In Vivo Biodistribution of Respirable Solid Lipid Nanoparticles Surface-Decorated with a Mannose-Based Surfactant: A Promising Tool for Pulmonary Tuberculosis Treatment?

The active targeting to alveolar macrophages (AM) is an attractive strategy to improve the therapeutic efficacy of ‘old’ drugs currently used in clinical practice for the treatment of pulmonary tuberculosis. Previous studies highlighted the ability of respirable solid lipid nanoparticle assemblies (SLNas), loaded with rifampicin (RIF) and functionalized with a novel synthesized mannose-based surfactant (MS), both alone and in a blend with sodium taurocholate, to efficiently target the AM via mannose receptor-mediated mechanism. Here, we present the in vivo biodistribution of these mannosylated SLNas, in comparison with the behavior of both non-functionalized SLNas and bare RIF. SLNas biodistribution was assessed, after intratracheal instillation in mice, by whole-body real-time fluorescence imaging in living animals and RIF quantification in excised organs and plasma. Additionally, SLNas cell uptake was determined by using fluorescence microscopy on AM from bronchoalveolar lavage fluid and alveolar epithelium from lung dissections. Finally, histopathological evaluation was performed on lungs 24 h after administration. SLNas functionalized with MS alone generated the highest retention in lungs associated with a poor spreading in extra-pulmonary regions. This effect could be probably due to a greater AM phagocytosis with respect to SLNas devoid of mannose on their surface. The results obtained pointed out the unique ability of the nanoparticle surface decoration to provide a potential more efficient treatment restricted to the lungs where the primary tuberculosis infection is located.

Newly synthesized surfactants for surface mannosylation of respirable SLN assemblies to target macrophages in tuberculosis therapy

The present study reports about new solid lipid nanoparticle assemblies (SLNas) loaded with rifampicin (RIF) surface-decorated with novel mannose derivatives, designed for anti-tuberculosis (TB) inhaled therapy by dry powder inhaler (DPI). Mannose is considered a relevant ligand to achieve active drug targeting being mannose receptors (MR) overexpressed on membranes of infected alveolar macrophages (AM), which are the preferred site of Mycobacterium tuberculosis. Surface decoration of SLNas was obtained by means of newly synthesized functionalizing compounds used as surfactants in the preparation of carriers. SLNas were fully characterized in vitro determining size, morphology, drug loading, drug release, surface mannosylation, cytotoxicity, macrophage internalization extent and ability to bind MR, and intracellular RIF concentration. Moreover, the influence of these new surface functionalizing agents on SLNas aerodynamic performance was assessed by measuring particle respirability features using next generation impactor. SLNas exhibited suitable drug payload, in vitro release, and more efficient ability to enter macrophages (about 80%) compared to bare RIF (about 20%) and to non-functionalized SLNas (about 40%). The involvement of MR-specific binding has been demonstrated by saturating MR of J774 cells causing a decrease of RIF intracellular concentration of about 40%. Furthermore, it is noteworthy that the surface decoration of particles produced a poor cohesive powder with an adequate respirability (fine particle fraction ranging from about 30 to 50%). Therefore, the proposed SLNas may represent an encouraging opportunity in a perspective of an efficacious anti-TB inhaled therapy.

Self-Assembled Lipid Nanoparticles for Oral Delivery of Heparin-Coated Iron Oxide Nanoparticles for Theranostic Purposes

Recently, solid lipid nanoparticles (SLNs) have attracted increasing attention owing to their potential as an oral delivery system, promoting intestinal absorption in the lymphatic circulation which plays a role in disseminating metastatic cancer cells and infectious agents throughout the body. SLN features can be exploited for the oral delivery of theranostics. Therefore, the aim of this work was to design and characterise self-assembled lipid nanoparticles (SALNs) to encapsulate and stabilise iron oxide nanoparticles non-covalently coated with heparin (Fe@hepa) as a model of a theranostic tool. SALNs were characterised for physico-chemical properties (particle size, surface charge, encapsulation efficiency, in vitro stability, and heparin leakage), as well as in vitro cytotoxicity by methyl thiazole tetrazolium (MTT) assay and cell internalisation in CaCo-2, a cell line model used as an indirect indication of intestinal lymphatic absorption. SALNs of about 180 nm, which are stable in suspension and have a high encapsulation efficiency (>90%) were obtained. SALNs were able to stabilise the heparin coating of Fe@hepa, which are typically unstable in physiological environments. Moreover, SALNs–Fe@hepa showed no cytotoxicity, although their ability to be internalised into CaCo-2 cells was highlighted by confocal microscopy analysis. Therefore, the results indicated that SALNs can be considered as a promising tool to orally deliver theranostic Fe@hepa into the lymphatic circulation, although further in vivo studies are needed to comprehend further potential applications.

Gastroretentive montmorillonite-tetracycline nanoclay for the treatment of Helicobacter pylori infection

The paper aims to explore the potential benefits provided by an organically modified montmorillonite (nanoclay) in the problematic management of the Helicobacter pylori gastric infection that is one of the most prevalent infectious diseases worldwide. Two nanoclay samples were produced by the intercalation of tetracycline (TC) into the interlayer of montmorillonite (MM) under two different pH reaction conditions (pH 3.0 and 8.7). MM/TC nanoclays were characterized by EDX, XRD, FTIR, DSC, drug adsorption extent, in vitro mucoadhesiveness and desorption in simulated gastric media. The reaction between MM and TC led to a complete MM cation (Na(+) and Ca(2+)) exchange process, an increase of MM characteristic interlayer spacing as well as an involvement of NHR3(+) group of TC, regardless of the reaction pH value. However, MM/TC nanoclay obtained under alkaline conditions provided a lower TC adsorption as well as a drug fraction weakly linked to MM in comparison with the nanoclay obtained in acidic conditions. Both the nanoclays exhibited good mucoadhesion properties to porcine mucin and TC desorption occurring mainly via a cation exchange process by H(+) ions. Based on the results obtained, TC intercalation into MM nanoplatelets could represent a potential advantageous approach allowing the antibiotic to distribute homogeneously on the gastric mucosa, diffuse through the gastric mucus layer and achieve the microorganism localization.

Nasal biocompatible powder of Geraniol oil complexed with cyclodextrins for neurodegenerative diseases: physicochemical characterization and in vivo evidences of nose to brain delivery

Recently, many studies have shown that plant metabolites, such as geraniol (GER), may exert anti-inflammatory effects in neurodegenerative diseases and, in particular, Parkinson's disease (PD) models. Unfortunately, delivering GER to the CNS via nose-to-brain is not feasible due to its irritant effects on the mucosae. Therefore, in the present study β-cyclodextrin (βCD) and its hydrophilic derivative hydroxypropyl-beta-cyclodextrin (HPβCD) were selected as potential carriers for GER nose-to-brain delivery. Inclusion complexes were formulated and the biocompatibility with nasal mucosae and drug bioavailability into cerebrospinal fluid (CSF) were studied in rats. It has been demonstrated by DTA, FT-IR and NMR analyses that both the CDs were able to form 1:1 GER-CD complexes, arising long-term stable powders after the freeze-drying process. GER-HPβCD-5 and GER-βCD-2 complexes exhibited comparable results, except for morphology and solubility, as demonstrated by SEM analysis and phase solubility study, respectively. Even though both complexes were able to directly and safely deliver GER to CNS, GER-βCD-2 displayed higher ability in releasing GER in the CSF. In conclusion, βCD complexes can be considered a very promising tool in delivering GER into the CNS via nose-to-brain route, preventing GER release into the bloodstream and ensuring the integrity of the nasal mucosa.

Bile salt-coating modulates the macrophage uptake of nanocores constituted by a zidovudine prodrug and enhances its nose-to-brain delivery

We have previously demonstrated that the ester conjugation of zidovudine (AZT) with ursodeoxycholic acid (UDCA) allows to obtain a prodrug (U-AZT) which eludes the active efflux transporters (AET). This allows the prodrug to more efficiently permeates and remains in murine macrophages than the parent compound. Here we demonstrate that U-AZT can be formulated, by a nanoprecipitation method, as nanoparticle cores coated by bile acid salt (taurocholate or ursodeoxycholate) corona, without any other excipients. The U-AZT nanoparticles appeared spherical with a mean diameter of ∼200 nm and a zeta potential of ∼-55 mV. During the incubation (5 h) in fetal bovine serum, the ursodeoxycholate-coated nanoparticle size did not change. Differently, taurocholate-coated particle size was firstly reduced and then increased up to 800 µm, thus suggesting the high aptitude of these nanoparticles to interact with serum proteins. The in vitro uptake of taurocholate coated particles by murine macrophages was strongly higher than that of ursodeoxycholate-coated particles or free U-AZT (∼500% and ∼7000%, respectively). AZT was also detected in macrophages following the prodrug uptake, with the greatest amounts observed after the taurocholate-coated nanoparticle incubation. As macrophages in the subarachnoid spaces of cerebrospinal fluid (CSF) constitute one of the most unreachable HIV sanctuaries in the body, we also tested the ability of taurocholate-coated nanoparticles (i.e., nanoparticles highly internalized by macrophages) to reach them after their nasal administration in the presence or absence of chitosan. The results indicate that chitosan allowed to obtain a relatively high uptake (up to 4 µg/ml) of U-AZT in CSF. Taking into account that chitosan may promote the direct brain nanoparticle uptake, these findings can be considered an initial step toward the in vivo targeting of the subarachnoid macrophages by U-AZT prodrug.

pH-Promoted Release of a Novel Anti-Tumour Peptide by "Stealth" Liposomes: Effect of Nanocarriers on the Drug Activity in Cis-Platinum Resistant Cancer Cells

PURPOSE

To evaluate the potential effects of PEGylated pH-sensitive liposomes on the intracellular activity of a new peptide recently characterized as a novel inhibitor of the human thymidylate synthase (hTS) over-expressed in many drug-resistant human cancer cell lines.

METHODS

Peptide-loaded pH-sensitive PEGylated (PpHL) and non-PEGylated liposomes (nPpHL) were carefully characterized and delivered to cis-platinum resistant ovarian cancer C13* cells; the influence of the PpHL on the drug intracellular activity was investigated by the Western Blot analysis of proteins involved in the pathway affected by hTS inhibition.

RESULTS

Although PpHL and nPpHL showed different sizes, surface hydrophilicities and serum stabilities, both carriers entrapped the drug efficiently and stably demonstrating a pH dependent release; moreover, the different behavior against J774 macrophage cells confirmed the ability of PEGylation in protecting liposomes from the reticuloendothelial system. Comparable effects were instead observed against C13* cells and biochemical data by immunoblot analysis indicated that PEGylated pH-sensitive liposomes do not modify the proteomic profile of the cells, fully preserving the activity of the biomolecule.

CONCLUSION

PpHL can be considered as efficient delivery systems for the new promising anti-cancer peptide.

In vivo β-carotene skin permeation modulated by Nanostructured Lipid Carriers

Nanostructured Lipid Carriers (NLC) were investigated with the purpose of promoting skin permeation of the highly lipophilic β-carotene (BC) across the stratum corneum (SC) barrier so that it may perform its antioxidant properties in photo-aging and epithelial skin cancer prevention. Two differently sized NLC samples were developed using stearic acid and squalene as lipid matrix and evaluated in comparison with Microstructured Lipid Carriers (MLC). The carriers were characterized for morphology, size, Z-potential, BC loading and release as well as physical state by means of DSC and XRPD analyses. In vivo penetration of the carriers was assessed on humans by determining BC concentrations within the SC stratum disjunctum and stratum compactum layers removed by means of the tape stripping test in comparison with pure BC. Unlike MLC and pure BC that were mostly retained within the outermost layers of the SC, the NLC sample having the smallest size (about 200 nm) has proved to penetrate more deeply into the SC barrier. Accordingly, the goal of providing β-carotene actions against oxidative damages within the looser skin viable tissues could be envisaged.

Drugs/lamellae interface influences the inner structure of double-loaded liposomes for inhaled anti-TB therapy: An in-depth small-angle neutron scattering investigation

With the aim of developing new drug carriers for inhalation therapy, we report here an in depth investigation of the structure of multilamellar liposomes loaded with two well-established anti-tubercular (anti-TB) drugs, isoniazid (INH) and rifampicin (RIF), by means of small-angle neutron-scattering (SANS) analysis. Unloaded, single drug-loaded and co-loaded liposomes were prepared using different amounts of drugs and characterized regarding size, encapsulation efficiency and drug release. Detailed information on relevant properties of the investigated host-guest structures, namely the steric bilayer thickness, particle dispersion, number of lamellae and drug localization was studied by SANS. Results showed that RIF-liposomes were less ordered than unloaded liposomes. INH induced a change in the inter-bilayer periodical spacing, while RIF-INH co-loading stabilized the multilamellar liposome architecture, as confirmed by the increment of the drug loading capacity. These findings could be useful for the understanding of in vitro and in vivo behavior of these systems and for the design of new drug carriers, intended for inhaled therapy.

Design, Characterization, and In Vitro Assays on Muscle Cells of Endocannabinoid-like Molecule Loaded Lipid Nanoparticles for a Therapeutic Anti-Inflammatory Approach to Sarcopenia

Inflammatory processes play a key role in the pathogenesis of sarcopenia owing to their effects on the balance between muscle protein breakdown and synthesis. Palmitoylethanolamide (PEA), an endocannabinoid-like molecule, has been well documented for its anti-inflammatory properties, suggesting its possible beneficial use to counteract sarcopenia. The promising therapeutic effects of PEA are, however, impaired by its poor bioavailability. In order to overcome this limitation, the present study focused on the encapsulation of PEA in solid lipid nanoparticles (PEA-SLNs) in a perspective of a systemic administration. PEA-SLNs were characterized for their physico-chemical properties as well as cytotoxicity and cell internalization capacity on C2C12 myoblast cells. Their size was approximately 250 nm and the encapsulation efficiency reached 90%. Differential scanning calorimetry analyses demonstrated the amorphous state of PEA in the inner SLN matrix, which improved PEA dissolution, as observed in the in vitro assays. Despite the high internalization capacity observed with the flow cytometer (values between 85 and 94% after 14 h of incubation), the Nile Red labeled PEA-SLNs showed practically no toxicity towards myoblasts. Confocal analysis showed the presence of SLNs in the cytoplasm and not in the nucleus. These results suggest the potentiality provided by PEA-SLNs to obtain an innovative and side-effect-free tool in the medical treatment of sarcopenia.

Self-assembled organogelators as artificial stratum corneum models: Key-role parameters for skin permeation prediction

Self-assembled organogelators were explored as artificial stratum corneum (SC) models for the in vitro skin permeation assessment. Four SC models consisting of binary (organogels) or ternary (microemulsion-based organogels) mixtures were developed using stearic acid, tristearin, or sorbitan tristearate, at two different concentrations, gelled in squalene. The permeation of lipophilic butyl-methoxydibenzoylmethane and hydrophilic methylene blue as the permeant compounds across the SC models was compared with ex vivo experiments using excised porcine ear skin. A multi-analytical approach was adopted to provide detailed understanding about organogelator organization within the SC models and find possible parameters playing key-roles in SC permeation prediction. The SC models were investigated for gelling properties and microstructure. Parameters such as gel occurrence, organogelator concentration, and rheological properties appeared as negligible conditions for skin permeation prediction. Conversely, arrangement packing, interactions, and crystallinity extent of the self-assembled organogelator were found to play a fundamental role in the simulation of SC barrier function according to the permeant feature.

Plant Resin Delivery by Nanovectors as an Emerging Approach to Boost Solubility, Permeability and Bioavailability

Resins are complex mixtures of natural constituents containing non-volatile and volatile terpenes, in combination with gums and polyphenols, used since ancient times for their medicinal properties. Current research has evidenced their therapeutic value with a plethora of activities. The main limits of resins and their constituents for their clinical use are low water solubility, poor stability and bioavailability. Therefore, nanovectors including vesicles, solid lipid nanoparticles, micelles, nanoemulsions, microemulsions and mesoporic nanoparticles have been investigated to optimize the biopharmaceutical properties after topical or oral administration of resins or fractions from them, including essential oils or single constituents. In this review, we report the results evidencing that developed nanovectors were able to entrap high amounts of resins or their components, modify the release properties, enhance their cellular uptake and penetration across biological barriers and optimize the biopharmaceutical properties. In addition, the resins or their fractions as enhancer penetration molecules can optimize the architecture and properties of nanovectors in their capacity to circumvent biological barriers. Although no clinical studies have been reported until now, nanovectors represent a huge platform for upgrading therapies and emerging new treatments of resins such as wound healing therapy.

Combination of Nanodelivery Systems and Constituents Derived from Novel Foods: A Comprehensive Review

Novel Food is a new category of food, regulated by the European Union Directive No. 2015/2283. This latter norm defines a food as "Novel" if it was not used "for human consumption to a significant degree within the Union before the date of entry into force of that regulation, namely 15 May 1997". Recently, Novel Foods have received increased interest from researchers worldwide. In this sense, the key areas of interest are the discovery of new benefits for human health and the exploitation of these novel sources of materials in new fields of application. An emerging area in the pharmaceutical and medicinal fields is nanotechnology, which deals with the development of new delivery systems at a nanometric scale. In this context, this review aims to summarize the recent advances on the design and characterization of nanodelivery systems based on materials belonging to the Novel Food list, as well as on nanoceutical products formulated for delivering compounds derived from Novel Foods. Additionally, the safety hazard of using nanoparticles in food products, i.e., food supplements, has been discussed in view of the current European regulation, which considers nanomaterials as Novel Foods.

Inflammatory-Targeted Lipid Carrier as a New Nanomaterial to Formulate an Inhaled Drug Delivery System

There is a pressing need for efficacious therapies in the field of respiratory diseases and infections. Lipid nanocarriers, administered through aerosols, represent a promising tool for maximizing therapeutic concentration in targeted cells and minimizing systemic exposure. However, this approach requires the application of efficient and safe nanomaterials. Palmitoylethanolamide (PEA), an endocannabinoid-like endogenous lipid, plays a crucial role in providing protective mechanisms during inflammation, making it an interesting material for preparing inhalable lipid nanoparticles (LNPs). This report aims to preliminarily explore the in vitro behavior of LNPs prepared with PEA (PEA-LNPs), a new inhalable inflammatory-targeted nanoparticulate drug carrier. PEA-LNPs exhibited a size of about 250 nm, a rounded shape, and an marked improvement in PEA solubility in comparison to naked PEA, indicative of easily disassembled nanoparticles. A twin glass impinger instrument was used to screen the aerosol performance of PEA-LNP powders, obtained via freeze-drying in the presence of two quantities of mannose as a cryoprotectant. Results indicated that a higher amount of mannose improved the emitted dose (ED), and in particular, the fine particle fraction (FPF). A cytotoxicity assay was performed and indicated that PEA-LNPs are not toxic towards the MH-S alveolar macrophage cell line up to concentrations of 0.64 mg/mL, and using coumarin-6 labelled particles, a rapid internalization into the macrophage was confirmed. This study demonstrates that PEA could represent a suitable material for preparing inhalable lipid nanocarrier-based dry powders, which signify a promising tool for the transport of drugs employed to treat respiratory diseases and infections.

Epitranscriptomics as a New Layer of Regulation of Gene Expression in Skeletal Muscle: Known Functions and Future Perspectives

Epitranscriptomics refers to post-transcriptional regulation of gene expression via RNA modifications and editing that affect RNA functions. Many kinds of modifications of mRNA have been described, among which are N6-methyladenosine (m6A), N1-methyladenosine (m1A), 7-methylguanosine (m7G), pseudouridine (Ψ), and 5-methylcytidine (m5C). They alter mRNA structure and consequently stability, localization and translation efficiency. Perturbation of the epitranscriptome is associated with human diseases, thus opening the opportunity for potential manipulations as a therapeutic approach. In this review, we aim to provide an overview of the functional roles of epitranscriptomic marks in the skeletal muscle system, in particular in embryonic myogenesis, muscle cell differentiation and muscle homeostasis processes. Further, we explored high-throughput epitranscriptome sequencing data to identify RNA chemical modifications in muscle-specific genes and we discuss the possible functional role and the potential therapeutic applications.