Nanoemulsions Embedded in Alginate Beads as Bioadhesive Nanocomposites for Intestinal Delivery of the Anti-Inflammatory Drug Tofacitinib.

Oral administration of nanoparticles (NPs) is a promising strategy to overcome solubility and stability issues of many active compounds. However, this route faces major obstacles related to the hostile gastrointestinal (GI) environment, which impairs the efficacy of orally administered nanomedicines. Here, we propose nanocomposites as a promising approach to increase the retention time of NPs in the intestinal tract by using bio- and mucoadhesive matrixes able to protect the cargo until it reaches the targeted area. A microfluidic-based approach has been applied for the production of tailored nanoemulsions (NEs) of about 110 nm, used for the encapsulation of small hydrophobic drugs such as the anti-inflammatory JAK-inhibitor tofacitinib. These NEs proved to be efficiently internalized into a mucus-secreting human intestinal monolayer of Caco-2/HT29-MTX cells and to deliver tofacitinib to subepithelial human THP-1 macrophage-like cells, reducing their inflammatory response. NEs were then successfully encapsulated into alginate hydrogel microbeads of around 300 µm, which were characterized by rheological experiments and dried to create a long-term stable system for pharmaceutical applications. Finally, ex vivo experiments on excised segments of rats' intestine proved the bioadhesive ability of NEs embedded in alginate hydrogels compared to free NEs, showing the advantage that this hybrid system can offer for the treatment of intestinal pathologies.

Repurposing pentamidine using hyaluronic acid-based nanocarriers for skeletal muscle treatment in myotonic dystrophy.

In a context of drug repurposing, pentamidine (PTM), an FDA-approved antiparasitic drug, has been proposed to reverse the splicing defects associated in myotonic dystrophy type 1 (DM1). However, clinical use of PTM is hinder by substantial toxicity, leading to find alternative delivery strategies. In this work we proposed hyaluronic acid-based nanoparticles as a novel encapsulation strategy to efficiently deliver PTM to skeletal muscles cells. In vitro studies on C2C12 myoblasts and myotubes showed an efficient nanoparticles' internalization with minimal toxicity. More interestingly, our findings evidenced for the first time the endosomal escape of hyaluronic acid-based nanocarriers. Ex vivo studies showed an efficient nanoparticles' internalization within skeletal muscle fibers. Finally, the therapeutic efficacy of PTM-loaded nanosystems to reduce the number of nuclear foci has been demonstrated in a novel DM1 in vitro model. So far, current data demonstrated the potency of hyaluronic acid-based nanosystems as efficient nanocarrier for delivering PTM into skeletal muscle and mitigate DM1 pathology.

Shape-selective synthesis of nanoceria for degradation of paraoxon as a chemical warfare simulant.

Repeated attacks using organophosphorus compounds, in military conflicts or terrorist acts, necessitate developing inexpensive and readily available decontamination systems. Nanosized cerium oxide is a suitable candidate, acting as a heterogeneous catalyst for the degradation of organophosphorus compounds such as VX agent or sarin. However, the reaction mechanism of the phosphatase mimetic activity of CeO2 nanoparticles is not fully described. Adsorption, surface-promoted hydrolysis, and desorption cycles strongly depend on the physico-chemical characteristics of the facets. In this study, CeO2 nanoparticles with different shapes were elaborated by hydrothermal synthesis. Nano-octahedra, nanocubes, or nanorods were selectively obtained under different conditions (temperature, concentration and nature of the precursors). The degradation activity according to the crystal faces was evaluated in vitro by measuring the degradation kinetics of paraoxon organophosphate in the presence of CeO2 nanoparticles. The results show an influence of both specific surface area and crystal faces of the nanoparticles, with higher activity for {111} facets compared to {100} facets at 32 °C. The relative activity between the facets is ascribed to the adsorption probability, assuming coordination between the phosphoryl oxygen and cerium atoms, but also to the surface density of the Ce doublets with relevant spacing for phosphatase mimetic activity.

Skin Absorption of Anions: Part Two. Skin Absorption of Halide Ions.

PURPOSE: The purpose of the study was to sort skin penetration of anions with respect to their properties and to assess their mechanisms of penetration. METHODS: Aqueous solutions of halides at two concentrations were prepared and quantitative penetration studies were carried out for 24 h using Franz diffusion cells. The iodide permeation was also measured after blocking of anion channels and transporters to investigate the role of this specific transport. RESULTS: Absorption of halide ions into skin revealed large differences of transport between these anions according to the Hofmeister series. Increasing steady-state fluxes and lag times in the order F(-) < Cl(-) < Br(-) < I(-) were observed in permeation experiments. The steady-state fluxes were proportional to the concentration for each halide ion. Longer lag times for iodide or bromide ions were explained by the ability of such sticky chaotropic anions to interact with apolar lipids especially in the stratum corneum. Inhibiting ion exchangers and channels decreased the flux of iodide ions by 75%, showing the high contribution of the facilitated transport over the passive pathway. CONCLUSION: Ions transport had contributions coming from passive diffusion through the skin layers and transport mediated by ion channels and binding to ion transporters.

Skin Absorption of Anions: Part One. Methodology for In Vitro Cutaneous Absorption Measurements.

PURPOSE: Measurement of skin absorption of ions requires specific experimental protocols regarding the use of pig skin as a model, the viability of excised skin in water medium over 24 h, the presence of endogenous ions, and evaluation of the contributions of facilitated transport through ion channels and ion transporters. METHOD: Absorption experiments of halide anions F(-), Cl(-), Br(-) and I(-) in excised skin were performed in Franz diffusion cells. Experiments were performed on human and porcine skin under various conditions so as to define and validate experimental protocols. RESULTS: The distributions of endogenous ions and the absorption kinetics of halide ions were similar in both porcine and human skin models. Fresh skin kept its viability over 24 h in salt-free water, allowing experiments following OECD guidelines. Permeation increased in the order F(-) < Cl(-) < Br(-) < I(-) for all receptor media and skin samples. Absorption was larger in fresh skin due to the transport through chloride channels or exchangers. CONCLUSION: Skin absorption experiments of ions in Franz cells rely on working with fresh excised skin (human or porcine) and pure water as receptor fluid. Experiments with chloride blockers or frozen/thawed skin allow discriminating passive diffusion and facilitated transport.

Processing-induced-transformations (PITs) during direct compression: impact of compression speeds on phase transition of caffeine.

For pharmaceutical industry, understanding solid-phase transition of the active pharmaceutical ingredient (API) induced by the manufacturing process is a key issue. Caffeine was chosen as a model API since it exhibits a polymorphic transformation during tableting. This study investigated the impact of the compression speed on the phase transition of anhydrous Form I (CFI) into Form II. Tablets were made from pure CFI and binary mixtures of CFI/microcrystalline cellulose, with an electric press well instrumented at three different compression speeds (50, 500 and 4500 mm min(-1)). For each velocity of the mobile punch studied, tablets made from three compression pressures (50, 100 and 200 MPa) were analyzed. The determination of the CFI transition degree was performed using a Differential Scanning Calorimetry (DSC). The CFI transition degree was monitored during three months in order to obtain the transformation profile of the API in tablets and in uncompressed powder. The modeling of the profile with a stretched exponential kinetic law (Johnson-Mehl-Avrami model) was used for the identification of the transition mechanism. The direct compression process triggered the polymorphic transformation in tablet when a sufficient compression pressure is applied. The velocity of the punch did neither impact the transition degree just after compression nor the transformation profile. The transition mechanism remained driven by nucleation for several operating conditions. Consequently, the punch velocity is not a decisive process parameter for avoiding such phase transition in tableting. As already observed, the compression pressure did not influence the transition whatever the compression speed and the velocity.

Encapsulation of hydrophobic allergens into nanoparticles improves the in vitro immunological diagnosis of allergic contact dermatitis.

The diagnosis of allergic contact dermatitis (ACD) relies on in vivo patch testing. In vitro immunological assays based on the characterization of circulating allergen-specific memory T cells represent a promising alternative to patch testing. However, their development is hampered by the technical challenge of assessing hydrophobic allergens in serum-based assays. In this study, we show that the encapsulation of fragrance mix 1 (FMI, a mixture of 8 hydrophobic allergens) into poly-ε-caprolactone nanoparticle (NP) vectors: (1) dramatically increases the solubilization of allergens in conventional cell culture media and (2) allows for a robust in vitro reactivation of allergen-specific T cells in large numbers of fragrance allergic patients. Therefore, the encapsulation of hydrophobic allergens into NP vectors opens new avenues to improve the in vitro immunobiological diagnosis of ACD. FROM THE CLINICAL EDITOR: Allergic Contact Dermatitis (ACD) is a delayed-type hypersensivity reaction prevalent in many individuals. Currently, skin patch testing has been the mainstay for diagnosis clinically. In this study, the authors described an improvement to in vitro immunological assays measuring circulating allergen-specific memory T cells, using nanoparticle vectors. The positive data might provide an exciting alternative to current practice of patch-testing.

Peptide-Based Hydrogel for Nanosystems Encapsulation: the Next Generation of Localized Delivery Systems for the Treatment of Intestinal Inflammations.

Conventional therapies for inflammatory bowel diseases are mainly based on systemic treatments which cause side effects and toxicity over long-term administration. Nanoparticles appear as a valid alternative to allow a preferential accumulation in inflamed tissues following oral administration while reducing systemic drug exposure. To increase their residence time in the inflamed intestine, the nanoparticles are here associated with a hydrogel matrix. A bioadhesive peptide-based hydrogel is mixed with nanoemulsions, creating a hybrid lipid-polymer nanocomposite. Mucopenetrating nanoemulsions of 100 nm are embedded in a scaffold constituted of the self-assembling peptide hydrogel product PuraStat. The nanocomposite is fully characterized to study the impact of lipid particles in the hydrogel structure. Rheological measurements and circular dichroism analyses are performed to investigate the system's microstructure and physical properties. Biodistribution studies demonstrate that the nanocomposite acts as a depot in the stomach and facilitates the slow release of the nanoemulsions in the intestine. Efficacy studies upon oral administration of the drug-loaded system show the improvement of the disease score in a mouse model of intestinal inflammation.

Poly(ethylene glycol)-poly(ε-caprolactone) iodinated nanocapsules as contrast agents for X-ray imaging.

PURPOSE: Synthesis and formulation of iodinated PCL-mPEG nanocapsules as new original blood pool contrast agents for computed tomography. METHODS: PCL-mPEG was synthesized and formulated following the emulsion-solvent diffusion process, in the form of iodinated nanocapsules. Physico-chemical characterization of such nano-materials was performed by DLS and transmission electron microscopy. A stability study of the nanocapsules suspension was followed-up to 3 month. Blood biocompatibility was performed. Finally, the nanocapsules suspension radiopacity was evaluated in vitro then in vivo in mice as micro-CT contrast agent. RESULTS: In this study, the iodine concentration in nanocapsules suspension was about 70 mgI/mL. Besides, these nanocarriers appeared non-toxic, and stable in suspension. In vivo, i.v. administration of 10 µL/g of mouse body weight of theses nano-particles induced a vascular contrast enhancement of 168 HU and a half-life in blood of 4.2 +/- 0.5 h. Elimination route of these particles appears mainly performed by the liver, without sequestration in spleen and lymph nodes confirming their stealth properties. CONCLUSIONS: This study proposes the first example of iodinated biodegradable polymeric blood pool contrast agent, able to induce an exploitable contrast enhancement. The main advantage of polymeric system compared to lipid ones, lies in their stability and handling, e.g. towards drying for storage.

Nano-encapsulation of vitamin D3 active metabolites for application in chemotherapy: formulation study and in vitro evaluation.

PURPOSE: Calcitriol (1,25-dihydroxyvitamin D3), the active metabolite of vitamin D3, is a potential anticancer agent but with high risk of hypercalcemia which limits the achievement of effective serum concentrations. Thus, calcitriol targeting delivery by nanoparticles may present a good solution. METHODS: Vitamin D3 active metabolites were encapsulated into polymeric nanoparticles and different formulation parameters were tested. The growth inhibitory efficiency of these nanoparticles was carried out in vitro on human breast adenocarinoma cells (MCF-7). RESULTS: Using cholecalciferol (the inactive metabolite), different polymer and oil ratios were compared to select nanoparticles presenting high encapsulation efficiency and sustained release profile. Calcidiol/calcitriol loaded nanoparticles had good encapsulation efficiencies (around 90%) associated with sustained releases over 7 days and enhanced stability. Moreover, loaded nanoparticles showed similar growth inhibition to non-encapsulated metabolites of vitamin D3 on day 4 and higher activities on days 7 and 10 after treatment initiation. CONCLUSION: The nano-encapsulation of vitamin D3 active metabolites may offer a new and potentially effective strategy for vitamin D3-based chemotherapy overcoming its actual limitations. The targeting delivery of vitamin D3 metabolites should be encouraged.

Development of an oral nanovaccine for dogs against Echinococcus granulosus.

Dogs are the main source of animal and human cystic echinococcosis caused by the Cestode parasite Echinococcus granulosus. Dog vaccination seems to be a good strategy to control this parasitic disease. Here we present the development of a polymeric nanoparticle-based oral vaccine for dogs against Echinococcus granulosus delivered in enteric-coated capsules. To achieve our target, we encapsulated two recombinant antigens into biodegradable polymeric nanoparticles in the presence of Monophosphoryl lipid A as an adjuvant to ensure efficient delivery and activation of a protective mucosal immune response. The formulated delivery system showed a nanoparticle size less than 200 nm with more than 80 % antigen encapsulation efficiency and conserved integrity and immunogenicity. The nanoparticle surface was coated with chitosan to enhance adhesion to the gut mucosa and a subsequent antigen delivery. Chitosan-coated nanoparticles showed a higher cell internalization in murine macrophages and dendritic cells as well as a higher penetration into Caco-2 cells in vitro. Antigen-loaded nanoparticles were freeze-dried and enteric-coated capsules were filled with the obtained powder. The obtained results show a promising nanoparticles delivery system for oral vaccination.

Hybrid core-shell particles for mRNA systemic delivery.

mRNA based infectious disease vaccines have opened the venue for development of novel nucleic acids-based therapeutics. For all mRNA therapeutics dedicated delivery systems are required, where different functionalities and targeting abilities need to be optimized for the respective applications. One option for advanced formulations with tailored properties are lipid-polymer hybrid nanoparticles with complex nanostructure, which allow to combine features of several already well described nucleic acid delivery systems. Here, we explored hyaluronic acid (HA) as coating of liposome-mRNA complexes (LRCs) to investigate effects of the coating on surface charge, physicochemical characteristics and biological activity. HA was electrostatically attached to positively charged complexes, forming hybrid LRCs (HLRCs). At different N/P ratios, physico-chemical characterization of the two sets of particles showed similarity in size (around 200 nm) and mRNA binding abilities, while the presence of the HA shell conferred a negative surface charge to otherwise positive complexes. High transfection efficiency of LRCs and HLRCs in vitro has been obtained in THP-1 and human monocytes derived from PBMC, an interesting target cell population for cancer and immune related pathologies. In mice, quantitative biodistribution of radiolabeled LRC and HLRC particles, coupled with bioluminescence studies to detect the protein translation sites, hinted towards both particles' accumulation in the hepatic reticuloendothelial system (RES). mRNA translated proteins though was found mainly in the spleen, a major source for immune cells, with preference for expression in macrophages. The results showed that surface modifications of liposome-mRNA complexes can be used to fine-tune nanoparticle physico-chemical characteristics. This provides a tool for assembly of stable and optimized nanoparticles, which are prerequisite for future therapeutic interventions using mRNA-based nanomedicines.

Encapsulation of a pressure-sensitive adhesive by spray-drying: microparticles preparation and evaluation of their crushing strength.

An industrial pressure-sensitive adhesive was microencapsulated by spray-drying using an aqueous colloidal ethylcellulose dispersion (Aquacoat® ECD) plasticised by triacetin to form the wall material. Unloaded (0:100) and adhesive-loaded (25:75) particles were produced in a Büchi B-191 mini spray-dryer with product yields of 62% and 57%, respectively. Microparticles were spherical and narrow sized with mean D3,2 diameters of 3.165 ± 0.001 and 5.544 ± 0.105 µm, respectively. The microparticles were found to redisperse well in water and exhibit enough stability in neutral and alkaline aqueous media to be further used in a coating slip. Crush tests on single microparticles with diameters ranging from 2 to 12 µm were performed using a nanoindenter. They revealed that the crushing force of both kinds of microparticles increased linearly with their diameter and that the adhesive loading reduced the mechanical strength of the prepared microparticles.

Ingredients tracking of cosmetic formulations in the skin: a confocal Raman microscopy investigation.

PURPOSE: Confocal Raman microspectroscopy (CRM) was used to follow the absorption of retinol into the skin and to track the absorption of ingredients in topically applied formulations. METHOD: Three surfactants, PEG20C12, PEG20C18:1 (hydrophilic) and PEG6C18:1 (lipophilic), were used in preparing three o/w emulsions and three surfactant solutions all containing retinol. Quantitative retinol penetration studies for 24 h were carried out using Franz diffusion cells. CRM was used to follow the skin penetration of retinol, oil and water and also to study a possible modification of the lipid skin barrier in the stratum corneum (SC) using the ratio of I(2880)/I(2850). RESULTS: The oily surfactant solution containing PEG6C18:1 and dodecane showed the highest retinol penetration rate. This appears to be related both to the short polar head group of the surfactant and to the effect of dodecane on skin lipids. All the surfactant solutions showed a higher penetration rate compared with the corresponding emulsions. CRM measurements showed that the ratios of I(2880)/I(2850) were significantly modified using surfactant solutions. CONCLUSIONS: Penetration behavior appeared to be dependent on the surfactant used in the formulation. CRM associated to the Franz cell method gives new insights on permeation of drug related to vehicle or ingredients.

Confocal Raman microspectroscopy of the skin.

Confocal Raman spectroscopy is a technique with considerable potential for the non-invasive study of biological tissues and skin samples in vitro or in vivo. It can be used to study skin physiology and possible pathological conditions and to obtain data about molecular composition and the structure of skin, for example, water content, moisturization and changes in the skin barrier function can all be observed. In-depth measurements also allow biopharmaceutical studies, such as analyzing the rate of penetration of a drug and the biochemical changes that may be induced by an applied formulation. Confocal Raman microspectroscopy is now at such a stage of refinement that it opens up new vistas. The big leap forward in its ease of use enables this technology to be used as an analytical method by more and more non-specialist laboratories. This review gives an overview of the state of the art of this technology by presenting an update on the principles of Raman spectroscopy and then by looking at examples of new developments in in vivo and in vitro applications.

Nanocomposite systems for precise oral delivery of drugs and biologics.

Oral delivery is considered the favoured route of administration for both local and systemic delivery of active molecules. Formulation of drugs in conventional systems and nanoparticles has provided opportunities for targeting the gastrointestinal (GI) tract, increasing drug solubility and bioavailability. Despite the achievements of these delivery approaches, the development of a product with the ability of delivering drug molecules at a specific site and according to patients' needs remains a challenging endeavour. The complexity of the physicochemical properties of colloidal systems, their stability in different regions of the gastrointestinal tract, and interaction with the restrictive biological barriers hampered their success for oral precise medicine. To overcome these issues, nanoparticles have been combined with polymers to create hybrid nanosystems, namely nanocomposites. They offer enormous possibilities of structural and mechanical modifications to both nanoparticles and polymeric matrixes to generate systems with new properties, functions, and applications for oral delivery. In this review, nanocomposites' physicochemical and functional properties intended to target specific regions of the GI tract-oral cavity, stomach, small bowel, and colon-are analysed. In parallel, it is provided an insight in the nanocomposite solutions for oral delivery intended for systemic and local absorption, together with a focus on inflammatory bowel diseases (IBDs). Additional difficulties in managing IBD related to the alteration in the physiology of the intestine are described. Finally, future perspectives and opportunities for advancement in this field are discussed.

Skin absorption of mixed halide anions from concentrated aqueous solutions.

Non-ideal behaviour of mixed ions is disclosed in skin absorption experiments of mixed halide anions in excised pig skin. Comparison of skin absorption of pure and mixed ions shows enhanced penetration of chaotropic ions from mixed solutions. An experimental design and statistical analysis using a Scheffé {3,2} simplex-lattice allows investigating the full ternary diagram of anion mixtures of fluoride, bromide and iodide. Synergism in mixed absorption is observed for chaotropic bromide and iodide anions. A refined analysis highlighting specific interactions is made by considering the ratio of the absorbed amount to the ion activity instead of the directly measured absorbed amount. Statistical analysis discards non-significant effects and discloses specific interactions. Such interactions between bromide and iodide cause an absorption enhancement of their partner by a factor of 2-3 with respect to the case of ideal mixing. It is proposed that enhanced absorption from mixed solution involves the formation of neutral complex species of mixed bromide and iodide with endogenous magnesium or calcium inside stratum corneum.

Nanomedicine for Gene Delivery and Drug Repurposing in the Treatment of Muscular Dystrophies.

Muscular Dystrophies (MDs) are a group of rare inherited genetic muscular pathologies encompassing a variety of clinical phenotypes, gene mutations and mechanisms of disease. MDs undergo progressive skeletal muscle degeneration causing severe health problems that lead to poor life quality, disability and premature death. There are no available therapies to counteract the causes of these diseases and conventional treatments are administered only to mitigate symptoms. Recent understanding on the pathogenetic mechanisms allowed the development of novel therapeutic strategies based on gene therapy, genome editing CRISPR/Cas9 and drug repurposing approaches. Despite the therapeutic potential of these treatments, once the actives are administered, their instability, susceptibility to degradation and toxicity limit their applications. In this frame, the design of delivery strategies based on nanomedicines holds great promise for MD treatments. This review focuses on nanomedicine approaches able to encapsulate therapeutic agents such as small chemical molecules and oligonucleotides to target the most common MDs such as Duchenne Muscular Dystrophy and the Myotonic Dystrophies. The challenge related to in vitro and in vivo testing of nanosystems in appropriate animal models is also addressed. Finally, the most promising nanomedicine-based strategies are highlighted and a critical view in future developments of nanomedicine for neuromuscular diseases is provided.

Nanocomposite sponges for enhancing intestinal residence time following oral administration.

In this work, nanocomposites that combine mucopenetrating and mucoadhesive properties in a single system are proposed as innovative strategy to increase drug residence time in the intestine following oral administration. To this aim, novel mucoadhesive chitosan (CH) sponges loaded with mucopenetrating nanoemulsions (NE) were developed via freeze-casting technique. The NE mucopenetration ability was determined studying the surface affinity and thermodynamic binding of the nanosystem with mucins. The ability of nanoparticles to penetrate across a preformed mucins layer was validated by 3D-time laps Confocal Laser Scanning Microscopy imaging. Microscopy observations (Scanning Electron Microscopy and Optical Microscopy) showed that NE participated in the structure of the sponge affecting its stability and in vitro release kinetics. When incubated with HCT 116 and Caco-2 cell lines, the NE proved to be cytocompatible over a wide concentration range. Finally, the in vivo biodistribution of the nanocomposite was evaluated after oral gavage in healthy mice. The intestinal retention of NE was highly enhanced when loaded in the sponge compared to the NE suspension. Overall, our results demonstrated that the developed nanocomposite sponge is a promising system for sustained drug intestinal delivery.

Supersaturable self-microemulsifying delivery systems: an approach to enhance oral bioavailability of benzimidazole anticancer drugs.

This study explored the design of supersaturable self-microemulsifying drug delivery systems (S-SMEDDS) to address poor solubility and oral bioavailability of a novel benzimidazole derivative anticancer drug (BI). Firstly, self-microemulsifying drug delivery systems SMEDDS made of Miglyol® 812, Kolliphor® RH40, Transcutol® HP, and ethanol were prepared and loaded with the BI drug. Upon dispersion, the systems formed neutrally charged droplets of around 20 nm. However, drug precipitation was observed following incubation with simulated gastric fluid (pH 1.2). Aiming at reducing this precipitation and enhancing drug payload, supersaturable systems were then prepared by adding 1% hydroxypropyl cellulose as precipitation inhibitor. Supersaturable systems maintained a higher amount of drug in a supersaturated state in gastric medium compared with conventional formulations and were stable in simulated intestinal medium (pH 6.8). In vitro cell studies using Caco-2 cell line showed that these formulations reduced in a transient manner the transepithelial electrical resistance of the monolayers without toxicity. Accordingly, confocal images revealed that the systems accumulated at tight junctions after a 2 h exposure. In vivo pharmacokinetic studies carried out following oral administration of BI-loaded S-SMEDDS, SMEDDS, and free drug to healthy mice showed that supersaturable systems promoted drug absorption compared with the other formulations. Overall, these data highlight the potential of using the supersaturable approach as an alternative to conventional SMEDDS for improving oral systemic absorption of lipophilic drugs.