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Press-coating (also called compression coating or dry coating) consists of a second compression of an outer layer of material over a preformed tablet core. Despite being old, this technology has returned to popularity due to its widespread use in preparation of chronotherapeutic dosage forms. The literature available on press-coated tablets has mainly investigated drug release kinetics, while there is a lack of information about their mechanical properties. Here we study, for the first time, the effect of material properties and manufacturing parameters on the mechanical characteristics of press-coated tablets. Firstly, we show that the stiffness of the bare core tablets depends on the material type and, in case of viscoelastic materials, also depends on the compression pressure. We then demonstrate that less stiff (i.e. more viscoelastic) core tablets deform to a greater extent upon the second compression and thus allow the formation of less porous, harder coats and with a more homogenous density distribution. Finally, we find that changes in the mechanical properties of press-coated tablets over one month storage are almost negligible. Our data suggest that viscoelastic rather than stiff cores should be used in dry coating, as they promote the formation of more homogenous coats and with better mechanical properties. Unlabelled Image [ABSTRACT FROM AUTHOR]

Surfactants are versatile excipients, which are commonly employed in several pharmaceutical formulations as emulsifiers, stabilizing or solubilizing agents. In this field, current research is aimed at the design or discovery of amphiphilic molecules with improved characteristics in terms of safety (toxicological profile) and biological activities (e.g. antimicrobial activity, interaction with biomembranes). Quaternary ammonium surfactants derived from amino acids are one such class of compounds with significant potential for pharmaceuticals. In this work, quaternary ammonium surfactants derived from the amino acids leucine and methionine and esterified with fatty acids of different lengths (C10, C12 and C14) were synthesized. These amphiphiles were characterized in terms of critical micelle concentration (CMC) by tensiometry and conductivity measurements, cytotoxicity (MTS and LDH assay on Caco-2 and Calu-3 cell lines) and antimicrobial activity on selected Gram-positive (S. aureus and E. faecalis), Gram-negative (E. coli and P. aeruginosa) and the fungus C. albicans. The derivatives bearing a C12 or a C14 chain displayed CMC, EC 50 (from cytotoxicity assays) and minimum inhibition concentration (MIC) values that are comparable to those of benzalkonium chloride (used as reference), especially towards Gram-positive and C. albicans. On the contrary, derivatives bearing a C10 chain have higher CMC, EC 50 and MIC values, highlighting the crucial role of the hydrophobic tail in determining both physicochemical and biological properties. The C12-C14 synthesized derivatives may represent a promising alternative to benzalkonium chloride as surface active molecules and antimicrobial agents. Unlabelled Image • Quaternary ammonium cationic surfactants derived from leucine and methionine were synthesized • Physicochemical properties, cytotoxicity and antimicrobial activities are dependent on the length of the hydrocarbon chain • Derivatives with a C12 or C14 hydrocarbon chain showed cytotoxicity and antibacterial profiles comparable to BAC [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Liposomes are lamellar nanovesicles made of phospholipids of a great interest as drug delivery carriers, able to encapsulate both hydrophilic and lipophilic compounds. Some liposomal formulations have reached the market, including the doxorubicin loaded PEGylated liposomal dispersion Doxil®. The aim of the work was to investigate the possibility of concentrating liposomes through the ultrafiltration process under nitrogen pressure, using Doxil® formulation as a model. The concentrated liposomal dispersions (4x and 8x) obtained from Doxil® were characterised in terms of size evolution (dynamic light scattering), morphology (cryo-TEM) and thermal behaviour (microcalorimetry, mDSC and high-resolution ultrasonic spectroscopy, HR-US) and compared to the unloaded liposomes of the same composition. The ultrafiltration process resulted to be effective in concentrating both loaded and unloaded liposomal dispersions, which showed a particle size and thermal properties comparable to those of the non concentrated ones. Moreover, all liposomal dispersions did not show any remarkable variation in term of particle size distribution and morphology for at least 8 weeks after concentration. Altogether, results demonstrated the effectiveness in using ultrafiltration as a methodology to concentrate both loaded and unloaded liposomes without affecting the quality of the processed product. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Anise, ajowain and sea fennel essential oils (EOs) have significant mosquito larvicidal effects. • These EOs were encapsulated into stable microemulsions (MEs). • MEs were tested against Culex quinquefasciatus larvae and non-target invertebrates. • All MEs were able to exert high toxicity against mosquito larvae. • Toxicity of MEs was scarce against non-target species Daphnia magna and Eisenia fetida. Abstract The development of effective and eco-friendly pesticides to manage mosquito vector larvae is a timely and crucial challenge nowadays. Insecticide resistance is on the rise, therefore plant-borne insecticides with multiple mode of action may represent promising candidates to control insect vectors. In the present work, we encapsulated selected essential oils (EOs) from Pimpinella anisum , Trachyspermum ammi and Crithmum maritimum into highly stable microemulsions (MEs) with the aim to develop effective and eco-friendly larvicidal formulations. MEs made with both single EOs and their mixtures were tested against 3rd instar larvae of Culex quinquefasciatus, assessing acute and chronic toxicity, emergence of adults, and their impact on non-target invertebrates, i.e., Daphnia magna , Tubifex tubifex and Eisenia fetida. All MEs were able to exert toxicity against mosquito larvae, with LC 50 values in the ranges 1.45–4.01 ml L−1, along with high larval mortality and low percentage of hatched adults following short-term exposure to sublethal concentrations. Low or no mortality was observed on D. magna and E. fetida. Taken together, these results give new insights for the exploitation of plant-borne EOs as active ingredients of novel and reliable larvicidal products. [ABSTRACT FROM AUTHOR]

Hydrocolloids have been intensively investigated due to their ability to modify the rheology of the system where they are employed. They find application as thickening and gelling agents in many food, cosmetic, and pharmaceutical preparations, due to their biocompatibility and biodegradability. The present study aims to provide an exhaustive and comprehensive viscoelastic characterization of a series of hydrocolloid formulations, as function of concentration, pH, and temperature. Glucomannan, xanthan gum, tara gum, guar gum, konjac gum, and gellan gum have been analyzed at two concentrations (0.5% w/w and 1.5% w/w), using three different pH conditions (pH 1.2, 5.5, and 6.8). Their viscoelastic properties have been monitored measuring the main rheological parameters, namely, storage modulus G′ and loss modulus G′′ as function of frequency, time, and temperature. The results obtained show a clear dependence of the linear viscoelastic properties of the systems on concentration and pH, while the temperature was not a critical factor. Glucomannan, xanthan gum, tara gum, and guar gum samples prepared in phosphate buffer (pH 6.8) at the final concentration of 1.5% (w/w) have been selected as the most promising systems for further investigations, exploring the possibility of combinations to improve the rheological properties. Practical Application: Glucomannan, xanthan gum, tara gum, guar gum, konjac gum, and gellan gum have been chosen among the most common thickening agents derived from plants to perform a systematic investigation of the influence of pH, concentration, and temperature on the rheological properties of their water dispersions. The data obtained may be useful for further application of these hydrogels in the nutraceutical field as thickeners, texture modifiers, emulsifiers, stabilizers, and gelling agents. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The investigation of colloidal properties of nanosystems represents a fundamental issue for the development of nanotechnology-based medicines. The aim of this study is to combine various techniques in order to characterize more comprehensively chimeric nanovesicles composed of block or gradient block copolymers with different architectures and compositions. Several chimeric systems were prepared and the impact of the block [poly(ε-caprolactone)−poly(ethylene oxide); PEO-b-PCL] and gradient block [poly(2-methyl-2-oxazoline)-grad-poly(2-phenyl-2-oxazoline); MPOx] copolymers on the physicochemical and morphological characteristics of conventional 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes was examined. Light scattering techniques and cryo-TEM were used for the physicochemical and morphological characterization of the prepared systems. The size and the morphology were strongly related to the architecture and the composition of the polymeric compounds. Micro differential scanning calorimetry and high-resolution ultrasound spectroscopy were used for investigating the interactions between the DPPC lipids and the polymeric guest. An increase in the main transition temperature was observed for the prepared chimeric systems in comparison to DPPC liposomes. In conclusion, a detailed characterization of the colloidal behavior of chimeric liposomes can benefit from the combination of the aforementioned techniques that operate synergistically, giving information on their physicochemical and morphological characteristics as well as on their thermotropic behavior. [ABSTRACT FROM AUTHOR]

The development of effective control strategies targeting non-native ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) represents an emerging challenge. This is due both to their rapid spread into climatically suitable newly invaded regions rich in susceptible host plants and to the limited knowledge concerning sustainable management tools. In this context, the use of botanical insecticides, such as plant essential oils (EOs), is considered a promising option in Integrated Pest Management (IPM) strategies as an alternative to conventional insecticides for sustainable crop protection. Here, the impact of five EO nanoemulsions (Rosmarinus officinalis L. cultivar verbenone, Carlina acaulis L., Laurus nobilis L., Cupressus sempervirens L., and Betula alba L.) on the choice behavior, host colonization and progeny production by the invasive ambrosia beetle Xylosandrus compactus (Eichhoff) was evaluated under laboratory and semi-field conditions. The chemical composition of tested EOs was firstly evaluated by means of gas chromatography-mass spectrometry (GC-MS) analyses. Then, EO nanoemulsions were prepared and characterized through dynamic light scattering (DLS). Tested EO nanoemulsions showed single or bimodal droplet size distributions in the nanometric range. Results highlighted a significant repellent activity of R. officinalis cv. verbenone and C. acaulis EO nanoemulsions (at 3% EO concentration). However, the trend for repellence of the R. officinalis EO against the beetle was not confirmed at decreasing EO concentrations (i.e., 1% and 0.5%). Nanoemulsions based on C. acaulis EO significantly affected the beetle choices regardless of the tested EO concentration. Indeed, in no choice bioassays, a significantly lower number of individuals started infesting stems treated with these nanoemulsions. On the other hand, no effect of the EO treatment was found on the number of offspring produced by survived beetle females. The repellence by R. officinalis and C. acaulis EOs was confirmed in semi-field conditions. Overall, our findings provide new insights toward the use of R. officinalis and C. acaulis EOs as repellents of X. compactus , suggesting their future incorporation in non-chemical strategies, such as 'push-pull', as part of sustainable IPM packages targeting this invasive pest. [Display omitted] • Little is known about the use of plant essential oils for managing Xylosandrus ambrosia beetles. • Essential oils of Rosmarinus officinalis cv verbenone and Carlina acaulis alter host colonization by Xylosandrus compactus. • Nanoemulsions based on Carlina acaulis EO repelled the beetle regardless of the tested EO concentration. [ABSTRACT FROM AUTHOR]

Chitosan is a biodegradable and biocompatible natural polysaccharide that has a wide range of applications in the field of pharmaceutics, biomedical, chemical, cosmetics, textile and food industry. One of the most interesting characteristics of chitosan is its antibacterial and antifungal activity, and together with its excellent safety profile in human, it has attracted considerable attention in various research disciplines. The antimicrobial activity of chitosan is dependent on a number of factors, including its molecular weight, degree of deacetylation, degree of substitution, physical form, as well as structural properties of the cell wall of the target microorganisms. While the sole use of chitosan may not be sufficient to produce an adequate antimicrobial effect to fulfil different purposes, the incorporation of this biopolymer with other active substances such as drugs, metals and natural compounds in nanosystems is a commonly employed strategy to enhance its antimicrobial potential. In this review, we aim to provide an overview on the different approaches that exploit the antimicrobial activity of chitosan-based nanosystems and their applications, and highlight the latest advances in this field. [ABSTRACT FROM AUTHOR]

Polymeric hydrogels are common dosage forms designed for the topical administration of antimicrobial drugs to treat vaginal infections. One of the major advantages of using chitosan in these formulations is related to the intrinsic and broad antimicrobial activity exerted on bacteria and fungi by this natural polymer. Most vaginal yeast infections are caused by the pathogenic fungus Candida albicans. However, despite the anti-Candida activity towards and strains susceptibility to low molecular weight chitosan being documented, no information is available regarding the antimicrobial efficacy of mixed hydrogels in which chitosan is dispersed in a polymeric matrix. Therefore, the aim of the study is to evaluate the anti-Candida activity against eight different albicans and non-albicans strains of a mixed hydroxypropyl methylcellulose (HPMC)/chitosan hydrogel. Importantly, chitosan was dispersed in HPMC matrix either assembled in nanoparticles or in a monomolecular state to eventually correlate any variation in terms of rheological and mucoadhesive properties, as well as anti-Candida activity, with the chitosan form. Hydrogels containing 1% w/w chitosan, either as free polymer chain or assembled in nanoparticles, showed an improved mucoadhesiveness and an anti-Candida effect against all tested albicans and non-albicans strains. Overall, the results demonstrate the feasibility of preparing HPMC/CS mixed hydrogels intended for the prevention and treatment of Candida infections after vaginal administration. [ABSTRACT FROM AUTHOR]

In this work, the profile of the volatile compounds has been determined for the first time in fresh donkey milk and in donkey milk subjected to accelerated shelf-life test, freeze-drying and spray-drying processes. The effects of freeze-drying and spray-drying processes in donkey milk have been analyzed also on three representative whey proteins, β-lactoglobulin, α-lactalbumin and lysozyme, by determining the total amount, the enzymatic activity and the thermal stability. Considering the volatile compounds in fresh donkey milk, 2-heptanone, 1,3-bis (1,1-dimethylethyl)-benzene, nonanal, d -limonene, octanoic acid, and 1-octanol were detected. The accelerated shelf-life test revealed a constant increase of octanoic acid, 2-heptanone, and nonanal compared to fresh donkey milk (P < 0.001) and the appearance of ethyl octanoate, ethyl dodecanoate, 2-nonanone and 2-undecanone, indicating that these compounds may be highly eligible markers of donkey milk shelf-life. Freeze-drying and spray-drying affected β-lactoglobulin and lysozyme content in donkey milk. In particular, spray-drying process decreased significantly lysozyme enzymatic activity (58% of residual activity) and β-lactoglobulin content (6.43 mg/mL in fresh milk vs 5.51 mg/mL in spry-dried milk) due to the high temperature to which donkey milk is subjected. [ABSTRACT FROM AUTHOR]

In this study, we evaluate the influence of zein aggregation in aqueous ethanol dispersions on the properties of zein films. The effects of zein concentration, ethanol content and temperature on transmittance of zein dispersions were investigated. Dynamic light scattering was used to measure the degree of zein aggregation in the dispersions. The results indicate that particle size of zein increased with higher zein concentration, lower ethanol level and at lower temperatures. Zein films were prepared by casting from 70% and 90% aqueous ethanol dispersions at different drying temperatures and were evaluated for appearance, thermomechanical and mechanical properties. Higher ethanol levels and higher drying temperatures promoted the formation of more homogenous films. Films made from higher ethanol dispersions had lower glass transition temperatures than those made from lower ethanol dispersions. Moreover, the fragility factor classified the films as strong systems. Mechanical properties of films were measured at different drying temperatures. Stiffer and more resistant films were developed as the drying temperature increased. In conclusion, film properties can be tailored by controlling the composition of the film casting solvent and the drying temperature. Differences in film properties were found to relate to differences in initial degree of aggregation of zein dispersions. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the relationship between controlled release behaviour, swelling and initial water sorption of zein powder filled into hard gelatin capsules. Release, release rate and dissolution efficiency of various physical mixtures of zein and propranolol HCl filled into capsules were measured by dissolution testing. As the gelatin shell dissolved, zein rapidly formed a matrix, providing prolonged drug release, after an initial drug burst. Drug loading and ionic strength of the medium significantly influenced drug release. Imaging and gravimetric analysis were used to investigate matrix swelling and erosion. Zein matrices swelled like hydrophilic matrices, yet were practically non-erodible. Moreover, a strong significant positive correlation was found between matrix swelling and drug release (Pearson's correlation coefficient, r ≥ 0.9657, p -value ≤ 0.0017), suggesting that the degree of swelling governed drug release. The tensiometry test revealed that the initial ingress of media through the pores of zein powder was significantly limited by a reduction of the capillary radii of these pores, as a result of rapid polymer hydration. In conclusion, the rapid hydration of zein powder could explain the matrix formation and the controlled release observed with the capsules in the dissolution studies. Initial hydration, swelling and release behaviour were dependent on the ionic strength of the medium. [ABSTRACT FROM AUTHOR]

Recently, plant secondary metabolites have been considered for developing new generation nematicides. Carlina acaulis L. (Asteraceae) contains an essential oil (EO) exhibiting significant insecticidal activity with limited impact on beneficial aquatic and terrestrial organisms. Herein, we report the development of a C. acaulis essential oil EO (CEO)-based nanoemulsion (CEONE) for managing the phytoparasitic nematode Meloidogyne incognita. Initially, pure C. acaulis essential oil EO (CEO) was evaluated for its toxicity against second stage juveniles (J2) of M. incognita as well as for the interruption of the nematode biological cycle into the roots of artificially inoculated tomato plants. CEO was analysed through gas chromatography-mass spectrometry (GC-MS) analysis. Therefore, CEONE was developed to ameliorate CEO efficacy, and physico-chemically characterized. GC-MS showed that the tested CEO was mainly composed by the polyacetylene carlina oxide (96%). CEO exhibited significant in vivo and in vitro activity against M. incognita. Of note, CEONE was more effective in controlling nematodes into tomato infested roots. Overall, the CEO could be practically exploited for a new class of nematicidal agents. [Display omitted] • Carlina acaulis essential oil EO (CEO)-based nanoemulsion (CEONE) controls Meloidogyne incognita. • CEO contains polyacetylene carlina oxide as the predominant component (96%). • CEO significant acts on M. incognita both in in vitro and in vivo experiments. • CEONE was more effective in controlling nematodes into tomato infested roots. • CEO could be practically exploited for a new class of nematicidal agents. [ABSTRACT FROM AUTHOR]

Carlina acaulis L., belonging to the Asteraceae (Compositae) family, is a perennial herb native to the Alps, which has a long history as a food and traditional remedy , being one of the most important medicinal plants in Europe. Its reported uses go from diuretic, cholagogic, and antibacterial agent for the treatment of gastritis, skin diseases, acne, eczema, and ulcers. Even if this plant presents a rich phytocomplex, its root essential oil (EO) is the product that surely raised most research interest. It has the exceptional feature of having as main constituent the polyacetylene carlina oxide, and is currently listed among botanicals employable in food supplements in Europe. This EO and carlina oxide showed an encouraging bioactivity on a variety of bacteria and fungi, such as Staphylococcus aureus , Escherichia coli , Klebsiella pneumoniae , Pseudomonas aeruginosa , Proteus vulgaris , Candida albicans and C. glabrata. Moreover, these products showed marked insecticidal and acaricidal activities against insect pests and vectors of medical, agricultural, and economic importance, revealing to be promising in the horizon of botanical insecticides and acaricides. Its EO as well as carlina oxide resulted to be active on vectors, e.g. Culex quinquefasciatus, urban and livestock pests e.g. Musca domestica , stored product pests e.g. Acarus siro , Trogoderma granarium and Prostephanus truncatus , and agricultural pests, e.g. Lobesia botrana , Bactrocera oleae and Ceratitis capitata, among others. These insecticidal properties are also accompanied by low-to-moderate toxicity on non-target organisms such as earthworms and aquatic microcrustaceans, as well as on vertebrate cells and mammals. Innovative formulations have been developed and tested for applying these products in real-world conditions with encouraging results. Different cultivation systems of C. acaulis have been carried out, with classic field cultivation having the greatest advantage over other systems, such as hydroponic and in vitro micropropagation in terms of insecticidal and acarcicidal compound yield. This review puts a focus for the first time on C. acaulis , its active compounds and its potential against vectors, pests, and pathogens, and on current issues related to its cultivation on a large-scale level. Moreover, its biological properties and related encapsulation techniques developed are extensively reviewed. [Display omitted] • Carlina acaulis potential as a green insecticide and acaricide was reviewed. • Carlina oxide was examined as the main responsible for the insecticidal action. • Non-target toxicity was investigated. • Challenges and perspectives for the plant cultivation were considered. • The crucial role of nanoformulations for essential oil delivery was discussed. [ABSTRACT FROM AUTHOR]

Smyrnium olusatrum L. is a horticultural crop cultivated during the Roman age for culinary and curative uses. The essential oil extracted from this plant (AEO) is rich in bioactive constituents such as isofuranodiene and germacrone. Several previous studies revealed that AEO and its isolated components possess interesting therapeutic features, such as antiproliferative, neuritogenic, hepatoprotective and antioxidant properties. Nevertheless, AEO has stability problems because of the high concentration of its main components. This issue makes AEO very difficult to handle and use. Thus, AEO was formulated as microemulsions known for their thermodynamic stability and easiness of preparation. AEO was hydrodistilled from inflorescences of S. olusatrum and its composition determined by different chromatographic methods. The microemulsions were developed using a central composite design and their activity tested using the MTT assay. The present study demonstrated the possibility to formulate stable AEOmicroemulsionswhere the crystallization of isofuranodiene is avoided, and the AEO biological activity is maintained. [ABSTRACT FROM AUTHOR]

Food safety is a fundamental concern for both consumers and the food industry, especially as the numbers of reported cases of food-associated infections continue to increase. Industrial surfaces can provide a suitable substrate for the development and persistence of bacterial organized in biofilms that represent a potential source of food contamination. The negative consumer perception of chemical disinfectants has shifted the attention to natural substances, such as plant extracts. The aim of this study was to investigate the possibility of using the essential oils (EOs) in the fight against S . aureus biofilms. First, the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Biofilm Inhibitory Concentration (MBIC), Minimum Biofilm Eradication Concentration (MBEC) of eleven EOs against S . aureus were determined. Cinnamomum cassia and Salvia officinalis EOs showed the greatest antibacterial properties with 1.25% MIC and MBC, 1.25% MBIC and 2.5% MBEC respectively. Gas Chromatography/Mass Spectrometry analysis revealed cinnamaldehyde (82.66%) and methoxy cinnamaldehyde (10.12%) as the most abundant substances of C . cassia , while cis-thujone (23.90%), camphor (19.22%) and 1.8-cineole (10.62%) of S . officinalis . Three different microemulsions, formulated with C . cassia , S . officinalis or both, were finally tested against S . aureus biofilms in different culture media and growth conditions, causing a > 3 logarithmic reductions in S . aureus 24 h-old biofilms and desiccated biofilms, and up to 68% of biofilm removal after 90 min of exposure. The obtained data suggest the potential use of EOs, alone or in combination, for the formulation of sanitizers as alternative or in support in the disinfection of contaminated surfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] The abilities of sub-cellular targeting and stimuli-responsiveness are critical challenges in pharmaceutical nanotechnology. In the present study, glyceryl monooleate (GMO)-based non-lamellar lyotropic liquid crystalline nanoparticles were stabilized by the poly(2-(dimethylamino)ethyl methacrylate)- b -poly(lauryl methacrylate) block copolymer carrying tri-phenyl-phosphine cations (TPP-QPDMAEMA- b -PLMA), either used alone or in combination with other polymers as co-stabilizers. The systems were designed to perform simultaneously sub-cellular targeting, stimuli-responsiveness and to exhibit stealthiness. The physicochemical characteristics and fractal dimensions of the resultant nanosystems were obtained from light scattering techniques, while their micropolarity and microfluidity from fluorescence spectroscopy. Their morphology was assessed by cryo-TEM, while their thermal behavior by microcalorimetry and high-resolution ultrasound spectroscopy. The analyzed properties, including the responsiveness to pH and temperature, were found to be dependent on the combination of the polymeric stabilizers. The subcellular localization was monitored by confocal microscopy, revealing targeting to lysosomes. Subsequently, resveratrol was loaded into the nanosystems, the entrapment efficiency was investigated and in vitro release studies were carried out at different conditions, in which a stimuli-triggered drug release profile was achieved. In conclusion, the proposed multi-functional nanosystems can be considered as potentially stealth, stimuli-responsive drug delivery nanocarriers, with targeting ability to lysosomes and presenting a stimuli-triggered drug release profile. [ABSTRACT FROM AUTHOR]

Toxicity is one of the main concerns limiting the use of surfactants. Many efforts have been devoted to the development of new amphiphilic molecules characterized by a lower toxicological profile and environmental impact. N -acyl amino acids are a class of anionic surfactants that can find applications in different technological fields as an alternative to sulphate-based surfactants (e.g., sodium dodecyl sulphate). The understanding of the relationship between chemical structure and toxicological profile is fundamental for the disclosure of the full potential of these amphiphiles. With this aim, two series of N -acyl surfactants, with different length of the hydrophobic tails and serine or alanine as polar head, were synthesized and fully characterized. The correlation between the surface and toxicological parameters allowed highlighting the role exerted by the length of the hydrocarbon chain and the polar head on cytotoxicity. The length of the hydrocarbon chain mainly influences surface properties and toxicological parameters, while the amino acid polar head may play a key role only on cellular toxicity. Overall, our data suggest that minor differences in the polar head, not significantly affecting CMC values, may have an impact on cytotoxicity. [ABSTRACT FROM AUTHOR]

This study focuses on the evaluation of microfoam produced from processed dairy milk using the steaming function of the espresso machine as a function of temperature (30–80 °C), milk type (pasteurised or UHT), and whey protein contents. Foam characteristics, i.e., foam stability, viscosity, bubble size distribution noticeably varied depending on milk processing type and steam heating temperature. Foams made from pasteurised whole milk tended to be more stable. Bubbles in pasteurised milk foam were better distributed, especially at the temperature of 60 °C. It was observed that the optimal final temperature of steam frothing was in the range of 50 °C–60 °C. The results of sensory tests showed that consumers differentiated between the aroma and flavour of pasteurised and UHT milk, describing the degree of this difference from moderate to strong. [ABSTRACT FROM AUTHOR]

The essential oils (EOs) produced by a number of Apiaceae species are well known for their insecticidal efficacy against a wide spectrum of insects, including vectors, stored product and agricultural pests. In the real world, rawly formulated EOs are scarcely effective due to their low chemical stability, limited persistence into the environment, and poor hydrophilicity. Therefore, for practical applications they need to be encapsulated using nanocarriers. In the present study, we evaluated two novel EO-based nanoemulsions (NEs) derived from Pimpinella anisum and Trachyspermun ammi , two plants with documented insecticidal effectiveness, for the management of stored product insects causing economic damages, including Tribolium castaneum , Tribolium confusum , Tenebrio molitor , Trogoderma granarium adults or larvae, and Acarus siro adults or nymphs. The NEs were prepared by a high-pressure homogenization procedure and determined according to the distribution of particle size through dynamic light scattering. Pimpinella anisum EO resulted mainly dominated by the phenylpropanoid (E)-anethole, while T. ammi EO was mainly composed of thymol, p -cymene, and γ -terpinene. Each EO-based NE was tested at two concentrations (500 and 1000 ppm) on stored wheat. We evaluated mortality values of the arthropod pests after 4 h, 8 h, and 16 h, and daily from 1 to 7 days. Complete mortality was achieved for T. castaneum larvae on wheat sprayed with 1000 ppm of 4% (w/w) P. anisum EO-based NE after 6 days of exposure. Similarly, the 8% (w/w) T. ammi EO-based NE killed 100.0% of the tested T. confusum larvae after 7 days to 1000 ppm. When A. siro adults were exposed to 1000 ppm of the 8% (w/w) T. ammi EO-based NE, 89.4% of the tested individuals were killed after 7 days. Binary EO-based NE combination toxicity tests were also carried out. Almost all T. molitor adults (97.8%) died after 7 days to 1000 ppm of 3% (w/w) T. ammi + 3% (w/w) P. anisum EO-based NE. The 3% (w/w) T. ammi + 3% (w/w) P. anisum EO-based NE killed 98.6% of T. granarium adults after 7 days at 1000 ppm. Overall, the tested Apiaceae EO-based NEs exhibited relevant pesticidal efficacy under short exposure intervals, therefore they could be taken into account as auxiliary management tools towards the sustainable protection of durable commodities in storages. [Display omitted] • 4% (w/w) P. anisum EO-based NE killed all T. castaneum larvae after 6 days at 1000 ppm. • 8% (w/w) T. ammi EO-based NE killed all T. confusum larvae after 7 days at 1000 ppm. • 3% (w/w) T. ammi + 3% (w/w) P. anisum EO-based NE killed 97.8% T. molitor adults after 7 days at 1000 ppm. • 3% (w/w) T. ammi + 3% (w/w) P. anisum EO-based NE killed 98.6% T. granarium adults after 7 days at 1000 ppm. [ABSTRACT FROM AUTHOR]

N -acyl amino acids-based surfactants are an attractive class of anionic amphiphiles alternative to sulphate-based surfactants, potentially employed as excipients for pharmaceutical applications in which an anionic surfactant is needed. Thus, a systematic characterization of their toxicological profile is required, particularly in comparison to sodium dodecyl sulphate (SDS), a widely employed surfactant in pharmaceutical formulations. This work reported a systematic study on the relationship between the structures of N -acyl amino acids-based surfactants, their physicochemical properties and toxicological profiles. N -Decanoyl aminoacids with different polar heads (leucine, methionine, serine and proline) were synthesized and characterized in terms of surface tension and aggregation properties. Different human cell lines (Caco-2, A549, Calu-3) and erythrocytes were selected as model for oral, respiratory or parenteral administration to evaluate surfactants cytotoxicity. Moreover, the ability of surfactants to interact with cell membranes was assessed by the Trans Epithelial Electrical Resistance (TEER). Results suggested that the different polar heads affect the aggregation state and cell toxicity profiles of surfactants, but not their surface properties. According to the toxicity assays, all N -decanoyl surfactants were less toxic than SDS, suggesting that hydrophilic interactions between amphiphiles and cell membranes play a key role in determining cellular toxicity. [ABSTRACT FROM AUTHOR]

The use of process analytical technologies (PAT) to ensure final product quality is by now a well established practice in pharmaceutical industry. To date, most of the efforts in this field have focused on development of analytical methods using spectroscopic techniques (i.e., NIR, Raman, etc.). This work evaluated the possibility of using the parameters derived from the processing of in-line raw compaction data (the forces and displacement of the punches) as a PAT tool for controlling the tableting process. To reach this goal, two commercially available formulations were used, changing the quantitative composition and compressing them on a fully instrumented rotary pressing machine. The Heckel yield pressure and the compaction energies, together with the tablets hardness and compaction pressure, were selected and evaluated as discriminating parameters in all the prepared formulations. The apparent yield pressure, as shown in the obtained results, has the necessary sensitivity to be effectively included in a PAT strategy to monitor the tableting process. Additional investigations were performed to understand the criticalities and the mechanisms beyond this performing parameter and the associated implications. Specifically, it was discovered that the efficiency of the apparent yield pressure depends on the nominal drug title, the drug densification mechanism and the error in pycnometric density. In this study, the potential of using some parameters derived from the compaction raw data has been demonstrated to be an attractive alternative and complementary method to the well established spectroscopic techniques to monitor and control the tableting process. The compaction data monitoring method is also easy to set up and very cost effective. [ABSTRACT FROM AUTHOR]

Horsemint, Mentha longifolia (L.) Huds. (Lamiales: Lamiaceae), is a member of the genus Mentha , widely used for the repellent and insecticidal effectiveness of its essential oil (EO). Several chemotypes have been reported for this species. Here, the efficacy of a M. longifolia EO, belonging to the piperitenone oxide-type, and a 10% (w/w) M. longifolia EO-based nanoemulsion (NE) were examined as wheat protectants, at 500 and 1000 ppm (μL/kg). The two products were tested against four insect and a mite species, i.e., the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), the yellow mealworm beetle, Tenebrio molitor (L.) (Coleoptera: Tenebrionidae), the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), and the flour mite, Acarus siro L. (Sarcoptiformes: Acaridae). The NE showed a mean hydrodynamic diameter below 200 nm after preparation and no relevant changes in particle size distribution at least up to 4 months. The highest concentration of M. longifolia EO was the most effective grain protectant, causing 84.4% and 100% mortality to T. castaneum adults and larvae respectively, 42.2% and 100% mortality to T. confusum adults and larvae respectively, 100% and 34.4% mortality to T. molitor adults and larvae respectively, 100% mortality to both adults and larvae of O. surinamensis , and 87.8% and 67.8% mortality to A. siro adults and nymphs, respectively. Tribolium castaneum larvae were controlled by 500 ppm of the EO and 1000 ppm of the NE, which caused 100% and 93.3% mortality, respectively. Similarly, 1000 ppm NE caused 96.7% mortality against T. confusum larvae, while 500 ppm EO and 1000 ppm NE killed 90.0% and 91.1% of T. molitor adults, respectively. Complete mortality (100%) of O. surinamensis adults was achieved by 500 ppm EO. The findings of the current study suggest that the M. longifolia EO and the M. longifolia EO-based NE may be considered as promising alternative wheat protectants against different insect and mite storage pests, depending on their developmental stage. [Display omitted] • Mentha longifolia EO killed all Tribolium castaneum larvae after 1 day at 500 ppm. • Mentha longifolia EO killed 100% of T. confusum larvae after 4 days at 1000 ppm. • Mentha longifolia EO killed all Tenebrio molitor adults 5 days post-exposure to 1000 ppm. • All Oryzaephilus surinamensis adults and larvae were dead within 2 days at 1000 ppm EO. • Both M. longifolia EO and NE killed >80% Acarus siro adults within 7 days at 1000 ppm. [ABSTRACT FROM AUTHOR]

[Display omitted] Hand sanitizers represent a primary measure for the prevention of transmissible infections, whose use has been greatly increased during CoViD-19 pandemic. Most of the commercially available products are hydrogels, employing carbomers as thickening agents. However, few information is still available regarding performances of carbomers in hydroalcoholic media containing a percentage of alcohols ≥ 60% v/v as recommended for disinfection. The aim of this study was to investigate the colloidal behaviour of carbomer 974 and carbomer 980 in hydroalcoholic media containing from 50 to 80% w/w of alcohol (ethanol or isopropanol) and neutralised with triethanolamine or aminomethyl propanol. Both carbomers provide transparent hydrogels in water, but carbomer 980 should be preferred for the formulation of hydrogel with a percentage of alcohol ≥ 50% w/w for its better solvation. The critical alcohol concentration (CAlC), above which polymer precipitation occurs, depends on the type of alcohol and base used. Carbomer dispersions with a higher content of alcohol can be prepared using aminomethyl propanol rather than triethanolamine. The choice of the more suitable components is fundamental for the isopropanol-based dispersions since the CAlC is closer to the recommended concentrations for disinfection. Overall, these results provide helpful insights for the correct preparation of alcohol-based hand sanitizers using carbomers. [ABSTRACT FROM AUTHOR]

Soluplus® is a graft copolymer, with PEG and vinylcaprolactam/vinyl acetate side chains, recently available as excipient used to promote fast drug release in pharmaceutical dosage forms and as solubility enhancer. Despite this copolymer is reported to be able to act as a thickening additive and even as gelling agent as a function of temperature, there is a lack of information about the physical-chemical properties of its water dispersions. Thus, the aim of this paper is to investigate the influence of Soluplus® concentration and experimental temperature on the modification of the rheological properties of Soluplus® water dispersions. The results clearly indicated the influence of both the studied parameters and of their interactions on the Soluplus® thickening ability. Although some systems appear gel by human perception at 37 °C, the mechanical spectra demonstrated the lack of the formation of a tridimensional network structure. Overall, in all the analyzed temperatures and concentrations, the systems always behave as a 'rheological' dilute or semidilute polymer solution. [ABSTRACT FROM AUTHOR]

Highlights: [•] Influence of inorganic salts on the micellisation of Poloxamer 407. [•] Deeper understanding of the micellisation process by using different techniques. [•] Anions act as “structure makers”, by straightening water–water interactions. [•] Ions enhance the whole gain in entropy during micellisation. [•] The change of the water molecules order is the real driving force of the process. [ABSTRACT FROM AUTHOR]

Abstract: The physicochemical and rheological properties of chitosan and two different inorganic sodium phosphate dispersions (NaH2PO4 and Na3PO4) were investigated in order to elucidate the role of different factors, such as ratios between polymer and sodium inorganic phosphates, different pHs and storage stability, on the gelling properties of chitosan. This was deemed opportune since physico-chemical characterizations of chitosan in the literature often appear incomplete and questionable. We also compared the elastic modulus values of the different chitosan/inorganic phosphate systems and examined their behaviour through optical microscopy analyses. The most efficient formulations that showed a thermogelling capacity with a significant gel transition behaviour after 24h were the NaH2PO4/chitosan and Na3PO4/chitosan systems at ratio 2 and pH 7.0. These results confirmed the importance of the pH value and ratio selection for the final systems. [Copyright &y& Elsevier]

Quetiapine is an atypical antipsychotic approved for treating schizophrenia, bipolar depression, and mania but is frequently used in an off-label manner to control the behavioral and psychological symptoms of dementia in elderly patients with dementia. Due to the need to personalize doses for elderly patients with dementia, quetiapine tablet manipulation is widespread in hospital settings, long-term care facilities, and patient homes. The aim of this study was to assess the impact of the different splitting techniques on quetiapine fumarate tablets by analysing the obtained sub-divided tablets and to discuss compliance with the European Pharmacopoeia limits on whole and split tablets. Quetiapine fumarate tablets of two dose strengths were taken at random (in a number able to assure a power of 0.8 during statistical comparison) and were split with a kitchen knife or tablet cutter. The weight and the drug content were determined for each half tablet. The obtained data were compared to the European Pharmacopoeia limits. The differences between the different splitting techniques were statistically tested. Data showed that split tablets, independently of the dose strength and the technique employed, were not compliant with the European Pharmacopoeia specifications for both entire and subdivided tablets in terms of weight and content uniformity. Thus, such a common practice could have potential effects on treatment efficacy and toxicity, especially when also considering the fragility of the elderly target population in which polypharmacotherapy is very common. These results indicate a compelling need for flexible quetiapine formulations that can assure more accurate dose personalization. [ABSTRACT FROM AUTHOR]

[Display omitted] Cellulosic-based thickeners are commonly used in the preparation of hydro-alcoholic hand sanitisers. Yet, little is known about the behaviour of these polymeric dispersions in hydro-alcoholic mixtures. Here, we studied the dispersion ability and rheology of hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose and sodium carboxymethyl cellulose in water–ethanol mixtures. Hydroxypropyl cellulose formed transparent dispersions across the entire range of ethanol concentrations, while a critical ethanol concentration (CEC), above which dispersions became turbid, was found for all the other polymers. At and below the CEC, all the rheological parameters followed a bell-like shape profile as a function of ethanol concentration. Moreover, the molecular weight and degree of substitution of the polymers influenced the rheological properties. The CEC and rheological behaviour of the dispersions were both dependent on the ethanol/polymer and water/polymer interactions. As hand disinfectants should contain 60–95% ethanol, polymers of higher CEC, such as hydroxypropyl cellulose and hydroxypropyl methylcellulose, are recommended. [ABSTRACT FROM AUTHOR]

1,4-Dihydropyridines (DHPs) are the most important class of L-type calcium channel blockers that are employed for the treatment of cardiovascular diseases, particularly hypertension. Various modifications on this scaffold lead to the discovery of new DHPs blocking different types of calcium channels. Among them, the T-type calcium channel has recently attracted great interest due to its role in chronic pain conditions. In this study, we selected three newly synthesized DHPs (HM8, HM10 and MD20) with different selectivity profiles to the T-type calcium channel and formulated them in micellar solutions and micellar-in-gel matrices to be tested for potential topical use in the treatment of neuropathic pain. To prevent the well-known sensitivity to light of the DHPs, the studied compounds were entrapped in colloidal aggregates obtained by using edible Pluronic® surfactants and adding α-tocopherol as an antioxidant. All the prepared formulations were exposed to stressing light, according to international rules. Along with the degradation experiments, the concentrations of the parent compounds and by-products were calculated by multivariate curve resolution—alternating least squares (MCR-ALS) applied to the spectral data. The defined formulations proved suitable as light-stable matrices for the DHP compounds, showing an increase in stability for HM8 and MD20 and an almost complete photoprotection for HM10, compared to ethanol solutions and standard gel formulations. [ABSTRACT FROM AUTHOR]

Most insecticides commonly used in storage facilities are synthetic, an issue that generates concerns about food safety and public health. Therefore, the development of eco-friendly pest management tools is urgently needed. In the present study, a 6% (w/w) Hazomalania voyronii essential oil-based nanoemulsion (HvNE) was developed and evaluated for managing Tribolium confusum, T. castaneum, and Tenebrio molitor, as an eco-friendly wheat protectant. Larval and adult mortality was evaluated after 4, 8, and 16 h, and 1, 2, 3, 4, 5, 6, and 7 days, testing two HvNE concentrations (500 ppm and 1000 ppm). T. confusum and T. castaneum adults and T. molitor larvae were tolerant to both concentrations of the HvNE, reaching 13.0%, 18.7%, and 10.3% mortality, respectively, at 1000 ppm after 7 days of exposure. However, testing HvNE at 1000 ppm, the mortality of T. confusum and T. castaneum larvae and T. molitor adults 7 days post-exposure reached 92.1%, 97.4%, and 100.0%, respectively. Overall, the HvNE can be considered as an effective adulticide or larvicide, depending on the target species. Our results highlight the potential of H. voyronii essential oil for developing green nanoinsecticides to be used in real-world conditions against key stored-product pests. [ABSTRACT FROM AUTHOR]

Flavours and fragrances are volatile compounds of large interest for different applications. Due to their high tendency of evaporation and, in most cases, poor chemical stability, these compounds need to be encapsulated for handling and industrial processing. Encapsulation, indeed, resulted in being effective at overcoming the main concerns related to volatile compound manipulation, and several industrial products contain flavours and fragrances in an encapsulated form for the final usage of customers. Although several organic or inorganic materials have been investigated for the production of coated micro- or nanosystems intended for the encapsulation of fragrances and flavours, polymeric coating, leading to the formation of micro- or nanocapsules with a core-shell architecture, as well as a molecular inclusion complexation with cyclodextrins, are still the most used. The present review aims to summarise the recent literature about the encapsulation of fragrances and flavours into polymeric micro- or nanocapsules or inclusion complexes with cyclodextrins, with a focus on methods for micro/nanoencapsulation and applications in the different technological fields, including the textile, cosmetic, food and paper industries. [ABSTRACT FROM AUTHOR]

The growing interest in the development of green pest management strategies is leading to the exploitation of essential oils (EOs) as promising botanical pesticides. In this respect, nanotechnology could efficiently support the use of EOs through their encapsulation into stable nanoformulations, such as nanoemulsions (NEs), to improve their stability and efficacy. This technology assures the improvement of the chemical stability, hydrophilicity, and environmental persistence of EOs, giving an added value for the fabrication of natural insecticides effective against a wide spectrum of insect vectors and pests of public and agronomical importance. Carlina acaulis (Asteraceae) root EO has been recently proposed as a promising ingredient of a new generation of botanical insecticides. In the present study, a highly stable C. acaulis-based NE was developed. Interestingly, such a nanosystem was able to encapsulate 6% (w/w) of C. acaulis EO, showing a mean diameter of around 140 nm and a SOR (surfactant-to-oil ratio) of 0.6. Its stability was evaluated in a storage period of six months and corroborated by an accelerated stability study. Therefore, the C. acaulis EO and C. acaulis-based NE were evaluated for their toxicity against 1st instar larvae of the European grapevine moth (EGVM), Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera: Tortricidae), a major vineyard pest. The chemical composition of C. acaulis EO was investigated by gas chromatography–mass spectrometry (GC–MS) revealing carlina oxide, a polyacetylene, as the main constituent. In toxicity assays, both the C. acaulis EO and the C. acaulis-based NE were highly toxic to L. botrana larvae, with LC50 values of 7.299 and 9.044 µL/mL for C. acaulis EO and NE, respectively. The C. acaulis-based NE represents a promising option to develop highly stable botanical insecticides for pest management. To date, this study represents the first evidence about the insecticidal toxicity of EOs and EO-based NEs against this major grapevine pest. [ABSTRACT FROM AUTHOR]

Among the various innovative products obtainable from hemp (Cannabis sativa L.) waste biomass originating from different industrial processes, the essential oil (EO) deserves special attention in order to understand its possible application in different fields, such as cosmetics, pharmaceuticals, and botanical insecticides. For the purpose, in the present work, we studied the chemical composition of EOs obtained from different hemp varieties, namely Felina 32 and Carmagnola Selezionata (CS) using monoecious, male, and female inflorescences, and we evaluated their mosquitocidal activities on larvae and pupae of two main malaria vectors, Anopheles gambiae and An. stephensi. Then, in order to evaluate the safe use of hemp EOs for operators, the potential pro- or anti-inflammatory effect of hemp EOs together with their toxicological profile were determined on dermal fibroblasts and keratinocytes. Given the promising results obtained by insecticidal and anti-inflammatory studies, a preliminary evaluation of EOs encapsulation into nanoemulsions (NEs) has been performed with the aim to develop a formulation able to improve their poor physicochemical stability. Felina 32 and CS inflorescences provided EOs with an interesting chemical profile, with monoterpene and sesquiterpene hydrocarbons as the major components. This study highlighted the potential application of male inflorescences, which are usually discharged during hemp product processing. These EOs could be exploited as potential sustainable and eco-friendly insecticides, given their capability to be toxic against mosquitoes and the possibility to use them to prepare stable and safe formulations. The LC50 values found in this study (<80 ppm) are lower, on average, than those of many plant EOs, with the advantage of using an industrial waste product. From MTT assay and gene and protein expression analysis, EOs showed no cytotoxicity at the appropriate doses and exerted an anti-inflammatory effect on the human cell lines tested. These findings encourage further applied research on hemp EOs in order support their industrial exploitation. [ABSTRACT FROM AUTHOR]

The world is facing a medical crisis amid the CoViD-19 pandemic and the role of adequate hygiene and hand sanitisers is inevitable in controlling the spread of infection in public places and healthcare institutions. There has been a great surge in demand for hand sanitisation products leading to shortages in their supply. A consequent increase of substandard products in the market has raised safety concerns. This article, therefore, presents a critical review of hand sanitation approaches and products available on the market in light of the scientific evidence available to date. This review also provides a range of hand sanitisation product formulations, and manufacturing instructions to allow for extemporaneous preparations at the community and hospital pharmacies during this urgent crisis. In addition, this emergent situation is expected to continue, hence hand sanitisers will be in demand for an extended time, and the availability and purchase of substandard products on the market create an ongoing safety concern. Therefore, this article shall also provide various commercial organisations, interested in stepping forward the production and marketing of hand sanitisers, with a guide on the development of products of standardised ingredients and formulations. [ABSTRACT FROM AUTHOR]

Non-lamellar liquid crystalline nanoparticles are promising drug delivery lipidic nanosystems, stabilized by amphiphilic block copolymers. In the present investigation, the widely used Poloxamer P407 is compared with the innovative stimuli-responsive polycationic block copolymer poly(2-(dimethylamino)ethyl methacrylate)-b-poly(lauryl methacrylate) (PDMAEMA-b-PLMA) as stabilizer for glyceryl monooleate (GMO) or phytantriol (PHYT)-based colloidal dispersions of liquid crystalline nanoparticles. As such, a variety of techniques was combined in order to comprehensively characterize these nanosystems in terms of physicochemical, morphological and thermal properties. Particle size, size distribution, ζ-potential and the fractal dimension parameter (d f), calculated from light scattering data, as well as the morphology (from cryo-TEM analysis) of nanoparticles were markedly affected by the different lipid and type of polymeric stabilizer, indicating different kind of interfacial lipid-polymer interactions. Notably, PDMAEMA-b-PLMA block copolymer was effective as well as P407 in stabilizing the GMO-based, but not PHYT-based nanosystems. Furthermore, microcalorimetry, high-resolution ultrasound spectroscopy and rheology were applied to characterize the thermal behavior of these nanosystems, highlighting their transition temperatures. In conclusion, a detailed evaluation was carried out on liquid crystalline nanoparticles, providing significant information, useful for the development of innovative non-lamellar therapeutic nanosystems with advanced properties that can be successfully applied in the pharmaceutical nanotechnology field. [ABSTRACT FROM AUTHOR]

A method for the aqueous synthesis of stable and biocompatible citrate-coated palladium nanoparticles (PdNPs) in the size range comparable to natural enzymes (4–8 nm) has been developed. The toxicological profile of PdNPs was assessed by different assays on several cell lines demonstrating their safety in vitro also at high particle concentrations. To elucidate their cellular fate upon uptake, the localization of PdNPs was analyzed by Transmission Electron Microscopy (TEM). Moreover, crucial information about their intracellular stability and oxidation state was obtained by Sputtering-Enabled Intracellular X-ray Photoelectron Spectroscopy (SEI-XPS). TEM/XPS results showed significant stability of PdNPs in the cellular environment, an important feature for their biocompatibility and potential for biomedical applications. On the catalytic side, these PdNPs exhibited strong and broad antioxidant activities, being able to mimic the three main antioxidant cellular enzymes, i.e., peroxidase, catalase, and superoxide dismutase. Remarkably, using an experimental model of a human oxidative stress-related disease, we demonstrated the effectiveness of PdNPs as antioxidant nanozymes within the cellular environment, showing that they are able to completely re-establish the physiological Reactive Oxygen Species (ROS) levels in highly compromised intracellular redox conditions. [ABSTRACT FROM AUTHOR]

The management of parasites, insect pests and vectors requests development of novel, effective and eco-friendly tools. The development of resistance towards many drugs and pesticides pushed scientists to look for novel bioactive compounds endowed with multiple modes of action, and with no risk to human health and environment. Several natural products are used as alternative/complementary approaches to manage parasites, insect pests and vectors due to their high efficacy and often limited non-target toxicity. Their encapsulation into nanosystems helps overcome some hurdles related to their physicochemical properties, for instance limited stability and handling, enhancing the overall efficacy. Among different nanosystems, micro- and nanoemulsions are easy-to-use systems in terms of preparation and industrial scale-up. Different reports support their efficacy against parasites of medical importance, including Leishmania, Plasmodium and Trypanosoma as well as agricultural and stored product insect pests and vectors of human diseases, such as Aedes and Culex mosquitoes. Overall, micro- and nanoemulsions are valid options for developing promising eco-friendly tools in pest and vector management, pending proper field validation. Future research on the improvement of technical aspects as well as chronic toxicity experiments on non-target species is needed. [ABSTRACT FROM AUTHOR]

Quaternary ammonium amphiphiles are a class of compounds with a wide range of commercial and industrial uses. In the pharmaceutical field, the most common quaternary ammonium surfactant is benzalkonium chloride (BAC), which is employed as a preservative in several topical formulations for ocular, skin, or nasal application. Despite the broad antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as fungi and small enveloped viruses, safety concerns regarding its irritant and cytotoxic effect on epithelial cells still remain. In this work, quaternary ammonium derivatives of leucine esters (C10, C12 and C14) were synthesised as BAC analogues. These cationic surfactants were characterised in terms of critical micelle concentration (CMC, by tensiometry), cytotoxicity (MTS and LDH assays on the Caco-2 and Calu-3 cell lines) and antimicrobial activity on the bacterial species Staphylococcus aureus and Enterococcus faecalis among the Gram-positives, Escherichia coli and Pseudomonas aeruginosa among the Gram-negatives and the yeast Candida albicans. They showed satisfactory surface-active properties, and a cytotoxic effect that was dependent on the length of the hydrophobic chain. Lower minimum inhibiting concentration (MIC) values were calculated for C14-derivatives, which were comparable to those calculated for BAC toward Gram-positive bacteria and slightly higher for Gram-negative bacteria and C. albicans. Thus, the synthesised leucine-based quaternary ammonium cationic surfactants can potentially find application as promising surface-active compounds with antimicrobial activity. [ABSTRACT FROM AUTHOR]