Different instrumental approaches to understand the chitosan coated niosomes/mucin interaction

Nano-Assembled Polyphosphazene Delivery System Enables Effective Intranasal Immunization with Nipah Virus Subunit Vaccine

The ultimate vaccine against infections caused by Nipah virus should be capable of providing protection at the respiratory tract─the most probable port of entry for this pathogen. Intranasally delivered vaccines, which target nasal-associated lymphoid tissue and induce both systemic and mucosal immunity, are attractive candidates for enabling effective vaccination against this lethal disease. Herein, the water-soluble polyphosphazene delivery vehicle assembles into nanoscale supramolecular constructs with the soluble extracellular portion of the Hendra virus attachment glycoprotein─a promising subunit vaccine antigen against both Nipah and Hendra viruses. These supramolecular constructs signal through Toll-like receptor 7/8 and promote binding interactions with mucin─an important feature of effective mucosal adjuvants. High mass contrast of phosphorus-nitrogen backbone of the polymer enables a successful visualization of nanoconstructs in their vitrified state by cryogenic electron microscopy. Here, we characterize the self-assembly of polyphosphazene macromolecule with biologically relevant ligands by asymmetric flow field flow fractionation, dynamic light scattering, fluorescence spectrophotometry, and turbidimetric titration methods. Furthermore, a polyphosphazene-enabled intranasal Nipah vaccine candidate demonstrates the ability to induce immune responses in hamsters and shows superiority in inducing total IgG and neutralizing antibodies when benchmarked against the respective clinical stage alum adjuvanted vaccine. The results highlight the potential of polyphosphazene-enabled nanoassemblies in the development of intranasal vaccines.

Formulation and Characterization of Curcumin Niosomes: Antioxidant and Cytotoxicity Studies

Curcumin's applications in the treatment of conditions including osteoarthritis, dementia, malignancies of the pancreas, and malignancies of the intestines have drawn increasing attention. It has several wonderful qualities, including being an anti-inflammatory agent, an anti-mutagenic agent, and an antioxidant, and has substantially reduced inherent cytotoxicity outcomes. Although curcumin possesses multiple known curative properties, due to its limited bioavailability, it is necessary to develop efficient strategies to overcome these hurdles. To establish an effective administration method, various niosomal formulations were optimized using the Box-Behnken design and assessed in the current investigation. To examine the curcumin niosomes, zeta sizer, zeta potential, entrapment efficiency, SEM, antioxidant potential, cytotoxicity, and release studies were performed. The optimized curcumin niosomes exhibited an average particle size of 169.4 nm, a low PDI of 0.189, and high entrapment efficiency of 85.4%. The release profile showed 79.39% curcumin after 24 h and had significantly higher antioxidant potential as compared with that of free curcumin. The cytotoxicity results of curcumin niosomes presented increased mortality in human ovarian cancer A2780.

Niosome as an Effective Nanoscale Solution for the Treatment of Microbial Infections

Numerous disorders go untreated owing to a lack of a suitable drug delivery technology or an appropriate therapeutic moiety, particularly when toxicities and side effects are a major concern. Treatment options for microbiological infections are not fulfilled owing to significant adverse effects or extended therapeutic options. Advanced therapy options, such as active targeting, may be preferable to traditional ways of treating infectious diseases. Niosomes can be defined as microscopic lamellar molecules formed by a mixture of cholesterol, nonionic surfactants (alkyl or dialkyl polyglycerol ethers), and sometimes charge-inducing agents. These molecules comprise both hydrophilic and hydrophobic moieties of varying solubilities. In this review, several pathogenic microbes such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Plasmodium, Leishmania, and Candida spp. have been evaluated. Also, the development of a proper niosomal formulation for the required application was discussed. This review also reviews that an optimal formulation is dependent on several aspects, including the choice of nonionic surfactant, fabrication process, and fabrication parameters. Finally, this review will give information on the effectiveness of niosomes in treating acute microbial infections, the mechanism of action of niosomes in combating microbial pathogens, and the advantages of using niosomes over other treatment modalities.

Mucoadhesive Rifampicin-Liposomes for the Treatment of Pulmonary Infection by Mycobacterium abscessus: Chitosan or ε-Poly-L-Lysine Decoration

Mycobacterium abscessus (Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to many different antibiotics which make its therapeutic management extremely difficult. Drug nanocarriers as liposomes may represent a promising delivery strategy against pulmonary Mabs infection, due to the possibility to be aerosolically administrated and to tune their properties in order to increase nebulization resistance and retainment of encapsulated drug. In fact, liposome surface can be modified by decoration with mucoadhesive polymers to enhance its stability, mucus penetration and prolong its residence time in the lung. The aim of this work is to employ Chitosan or ε-poly-L-lysine decoration for improving the properties of a novel liposomes composed by hydrogenated phosphatidyl-choline from soybean (HSPC) and anionic 1,2-Dipalmitoyl-sn-glycero-3-phosphorylglycerol sodium salt (DPPG) able to entrap Rifampicin. A deep physicochemical characterization of polymer-decorated liposomes shows that both polymers improve mucoadhesion without affecting liposome features and Rifampicin entrapment efficiency. Therapeutic activity on Mabs-infected macrophages demonstrates an effective antibacterial effect of ε-poly-L-lysine liposomes with respect to chitosan-decorated ones. Altogether, these results suggest a possible use of ε-PLL liposomes to improve antibiotic delivery in the lung.

Current Advances in Specialised Niosomal Drug Delivery: Manufacture, Characterization and Drug Delivery Applications

Development of nanomaterials for drug delivery has received considerable attention due to their potential for achieving on-target delivery to the diseased area while the surrounding healthy tissue is spared. Safe and efficiently delivered payloads have always been a challenge in pharmaceutics. Niosomes are self-assembled vesicular nanocarriers formed by hydration of a non-ionic surfactant, cholesterol or other molecules that combine to form a versatile drug delivery system with a variety of applications ranging from topical delivery to targeted delivery. Niosomes have advantages similar to those of liposomes with regards to their ability to incorporate both hydrophilic and hydrophobic payloads. Moreover, niosomes have simple manufacturing methods, low production cost and exhibit extended stability, consequently overcoming the major drawbacks associated with liposomes. This review provides a comprehensive summary of niosomal research to date, including the types of niosomes and critical material attributes (CMA) and critical process parameters (CPP) of niosomes and their effects on the critical quality attributes (CQA) of the technology. Furthermore, physical characterisation techniques of niosomes are provided. The review then highlights recent applications of specialised niosomes in drug delivery. Finally, limitations and prospects for this technology are discussed.

Resveratrol-Loaded Nanoemulsions: In Vitro Activity on Human T24 Bladder Cancer Cells

The chemopreventive potential of Resveratrol (RV) against bladder cancer and its mechanism of action have been widely demonstrated. The physicochemical properties of RV, particularly its high reactivity and low solubility in aqueous phase, have been limiting factors for its bioavailability and in vivo efficacy. In order to overcome these limitations, its inclusion in drug delivery systems needs to be taken into account. In particular, oil-in-water (O/W) nanoemulsions (NEs) have been considered ideal candidates for RV encapsulation. Since surfactant and oil composition can strongly influence NE features and their application field, a ternary phase diagram was constructed and evaluated to select a suitable surfactant/oil/water ratio. The selected sample was deeply characterized in terms of physical chemical features, stability, release capability and cytotoxic activity. Results showed a significant decrease in cell viability after the incubation of bladder T24 cancer cells with RV-loaded NEs, compared to free RV. The selected NE formulation was able to preserve and improve RV cytotoxic activity by a more rapid drug uptake into the cells. O/W NEs represent an effective approach to improve RV bioavailability.

Hyaluronic Acid Derivative Effect on Niosomal Coating and Interaction with Cellular Mimetic Membranes

Hyaluronic acid (HA) is one of the most used biopolymers in the development of drug delivery systems, due to its biocompatibility, biodegradability, non-immunogenicity and intrinsic-targeting properties. HA specifically binds to CD44; this property combined to the EPR effect could provide an option for reinforced active tumor targeting by nanocarriers, improving drug uptake by the cancer cells via the HA-CD44 receptor-mediated endocytosis pathway. Moreover, HA can be easily chemically modified to tailor its physico-chemical properties in view of specific applications. The derivatization with cholesterol confers to HA an amphiphilic character, and then the ability of anchoring to niosomes. HA-Chol was then used to coat Span^® or Tween^® niosomes providing them with an intrinsic targeting shell. The nanocarrier physico-chemical properties were analyzed in terms of hydrodynamic diameter, ζ-potential, and bilayer structural features to evaluate the difference between naked and HA-coated niosomes. Niosomes stability was evaluated over time and in bovine serum. Moreover, interaction properties of HA-coated nanovesicles with model membranes, namely liposomes, were studied, to obtain insights on their interaction behavior with biological membranes in future experiments. The obtained coated systems showed good chemical physical features and represent a good opportunity to carry out active targeting strategies.

Characteristic Evaluation of Gel Formulation Containing Niosomes of Melatonin or Its Derivative and Mucoadhesive Properties Using ATR-FTIR Spectroscopy

Chitosan or polyvinyl pyrrolidone (PVP) were used in combination with hydroxypropyl methylcellulose (HPMC) and poloxamer 407 (P407) as gelling agents for oral drug delivery. The performance interaction with mucin of chitosan-composed gel (F1) and PVP-composed gel (F2) was compared using attenuated total reflectance-Fourier-transform infrared (ATR-FTIR) spectroscopy at controlled temperatures of 25 and 37 °C for 1 and 5 min. F1 containing niosome-entrapped melatonin or its derivatives was investigated for mucoadhesive interaction on mucosa by ATR-FTIR spectroscopy under the same conditions. The results showed that F1-treated mucin gave a significantly lower amide I/amide II ratio than untreated mucin and F2-treated mucin did within 1 min, suggesting improved rapid affinity between mucin and chitosan. The spectra of mucosa treated with F1 incorporating niosomes of melatonin or its derivatives showed peak shifts at C=O (amide I), N-H (amide II), and carbohydrate regions and an associated decrease in the amide I/amide II ratio and increase in the carbohydrate/amide II ratio. These results indicated electrostatic interaction and hydrogen bonding between chitosan and mucin on the mucosa. In conclusion, the molecular interaction between gels and mucin/mucosa detected at amide I and amide II of proteins and the carbohydrate region could lead to an improved mucoadhesive property of the gel on the mucosa.

Improvement of the multi-performance biocharacteristics of cordycepin using BiloNiosome-core/chitosan-shell hybrid nanocarriers

Cordycepin, a derivative of the nucleotide adenosine, has displayed several pharmacological activities including enhanced apoptosis and cancer cells inhibition. However, oral administration of cordycepin has limited practical use due to its poor bioavailability in the intestine. Herein, we developed and demonstrated a hybrid nanocarrier system in the form of biloniosome-core/chitosan-shell hybrid nanocarriers (HNCs) in order to improve the bio-characteristics of cordycepin. In this study, HNCs were prepared by using a solvent (ethanol) injection method involving cordycepin as the biloniosome core and mucoadhesive chitosan biopolymer as a coating shell. Our results showed that the cordycepin-loaded HNCs were positively charged with enhanced mucoadhesive characteristics and highly stable in gastric fluid. The increased permeability of cordycepin-loaded HNCs compared with standard cordycepin was confirmed by in vitro intestinal permeation study across the human intestinal barrier. In addition, we demonstrated that the cordycepin-loaded HNCs are able to release their components in an active form resulting in enhanced anti-cancer activity in two-dimensional (2D) cell cultures as well as in three-dimensional (3D) multi-cellular spheroids of colon cancer cells. Further, quantitative real time PCR analysis of apoptotic gene expression revealed that cordycepin HNCs can induce apoptosis in cancer cells by negatively regulating the expression of B-cell lymphoma-extra large (BCL-XL). I Overall our results showed that the hybrid nanocarrier systems represent a promising strategy for improving the bio-characteristics of cordycepin which can be considered as a potential anti-cancer agent for colorectal cancer chemotherapy.

Antimicrobial Essential Oil Formulation: Chitosan Coated Nanoemulsions for Nose to Brain Delivery

Brain infections as meningitis and encephalitis are attracting a great interest. Challenges in the treatment of these diseases are mainly represented by the blood brain barrier (BBB) that impairs the efficient delivery of even very potent drugs to reach the brain. The nose to the brain administration route, is a non-invasive alternative for a quick onset of action, and enables the transport of numerous medicinal agents straight to the brain thus workarounding the BBB through the highly vascularized olfactory region. In this report, Thymus vulgaris and Syzygium aromaticum essential oils (EOs) were selected to be included in chitosan coated nanoemulsions (NEs). The EOs were firstly analyzed to determine their chemical composition, then used to prepare NEs, that were deeply characterized in order to evaluate their use in intranasal administration. An in vitro evaluation against a collection of clinical isolated bacterial strains was carried out for both free and nanoemulsioned EOs. Chitosan coated NEs showed to be a potential and effective intranasal formulation against multi-drug resistant Gram-negative bacteria such as methicillin-susceptible Staphylococcus aureus and multi-drug resistant Gram-negative microorganisms including carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae.