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Abstract Topotecan is a relatively large, planar, asymmetric and polar molecule with a lactone moiety. In neutral or basic aqueous solutions, this ring opens forming the carboxylate form of Topotecan that is biologically inactive and uncapable of passively cross membranes. Nevertheless, despite this inability to cross membranes at this form, Topotecan may still be able to interact with phospholipid bilayers, disturbing them. In this context, phospholipid models, mimicking normal (DMPC at pH 7.4) and cancer cell lipid membranes (DMPC:DMPS (5:1) at pH 6.5), were used to assess structural modifications upon interaction with Topotecan. Langmuir isotherms of monolayers coupled with Brewster angle microscopy, differential scanning calorimetry of liposomes and X-ray scattering of small and wide angle of stacked multilayers were used as complementary techniques. The overall results show that the interaction of Topotecan with lipid membranes is deeply conditioned by their composition and that Topotecan seems to have a preferential interaction with the glycerol backbone of phosphatidylcholine phospholipids. Graphical Abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Lyophilization has been used to improve the long-term stability of polymeric nanoparticles for drug delivery applications, avoiding their instability in suspension. However, this dehydration process may induce stresses to nanoparticles, mitigated by the use of some excipients such as cryo- and lyoprotectants. Still, the lyophilization of polymeric nanoparticles is frequently based in empirical principles, without considering the physical–chemical properties of formulations and the engineering principles of lyophilization. Therefore, the optimization of formulations and the lyophilization cycle is crucial to obtain a good lyophilizate, and guarantee the preservation of nanoparticle stability. The proper characterization of the lyophilizate and nanoparticles has a great importance in achieving these purposes. This review updates the fundaments involved in the optimization procedures for lyophilization of polymeric nanoparticles, with the aim of obtaining the maximum stability of formulations. Different characterization methods to obtain and guarantee a good lyophilized product are also discussed. A special focus is given to encapsulated therapeutic proteins. Overall, this review is a contribution for the understanding of the parameters involved in the lyophilization of polymeric nanoparticles. This may definitely help future works to obtain lyophilized nanoparticles with good quality and with improved therapeutic benefits. [ABSTRACT FROM AUTHOR]

Inflammation plays a crucial role in rheumatoid arthritis progress. In the present work, a novel stealth polymeric nanospheres platform able to carry anti-inflammatory drugs and an imaging agent was developed. Incorporation of gold nanoparticles will allow photoacoustic imaging and near infra-red photothermal application. Through emulsion–diffusion evaporation technique methotrexate and gold nanoparticles were incorporated in the pegylated-poly( dl -lactic-co-glycolic acid) nanospheres. In vitro drug release assays revealed pH and temperature-dependence on gold nanoparticles. Blank nanospheres exhibited negligible in vitro cytotoxicity, while methotrexate-loaded nanospheres hampered monocytes and macrophages viability at a higher level than free methotrexate. Confocal fluorescent microscopy and flow cytometry revealed effective nanospheres internalization, and that their cellular uptake was energy dependent mediated by caveolae and clathrin-endocytosis mechanism. Finally, MTX-loaded multifunctional nanospheres containing gold lead to a significant reduction of IL-1β, IL-6 and TNF-α inflammatory cytokines produced by monocytes and macrophages upon in vitro inflammatory stimulation, suggesting a favorable anti-inflammatory activity. These results confirm that the multifunctional nanospheres represent a promising theranostic platform for RA diagnosis and intracellular treatment, by combining methotrexate and gold nanoparticles for a highly effective targeted chemo-photothermal therapy. [ABSTRACT FROM AUTHOR]

The major risk factor associated with the development of gastric cancer is chronic infection with Helicobacter pylori. The available treatments, based on a cocktail of antibiotics, fail in up to 40% of patients and disrupt their gut microbiota. The potential of blank nanostructured lipid carriers (NLC) for H. pylori eradication was previously demonstrated by us. However, the effect of NLC charge, size and protein corona on H. pylori-specific bactericidal activity herein studied was unknown at that time. All developed NLC formulations proved bactericidal against H. pylori. Although cationic NLC had 10-fold higher bactericidal activity than anionic NLC, they lacked specificity, since Lactobacillus acidophilus was also affected. Anionic NLC achieved complete clearance in both H. pylori morphologies (rod- and coccoid-shape) by inducing alterations in bacteria membranes and the cytoplasm, as visualized by transmission electron microscopy (TEM). The presence of an NLC protein corona, composed of 93% albumin, was confirmed by mass spectrometry. This protein corona delayed the bactericidal activity of anionic NLC against H. pylori and hindered NLC activity against Escherichia coli. Overall, these results sustain the use of NLC as a promising antibiotic-free strategy targeting H. pylori. [ABSTRACT FROM AUTHOR]

Abstract: The work here described aimed to find out the location of the different species of two families of pharmaceutical substances, namely two β-blockers (atenolol and nadolol) and two benzodiazepines (midazolam and nitrazepam) in synthetic (sodium dodecyl sulphate, SDS) and natural (bile salts-sodium cholate and sodium deoxycholate) micellar aggregate solutions. Electronic spin resonance spectroscopy studies were carried out, at 25°C and at an ionic strength of 0.10M in NaCl, using 5-, 12- and 16-doxylstearic acid probes (AS). The immobilization degree of solubilized stearic acid spin probes was found to vary with the position of the nitroxide group in the sequence 5-doxylstearic acid>12-doxylstearic acid>16-doxylstearic acid for SDS and 12-doxylstearic acid>5-doxylstearic acid>16-doxylstearic acid for both bile salts investigated. Therefore, from the rotational correlational time values obtained, it can be inferred that the structure of bile salt micelles is markedly different from that of SDS micelles and the results suggest that the bile salt micelles studied have similar structure independently of differences in the molecular structure of the respective bile salts. Drug location studies were performed at pH 4.0 (SDS solutions) or 7.0 (bile salt solutions) and 10.8 in order to study the effect of the drug ionisation on its relative position on micelles. The results have shown that drug location is controlled by the (i) drug hydrophilicity and acid/base properties, with the more soluble compound in water (atenolol) exhibiting smaller variation of rotational correlational time (in SDS and bile salts solutions), and with both β-blockers exhibiting smaller deviations in the protonated forms and (ii) the bile salt monomers, with the dihydroxylic bile salt (deoxycholate) producing larger differences. The work described herein allow us to conclude that the (protonated) β-blockers are probably located on the surface of the detergent micelles, and linked to them by means of essentially electrostatic forces, while the (neutral) benzodiazepines are probably located deeper in the interior of the micelles. [Copyright &y& Elsevier]

In this work the critical micelle concentrations (cmc) of four bile salts, sodium cholate, sodium glycocholate, sodium deoxycholate, and sodium glycodeoxycholate, are determined and presented. Three independent noninvasive methodologies (potentiometry, derivative spectrophotometry, and light scattering) were used for cmc determination, at 25°C with ionic strength adjusted to 0.10M with NaCl. Spectrophotometric and potentiometric studies of some bile salts were also executed at various ionic strength values, thus allowing the influence of the ionic strength on the cmc value of the bile salt to be assessed. A critical comparison of the cmc values obtained with data collected from the literature is presented. Furthermore, this work makes an evaluation of the conceptual bases of different methodologies commonly used for cmc determination, since variations in the results obtained can be related mainly to different intrinsic features of the methods used (such as sensitivity or the need to include tracers or probes) or to the operational cmc definition applied. The undoubted definition of the experimental bile salt concentration that corresponds to cmc (operational cmc) is essential since in the case of these amphiphiles the formation of micelles is not as abrupt as in the case of ordinary association colloids. The biphasic nature of their aggregation leads to a “round-shaped” variation of the experimental parameters under analysis, which makes difficult the evaluation of the cmc values and can be responsible for the different results obtained. [Copyright &y& Elsevier]

A series of unique PLGA-chitosan hybrid polymers with tailored and tunable physicochemical characteristics were obtained with two different synthetic methods: solid-phase synthesis on a film or in solution chemical reaction with polycaprolactone as intermediate. These dependent variables were affected by the chitosan, alginate, and calcium chloride concentrations, while zeta potential depended only on the alginate and calcium chloride concentrations. Polydimethylsiloxane molds were used to obtain poly(vinyl alcohol)-poly(vinyl pyrrolidone) microneedles to carry the freeze-dried PLP-loaded PLGA nanoparticles. Shin et al. developed PLGA nanoparticles as siRNA carriers to overcome ROS/oxidative stress-induced chondrocyte damage in osteoarthritis [[5]]. [Extracted from the article]

Abundant in citrus fruits, naringin (NAR) is a flavonoid that has a wide spectrum of beneficial health effects, including its anti-inflammatory activity. However, its use in the clinic is limited due to extensive phase I and II first-pass metabolism, which limits its bioavailability. Thus, lipid nanoparticles (LNPs) were used to protect and concentrate NAR in inflamed issues, to enhance its anti-inflammatory effects. To target LNPs to the CD44 receptor, overexpressed in activated macrophages, functionalization with hyaluronic acid (HA) was performed. The formulation with NAR and HA on the surface (NAR@NPsHA) has a size below 200 nm, a polydispersity around 0.245, a loading capacity of nearly 10%, and a zeta potential of about 10 mV. In vitro studies show the controlled release of NAR along the gastrointestinal tract, high cytocompatibility (L929 and THP-1 cell lines), and low hemolytic activity. It was also shown that the developed LNPs can regulate inflammatory mediators. In fact, NAR@NPsHA were able to decrease TNF-α and CCL-3 markers expression by 80 and 90% and manage to inhibit the effects of LPS by around 66% for IL-1β and around 45% for IL-6. Overall, the developed LNPs may represent an efficient drug delivery system with an enhanced anti-inflammatory effect. [ABSTRACT FROM AUTHOR]

Nowadays, incrising global demand for milk and milk-derived products throughout the world has led to a massive growth of the dairy sector, and with it an increase in the associated environmental impacts. Milk surplus and by-products disposal represent a serious burden in this scope. Thus, it is essential to improve the valorization of this resource. In light of milk's natural delivery function, this review provides an up-to-date collection of the milk-derived delivery systems (MDDS). Special focus is given to the colloidal structures found naturally in bovine milk or reassembled architectures produced with materials derived from milk (milk fat globules, caseins, whey proteins and extracellular vesicles). Furthermore, this review takes a critical perspective on public health, environmental and regulatory issues related to milk production and consumption. Milk has been shown to be a safe and low-cost source of materials with huge potential as delivery systems, applied both in nutrition and medicine. However, there are hurdles to overcome prior to their implementation. From a health perspective, testing carrier biocompatibility and considering milk intolerance and allergy is crucial. Dairy farming is associated with serious environmental burdens, which have been leading to increasing support for animal-free diets and products. The lack of standardized methods for producing these MDDS also hampers their translation. Thus, more research is still needed to surpass these problems and allow us to fully exploit milk's potential. [Display omitted] • Repurposing milk constituents may mitigate their excessive production impact. • MDDS (milk-derived delivery systems) are promising strategies to be applied in nutrition and medicine. • MDDS show potential as cost-effective and versatile alternatives to synthetic nanosystems. • Health, environmental and standardization issues hinder MDDS implementation. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is a primary malignant tumor of the central nervous system responsible for the most deaths among patients with primary brain tumors. Current therapies for GBM are not effective, with the average survival of GBM patients after diagnosis being limited to a few months. Chemotherapy is difficult in this case due to the heterogeneity of GBM and the high efficacy of the blood–brain barrier, which makes drug absorption into the brain extremely difficult. In a previous study, 3′,4′,3,4,5-trimethoxychalcone (MB) showed antiproliferative and anti-invasion activities toward GBM cells. Polymersomes (PMs) are an attractive, new type of nanoparticle for drug administration, due to their high stability, enhanced circulation time, biodegradability, and sustained drug release. In the present study, different MB formulations, PEG2000-PCL and PEG5000-PCL, were synthesized, characterized, and compared in terms of 14-day stability and in vitro cytotoxicity (hCMEC/D3 and U-373 MG). [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is the most common and deadly primary malignant brain tumor. Current therapies are insufficient, and survival for individuals diagnosed with GBM is limited to a few months. New GBM treatments are urgent. Polymeric nanoparticles (PNs) can increase the circulation time of a drug in the brain capillaries. Polymersomes (PMs) are PNs that have been described as having attractive characteristics, mainly due to their stability, prolonged circulation period, biodegradability, their ability to sustain the release of drugs, and the possibility of surface functionalization. In this work, a poly(ethylene glycol)-ε-caprolactone (PEG-PCL) copolymer was synthesized and PMs were prepared and loaded with an hydrolytic instable compound, previously synthesized by our research team, the 3,6-bis(2,3,4,6-tetra-O-acetyl-β-glucopyranosyl)xanthone (XGAc), with promising cytotoxicity on glioblastoma cells (U-373 MG) but also on healthy cerebral endothelial cells (hCMEC/D3). The prepared PMs were spherical particles with uniform morphology and similar sizes (mean diameter of 200 nm) and were stable in aqueous suspension. The encapsulation of XGAc in PMs (80% encapsulation efficacy) protected the healthy endothelial cells from the cytotoxic effects of this compound, while maintaining cytotoxicity for the glioblastoma cell line U-373 MG. Our studies also showed that the prepared PMs can efficiently release XGAc at intratumoral pHs. [ABSTRACT FROM AUTHOR]

An enormous interest in the development of efficient protocols for cellulose extraction has been demonstrated in the last few years, although usually based on non-sustainable chemical and thermal approaches. In this work, we propose a new and more sustainable method for cellulose extraction from eucalyptus and pine tree wood waste products exclusively performed using microwave-assisted radiation. The methodology includes three main steps: (i) alkaline treatment; (ii) bleaching I, using H2O2; and (iii) bleaching II, an acidic treatment. Samples obtained in each step were characterized by Fourier-transform Infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results were compared with the structural and thermal profile of the starting materials, a commercially available microcrystalline cellulose and with an industrial paper pulp sample. Results confirmed that for both types of wood wastes, cellulose was retained during the extraction procedures and that the removal of hemicellulose and lignin was mainly achieved in the last step, as seen by the FTIR spectra and TGA curves. The developed protocol is innovative, as it constitutes an easy and quick approach for extracting cellulose from eucalyptus and pine tree wood waste. Mild chemical and thermal conditions are used during the three extraction steps (microwave irradiation, aqueous solutions, maximum of 120 °C in a total of 3 h). Moreover, environmentally friendly purification steps are applied based on the use of water and ethanol. This approach offers the possibility of a future scale-up study to potentially apply the developed protocol to the extraction of cellulose on an industrial scale. [ABSTRACT FROM AUTHOR]

Background: The World Health Organization has identified Helicobacter pylori, a Gram‐negative bacterium responsible for several gastric disorders, as one of the pathogenic bacteria that requires newer non‐antibiotic approaches for its management. We previously demonstrated that nanostructured lipid carriers (NLC) loaded with docosahexaenoic acid (DHA‐NLC) have excellent in vitro performance against H. pylori. Materials and Methods: NLC were tested against different H. pylori strains and bacteria representative from human gut microbiota. For H. pylori, resistance development and membrane permeability assays were also performed. In vivo efficacy studies were done using an H. pylori‐infected mouse model. Microbiome analysis (16S rRNA sequencing analysis) was performed on mice feces before and after DHA‐NLC treatment. Results: NLC specifically killed different H. pylori strains by membrane disruption without inducing bacterial resistance. In vivo studies demonstrated that DHA‐NLC (2 mg/mL containing 50 μM of DHA) reduced 90%–95% of the H. pylori burden and eradicated infection in 50% of the animals when treatment was administrated ad libitum for 14 days. No significant differences were found between the administration procedure (ad libitum vs oral gavage). Also, increasing the DHA‐NLC concentration to 4 and 8 mg/mL did not translate into an improvement in antibacterial performance. Notably, gut microbiome analysis showed no alterations, highlighting the safety to the gut microbiota. Finally, no histopathological changes were reported (stomach/liver sections). Conclusions: Overall, our results emphasize DHA‐NLC as a promising approach for H. pylori infection management, since they can effectively reduce the H. pylori burden without affecting gut microbiota and, in opposition to antibiotics, without anticipating the development of resistance to this treatment. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIPs) have a high potential for use as drug delivery carriers. These materials exhibit beneficial properties such as stability, low toxicity, biodegradability, and the ability to form specific binding sites. New systems capable of crossing the blood–brain barrier (BBB) are important for the development of new treatments for nervous central system diseases. Due to the presence of apolipoprotein E (ApoE) receptors in the BBB, some nanomaterials functionalized with ApoE may be efficient systems for the drug delivery in the brain. In this way, a nano-MIP conjugated with ApoE (MIP-ApoE) was synthesized, characterized and evaluated as a possible drug nanocarrier to the brain. A non-imprinted polymer (NIPs) and a NIP conjugated with ApoE (NIP-ApoE) were also synthesized and compared with MIP and MIP-ApoE. The nanoparticles were loaded with donepezil (drug used for a proof-of-principle study), and the formulations were tested for cytocompatibility, in vitro release, and permeability through BBB model using hCMEC/D3 cells. Free donepezil, donepezil-loaded nanoparticles, and unloaded nanoparticles had a hemolytic activity lower than 15% and cell viability greater than 70%. The quantified donepezil in the plasma samples of animals treated with MIP and MIP-ApoE supported the in vitro results of sustainable donepezil release by these nanoparticles. When the nanoparticles were functionalized with ApoE, the permeability in the hCMEC/D3 monolayer increased (1.9 times). The brain samples of animals treated with MIP-ApoE had a slightly lower concentration of donepezil than the MIP treatment. One possible explanation is that, only the MIP-ApoE, with part of the donepezil complexed at its binding sites, can penetrate the brain. As a result, a reduced amount of donepezil remains free to be quantified. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is a silent pandemic considered a public health concern worldwide. Strategic therapies are needed to replace antibacterials that are now ineffective. One approach entails the use of well-known antibacterials along with adjuvants that possess non-antibiotic properties but can extend the lifespan and enhance the effectiveness of the treatment, while also improving the suppression of resistance. In this regard, a group of uniform materials based on organic salts (GUMBOS) presents an alternative to this problem allowing the combination of antibacterials with adjuvants. Fluoroquinolones are a family of antibacterials used to treat respiratory and urinary tract infections with broad-spectrum activity. Ciprofloxacin and moxifloxacin-based GUMBOS were synthesized via anion exchange reactions with lithium and sodium salts. Structural characterization, thermal stability and octanol/water partition ratios were evaluated. The antibacterial profiles of most GUMBOS were comparable to their cationic counterparts when tested against Gram-positive S. aureus and Gram-negative E. coli, except for deoxycholate anion, which demonstrated the least effective antibacterial activity. Additionally, some GUMBOS were less cytotoxic to L929 fibroblast cells and non-hemolytic to red blood cells. Therefore, these agents exhibit promise as an alternative approach to combining drugs for treating infections caused by resistant bacteria. [ABSTRACT FROM AUTHOR]

Skin drug delivery is an emerging route in drug development, leading to an urgent need to understand the behaviour of active pharmaceutical ingredients within the skin. Given, As one of the body's first natural defences, the barrier properties of skin provide an obstacle to the successful outcome of any skin drug therapy. To elucidate the mechanisms underlying this barrier, reductionist strategies have designed several models with different levels of complexity, using non-biological and biological components. Besides the detail of information and resemblance to human skin in vivo, offered by each in vitro model, the technical and economic efforts involved must also be considered when selecting the most suitable model. This review provides an outline of the commonly used skin models, including healthy and diseased conditions, in-house developed and commercialized models, their advantages and limitations, and an overview of the new trends in skin-engineered models. [ABSTRACT FROM AUTHOR]

• Antibiotics are among the most frequently prescribed medications in modern medicine. • Biophysical interaction studies constitute a platform for antibiotics development. • Drug-membrane interaction studies allow to predict the ADME-Tox of new molecules. • Biophysical studies permit to estalish drug'structure/membrane'activity correlation. Lipidomics and proteomics have undergone a tremendous revolution, and the knowledge about drugs' mechanism of action in biological membranes has been deepened. Methods to study the interactions of drugs with biological membranes have opened new perspectives to rational drug design, based not only in the pharmacological target of the drugs but also on the interaction with biological membranes. These methods expand our ability to acquire the ADME-Tox profile of drugs, simplifying the complexity of biological membranes. Particularly, antibiotic resistance is considered one of the greatest threats to human health, being the prospects for replacing current antimicrobial drugs extremely scarce. With the decline of the discovery and the emergence of multidrug resistant pathogens to the existing arsenal, the objective in the development of new drugs to combat the resistance to antibiotics has been replaced by the modification of existing antibiotics. Therefore, drug-membrane interaction studies using membrane models of the eukaryotic and prokaryotic cell membranes, associated with a broad of complementary methods, may contribute to a deep picture concerning the effect of antibiotics upon their intake until their pharmacological target. This critical review will discuss the relevance of a range of different methods to study the interaction of antibiotic drugs using liposomes as biological membranes models. The advantages and the limitations of these methods will be discussed and future perspectives in this field will be proposed. [ABSTRACT FROM AUTHOR]

Supplementing diets with rumen-protected lysine is a common strategy to meet the nutritional needs of high-producing dairy cows. This work addressed two separate but crucial issues: the lysine protection degree across the entire digestive tract as well as the production scalability of the proposed delivery systems. This was achieved by evaluating, in vitro or ex vivo, previously developed rumen-resistant lipid nanoparticles regarding their stability in the digestive tract and in the bloodstream of the dairy cow as well as how their production could be scaled-up. Results showed that the developed nanoparticles were able to resist digestion along the digestive tract but were degraded in the blood over 24 h. Thus, releasing their content to be used by the animal. In vitro viability assays were also performed, with the nanoparticles being found not to be inherently toxic when using nanoparticle concentrations up to 1 mg/mL. Results showed that neither the purity of the used lipids nor the production method significantly altered the nanoparticles' properties or their ruminal resistance. Furthermore, the shelf-life of these nanoparticles was assessed, and they were found to retain their properties and remain usable after at least 1 month of storage. Moreover, a pilot-scale production allowed the production of nanoparticles with similar properties to the previous ones made using standard methods. To summarize, the proposed rumen-resistant nanoparticles presented potential as orally ingested lysine delivery systems for dairy cattle supplementation, being capable of a large-scale production using cheaper components while maintaining their properties and without any efficiency loss. It should however be noted that these results were obtained mainly in vitro and further in vivo bioavailability and production experiments are needed before this technology can be confirmed as a viable way of delivering lysine to dairy cows. [ABSTRACT FROM AUTHOR]

Abstract In this study, fucoidan/chitosan nanoparticles were developed for the topical delivery of methotrexate towards the treatment of skin-related inflammatory diseases. Based on the fucoidan/chitosan (F/C) weight ratio, three different nanoparticles (1F/1C; 3F/1C; 5F/1C) were produced and characterized. Methotrexate was loaded in these polymeric nanoparticles achieving a drug loading of ca. 14% and an entrapment efficiency of 96, 87 and 80% for 1F/1C; 3F/1C and 5F/1C nanoparticles, respectively. Methotrexate-loaded fucoidan/chitosan nanoparticles exhibited size within the 300–500 nm range, positive zeta potential for 1F/1C nanoparticles (+60 mV) and negative surface charge for the 3F/1C and 5F/1C nanoparticles (−40 and −45 mV, respectively). Methotrexate loaded in 3F/1C and 5F/1C nanoparticles did not affect cells viability and presented lower cytotoxicity than free methotrexate, in fibroblasts and human keratinocytes. MTX-loaded fucoidan/chitosan nanoparticles lead to a significant reduction of pro-inflammatory cytokines produced by activated human monocytes. Skin permeation studies showed that methotrexate-loaded nanoparticles permeated the pig ear skin barrier reaching after 6 h, a 2.7- and 3.3-fold increase for 3F/1C and 5F/1C nanoparticles, relative to free methotrexate. In conclusion, fucoidan/chitosan nanoparticles, in particular the ratio 5F/1C, is safe, exerts an anti-inflammatory effect and increase skin permeation thus can potentially be used for methotrexate topical delivery. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Understanding how nanoparticles' properties influence their cellular interactions is a bottleneck for improving the design of carriers. Macrophage polarization governs their active role in solving infections or tissue repair. To unravel the effect of carbohydrate-targeting mannose receptors on the macrophage surface, drug-free fucoidan/chitosan nanoparticles were functionalized using mannose (M) and mannan (Mn). Polyelectrolyte complex nanoparticles were obtained upon chitosan self-assembly using fucoidan. The functionalized nanoparticles were characterized in terms of their physicochemical characteristics, chemical profile, and carbohydrate orientation. The nanoparticles varied in size from 200 to 400 nm, were monodisperse, and had a stable negative zeta potential with a low aggregation tendency. The nonfunctionalized and functionalized nanoparticles retained their properties for up to 12 weeks. Cell viability and internalization studies were performed for all the designed nanoparticles in the THP-1 monocytes and THP-1-differentiated macrophages. The expression of the mannose receptor was verified in both immune cells. The carbohydrate-functionalized nanoparticles led to their activation and the production of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumour necrosis factor (TNF)-α. Both M- and Mn-coated nanoparticles modulate macrophages toward an M1-polarized state. These findings demonstrate the tailoring of these nanoplatforms to interact and alter the macrophage phenotype in vitro and represent their therapeutic potential either alone or in combination with a loaded drug for future studies. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles offer multiple possibilities for biomedical applications. Besides their physico-chemical properties, nanoparticle-cellular interactions are determinant for biological safety. In this work, magnetic nanoparticles were synthesized by one-shot precipitation or two-step reaction and coated with biocompatible polymers, such as poly( l -lysine) and poly( N,N -dimethylacrylamide- co -acrylic acid), and carbohydrates, like l -ascorbic acid, d -galactose, d -mannose, and sucrose. The resulting magnetic nanoparticles were characterized by dynamic light scattering, FT-Raman spectroscopy, transmission electron microscopy, SQUID magnetometry, and Mössbauer spectroscopy. Ability of the nanoparticles to be used in theranostic applications was also evaluated, showing that coating with biocompatible polymers increased the heating efficiency. Nanoparticles synthesized by one-shot precipitation were 50% larger ( ∼ 13 nm) than those obtained by a two-step reaction ( ∼ 8 nm). Magnetic nanoparticles at concentrations up to 500 μg mL −1 were non-cytotoxic to L929 fibroblasts. Particles synthesized by one-shot precipitation had little effect on viability, cell cycle and apoptosis of the three human colon cancer cell lines used: Caco-2, HT-29, and SW-480. At the same concentration (500 μg mL −1 ), magnetic particles prepared by a two-step reaction reduced colon cancer cell viability by 20%, affecting cell cycle and inducing cell apoptosis. Uptake of surface-coated magnetic nanoparticles by colon cancer cells was dependent on particle synthesis, surface coating and incubation time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cutaneous melanoma (CM) is a multifactorial and heterogeneous disease. • Understanding CM molecular biology is crucial to design targeted nanomedicines. • Biomimetic nanovaccines may constitute future strategies for CM immunotherapy. • Magnetic nanosystems can be used as CM theranostic platforms. • Different advanced CM therapeutic modalities can be combined using nanosystems. Cutaneous melanoma (CM) is a multifactorial disease whose treatment still presents challenges: the rapid progression to advanced CM, which leads to frequent recurrences even after surgical excision and, notably, the low response rates and resistance to the available therapies, particularly in the case of unresectable metastatic CM. Thereby, alternative innovative therapeutic approaches for CM continue to be searched. In this review we discuss relevant preclinical research studies, and provide a broad-brush analysis of patents and clinical trials which involve the application of nanotechnology-based delivery systems in CM therapy. Nanodelivery systems have been developed for the delivery of anticancer biomolecules to CM, which can be administered by different routes. Overall, nanosystems could promote technological advances in several therapeutic modalities and can be used in combinatorial therapies. Nevertheless, the results of these preclinical studies have not been translated to clinical applications. Thus, concerted and collaborative research studies involving basic, applied, translational, and clinical scientists need to be performed to allow the development of effective and safe nanomedicines to treat CM. [ABSTRACT FROM AUTHOR]

A multifunctional nanomedicine platform was designed and evaluated for efficient colon cancer therapy by a combinatorial therapeutic approach based on a chemotherapeutic drug and mild hyperthermia. Advantage was taken from the dual role of methotrexate (MTX), as folate receptor-targeting, overexpressed in tumor cells, and as anticancer drug. Incorporation of superparamagnetic iron oxide nanoparticles (SPIONs) allows to heat cancer cells externally through an alternating magnetic field. The developed nanocarrier was based on polyethylene glycol–polylactic acid (PEG-PLA) nanospheres to improve biocompatibility, enhancing their targeting by prolonging blood circulation time. By an emulsion-evaporation method the nanospheres were produced and then characterized for size distribution, zeta-potential, in vitro drug release profile and cellular studies. The co-delivery of MTX and SPIONs on PEG-PLA nanospheres resulted in nanocarriers with a size of 160 nm in diameter, a polydispersity index below 0.2 and a zeta potential of ca. − 18 mV. Multifunctional nanospheres were monodisperse and stable up to 3 months. MTX was released preferentially under mild hyperthermia conditions. The multifunctional nanospheres were able to increase the cytotoxicity of MTX towards Caco-2 and SW-480 colon cancer cells, in comparison to free drug. Also, the nanospheres allowed the incorporated MTX to induce greater cell cycle arrest and apoptotic effects than the free MTX. This study provides evidences that MTX-SPIONs-PEG-PLA nanospheres are a promising solution to address colorectal cancer over-expressing folate receptors, by a combinatory approach. [ABSTRACT FROM AUTHOR]

Simple Summary: Although colorectal cancer is the third most common type of cancer, its treatment strategies still have room for improvement, as current techniques carry risks that aggressively deteriorate patients' quality of life. Medical physics using nanotechnology tools can significantly contribute to solving this challenge. The high biocompatibility, easy functionalization, and targeting capabilities of plasmonic (gold) nanoparticles, together with their high atomic number, which provides a large X-ray absorption cross-section, makes them potential agents for enhancing cancer therapeutics as photothermal therapy agents and as radiosensitizers. Hence, the auspicious possibility of synergistically combining radio- and phototherapies is of imperative importance and must be explored to enhance their clinical application. Colorectal cancer is the third most common cancer worldwide. Despite recent advances in the treatment of this pathology, which include a personalized approach using radio- and chemotherapies in combination with advanced surgical techniques, it is imperative to enhance the performance of these treatments and decrease their detrimental side effects on patients' health. Nanomedicine is likely the pathway towards solving this challenge by enhancing both the therapeutic and diagnostic capabilities. In particular, plasmonic nanoparticles show remarkable potential due to their dual therapeutic functionalities as photothermal therapy agents and as radiosensitizers in radiotherapy. Their dual functionality, high biocompatibility, easy functionalization, and targeting capabilities make them potential agents for inducing efficient cancer cell death with minimal side effects. This review aims to identify the main challenges in the diagnosis and treatment of colorectal cancer. The heterogeneous nature of this cancer is also discussed from a single-cell point of view. The most relevant works in photo- and radiotherapy using nanotechnology-based therapies for colorectal cancer are addressed, ranging from in vitro studies (2D and 3D cell cultures) to in vivo studies and clinical trials. Although the results using nanoparticles as a photo- and radiosensitizers in photo- and radiotherapy are promising, preliminary studies showed that the possibility of combining both therapies must be explored to improve the treatment efficiency. [ABSTRACT FROM AUTHOR]

Marine polysaccharides are recognized for their biological properties and their application in the drug delivery field, favoring hydrogel-forming capacities for cutaneous application towards several dermatological conditions. Essential oils have been widely used in skin, not only for their remarkable biological properties, but also for their capacity to enhance permeation through the skin layers and to confer a pleasant scent to the formulation. In this study, menthol, L-linalool, bergamot oil, and β-pinene were incorporated in alginate/fucoidan hydrogels to evaluate their skin permeation enhancement profile and assess their influence on the skin organization. The combinations of different essential oils with the marine-based fucoidan/alginate hydrogel matrix were characterized, resulting in formulations with pseudoplastic rheological properties favorable for a uniform application in the skin. The ex vivo Franz diffusion permeation assays revealed that calcein loaded in bergamot-alginate/fucoidan hydrogel permeated more than 15 mg out of the initial 75 mg than when in linalool-alginate/fucoidan, alginate/fucoidan or hydrogel without any incorporated oil. Skin calcein retention for menthol- and pinene-alginate/fucoidan hydrogels was 15% higher than in the other conditions. Infrared micro-spectroscopic analysis through synchrotron-based Fourier Transform Infrared Microspectroscopy evidenced a symmetric shift in CH3 groups towards higher wavenumber, indicating lipids' fluidization and less lateral packing, characterized by a band at 1468 cm−1, with the bergamot-alginate/fucoidan, which contributes to enhancing skin permeation. The study highlights the effect of the composition in the design of formulations for topical or transdermal delivery systems. [ABSTRACT FROM AUTHOR]

Bacterial biofilms of Staphylococcus aureus, formed on implants, have a massive impact on the increasing number of antimicrobial resistance cases. The current treatment for biofilm-associated infections is based on the administration of antibiotics, failing to target the biofilm matrix. This work is focused on the development of multiple lipid nanoparticles (MLNs) encapsulating the antibiotic moxifloxacin (MOX). The nanoparticles were functionalized with d-amino acids to target the biofilm matrix. The produced formulations exhibited a mean hydrodynamic diameter below 300 nm, a low polydispersity index, and high encapsulation efficiency. The nanoparticles exhibited low cytotoxicity towards fibroblasts and low hemolytic activity. To target bacterial cells and the biofilm matrix, MOX-loaded MLNs were combined with a nanosystem encapsulating a matrix-disruptive agent: N-acetyl-L-cysteine (NAC). The nanosystems alone showed a significant reduction of both S. aureus biofilm viability and biomass, using the microtiter plate biofilm model. Further, biofilms grown inside polyurethane catheters were used to assess the effect of combining MOX-loaded and NAC-loaded nanosystems on biofilm viability. An increased antibiofilm efficacy was observed when combining the functionalized MOX-loaded MLNs and NAC-loaded nanosystems. Thus, nanosystems as carriers of bactericidal and matrix-disruptive agents are a promising combinatory strategy towards the eradication of S. aureus biofilms. [ABSTRACT FROM AUTHOR]

Bacterial biofilms account for 80% of all chronic infections, with cells being up to 1000 times more resistant to antibiotics than their planktonic counterparts. The recently discovered ability of Helicobacter pylori to form biofilms once again highlights why this bacterium is one of the most successful human pathogens. The current treatments failure rate reaches 40% of cases, emphasizing that new therapeutic options are a pressing need. Nanostructured lipid carriers (NLC), with and without docosahexaenoic acid (DHA), were very effective against H. pylori planktonic cells but their effect on H. pylori biofilms was unknown. Here, DHA-loaded NLC (DHA-NLC) and NLC without any drug (blank NLC) were tested on an optimized H. pylori in vitro floating mature biofilm model. DHA-NLC and blank NLC reduced the total biofilm biomass and had a bactericidal effect against both biofilm and planktonic bacteria in all the concentrations tested (0.125–2 mg/mL). DHA-NLC achieved biofilm biomass reduction in a concentration ~ 8 times lower than blank NLC (0.125 vs 1 mg/mL, respectively). Both NLC were bactericidal at the lowest concentration tested (0.125 mg/mL) although with different efficiency, i.e. a decrease of ∼6 log 10 for DHA-NLC and ∼5 log 10 for blank NLC. In addition, the equivalent amount of free DHA (3.1 μM) only reduced bacterial viability in ∼2 log 10 , demonstrating the synergistic effect of DHA and NLC in the treatment of H. pylori biofilms. Nevertheless, although viable bacteria were not detected by colony forming unit (CFU) counting after treatment with both NLC, confocal microscopy imaging highlighted that some H. pylori cells remained alive. In addition, scanning electron microscopy (SEM) analysis confirmed an increase in bacteria with a coccoid morphology after treatment, suggesting a transition to a viable but non-culturable (VBNC) state. Altogether, it is herein established that NLC, even without any drug, are promising for the management of H. pylori bacteria organized in biofilms, opening new perspectives for the eradication of this gastric pathogen. [Display omitted] • An Helicobacter pylori in vitro floating biofilm model was established. • The H. pylori in vitro floating biofilm was grown for 3 days in medium with 5% FBS. • DHA-NLC & NLC reduce biomass and kill bacteria at low concentrations (0.1 mg/mL). • DHA-NLC & blank NLC are more effective than free DHA. • DHA-NLC & blank NLC may convert biofilm bacteria into viable but non-culturable. [ABSTRACT FROM AUTHOR]

Background: The present study takes advantage of the beneficial effects of resveratrol as a neuroprotective compound. Resveratrol-loaded solid lipid nanoparticles were functionalized with apolipoprotein E which can be recognized by the LDL receptors overexpressed on the blood–brain barrier. Results: Transmission electron microscopy images revealed spherical nanoparticles, dynamic light scattering gave a Z-average lower than 200 nm, and a zeta potential of around -13 mV and very high resveratrol entrapment efficiency (ca. 90 %). In vitro cytotoxic effects were assessed by MTT and LDH assays in hCMEC/D3 cell line and revealed no toxicity up to 50 µM over 4 h of incubation. The permeability through hCMEC/D3 monolayers showed a significant increase (1.8-fold higher) for resveratrol-loaded solid lipid nanoparticles functionalized with apolipoprotein E when compared to non-functionalized ones. Conclusions: In conclusion, these nanosystems might be a promising strategy for resveratrol delivery into the brain, while protecting it from degradation in the blood stream. [ABSTRACT FROM AUTHOR]

Resveratrol is a polyphenol compound with great value in cancer therapy, cardiovascular protection, and neurodegenerative disorders. The mechanism by which resveratrol exerts such pleiotropic effects is not yet clear and there is a huge need to understand the influence of this compound on the regulation of lipid domains formation on membrane structure. The aim of the present study was to reveal potential molecular interactions between resveratrol and lipid rafts found in cell membranes by means of Förster resonance energy transfer, DPH fluorescence quenching, and triton X-100 detergent resistance assay. Liposomes composed of egg phosphatidylcholine, cholesterol, and sphingomyelin were used as model membranes. The results revealed that resveratrol induces phase separation and formation of liquid-ordered domains in bilayer structures. The formation of such tightly packed lipid rafts is important for different signal transduction pathways, through the regulation of membrane-associating proteins, that can justify several pharmacological activities of this compound. [ABSTRACT FROM AUTHOR]

Carbon nanotubes are promising materials for biomedical applications like delivery systems and tissue scaffolds. In this paper, magnetic carbon nanotubes (M-CNTs) covered with bovine serum albumin (M-CNTs-BSA) or functionalized with hydrophilic monomers (M-CNTs-HL) were synthesized, characterized, and evaluated concerning their interaction with Caco-2 cells. There is no comparison between these two types of functionalization, and this study aimed to verify their influence on the material's interaction with the cells. Different concentrations of the nanotubes were applied to investigate cytotoxicity, cell metabolism, oxidative stress, apoptosis, and capability to cross biomimetic barriers. The materials showed cytocompatibility up to 100 μg mL−1 and a hemolysis rate below 2 %. Nanotubes' suspensions were allowed to permeate Caco-2 monolayers for up to 8 h under the effect of the magnetic field. Magnetic nanoparticles associated with the nanotubes allowed estimation of permeation through the monolayers, with values ranging from 0.50 to 7.19 and 0.27 to 9.30 × 10−3 μg (equivalent to 0.43 to 6.22 and 0.23 to 9.54 × 10−2 % of the initially estimated mass of magnetic nanoparticles) for cells exposed and non-exposed to the magnets, respectively. Together, these results support that the developed materials are promising for applications in biomedical and biotechnological fields. [Display omitted] • Functionalization can modify the interaction between carbon nanotubes and cells. • The synthesized carbon nanotubes were cytocompatible up to 100 μg mL−1. • The BSA layer promoted a higher permeability when cells were not exposed to magnets. • Magnets significantly improved the permeation of M-CNT-HL. • There was a tendency to boost the permeability of M-CNT and M-CNT-BSA with the magnets. [ABSTRACT FROM AUTHOR]

The therapeutic use of rose bengal (RB) has been limited by its anionic nature, high water solubility, and short half-life. Herein, RB was converted into a group of uniform materials based on organic salts (GUMBOS) via ion metathesis reactions to replace its sodium counterions with distinct cationic antiseptics (i.e., benzyldimethylhexadecylammonium, BZK; cetylpyridinium, C 16 Py; and chlorhexidine, CHX). The potential use of RB-based GUMBOS as antibacterial agents was investigated against a panel of Gram-positive and Gram-negative bacteria, namely Staphylococcus aureus (S. aureus), methicillin-resistant S. aureus (MRSA), Enterococcus faecalis (E. faecalis), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli). The micro-broth dilution method was used to determine the minimum inhibitory concentration (MIC) of synthesized GUMBOS as well as their parent compounds and unreacted stoichiometric mixtures. Hemolytic effects were further studied using human red blood cells. When compared to parent compounds and unreacted mixtures, GUMBOS showed equal or improved activity towards the non-resistant strain of S. aureus (i.e., DSM 2569) and E. faecalis. Additionally, [CHX][RB] was found to be active against E. coli with a MIC of 6.4–0.8 nmol mL−1, being 79 and 48 times more potent than RB and the corresponding unreacted mixture. The [CHX][RB] GUMBOS also showed the lowest hemolytic activity among all tested compounds and mixtures (percentage of hemolysis <5%). Overall, these results demonstrated that this ion metathesis strategy can improve the antibacterial activity of RB against Gram-positive bacteria and extend its spectrum of action towards E. coli , which could further contribute to safety improvements in multiple industries. [Display omitted] • Three novel rose bengal-based GUMBOS were synthesized and characterized. • GUMBOS showed improved activity towards S. aureus DSM 2569 and E. faecalis. • [CHX][RB] was found to be active against E. coli , with a MIC of 6.4–0.8 nmol mL−1. • The lowest hemolytic activity was also observed for [CHX][RB] (free Hb < 5%). [ABSTRACT FROM AUTHOR]

Tuning the 8-anilino-1-naphthalenesulfonic acid (ANS) structure usually requires harsh conditions and long reaction times, which can result in low yields. Herein, ANS was modified to form an ANS group of uniform materials based on organic salts (GUMBOS), prepared with simple metathesis reactions and distinct cations, namely tetrabutylammonium (N4444), tetrahexylammonium (N6666), and tetrabutylphosphonium (P4444). These ANS-based GUMBOS were investigated as fluorescent probes for membrane binding studies with four proteins having distinct physicochemical properties. Liposomes of 1,2-dimyristoyl-sn-glycero-3-phosphocholine were employed as membrane models as a result of their ability to mimic the structure and chemical composition of cell membranes. Changes in fluorescence intensity were used to monitor protein binding to liposomes, and adsorption data were fitted to a Freundlich-like isotherm. It was determined that [N4444][ANS] and [P4444][ANS] GUMBOS have enhanced optical properties and lipophilicity as compared to parent ANS. As a result, these two GUMBOS were selected for subsequent protein-membrane binding studies. Both [N4444][ANS] and [P4444][ANS] GUMBOS and parent ANS independently reached membrane saturation within the same concentration range. Furthermore, distinct fluorescence responses were observed upon the addition of proteins to each probe, which demonstrates the impact of properties such as lipophilicity on the binding process. The relative maintenance of binding cooperativity and maximum fluorescence intensity suggests that proteins compete with ANS-based probes for the same membrane binding sites. Finally, this GUMBOS-based approach is simple, rapid, and involves relatively small amounts of reagents, making it attractive for high-throughput purposes. These results presented herein can also provide relevant information for designing GUMBOS with ameliorated properties. [ABSTRACT FROM AUTHOR]

In this research, we propose to engineer a nanostructured mat that can simultaneously kill bacteria and promote an environment conducive to healing for prospective wound care. Polyvinyl alcohol (PVA) and cellulose acetate (CA) were combined at different polymer ratios (100/0, 90/10, 80/20% v /v), electrospun and crosslinked with glutaraldehyde vapor. Crosslinked fibers increased in diameter (from 194 to 278 nm), retaining their uniform structure. Fourier-transform infrared spectroscopy and thermal analyses proved the excellent miscibility between polymers. CA incorporation incremented the fibers swelling capacity and reduced the water vapor and air permeabilities of the mats, preventing the excessive drying of wounds. The antimicrobial peptide cys-pexiganan and the immunoregulatory peptide Tiger 17 were incorporated onto the mats via polyethylene glycol spacer (hydroxyl-PEG2-maleimide) and physisorbed, respectively. Time-kill kinetics evaluations revealed the mats effectiveness against Staphylococcus aureus and Pseudomonas aeruginosa. Tiger 17 played a major role in accelerating clotting of re-calcified plasma. Data reports for the first time the collaborative effect of pexiganan and Tiger 17 against bacterial infections and in boosting hemostasis. Cytocompatibility data verified the peptide-modified mats safety. Croslinked 90/10 PVA/CA mats were deemed the most promising combination due to their moderate hydrophilicity and permeabilities, swelling capacity, and high yields of peptide loading. [Display omitted] [ABSTRACT FROM AUTHOR]

This work focuses on the interaction of the anti-tuberculosis (anti-TB) drug, rifabutin (RFB) with cell membrane models formed by 1,2-dipalmitoyl- sn -glycero-3-phosphocholine (DPPC). The experiments were performed under acidic conditions ( i.e. , pH 5.0) taking into account the pH conditions that RFB may find in the course of its in vivo pharmacological activity. The partition of the drug to the membrane was quantified through the partition coefficient ( K p ). Fluorescence quenching studies were performed to predict the drug’s location across the cell membrane model. The effect of RFB on the biophysical parameters of the cell membrane model was studied by steady-state anisotropy and small-angle X-ray scattering (SAXS). The overall results point to a marked interaction of RFB with cell membranes under acidic pH, which may be related with its pharmacological effects. The in vivo success of RFB may be associated with the drug’s disordering effect of the membranes under acidic pH values environments, and consequently drug accumulation in the gastric infected tissues and inside phagolysosomes. On the other hand, the present study allowed establishing important correlations with the gastrointestinal side effects caused by RFB. [ABSTRACT FROM AUTHOR]

In the last years, microneedles (MNs) have been considered a valuable, painless, and minimally invasive approach for controlled transdermal drug delivery (TDD). Rivastigmine (RV), a drug administered to patients suffering from dementia, is currently delivered by oral or transdermal routes; however, both present limitations, mainly gastrointestinal adverse symptoms or local skin irritation and drug losses, respectively, for each route. Given this, the objective of the present work was to develop and evaluate the potential of polymeric MNs for RV transdermal delivery in a controlled manner. Polymeric MNs with two needle heights and different compositions were developed with calcein as a fluorescent model molecule. Morphology and mechanical characterisation were accessed. Skin permeation experiments showed the ability of the devices to deliver calcein and confirmed that the arrays were able to efficiently pierce the skin. To obtain a new TDD anti-dementia therapeutic solution, RV was loaded in 800 µm polymeric MNs of alginate and alginate/k-carrageenan MNs. In the presence of RV, the MN's morphology was maintained; however, the presence of RV influenced the compression force. Skin permeation studies revealed that RV-loaded MNs allowed a more efficient controlled release of the drug than the commercial patch. In vivo, skin irritation tests in rabbits revealed that the developed MNs were innocuous upon removal, in contrast with the evidence found for Exelon®, the commercial patch, which caused slight mechanical damage to the skin. The herein-produced MNs demonstrated a more controlled release of the drug, being the more suitable option for the transdermal delivery of RV. [ABSTRACT FROM AUTHOR]

Highlights: [•] Method developed for phenolic-rich food samples to measure antioxidant capacity. [•] A kinetic matching approach better assesses endpoint antioxidant capacity. [•] Method relies on standard selected with oxidation profile similar to food sample. [•] TEAC values were calculated from reactivity of standard and Trolox at endpoint. [•] Consumer-friendly index VCEAC (vitamin C equivalent antioxidant capacity) was given. [ABSTRACT FROM AUTHOR]

Abstract: Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used drugs in the world due to their anti-inflammatory, analgesic and antipyretic properties. Nevertheless, the consumption of these drugs is still associated with the occurrence of a wide spectrum of adverse effects. Regarding the major role of membranes in cellular events, the hypothesis that the biological actions of NSAIDs may be related to their effect at the membrane level has triggered the in vitro assessment of NSAIDs-membrane interactions. The use of membrane mimetic models, cell cultures, a wide range of experimental techniques and molecular dynamics simulations has been providing significant information about drugs partition and location within membranes and also about their effect on diverse membrane properties. These studies have indeed been providing evidences that the effect of NSAIDs at membrane level may be an additional mechanism of action and toxicity of NSAIDs. In fact, the pharmacokinetic properties of NSAIDs are closely related to the ability of these drugs to interact and overcome biological membranes. Moreover, the therapeutic actions of NSAIDs may also result from the indirect inhibition of cyclooxygenase due to the disturbing effect of NSAIDs on membrane properties. Furthermore, increasing evidences suggest that the disordering effects of these drugs on membranes may be in the basis of the NSAIDs-induced toxicity in diverse organ systems. Overall, the study of NSAIDs-membrane interactions has proved to be not only important for the better understanding of their pharmacological actions, but also for the rational development of new approaches to overcome NSAIDs adverse effects. [Copyright &y& Elsevier]

Abstract: The determination of hydrogen peroxide (H2O2) and the evaluation of scavenging capacity against this species were performed using five colorimetric reactions, which were adapted to flow injection analysis. The reactions chosen were based on the oxidation of iodide (I− method), on the formation of titanium-peroxide complex (TiP method), on the formation of titanium-xylenol orange-peroxide complex (TiXoP method), on the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB method) and on the co-oxidation of phenol-4-sulfonic acid and 4-aminoantipyrine (PSA/4-AAP method). The operational conditions were studied in order to improve the sensitivity of each method. Concerning to the method sensitivity, the ranking order was TMB method>I− method>TiXoP method ∼PSA/4-AAP method>TiP method. All methods showed an excellent repeatability (RSD<2%) and, except for I− method, relative deviations from the reference method were <1.9%. The FIA manifolds were adapted to perform the determination of scavenging capacity against H2O2 and glutathione (GSH) was applied as model compound. TiP and TiXoP methods were not suitable as no inhibition or an increase of analytical signal was attained. PSA/4-AAP method was chosen for further application to dietary phenolics and pharmaceutical compounds, providing IC50 values for those compounds that are fast reacting antioxidants. [Copyright &y& Elsevier]

Hyaluronic acid (HA) is a natural polymer, produced endogenously by the human body, which has unique physicochemical and biological properties, exhibiting desirable biocompatibility and biodegradability. Therefore, it has been widely studied for possible applications in the area of inflammatory diseases. Although exogenous HA has been described as unable to restore or replace the properties and activities of endogenous HA, it can still provide satisfactory pain relief. This review aims to discuss the advances that have been achieved in the treatment of inflammatory diseases using hyaluronic acid as a key ingredient, essentially focusing on studies carried out between the years 2017 and 2021. [ABSTRACT FROM AUTHOR]

Transdermal drug delivery is considered one of the most attractive routes for administration of pharmaceutic and cosmetic active ingredients due to the numerous advantages, especially over oral and intravenous methodologies. However, some limitations still exist mainly regarding the need to improve the drugs permeation across the skin. For this, several strategies have been described, considering the application of chemical permeation enhancers, drugs' nanoformulations and physical methods. Of these, microneedles have been proposed in the last years as promising strategies to enhance transdermal drug delivery. In this review, different types of microneedles are described, and the most commonly used methods of fabrication systematized, as well as the materials typically used and their main therapeutical applications. A special attention is paid to polymeric microneedles, particularly those made from sustainable marine polysaccharides like chitosan, alginate and hyaluronic acid. The applications of marine based polymeric microneedle devices for transdermal drug delivery are examined in detail and the perspectives of translation from the clinical trials to the market demonstrated. • Polymeric microneedles are promising strategies to enhance transdermal drug delivery. • Marine polysaccharides have been used for the preparation of the devices. • Microneedles made from chitosan, alginate and hyaluronic acid are reviewed. • Applications of these devices for transdermal drug delivery are examined. • Challenges and future perspectives of translation to the market are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Several of the most commonly used methods for in vitro determination of antioxidant capacity are reviewed in the present paper. The chemical principles of methods based either on biological oxidants (peroxyl radical, superoxide radical anion, hydrogen peroxide, hydroxyl radical, hypochlorous acid, singlet oxygen, nitric oxide radical, and peroxynitrite) or on non-biological assays (scavenging of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cation (TEAC assay), scavenging of 2,2-diphenyl-1-picrylhydrazyl radical (DPPHferric reducing antioxidant power (FRAP assay), Folin–Ciocalteu reducing capacity (FC assay), electrochemical total reducing capacity) are outlined and critically discussed. The scope of application, the advantages and shortcomings of each method are also highlighted. [Copyright &y& Elsevier]

Abstract: In the present work, an automatic flow procedure for the sequential spectrophotometric determination of Folin-Ciocalteu reducing capacity (FC assay) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS +) scavenging capacity expressed as the trolox equivalent (TEAC assay) is proposed for a comparative study of antioxidant properties in food products. Exploiting the flexibility of flow management associated to the computer control offered by multisyringe flow injection analysis, both methodologies were carried out in the same manifold using gallic acid and trolox as standard compounds. The proposed system configuration allowed the performance of each method separately or in tandem, providing 24 determinations per hour, which accounts for its application in routine analysis. The present methodology was applied to a large number of beverages (n =72), namely red and white wines, herbal and tea infusions, juices and beers. The results obtained showed that FC reducing capacity and TEAC values of red wines were significantly different from those obtained for the other beverages, while tea infusions provided significantly higher TEAC values when compared to white wines, herbal infusions, juices and beers. A good correlation was found between TEAC and FC reducing capacity (R >0.9) for red wines, herbal and tea infusions, and beers. For these beverages, similar slope values were found (106–140mgL−1 of gallic acid per mM of Trolox), except for beers that showed a higher response for FC assay. These results provided evidence that the correlation between these assays vary according to the type of sample, reinforcing the idea that more than one method should be used for evaluation of antioxidant capacity. [Copyright &y& Elsevier]

In the present work, a chemiluminometric automatic flow methodology for the in via-o determination of hypochlorous acid scavenging capacity, under pH and concentration conditions similar to those found in vivo, is proposed. As the pH found in physiological conditions (7.4) and the pH required for the chemiluminescence detection reaction (> 10) are different, the multisyringe flow injection analysis features were exploited to perform the in-line reaction of HOCl and the scavenger molecule at physiological pH prior to reaction of the remaining HOCl with luminol at alkaline conditions. These two reactions were carded out in about 3 s, allowing the determination of fast reacting antioxidants, in a time frame closer to in vivo generation of HOCl when compared to previously described methods. The developed method was applied to nonsteroidal anti-inflammatory drugs of different chemical families, and positive controls (cysteine, gallic acid, lipoic acid). The HOCl scavenging capacity was evaluated at pH 7.4 and 10.0; different results were found for oxicam derivatives, providing evidence that the pH of in vitro methods should be carefully selected to allow assumptions about putative in vivo effects. [ABSTRACT FROM AUTHOR]

Abstract: Knowledge of the partition process of environmentally significant molecules between biological membranes and their surroundings is of vital importance to explain their activity and toxicity, as well as phenomena like absorption, distribution and metabolism. In this research effort, we have studied membrane interactions of three surfactants: t-octylphenoxypolyethoxyethanol (Triton X-100), cetyltrimethylammonium chloride (CTAC) and dodecylbenzene sulphonate (SDBS). Unilamellar liposomes (LUVs) of egg yolk phosphatidylcholine (EPC) were used as membrane models. The partition coefficient, a fundamental parameter in assessing the behaviour of xenobiotic compounds, was determined for SDBS and Triton X-100 by derivative spectrophotometry and fluorescence quenching. The effect of these surfactants upon the physico-chemical characteristics (fluidity, diameter and surface charge) of the liposome membrane was also determined. Results show that all the three surfactants cause an increase in fluidity of the liposome membrane, although for low surfactant concentrations uncharacteristic membrane rigidity was observed, probably due to a change in lipid packing density. [Copyright &y& Elsevier]

Abstract: In the present work, an automatic method based on multi-syringe flow injection analysis (MSFIA) was developed for the determination of total antioxidant capacity, measured as the cumulative capacity of the compounds present in the sample to scavenge free radicals, using the 2,2-diphenyl-1-picrylhydrazyl (DPPHn. The determination is based on the colour disappearance due to the scavenging of DPPHxidant compounds monitored spectrophotometrically at 517nm. The influence of initial DPPHation and sample dilution in the present methodology was studied. It was verified that the amount of DPPH by antioxidant standards (ascorbic and caffeic acids) was independent of the initial concentration of radical except for situations where DPPHant molar ratio was lower than the stoichiometric value. Furthermore, the sample dilution factor plays an important role for achieving results comparable to those from end-point batch method since the exhausting of scavenging ability of the sample should take place during the period of absorbance measurement. The proposed method was applied to several food products and the total antioxidant capacity was expressed as Vitamin C equivalent antioxidant capacity (VCEAC). The results obtained by the proposed method ranged from 1.1 to 318mg of ascorbic acid/100ml and they were statistically comparable to those provided by the batch method. The detection limit was 0.34mg of ascorbic acid/100ml and the determination frequency was about 13h−1 with an excellent repeatability (R.S.D.<1%, n =10). [Copyright &y& Elsevier]

A multi-syringe flow injection system for the determination of total phenolics based on the 4-aminoantipyrine reaction is proposed. In-line preconcentration using solid-phase extraction was implemented, offering an environmentally friendly alternative to organic solvent extraction performed in the batch procedure and in previously described flow methodologies. Therefore, phenolic compounds were retained in Amberlite XAD4 resin using acidic conditions. The elution was carried out using 0.10?mol?L-1 NaOH solution, promoting the ionisation of the retained phenolic compounds, and thus their desorption.Since different elution profiles were obtained for several phenol derivatives, the calibration curves were established using the peak area as analytical signal. Moreover, a dynamic calibration range was applied by using a variable sample volume (0.500-6.00?mL) and calibration curves based on the mass of phenol retained in the pre-concentration column. A methodology based on a fixed sample volume (24.0?mL) was also proposed for determination at concentration levels below 50?µg?L-1. A limit of detection of 52?ng of phenol (9 or 2?µg?L-1) was achieved with a sampling frequency of 10-16?h-1 for the variable volume method and 4?h-1 for the fixed volume method. The application of the proposed methodology to reference material provided results that were within the certified acceptance limits. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen peroxide (H2O2) has been shown to be formed during inflammatory processes and is implicated in its pathophysiology. Thus, a putative scavenging activity against this reactive oxygen specie (ROS) by anti-inflammatory drugs may be of great therapeutical value. The present study was undertaken to evaluate the scavenging activity for H2O2 by several non-steroidal anti-inflammatory drugs (NSAIDs), namely indomethacin, acemetacin, etodolac, tolmetin, ketorolac, oxaprozin, sulindac and its metabolites sulindac sulfide and sulindac sulfone. The H2O2 scavenging assay was performed by measuring H2O2-elicited lucigenin chemiluminescence using a microplate reader. The specificity of the method was confirmed by the use of catalase, which completely prevented the H2O2-induced lucigenin chemiluminescence. The endogenous antioxidants melatonin and reduced glutathione (GSH) were used as positive controls. The obtained results demonstrated that all the studied NSAIDs display H2O2 scavenging activity, although in different extents. The ranking order of potency found was sulindac sulfone > sulindac sulfide > GSH > sulindac > indomethacin > acemetacin > etodolac > oxaprozin > ketorolac ≈ melatonin > tolmetin. [Copyright &y& Elsevier]

Abstract: An automatic system that performs two analytical procedures, allowing the evaluation of the relative antioxidant capacity of wine samples, was developed. Automation was carried out using a sequential injection analysis (SIA) system that allowed, thanks to its versatility, the development of two methodologies. One is based on the decolorization assay of the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, using a spectrophotometric detector. A second methodology allowed the evaluation of the hydrogen peroxide scavenging activity by measuring the oxidation of homovanylic acid (HVA) to its fluorescent dimer, using a fluorescent detector. The developed automatic methodologies were evaluated using trolox as standard and subsequently using other antioxidant substances as gallic acid, caffeic acid, ascorbic acid, catechin and taxifolin which are abundant in wine and whose antioxidant activities were compared to that shown by trolox. The spectrophotometric and fluorimetric assays showed linearity intervals between 0.001 and 0.01mM, and 0.001 and 0.008mM of trolox, respectively. The evaluation of the antioxidant power of 20 white and red wine samples, from different Portuguese wine producing regions, was carried out sequentially, in the automatic system. The results were expressed in trolox equivalent antioxidant capacity (TEAC) and presented, for the ABTS and hydrogen peroxide scavenging activity methodologies, detection limits of 8.4×10-7 and 1.4×10-4mM and relative standard deviation (R.S.D. (%)) in the range 0.6–2.4 and 1–1.8, respectively. [Copyright &y& Elsevier]

Xanthone derivatives have a dibenzo‐y‐pyrone scaffold which has gained great interest in Medicinal Chemistry due to their diverse biological activities. Usually, its synthesis requires multi‐step synthetic routes using harsh conditions and high catalyst loadings. In this communication, we report for the first time a one‐pot synthesis of the xanthone scaffold based on a carbonylative Suzuki coupling. Iodophenol and (2‐methoxyphenyl)boronic acid were coupled under carbon monoxide, generated from a carbon monoxide surrogate. An experimental data‐based model was built to guide the reaction optimization. The optimized conditions were 1 mol% of a pincer complex as palladium catalyst, 5 equivalents of K2CO3 as base, and DMF:water (7 : 3) as solvent. The robustness of the synthetic method, namely in terms of the reactants scope, was also evaluated. This approach provided the xanthone scaffold in high yields and provided a deep insight into the carbonylative Suzuki couplings. [ABSTRACT FROM AUTHOR]