Extracellular Vesicles Produced by the Cardiac Microenvironment Carry Functional Enzymes to Produce Lipid Mediators In Situ

The impact of the polyunsaturated fatty acids (PUFAs) at physiological concentrations on the composition of eicosanoids transported within the extracellular vesicles (EVs) of rat bone marrow mesenchymal stem cells and cardiomyoblasts was reported by our group in 2020. The aim of this article was to extend this observation to cells from the cardiac microenvironment involved in the processes of inflammation, namely mouse J774 macrophages and rat heart mesenchymal stem cells cMSCs. Moreover, to enhance our capacity to understand the paracrine exchange between these orchestrators of cardiac inflammation, we investigated some machinery involved in the eicosanoid’s synthesis transported by the EVs produced by these cells (including the two formerly described cells: bone marrow mesenchymal stem cells BM-MSC and cardiomyoblasts H9c2). We analyzed the oxylipin and the enzymatic content of the EVs collected from cell cultures supplemented (or not) with PUFAs. We prove that large eicosanoid profiles are exported in the EVs by the cardiac microenvironment cells, but also that these EVs carry some critical and functional biosynthetic enzymes, allowing them to synthesize inflammation bioactive compounds by sensing their environment. Moreover, we demonstrate that these are functional. This observation reinforces the hypothesis that EVs are key factors in paracrine signaling, even in the absence of the parent cell. We also reveal a macrophage-specific behavior, as we observed a radical change in the lipid mediator profile when small EVs derived from J774 cells were exposed to PUFAs. To summarize, we prove that the EVs, due to the carried functional enzymes, can alone produce bioactive compounds, in the absence of the parent cell, by sensing their environment. This makes them potential circulating monitoring entities.

Hydrogels for dermal and transdermal drug delivery

A painless and non-invasive method to deliver drugs using dermal and transdermal administration routes is expanding for more than 30 years as it reduces the risk of drug overdoses that...

Vesicular systems for dermal and transdermal drug delivery

Dermal/transdermal drug delivery continues to grow in importance as a means of enhancing treatment activity while reducing toxicity by avoiding the systemic absorption of the drug. At the same time, this has led to the adjustment of a wide diversity of drug carriers. This paper begins with a review of the skin, including its structure and the parameters that influence drug diffusion, followed by strategies to improve dermal drug delivery. Of the multitude of existing carriers, we will focus on the most advanced vectors in dermal/transdermal delivery, and in particular, on vesicular systems. This review will present the state of the art as well as the new trends in this domain. Through the description of these systems, we will try to obtain information on the ideal properties that the carrier must have in order to improve the cutaneous and transcutaneous penetration of the drug.

Supramolecular and Macromolecular Matrix Nanocarriers for Drug Delivery in Inflammation-Associated Skin Diseases

Skin is our biggest organ. It interfaces our body with its environment. It is an efficient barrier to control the loss of water, the regulation of temperature, and infections by skin-resident and environmental pathogens. The barrier function of the skin is played by the stratum corneum (SC). It is a lipid barrier associating corneocytes (the terminally differentiated keratinocytes) and multilamellar lipid bilayers. This intricate association constitutes a very cohesive system, fully adapted to its role. One consequence of this efficient organization is the virtual impossibility for active pharmaceutical ingredients (API) to cross the SC to reach the inner layers of the skin after topical deposition. There are several ways to help a drug to cross the SC. Physical methods and chemical enhancers of permeation are a possibility. These are invasive and irritating methods. Vectorization of the drugs through nanocarriers is another way to circumvent the SC. This mini-review focuses on supramolecular and macromolecular matrices designed and implemented for skin permeation, excluding vesicular nanocarriers. Examples highlight the entrapment of anti-inflammatory API to treat inflammatory disorders of the skin.

Extracellular vesicles of MSCs and cardiomyoblasts are vehicles for lipid mediators

Recent works reported the relevance of cellular exosomes in the evolution of different pathologies. However, most of these studies focused on the ability of exosomes to convey mi-RNA from cell to cell. The level of knowledge concerning the transport of lipid mediators by these nanovesicles is more than fragmented. The role of lipid mediators in the inflammatory signaling is fairly well described, in particular concerning the derivatives of the arachidonic acid (AA), called eicosanoïds or lipid mediators. The aim of the present work was to study the transport of these lipids within the extracellular vesicles of rat bone marrow mesenchymal stem cells (BM-MSC) and the cardiomyoblast cell line H9c2. We were able to characterize, for the first time, complete profiles of oxilipins within these nanovesicles. We studied also the impact on these profiles, of the polyunsaturated fatty acids (PUFAs) know to be precursors of the inflammatory signaling molecules (AA, eicosapentaenoic acid EPA and Docosahexaenoic acid DHA), at physiological concentrations. By growing the progenitor cells under PUFAs supplementation, we provide a comprehensive assessment of the beneficial effect of ω-3 PUFA therapy. Actually, our results tend to support the resolving role of the inflammation that stromal cell-derived extracellular vesicles can have within the cardiac microenvironment.

In vitro and in vivo cardioprotective and metabolic efficacy of vitamin E TPGS/Apelin

AIMS

Apelin and vitamin E have been proposed as signaling molecules, but their synergistic role is unknown. The aim of this work was to develop vitamin E TPGS/Apelin system to test their cardioprotective and metabolic efficacy in vitro and in vivo.

METHODS

FDA-approved surfactant D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS-1000) and Apelin complex were characterized by physico-chemical methods (CMC determination, dynamic light scattering and circular dichroism). In vitro studies were carried out on H9C2 cardiomyoblasts and isolated murine cardiomyocytes. In vivo studies were performed in isoproterenol- and high-fat diet-induced cardiac remodeling models in mice.

RESULTS

We found that vitamin E TPGS/Apelin provide cardioprotective and metabolic efficacy in vitro and in vivo. In vitro studies revealed that vitamin E TPGS/Apelin reduces hypoxia-induced mitochondrial ROS production in cultured cardiomyocytes and H9C2 cardiomyoblasts. In addition, vitamin E TPGS/Apelin confers apoptotic response to hypoxic stress in cells. In a mouse model of isoproterenol-induced cardiac injury, TPGS is not able to affect cardiac remodeling, however combination of vitamin E TPGS and Apelin counteracts myocardial apoptosis, oxidative stress, hypertrophy and fibrosis. Furthermore, combination treatment attenuated obesity-induced cardiometabolic and fibrotic remodeling in mice.

CONCLUSION

Together, our data demonstrated the therapeutic benefits of vitamin E TPGS/Apelin complex to combat cardiovascular and metabolic disorders.

Biodistribution and Biosafety of a Poly(Phosphorhydrazone) Dendrimer, an Anti-Inflammatory Drug-Candidate

Dendrimers are nanosized, arborescent polymers of which size and structure are perfectly controlled. This is one reason why they are widely used for biomedical purposes. Previously, we showed that a phosphorus-based dendrimer capped with anionic azabisphosphonate groups (so-called ABP dendrimer) has immuno-modulatory and anti-inflammatory properties towards human immune cells in vitro. Thereafter, we have shown that the ABP dendrimer has a promising therapeutic efficacy to treat models of chronic inflammatory disorders. On the way to clinical translation, the biodistribution and the safety of this drug-candidate has to be thoroughly assessed. In this article, we present preliminary non-clinical data regarding biodistribution, hematological safety, genotoxicity, maximal tolerated doses, and early cardiac safety of the ABP dendrimer. One of the genotoxicity assays reveals a potential mutagen effect of the item at a concentration above 200 µM, i.e., up to 100 times the active dose in vitro on human immune cells. However, as the results obtained for all the other assays show that the ABP dendrimer has promising biodistribution and safety profiles, there is no red flag raised to hamper the regulatory pre-clinical development of the ABP dendrimer.

Influence of PPH dendrimers' surface functions on the activation of human monocytes: a study of their interactions with pure lipid model systems

The influence of surface functions on the interactions between Poly(PhosphorHydrazone) PPH dendrimers and human monocytes is discussed on the basis of complementary biological and physicochemical studies on membrane models (monolayers and multi-lamellar vesicles). The studies were performed on both an active and non-toxic phosphonic acid capped dendrimer and a non-active but toxic carboxylic acid capped one. On the one hand, comparative studies of the behaviour of DPPC monolayers in the presence or absence of PPH dendrimers in the subphase showed differences in the phase transitions, highlighting interactions between both dendrimers and phospholipid monolayers, with a larger incidence for the carboxylic acid capped dendrimer (negative control), validating its cellular toxicity. On the other hand, comparative biological studies (activation of human monocytes and binding of fluorescent dendrimers on human monocytes) show the pre-eminence of phosphonic acid capped dendrimers towards specific binding and subsequent activation of human monocytes.

Cationic Porphyrin-Anionic Surfactant Mixtures for the Promotion of Self-Organized 1:4 Ion Pairs in Water with Strong Aggregation Properties

We performed a systematic study on the spectroscopic and aggregation properties of stoichiometric mixtures (1:4) of the tetracationic meso-tetrakis(4-N-methylpyridinium)porphyrin (H2 TMPyP) and three sodium alkylsulfate surfactants (tetradecyl, hexadecyl, and octadecylsulfate) in an aqueous solution. The objective was to build a supramolecular aggregate, which would favor the internalization of tetracationic porphyrins in cells without chemical modification of the structure of the porphyrin. We show that stoichiometric H2 TMPyP/alkylsulfate (1:4) mixtures lead to the formation of large hollow spherical aggregates (60-160 nm). The TEM images show that the membrane of these aggregates are composed of smaller aggregates, which are probably rod-like micelles. These rod-like micelles have a hydrophobic core composed of the alkyl chains of the alkylsulfate surfactant, whereas the charged surface corresponds to the tetracationic porphyrins.

Interaction studies reveal specific recognition of an anti-inflammatory polyphosphorhydrazone dendrimer by human monocytes

Dendrimers are nano-materials with perfectly defined structure and size, and multivalency properties that confer substantial advantages for biomedical applications. Previous work has shown that phosphorus-based polyphosphorhydrazone (PPH) dendrimers capped with azabisphosphonate (ABP) end groups have immuno-modulatory and anti-inflammatory properties leading to efficient therapeutic control of inflammatory diseases in animal models. These properties are mainly prompted through activation of monocytes. Here, we disclose new insights into the molecular mechanisms underlying the anti-inflammatory activation of human monocytes by ABP-capped PPH dendrimers. Following an interdisciplinary approach, we have characterized the physicochemical and biological behavior of the lead ABP dendrimer with model and cell membranes, and compared this experimental set of data to predictive computational modelling studies. The behavior of the ABP dendrimer was compared to the one of an isosteric analog dendrimer capped with twelve azabiscarboxylate (ABC) end groups instead of twelve ABP end groups. The ABC dendrimer displayed no biological activity on human monocytes, therefore it was considered as a negative control. In detail, we show that the ABP dendrimer can bind both non-specifically and specifically to the membrane of human monocytes. The specific binding leads to the internalization of the ABP dendrimer by human monocytes. On the contrary, the ABC dendrimer only interacts non-specifically with human monocytes and is not internalized. These data indicate that the bioactive ABP dendrimer is recognized by specific receptor(s) at the surface of human monocytes.

Influence of Structural Parameters on the Self-Association Properties of Anti-HIV Catanionic Dendrimers

The self-association properties of anti-HIV catanionic dendrimers as multivalent galactosylceramide (GalCer)-derived inhibitors are presented. The study was designed to elucidate the origin of the relatively high cytotoxicity values of these anti-HIV catanionic dendrimers, which have previously been found to exhibit in vitro anti-HIV activity in the submicromolar range. The physicochemical properties of these catanionic dendrimers were studied to tentatively correlate the structural parameters with self-association and biological properties. We can conclude from this study that the absence of correlation between the hydrophobicity and the cytotoxicity of the catanionic systems could be explained by the partial segregation of the different partners of the catanionic entities.

Versatile cellular uptake mediated by catanionic vesicles: simultaneous spontaneous membrane fusion and endocytosis

Lactose-derived catanionic vesicles offer unique opportunities to overcome cellular barriers. These potential nanovectors, very easy to formulate as drug delivery systems, are able to encapsulate drugs of various hydrophilicity. This article highlights versatile interaction mechanisms between these catanionic vesicles, labeled with hydrophilic and amphiphilic fluorescent probes, and a mammalian cell line, Chinese Hamster Ovary. Confocal microscopy and flow cytometry techniques show that these vesicles are internalized by cells through cellular energy dependent processes, as endocytosis, but are simultaneously able to spontaneously fuse with cell plasma membranes and release their hydrophilic content directly inside the cytosol. Such innovative and polyvalent nanovectors, able to deliver their content via different internalization pathways, would positively be a great progress for the coadministration of drugs of complementary efficiency.

Multivalent catanionic GalCer analogs derived from first generation dendrimeric phosphonic acids

The synthesis and characterization of a new series of catanionic multivalent analogs of GalCer is described. These systems are based on phosphonic acid terminated dendrimers and N-hexadecylamino lactitol moieties. Despite important structural differences that affect the dendrimers' outer-shell, these supramolecular assemblies showed a fairly comparable anti-HIV-1 activity. All compounds have submicromolar IC(50) in a cell-based HIV-infection model but also a high general cytotoxicity.

Sugar-derived tricatenar catanionic surfactant: self-assembly and aggregation behavior in the cationic-rich side of the system

The aggregation behavior of the cationic-rich side of a sugar-based tricatenar catanionic mixture was investigated in water, and it was shown that the excess of cationic sugar-based surfactant enhanced vesicle stability as well as encapsulation properties. Moreover, when the system was diluted, the vesicular solution collapsed into a lamellar phase, whereas, when it was concentrated, no major impact on the shape and stability of the aggregates was observed. We also showed that both an increase in temperature and the addition of salt induced reversible vesicle aggregation, which appeared to be salt-specific, following the direct order of the Hofmeister series. A proper adjustment of these parameters should then enable better control of the shape, stability, and even encapsulation ability of the aggregates formed by these tricatenar cationic/anionic mixtures.

Sugar-derived tricatenar catanionic surfactant: synthesis, self-assembly properties, and hydrophilic probe encapsulation by vesicles

A new sugar-derived tricatenar catanionic surfactant (TriCat) was developed to obtain stable vesicles that could be exploited for drug encapsulation. The presence of the sugar moiety led to the formation of highly hydrophilic stoichiometric catanionic surfactant systems. The three hydrophobic chains permitted vesicles to form spontaneously. The self-assembly properties (morphology, size, and stability) of TriCat were examined in water and in buffer solution. Encapsulation studies of a hydrophilic probe, arbutin, commonly used in cosmetics for its whitening properties, were performed to check the impermeability of the vesicle bilayer. The enhancement of hydrophobic forces by the three chains of TriCat prevented surfactant equilibrium between the bilayer and the solution and enabled the probe to be retained in the aqueous cavity of the vesicles for at least 30 h. Thus, the present study suggests that this tricatenar catanionic surfactant could be a promising delivery system for hydrophilic drugs.

Design of Original Bioactive Formulations Based on Sugar–Surfactant/Non-steroidal Anti-inflammatory Catanionic Self-Assemblies: A New Way of Dermal Drug Delivery

A new kind of catanionic assembly was developed that associates a sugar-based surfactant with a non-steroidal anti-inflammatory drug (NSAID). Three different assemblies using indomethacin, ibuprofen and ketoprofen as NSAIDs were easily obtained in water by an acid-base reaction. These assemblies formed new amphiphilic entities because of electrostatic and hydrophobic effects in water and led to the spontaneous formation of vesicles. These catanionic vesicles were then tested as potential NSAID delivery systems for dermatological application. The anti-inflammatory activity was evaluated in vivo, and this study clearly showed an improved therapeutic effect for NSAIDs that were formulated as catanionic vesicles. These vesicles ensured a slower diffusion of the NSAID through the skin. This release probably increased the time of retention of the NSAID in the targeted strata of the skin. Thus, the present study suggests that this catanionic bioactive formulation could be a promising dermal delivery system for NSAIDs in the course of skin inflammation treatment.

Dendritic catanionic assemblies: in vitro anti-HIV activity of phosphorus-containing dendrimers bearing galbeta1cer analogues

Two series of water-soluble dendritic catanionic assemblies, acting as multisite analogues of galactosylceramide (Galbeta1cer), have been prepared with the goal of blocking HIV infection prior to the entry of the virus into human cells. Trifunctional and hexafunctional cinnamic acid-terminated dendrimers have been synthesized from phosphorus-containing dendrimers bearing aldehyde end groups. A classical acid-base reaction performed in water between acid-terminated dendrimers and stoichiometric amounts of N-hexadecylamino-1-deoxylactitol provided the expected catanionic assemblies. Antiviral assays on these supramolecular entities confirmed the crucial roles both of multivalency effects and of lipophilicity on the biological activity of Galbeta1cer analogues. Moreover, correlation between in vitro tests and molecular modeling highlights the specific influence of the assembly shape on the anti-HIV efficiency, with the tri- and hexafunctional cored dendrimers, both decorated with 12 sugar moieties, exhibiting IC50 values of 1.1 and 0.12 microM, respectively.

In-plane miscibility and mixed bilayer microstructure in mixtures of catanionic glycolipids and zwitterionic phospholipids

SAXS/WAXS studies were performed in combination with freeze fracture electron microscopy using mixtures of a new Gemini catanionic surfactant (Gem16-12, formed by two sugar groups bound by a hydrocarbon spacer with 12 carbons and two 16-carbon chains) and the zwitterionic phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) to establish the phase diagram. Gem16-12 in water forms bilayers with the same amount of hydration water as DPPC. A frozen interdigitated phase with a low hydration number is observed below room temperature. The kinetics of the formation of this crystalline phase is very slow. Above the chain melting temperature, multilayered vesicles are formed. Mixing with DPPC produces mixed bilayers above the corresponding chain melting temperature. At room temperature, partially lamellar aggregates with local nematic order are observed. Splitting of infinite lamellae into discs is linked to immiscibility in frozen state. The ordering process is always accompanied by dehydration of the system. As a consequence, an unusual order-disorder phase transition upon cooling is observed.

New Rebek imide-type receptors for adenine featuring acetylene-linked pi-stacking platforms

Rebek imide-type molecular clefts with pi-stacking platforms attached to the imide scaffold by an acetylene linker have been prepared by Sonogashira cross-coupling. In the solid state, a novel dimerisation mode for this class of imide receptors was found by crystal structure analysis, whereas efficient 1 : 1 complexation with 9-ethyladenine was observed in CDCl3 solution.

Correlation between structure, aggregation behaviour and cellular toxicity of anti-HIV catanionic analogues of galactosylceramide

The self-association process of catanionic analogues of galactosylceramide and in particular the arrangement of their hydrophobic part seems to play a key role in their cellular toxicity

Phosphorus-containing dendrimers bearing galactosylceramide analogs: Self-assembly propertiesElectronic supplementary information (ESI) available: experimental. See http://www.rsc.org/suppdata/cc/b2/b204287h/

We report the synthesis and the supramolecular auto-assembly of catanionic phosphorus-containing dendrimers mimicking multisite analogs of galactosylceramide.