Drug delivery in overcoming the blood-brain barrier: role of nasal mucosal grafting

The blood–brain barrier (BBB) plays a fundamental role in protecting and maintaining the homeostasis of the brain. For this reason, drug delivery to the brain is much more difficult than that to other compartments of the body. In order to bypass or cross the BBB, many strategies have been developed: invasive techniques, such as temporary disruption of the BBB or direct intraventricular and intracerebral administration of the drug, as well as noninvasive techniques. Preliminary results, reported in the large number of studies on the potential strategies for brain delivery, are encouraging, but it is far too early to draw any conclusion about the actual use of these therapeutic approaches. Among the most recent, but still pioneering, approaches related to the nasal mucosa properties, the permeabilization of the BBB via nasal mucosal engrafting can offer new potential opportunities. It should be emphasized that this surgical procedure is quite invasive, but the implication for patient outcome needs to be compared to the gold standard of direct intracranial injection, and evaluated whilst keeping in mind that central nervous system diseases and lysosomal storage diseases are chronic and severely debilitating and that up to now no therapy seems to be completely successful

CARATTERIZZAZIONE ACUSTICA DI NANOBOLLE LIPIDICHE

Vengono riportate misure riguardo l’efficienza di scattering di nanobolle lipidiche con diametro medio di 200 nm contenenti tetradecafluoroesano; le misure, effettuate con la tecnica pulse-echo, rivelano un’attenuazione dipendente dalla concentrazione in soluzione delle nanobolle con valori che, per una concentrazione del 35% di nanobolle in hepes, raggiungono, a 14 MHz, il valore di circa 6 dB/cm. Tale valore è confrontabile con le attenuazioni prodotte da agenti di contrasto commercialmente disponibili come, ad esempio, il SonoVue®. È stata inoltre utilizzata una tecnica fotoacustica per la valutazione dell’efficacia di intrappolamento del gas all’interno delle nanobolle, riscontrando, anche in questo caso, valori simili a quelli misurati nel SonoVue®

Neem oil nanoemulsions: characterisation and antioxidant activity

The aim of the present work is to develop nanoemulsions (NEs), nanosized emulsions, manufactured for improving the delivery of active pharmaceutical ingredients. In particular, nanoemulsions composed of Neem seed oil, contain rich bioactive components, and Tween 20 as nonionic surfactant were prepared. A mean droplet size ranging from 10 to 100nm was obtained by modulating the oil/surfactant ratio. Physicochemical characterisation was carried out evaluating size, f-potential, microviscosity, polarity and turbidity of the external shell and morphology, along with stability in simulated cerebrospinal fluid (CSF), activity of Neem oil alone and in NEs, HEp-2 cell interaction and cytotoxicity studies. This study confirms the formation of NEs by Tween 20 and Neem oil at different weight ratios with small and homogenous dimensions. The antioxidant activity of Neem oil alone and in NEs was comparable, whereas its cytotoxicity was strongly reduced when loaded in NEs after interaction with HEp-2 cells

Chitosan Glutamate-Coated Niosomes: a proposal for Nose-to-Brain delivery

The aim of this in vitro study is to prepare and characterize drug free and pentamidine loaded chitosan glutamate coated niosomes for intranasal drug delivery to reach the brain through intranasal delivery. Mucoadhesive properties and stability testing in various environments were evaluated to examine the potential of these formulations to be effective drug delivery vehicles for intranasal delivery to the brain. Samples were prepared using thin film hydration method. Changes in size and ζ-potential of coated and uncoated niosomes with and without loading of pentamidine in various conditions were assessed by dynamic light scattering (DLS), while size and morphology were also studied by atomic force microscopy (AFM). Bilayer properties and mucoadhesive behavior were investigated by fluorescence studies and DLS analyses, respectively. Changes in vesicle size and ζ-potential values were shown after addition of chitosan glutamate to niosomes, and when in contact with mucin solution. In particular, interactions with mucin were observed in both drug free and pentamidine loaded niosomes regardless of the presence of the coating. The characteristics of the proposed systems, such as pentamidine entrapment and mucin interaction, show promising results to deliver pentamidine or other possible drugs to the brain via nasal administration

Influence of drug/lipid interaction on the entrapment efficiency of isoniazid in liposomes for antitubercular therapy: a multi-faced investigation

Hypothesis. Isoniazid is one of the primary drugs used in tuberculosis treatment. Isoniazid encapsulation in liposomal vesicles can improve drug therapeutic index and minimize toxic and side effects. In this work, we consider mixtures of hydrogenated soy phosphatidylcholine/phosphatidylglycerol (HSPC/DPPG) to get novel biocompatible liposomes for isoniazid pulmonary delivery. Our goal is to understand if the entrapped drug affects bilayer structure. Experiments. HSPC-DPPG unilamellar liposomes are prepared and characterized by dynamic light scattering, $\zeta$-potential, fluorescence anisotropy and Transmission Electron Microscopy. Isoniazid encapsulation is determined by UV and Laser Transmission Spectroscopy. Calorimetry, light scattering and Surface Pressure measurements are used to get insight on adsorption and thermodynamic properties of lipid bilayers in the presence of the drug. Findings. We find that INH-lipid interaction can increase the entrapment capability of the carrier due to isoniazid adsorption. The preferential INH-HSPC dipole-dipole interaction promotes modification of lipid packing and ordering and favors the condensation of a HSPC-richer phase in molar excess of DPPG. Our findings highlight the importance of fundamental investigations of drug-lipid interactions for the optimal design of liposomal nanocarriers.Comment: 28 pages (main manuscript + supplementary information

Ultrastable shelled PFC nanobubbles:a platform for ultrasound-assisted diagnostics and therapy

Nanoscale echogenic bubbles (NBs), can be used as a theranostic platform for the localized delivery of encapsulated drugs. However, the generation of NBs is challenging, because they have lifetimes as short as milliseconds in solution. The aim of this work has been the optimization of a preparation method for the generation of stable NBs, characterized by measuring: a) acoustic efficiency, b) nano-size, to ensure passive tumour targeting, c) stability during storage and after injection and d) ability to entrap drugs. NBs are monodisperse and ultrastable, their stability achieved by generation of an amphiphilic multilamellar shell able to efficiently retain the PFC gas. The NBs perform as good acoustic enhancers over a wide frequency range and out of resonant conditions, as tested in both in vitro and in vivo experiments, proving to be a potential platform for the production of versatile carriers to be used in ultrasound-assisted diagnostic, therapeutic and theranostic applications

Rifampicin-liposomes for mycobacterium abscessus infection treatment: intracellular uptake and antibacterial activity evaluation

: Treatment of pulmonary infections caused by Mycobacterium abscessus are extremely difficult to treat, as this species is naturally resistant to many common antibiotics. Liposomes are vesicular nanocarriers suitable for hydrophilic and lipophilic drug loading, able to deliver drugs to the target site, and successfully used in different pharmaceutical applications. Moreover, liposomes are biocompatible, biodegradable and nontoxic vesicles and nebulized liposomes are efficient in targeting antibacterial agents to macrophages. The present aim was to formulate rifampicin-loaded liposomes (RIF-Lipo) for lung delivery, in order to increase the local concentration of the antibiotic. Unilamellar liposomal vesicles composed of anionic DPPG mixed with HSPC for rifampicin delivery were designed, prepared, and characterized. Samples were prepared by using the thin-film hydration method. RIF-Lipo and unloaded liposomes were characterized in terms of size, ζ-potential, bilayer features, stability and in different biological media. Rifampicin's entrapment efficiency and release were also evaluated. Finally, biological activity of RIF-loaded liposomes in Mycobacterium abscessus-infected macrophages was investigated. The results show that RIF-lipo induce a significantly better reduction of intracellular Mycobacterium abscessus viability than the treatment with free drug. Liposome formulation of rifampicin may represent a valuable strategy to enhance the biological activity of the drug against intracellular mycobacteria

Effect of ciprofloxacin-loaded niosomes on escherichia coli and staphylococcus aureus biofilm formation

Infections caused by bacterial biofilms represent a global health problem, causing considerable patient morbidity and mortality in addition to an economic burden. Escherichia coli, Staphylococcus aureus, and other medically relevant bacterial strains colonize clinical surfaces and medical devices via biofilm in which bacterial cells are protected from the action of the immune system, disinfectants, and antibiotics. Several approaches have been investigated to inhibit and disperse bacterial biofilms, and the use of drug delivery could represent a fascinating strategy. Ciprofloxacin (CIP), which belongs to the class of fluoroquinolones, has been extensively used against various bacterial infections, and its loading in nanocarriers, such as niosomes, could support the CIP antibiofilm activity. Niosomes, composed of two surfactants (Tween 85 and Span 80) without the presence of cholesterol, are prepared and characterized considering the following features: hydrodynamic diameter, ζ-potential, morphology, vesicle bilayer characteristics, physical-chemical stability, and biological efficacy. The obtained results suggest that: (i) niosomes by surfactants in the absence of cholesterol are formed, can entrap CIP, and are stable over time and in artificial biological media; (ii) the CIP inclusion in nanocarriers increase its stability, with respect to free drug; (iii) niosomes preparations were able to induce a relevant inhibition of biofilm formation