce the transmission of SARS-CoV-2 and to diminish the chances of becoming infected. It is well established in the scientific literature that surfactants and alcohols are capable of inactivating enveloped viruses such as SARS-CoV-2. However, given the novel nature of the virus, Unilever adopted an evidence-based approach to demonstrate virucidal efficacy of marketed bar soaps, liquid handwashes, and alcohol-based hand sanitizers against the original and selected variants of SARS-CoV-2. Methods: High titers of clinically isolated and laboratory-propagated SARS-CoV-2 strains were subjected to a range of selected proprietary formulations from Unilever at end-user–relevant dilutions, temperature, and contact duration, and were tested according to the internationally recognized ASTM E-1052 test protocol. Results: All tested personal-care formulations were effective against the parental SARS-CoV-2 strain as well as the β (beta) and δ (delta) variants of concern. More specifically, bar soaps with a varying concentration of total fatty matter content and liquid handwashes with varying levels of total surfactants reduced the viral titer by >99.9% within 20 seconds. Alcohol-based hand sanitizers demonstrated >99.99% reduction of input viral load within 15 seconds of contact with the viral inoculum. Conclusions: In conclusion, we have provided empirical proof that well-designed personal-care formulations that act through generic physicochemical mechanism against the basic structure of the virus particle have high virucidal efficacy against the original and evolved SARS-CoV-2 variants. Furthermore, we argue that due to the broad-spectrum mode of action of these tested formulations, the continued practice of good hand hygiene practices with everyday products holds significant promise as an easily accessible, economic, and effective nontherapeutic public health intervention toward reducing the transmission of present and future variants of SARS-CoV-2 across communities and populations.

Can pulmonary surfactant proteins be reliable indicators of COVID-19-associated pulmonary injury?

The COVID-19 pandemic is still raging all over the world. New variants of the coronavirus emerge and infect recovered from previous infections, vaccinated, and unvaccinated subjects. One aspect remains unchanged that is the lungs are the main targets of the pandemic coronavirus. This challenging situation requires the search for reliable predictive markers of severe and complicated course of the disease. Serum surfactant proteins are known to correlate with pulmonary injury severity in numerous diseases. Measurement of such protein levels may help timely predict the risk. Surfactant proteins can also be helpful diagnostic purposes in COVID-19.

Effects of physical property changes of expelled respiratory liquid on atomization morphology

A better understanding of the fluid dynamics of disease transmission by disintegrated respiratory droplets has been the focus of great attention since the recent outbreak of COVID-19. In particular, human respiratory activities such as coughing, sneezing and even talking and eating expel a large amount of pathogen-laden droplets. Particularly, during eating or drinking, the physical properties of saliva can be changed. In this study, we investigate the atomization morphology of expelled artificial saliva mixtures from the perspective of varying fluid physical properties, specifically surface tension and dynamic viscosity. Using high-speed shadowgraph experiments on artificial saliva, we visualize and analyse the disintegration of saliva liquid sheets into ligaments and droplets. We find that the viscosity and surface tension affect the droplet size formed from expelled saliva and follow scaling laws that have been previously observed and predicted for constant shear viscosity. We conclude that the changes in physical properties of saliva induced by eating and drinking tend to favour the formation of smaller droplets during sneezing or coughing, which could drive the airborne transmission pathway of pathogens. Furthermore, we derive a theoretical model based on scaling arguments that shows the breakup time of ligaments produced from the artificial saliva mixtures is dependent on the capillary number.

Role of Surfactants Against Covid-19: A Scientific Approach

Pandemic emerged due to the spread of SARS-COV-2 has become a most serious problem faced by today's world. Even after about 8 months, neither there is any decrease in its magnitude or in the spread. In some countries, it has reached the peak of its horrors, while some countries are still forced to guess only what will be the peak maxima of number of Covid-19 patients. People are compelled to maintain social distancing, cleanliness, and high level of hygiene. Right from the beginning of this epidemic, it has been concluded that washing hands every hour with soap (surfactants) can help people to protect themselves from this disease. Surfactants can play a major role in stopping the spread of this epidemic? In this review article, the role of surfactants to stop the spread of Covid-19 has been discussed. In addition, some of the other prospects of surfactants in Covid-19 such as a drug delivery of pulmonary drugs have also been explained. © 2023 Wiley-VCH GmbH.

Cationic surfactants: A review

Cationic surfactants have gained significant interest since their introduction. Their properties and adsorption behavior onto different surfaces have driven the development of a plethora of surfactants with distinctive functionalities. This paper reviews self-assembly, intermolecular interactions, and the properties of cationic surfactants also when interacting with co-solutes, which may be small molecules or macromolecules, and surfaces. The versatile properties of single- and double-chain cationic surfactants and other special cationics such as gemini, catanionic, bolaform, amino acid- and sugar-based surfactants, are presented and discussed together with skin toxicity and environmental considerations. The effects of cationic surfactant mixing with other surfactants, polymers, proteins, and DNA are also shown and examined. We also outline established applications of cationic surfactants as disinfectants, in fabric softening, hard surface cleaning, personal care applications, road surfacing, and oil field applications, as well as emerging applications such as soft antimicrobial agents and nucleic acid delivery, which has contributed, for instance, to the enormously successful surfactant-based mRNA COVID-19 vaccines. © 2023 Elsevier B.V.

Adsorption of benzalkonium chlorides onto powdered activated carbon: mechanisms and detoxification

Because disinfectants have been essential during the COVID-19 pandemic, the global demand for benzalkonium chlorides (BACs) has significantly increased. BACs can inactivate coronaviruses, but are known as toxic. In this study, we investigated the adsorption mechanisms of BAC12, BAC14, and BAC16 in water using powdered activated carbon (PAC). The effects of the reaction time, pH, and temperature on the adsorption kinetics of BACs were examined. The adsorption reaction followed pseudo-second-order kinetics, and better fitted to the Langmuir isotherm than the Freundlich isotherm. The best adsorption of BACs was achieved at neutral pH conditions. Thermodynamic analysis revealed that adsorption of BACs onto PAC is a spontaneous and endothermic process. Competitive adsorption experiments revealed that BACs with longer alkyl chains were adsorbed more effectively onto PAC than shorter alkyl chain BACs, implying that, while the electrostatic interaction is an important adsorption mechanism for BAC12, van der Waals interaction plays a more important role during the adsorption of BAC14 and BAC16. Finally, we observed the partial detoxification (69%) BAC in adsorption treated water with PAC using a Microtox test. © 2022 Korean Society of Environmental Engineers.

Chapter 23 - Nasal and pulmonary routes of drug delivery

Nasal and pulmonary drug delivery are attractive routes for the administration of a growing number of drugs for topical and systemic treatment as well as for prevention by vaccines. This is of particular interest for drugs with poor bioavailability, as the gastrointestinal passage and hepatic first pass effect can be avoided. The development of drugs, vehicles, and devices made substantial progress. The drug delivery research is focused on transmucosal absorption enhancers such as surfactants, enzyme inhibitors, biopolymers, tight junction modulators, cyclodextrins, and gelling systems and on nasal and pulmonary carrier systems like nanoparticles, microspheres, nano- or microemulsions, and liposomes. Many approaches are still in early development and need further investigation. The trend for devices is going to nasal dry powder inhalers and smart pulmonary nebulizers. A new research area includes inhalable vaccines, biological drugs, and coronavirus treatments.

Ecological Risk Analysis for Benzalkonium Chloride, Benzethonium Chloride, and Chloroxylenol in US Disinfecting and Sanitizing Products.

Use of three topical antiseptic compounds-benzalkonium chloride (BAC), benzethonium chloride (BZT), and chloroxylenol (PCMX)-has recently increased because of the phaseout of other antimicrobial ingredients (such as triclosan) in soaps and other disinfecting and sanitizing products. Further, use of sanitizing products in general increased during the coronavirus (COVID-19) pandemic. We assessed the environmental safety of BAC, BZT, and PCMX based on best available environmental fate and effects data from the scientific literature and privately held sources. The ecological exposure assessment focused on aquatic systems receiving effluent from wastewater-treatment plants (WWTPs) and terrestrial systems receiving land-applied WWTP biosolids. Recent exposure levels were characterized based on environmental monitoring data supplemented by modeling, while future exposures were modeled based on a hypothetical triclosan replacement scenario. Hazard profiles were developed based on acute and chronic studies examining toxicity to aquatic life (fish, invertebrates, algae, vascular plants) and terrestrial endpoints (plants, soil invertebrates, and microbial functions related to soil fertility). Risks to higher trophic levels were not assessed because these compounds are not appreciably bioaccumulative. The risk analysis indicated that neither BZT nor PCMX in any exposure media is likely to cause adverse ecological effects under the exposure scenarios assessed in the present study. Under these scenarios, total BAC exposures are at least three times less than estimated effect thresholds, while margins of safety for freely dissolved BAC are estimated to be greater than an order of magnitude. Because the modeling did not specifically account for COVID-19 pandemic-related usage, further environmental monitoring is anticipated to understand potential changes in environmental exposures as a result of increased antiseptic use. The analysis presented provides a framework to interpret future antiseptic monitoring results, including monitoring parameters and modeling approaches to address bioavailability of the chemicals of interest. Environ Toxicol Chem 2022;41:3095-3115. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Evaluation of Hesperidin on Sausages Stuffed in a New Modified Casing during Long-Term Storage—A Preliminary Study

The effects of hesperidin and different casings on pH, moisture content, water-holding capacity, and total viable count (TVC) of sausages stored for 171 days were evaluated by principal component analysis (PCA) and discriminant analysis (DA). Sausages stuffed in a modified casing with treatment B (soy lecithin concentration: 1:30, soy oil concentration: 2.5%, lactic acid concentration: 21 mL/kg NaCl [solid], treated time: 90 min) had a significantly lower pH value (6.89 ± 0.01) at d 31 but higher (6.55 ± 0.03) than that of control casings at d 171 (p < 0.05). Hesperidin plays an important role in antimicrobial property that renders the sausages with modified casing by treatment A (soy lecithin concentration: 1:27.5, soy oil concentration: 1.25%, lactic acid concentration: 19.5 mL/kg NaCl [solid], treated time: 75 min) stable (p > 0.05), with the final TVC of 5.03 ± 0.10 log cfu/g. According to the PCA results, water-holding capacity has a positive correlation to pH. Moisture content was the best discriminator for differentiating sausages with control and modified casings, whilst pH was able to discriminate sausages stored after 138 days from other days.

Reduced DMPC and PMPC in Lung Surfactant Promotes SARS-CoV-2 Infection in Obesity

Background: Obesity is an established risk factor for higher SARS-CoV-2 viral loads, severe COVID-pneumonia requiring hospitalization, and worse outcomes. However, the underlying mechanisms for the increased risk are not well understood. SARS-CoV-2 is a respiratory virus with the primary route of entry through lungs, where the Spike protein of SARS-CoV-2 binds to ACE2 receptor on pneumocytes. Lung surfactant produced by type II pneumocytes plays a major role in respiratory defense against infections. Surfactant predominantly contains lipids especially phosphatidylcholines (PC) and obesity is characterized by aberrant lipid metabolism. We hypothesized that altered lipid composition in lung surfactant in obesity may promote SARS-CoV-2 infection, leading to severe COVID-disease. Methods: Lipidomic analysis of lung tissue and bronchoalveolar lavage fluid (BALF) was performed using LC-MS/MS. The effects of PCs on SARS-CoV-2 pseudovirus infection were studied in HEK293T cells with ACE2 overexpression and in Vero-E6 cells with endogenous ACE2 expression. Results: Lipidomic analysis revealed that myristic acid containing dimyristoyl-PC (DMPC) and palmitoylmirystoyl-PC (PMPC) were commonly reduced in lung tissue and BALF from high fat diet-induced obese mice. DMPC and PMPC markedly inhibited wild type and D614G mutant SARS-CoV-2 infection in HEK293T-ACE2 and Vero-E6 cells. Feeding obese mice with trimyristin, the triglycerides of myristic acid, increased DMPC and PMPC in lung surfactant. Lipid extract from BALF of trimyristin-treated obese mice reduced wild type and D614G mutant SARS-CoV-2 infection. The inhibitory effects of DMPC and PMPC on SARS-CoV-2 infection were reversed by cholesterol. Conclusions: The reduced DMPC and PMPC in lung surfactant contributes to the increased SARS-CoV-2 infection. Increasing DMPC and PMPC in lung surfactant may be an innovative strategy for preventing and treating severe COVID-disease in obesity.

Identification and quantification of bioactive compounds suppressing SARS-CoV-2 signals in wastewater-based epidemiology surveillance.

Recent SARS-CoV-2 wastewater-based epidemiology (WBE) surveillance have documented a positive correlation between the number of COVID-19 patients in a sewershed and the level of viral genetic material in the wastewater. Efforts have been made to use the wastewater SARS-CoV-2 viral load to predict the infected population within each sewershed using a multivariable regression approach. However, reported clear and sustained variability in SARS-CoV-2 viral load among treatment facilities receiving industrial wastewater have made clinical prediction challenging. Several classes of molecules released by regional industries and manufacturing facilities, particularly the food processing industry, can significantly suppress the SARS-CoV-2 signals in wastewater by breaking down the lipid-bilayer of the membranes. Therefore, a systematic ranking process in conjugation with metabolomic analysis was developed to identify the wastewater treatment facilities exhibiting SARS-CoV-2 suppression and identify and quantify the chemicals suppressing the SARS-COV-2 signals. By ranking the viral load per diagnosed case among the sewersheds, we successfully identified the wastewater treatment facilities in Missouri, USA that exhibit SARS-CoV-2 suppression (significantly lower than 5 × 1011 gene copies/reported case) and determined their suppression rates. Through both untargeted global chemical profiling and targeted analysis of wastewater samples, 40 compounds were identified as candidates of SARS-CoV-2 signal suppressors. Among these compounds, 14 had higher concentrations in wastewater treatment facilities that exhibited SARS-CoV-2 signal suppression compared to the unsuppressed control facilities. Stepwise regression analyses indicated that 4-nonylphenol, palmitelaidic acid, sodium oleate, and polyethylene glycol dioleate are positively correlated with SARS-CoV-2 signal suppression rates. Suppression activities were further confirmed by incubation studies, and the suppression kinetics for each bioactive compound were determined. According to the results of these experiments, bioactive molecules in wastewater can significantly reduce the stability of SARS-CoV-2 genetic marker signals. Based on the concentrations of these chemical suppressors, a correction factor could be developed to achieve more reliable and unbiased surveillance results for wastewater treatment facilities that receive wastewater from similar industries.

Cationic Surfactants as Disinfectants against SARS-CoV-2.

The virucidal activity of a series of cationic surfactants differing in the length and number of hydrophobic tails (at the same hydrophilic head) and the structure of the hydrophilic head (at the same length of the hydrophobic n-alkyl tail) was compared. It was shown that an increase in the length and number of hydrophobic tails, as well as the presence of a benzene ring in the surfactant molecule, enhance the virucidal activity of the surfactant against SARS-CoV-2. This may be due to the more pronounced ability of such surfactants to penetrate and destroy the phospholipid membrane of the virus. Among the cationic surfactants studied, didodecyldimethylammonium bromide was shown to be the most efficient as a disinfectant, its 50% effective concentration (EC50) being equal to 0.016 mM. Two surfactants (didodecyldimethylammonium bromide and benzalkonium chloride) can deactivate SARS-CoV-2 in as little as 5 s.

Highlights from this issue

The observation is similar to that of Ju Lee Oei and colleagues, who report an individual patient data meta-analysis of 3 randomised clinical trials comparing the effects on a composite of death or disability of initial resuscitation with 30% or 60% oxygen for preterm infants born <32 weeks gestation. See pages F437 and F386 Surfactant in late preterm and term infants Viraraghavan Vadakkencherry Ramaswamy and colleagues performed a systematic review and meta-analysis of studies of surfactant therapy for term and late preterm infants with respiratory distress syndrome. Most of the information in these more mature infants was derived from observational studies so there were issues with the level of certainty of the evidence showing that surfactant therapy decreased mortality, air leak, persistent pulmonary hypertension of the newborn, duration of ventilation and of hospital stay.

Application of surfactants for better tomorrow

Surfactants are the important class of amphiphilic species, which consists of both hydrophilic as well as hydrophobic part. They are characterized by some important properties like critical micelle concentration (CMC), charge, hydrophile-lypophile balance (HLB), aggregation, and chemical structure, which make them good emulsifying, dispersing and foaming agents. Presently, the global demand of the surfactants is on the peak due to their increased applications in detergents, paints, food emulsion, biotechnological processes, biosciences, pharmaceuticals, cosmetic products, etc. In order to prevent Corona pandemic disease, WHO and other regulatory authorities have recommended frequent use of soaps and sanitizers that makes surfactants an important class of species to be explored more in terms of their applications.

Cholesterol Significantly Affects the Interactions between Pirfenidone and DPPC Liposomes: Spectroscopic Studies

In this work, we studied the effect of as on the interaction of membrane DPPC with the key antifibrotic drug pirfenidone. Liposomal forms of pirfenidone were obtained using passive loading. The addition of cholesterol reduces the loading efficiency of pirfenidone by 10%. The main binding site of pirfenidone in DPPC liposomes is the carbonyl group: the interaction with PF significantly increases the proportion of low-hydrated carbonyl groups as revealed by ATR-FTIR spectroscopy. The phosphate group acts as an additional binding site;however, due to shielding by the choline group, this interaction is weak. The hydrophobic part of the bilayer is not involved in PF binding at room temperature. Cholesterol changes the way of interaction between carbonyl groups and pirfenidone probably because of the formation of two subpopulations of DPPC and causes a dramatic redistribution of carbonyl groups onto the degrees of hydration. The proportion of moderately hydrated carbonyl groups increases, apparently due to the deepening of pirfenidone into the circumpolar region of the bilayer. For the first time, a change in the microenvironment of pirfenidone upon binding to liposomes was shown: aromatic moiety interacts with the bilayer.