Stealth nanocarriers based sterosomes using PEG post-insertion process

Sterosomes (STEs), a new and promising non-phospholipidic liposome platform based on palmitic acid (PA) and cholesterol (Chol) mixtures, need to have polyethylene glycol (PEG) chains grafted to their surface in order to obtain long-circulating nanocarriers in the blood stream. A post-insertion method was chosen to achieve this modification. The post-insertion process of PEG-modified distearoylphosphoethanolamine (DSPE-PEG) was monitored using the zeta potential value of STEs. Various conditions including PEG chain length and the DSPE-PEG/PA-Chol ratio, were explored. Zeta potential of STEs changed from about -40mV for non-modified STEs to values close to 0 mV by the end of the process, i.e. for PEG-modified STEs. The kinetics of DSPE-PEG insertion and the stability of the resulting PEG-modified STEs were not considerably influenced, within the investigated range, by changes in PEG chain lengths and in DSPE-PEG/PA-Chol proportion. The post-insertion of PEG chains reduced in vitro complement activation as well as in vitro macrophage uptake compared to the non-modified STEs. Moreover, longer blood circulation time in mice was established for PEG-modified STEs intravenously injected compared to non-modified STEs. These results establish that post-insertion process of PEG chains to STEs is a promising strategy for developing long-term circulating drug delivery nanocarriers

La chimiothérapie inhalée – partie 1 : concept et challenges technologiques actuels

Despite severe adverse effects, chemotherapy is still widely used in the treatment of lung tumors, including primary lung tumors and metastases. In order to reduce the risk of harm and to intensify treatment responses, several strategies have been described recently. These include the use of nanomedicine-based chemotherapies and pulmonary drug delivery. However, to treat lung tumors, inhalation cannot be effective and safe without an adaptation of current inhalation techniques, i.e. inhalation devices and drug formulations. This can be very challenging. This review presents recent preclinical developments that could address the limitations observed with aerosolized chemotherapy. The solutions involve the use of dry powder inhalers and advanced drug formulations, such as controlled and sustained release formulations and nanomedicine-based formulations

La chimiothérapie inhalée – partie 2 : clinique et applications potentielles

Lung tumours have a high incidence and cause many deaths worldwide. Despite progresses in treatment with targeted therapies and immunotherapies, the global 5-year survival rate remains low. In this context, inhaled chemotherapy could provide a means to intensify current therapeutic modalities. This review is based on clinical studies of inhaled chemotherapy against lung tumours. The advantages of this approach in terms of pharmacokinetic ratio and therapeutic index are presented as well as the limitations including contraindications and pulmonary side effects. Moreover, the challenges linked to technical aspects around administration are identified (inhalation device and facilities to limit aerosol propagation and exposure of healthcare professionals). The current developments proposed to overcome these challenges are described briefly. Also discussed are the potential applications for the distribution of the inhaled anticancer drug into tumour-bearing respiratory tracts and finally the potential indications for current therapeutic modalities

Safe lipid nanocapsule-based gel technology to target lymph nodes and combat mediastinal metastases from an orthotopic non-small-cell lung cancer model in SCID-CB17 mice

The purpose of this study is the assessment of gel technology based on a lauroyl derivative of gemcitabine encapsulated in lipid nanocapsules delivered subcutaneously or intravenously after dilution to target lymph nodes, induce less systemic toxicity and combat mediastinal metastases from an orthotopic model of human, squamous, non-small-cell lung cancer Ma44-3 cells implanted in severe combined immunodeficiency mice. The gel technology mainly targeted lymph nodes as revealed by the biodistribution study. Moreover, the gel technology induced no significant myelosuppression (platelet count) in comparison with the control saline group, unlike the conventional intravenous gemcitabine hydrochloride treated group (P < 0.05). Besides, the gel technology, delivered subcutaneously twice a week, was able to combat locally mediastinal metastases from the orthotopic lung tumor and to significantly delay death (P < 0.05) as was the diluted gel technology delivered intravenously three times a week

Targeted PEG-poly(glutamic acid) complexes for inhalation protein delivery to the lung

Pulmonary delivery is increasingly seen as an attractive, non-invasive route for the delivery of forthcoming protein therapeutics. In this context, here we describe protein complexes with a new ‘complexing excipient’ - vitamin B12-targeted poly(ethylene glycol)-block-poly(glutamic acid) copolymers. These form complexes in sub-200 nm size with a model protein, suitable for cellular targeting and intracellular delivery. Initially we confirmed expression of vitamin B12-internalization receptor (CD320) by Calu-3 cells of the in vitro lung epithelial model used, and demonstrated enhanced B12 receptor-mediated cellular internalization of B12-targeted complexes, relative to non-targeted counterparts or protein alone. To develop an inhalation formulation, the protein complexes were spray dried adopting a standard protocol into powders with aerodynamic diameter within the suitable range for lower airway deposition. The cellular internalization of targeted complexes from dry powders applied directly to Calu-3 model was found to be 2–3 fold higher compared to non-targeted complexes. The copolymer complexes show no complement activation, and in vivo lung tolerance studies demonstrated that repeated administration of formulated dry powders over a 3 week period in healthy BALB/c mice induced no significant toxicity or indications of lung inflammation, as assessed by cell population count and quantification of IL-1β, IL-6, and TNF-α pro-inflammatory markers. Importantly, the in vivo data appear to suggest that B12-targeted polymer complexes administered as dry powder enhance lung retention of their protein payload, relative to protein alone and non-targeted counterparts. Taken together, our data illustrate the potential developability of novel B12-targeted poly(ethylene glycol)-poly(glutamic acid) copolymers as excipients suitable to be formulated into a dry powder product for the inhalation delivery of proteins, with no significant lung toxicity, and with enhanced protein retention at their in vivo target tissue

New inhalation-optimized itraconazole nanoparticle-based dry powders for the treatment of invasive pulmonary aspergillosis

Christophe Duret,1 Nathalie Wauthoz,1 Thami Sebti,2 Francis Vanderbist,2 Karim Amighi11Laboratoire de Pharmacie Galénique et de Biopharmacie, Université Libre de Bruxelles, Brussels, Belgium; 2SMB Laboratoires, Brussels, BelgiumPurpose: Itraconazole (ITZ) dry powders for inhalation (DPI) composed of nanoparticles (NP) embedded in carrier microparticles were prepared and characterized.Methods: DPIs were initially produced by reducing the ITZ particle size to the nanometer range using high-pressure homogenization with tocopherol polyethylene 1000 succinate (TPGS, 10% w/w ITZ) as a stabilizer. The optimized nanosuspension and the initial microsuspension were then spray-dried with different proportions of or in the absence of mannitol and/or sodium taurocholate. DPI characterization was performed using scanning electron microscopy for morphology, laser diffraction to evaluate the size-reduction process, and the size of the dried NP when reconstituted in aqueous media, impaction studies using a multistage liquid impactor to determine the aerodynamic performance and fine-particle fraction that is theoretically able to reach the lung, and dissolution studies to determine the solubility of ITZ.Results: Scanning electron microscopy micrographs showed that the DPI particles were composed of mannitol microparticles with embedded nano- or micro-ITZ crystals. The formulations prepared from the nanosuspension exhibited good flow properties and better fine-particle fractions, ranging from 46.2% ± 0.5% to 63.2% ± 1.7% compared to the 23.1% ± 0.3% that was observed with the formulation produced from the initial microsuspension. Spray-drying affected the NP size by inducing irreversible aggregation, which was able to be minimized by the addition of mannitol and sodium taurocholate before the drying procedure. The ITZ NP-based DPI considerably increased the ITZ solubility (58 ± 2 increased to 96 ± 1 ng/mL) compared with that of raw ITZ or an ITZ microparticle-based DPI (<10 ng/mL).Conclusion: Embedding ITZ NP in inhalable microparticles is a very effective method to produce DPI formulations with optimal aerodynamic properties and enhanced ITZ solubility. These formulations could be applied to other poorly water-soluble drugs and could be a very effective alternative for treating invasive pulmonary aspergillosis.Keywords: aspergillosis, spray-drying, homogenization, inhalation, saturation, solubilit

Nano-emulsions of fluorinated trityl radicals as sensors for EPR oximetry.

This article reports the development and evaluation of two nano-emulsions (F45T-03/HFB and F15T-03/PFOB) containing fluorinated trityl radicals dissolved in perfluorocarbons. Preparation with a high-pressure homogenizer conferred sub-micronic size to both nano-emulsions. In vitro and in vivo EPR spectroscopy showed that the nano-emulsions had much greater oxygen sensitivity than the hydrophilic trityl, CT-03. In vivo experiments in rodents confirmed the ability of the nano-emulsions to follow the changes in oxygen concentration after induced ischemia. Histological evaluation of the tissue injected with the nano-emulsions revealed some acute toxicity for the F45T-03/HFB nano-emulsion but none for the F15T-03/PFOB nano-emulsion. These new formulations should be considered for further EPR oximetry experiments in pathophysiological situations where subtle changes in tissue oxygenation are expected.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Development of coated liposomes loaded with ghrelin for nose-to-brain delivery for the treatment of cachexia

Laurent Salade,1 Nathalie Wauthoz,1 Magali Deleu,2 Marjorie Vermeersch,3 Carine De Vriese,1 Karim Amighi,1 Jonathan Goole1 1Laboratoire de Pharmacie Galénique et de Biopharmacie, Université libre de Bruxelles (ULB), Brussels, 2Laboratoire de Biophysique Moléculaire aux Interfaces, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, 3Centre for Microscopy and Molecular Imaging (CMMI), Charleroi, Belgium Abstract: The aim of the present study was to develop a ghrelin-containing formulation based on liposomes coated with chitosan intended for nose–brain delivery for the treatment of cachexia. Among the three types of liposomes developed, anionic liposomes provided the best results in terms of encapsulation efficiency (56%) and enzymatic protection against trypsin (20.6% vs 0% for ghrelin alone) and carboxylesterase (81.6% vs 17.2% for ghrelin alone). Ghrelin presented both electrostatic and hydrophobic interactions with the anionic lipid bilayer, as demonstrated by isothermal titration calorimetry. Then, anionic liposomes were coated with N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride. The coating involved a size increment from 146.9±2.7 to 194±6.1 nm, for uncoated and coated liposomes, respectively. The ζ-potential was similarly increased from -0.3±1.2 mV to 6±0.4 mV before and after coating, respectively. Chitosan provided mucoadhesion, with an increase in mucin adsorption of 22.9%. Enhancement of permeation through the Calu3 epithelial monolayer was also observed with 10.8% of ghrelin recovered in the basal compartment in comparison to 0% for ghrelin alone. Finally, aerosols generated from two nasal devices (VP3 and SP270) intended for aqueous dispersion were characterized with either coated or uncoated liposomes. Contrarily to the SP270 device, VP3 device showed minor changes between coated and uncoated liposome aerosols, as shown by their median volume diameters of 38.4±5.76 and 37.6±5.74 µm, respectively. Overall, the results obtained in this study show that the developed formulation delivered by the VP3 device can be considered as a potential candidate for nose–brain delivery of ghrelin. Keywords: nasal delivery, peptide, liposome, cachexia, brain targeting, enzym

Development of a new indole derivative dry powder for inhalation for the treatment of biofilm-associated lung infections

The aim of this work was to produce an inhalable dry powder formulation of a new anti-biofilm compound (SC38). For this purpose, chitosan was used as a polymeric carrier and L-leucine as a dispersibility enhancer. SC38 was entrapped by spray-drying into previously optimized chitosan microparticles. The final formulation was fully characterized in vitro in terms of particle morphology, particle size and distribution, flowability, aerodynamic properties, anti-biofilm activity and effects on lung cell viability. The SC38-loaded chitosan microparticles exhibited favorable aerodynamic properties with emitted and respirable fractions higher than 80 % and 45 % respectively. The optimized formulation successfully inhibited biofilm formation at microparticle concentrations starting from 20 μg/mL for methicillin-sensitive and 100 μg/mL for methicillin-resistant Staphylococcus aureus and showed a relatively safe profile in lung cells after 72 h exposure. Future in vivo tolerability and efficacy studies are needed to unravel the potential of this novel formulation for the treatment of difficult-to-treat biofilm-mediated lung infections