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During the past decades, lipid nanocarriers are gaining momentum with their multiple advantages for the management of skin diseases. Lipid nanocarriers enable to target the ...therapeutic payload to deep skin layers or even to reach the blood circulation making them a promising cutting-edge technology.
Lipid nanocarriers refer to a large panel of drug delivery systems. Lipid vesicles are the most conventional, known to be able to carry lipophilic and hydrophilic active agents. A variety of lipid vesicles with high flexibility and deformability could be obtained by adjusting their composition; namely ethosomes, transfersomes and penetration enhancer lipid vesicles which achieve the best results in term of skin permeation. Others are designed with the objective to perform higher encapsulation rate and higher stability, such as solid lipid nanoparticles and nanostructured lipid nanocarriers.
In this review, we attempted to give an overview of lipid based nanocarriers developed with the aim to enhance dermal and transdermal drug delivery. A special focus is put on the nanocarrier composition, behavior and interaction mechanisms with the skin. Recent applications of lipid-based nanocarriers for the management of skin diseases and other illnesses are highlighted as well.
Gene therapy and DNA delivery systems Ibraheem, D.; Elaissari, A.; Fessi, H.
International journal of pharmaceutics,
01/2014, Letnik:
459, Številka:
1-2
Journal Article
Recenzirano
Gene therapy is a promising new technique for treating many serious incurable diseases, such as cancer and genetic disorders. The main problem limiting the application of this strategy in vivo is the ...difficulty of transporting large, fragile and negatively charged molecules like DNA into the nucleus of the cell without degradation. The key to success of gene therapy is to create safe and efficient gene delivery vehicles. Ideally, the vehicle must be able to remain in the bloodstream for a long time and avoid uptake by the mononuclear phagocyte system, in order to ensure its arrival at the desired targets. Moreover, this carrier must also be able to transport the DNA efficiently into the cell cytoplasm, avoiding lysosomal degradation. Viral vehicles are the most commonly used carriers for delivering DNA and have long been used for their high efficiency. However, these vehicles can trigger dangerous immunological responses. Scientists need to find safer and cheaper alternatives. Consequently, the non-viral carriers are being prepared and developed until techniques for encapsulating DNA can be found. This review highlights gene therapy as a new promising technique used to treat many incurable diseases and the different strategies used to transfer DNA, taking into account that introducing DNA into the cell nucleus without degradation is essential for the success of this therapeutic technique.
Psoriasis is a chronic inflammatory disease affecting mainly the skin but which can be complicated by psoriatic arthritis (PsA).This autoimmune skin disorder concerns 2–5% of the world population. To ...date, the physiopathology of psoriasis is not still completely elucidated but many researches are ongoing which have led for example to the discovery of the Th17/Th22 pathway. The conventional therapeutic approaches (local or systemic route) appeal to various classes of drugs with complex mechanisms of action and non-negligible side effects. Although there is no therapy capable to cure psoriasis, the current goal is to relieve symptoms as longer as possible with a good benefit/risk ratio. That is one of the principal limits of conventional antipsoriatic drugs. New formulations based on nanoencapsulation are a promising opportunity to answer to this limit by offering an optimization of the conventional antipsoriatic drug use (higher activity, lower side effects and frequency of application, etc.). Herein, we tried to put in perspective the mechanistic insights (histological and immunological views) proposed into scientific literature these last years in order to have a better comprehension of psoriasis physiopathology resulting in skin lesions and PsA. The therapeutic armamentarium and the different strategies in the management of psoriasis are discussed in greater details. To finish, the field of encapsulation in nanoparticles is broached in order to put forward recent advances in innovative skin drug delivery systems (ISDDSs) of antipsoriatic active agents for a better efficacy, safety and compliance.
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Polymer-based nanocapsules for drug delivery Mora-Huertas, C.E.; Fessi, H.; Elaissari, A.
International journal of pharmaceutics,
01/2010, Letnik:
385, Številka:
1
Journal Article
Recenzirano
A review of the state of knowledge on nanocapsules prepared from preformed polymers as active substances carriers is presented. This entails a general review of the different preparation methods: ...nanoprecipitation, emulsion–diffusion, double emulsification, emulsion-coacervation, polymer-coating and layer-by-layer, from the point of view of the methodological and mechanistic aspects involved, encapsulation of the active substance and the raw materials used. Similarly, a comparative analysis is given of the size, zeta-potential, dispersion pH, shell thickness, encapsulation efficiency, active substance release, stability and
in vivo and
in vitro pharmacological performances, using as basis the data reported in the different research works published. Consequently, the information obtained allows establishing criteria for selecting a method for preparation of nanocapsules according to its advantages, limitations and behaviours as a drug carrier.
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Proteins are a vital constituent of the body as they perform many of its major physiological and biological processes. Recently, proteins and peptides have attracted much attention as ...potential treatments for various dangerous and traditionally incurable diseases such as cancer, AIDS, dwarfism and autoimmune disorders. Furthermore, proteins could be used for diagnostics. At present, most therapeutic proteins are administered via parenteral routes that have many drawbacks, for example, they are painful, expensive and may cause toxicity. Finding more effective, easier and safer alternative routes for administering proteins and peptides is the key to therapeutic and commercial success. In this context, much research has been focused on non-invasive routes such as nasal, pulmonary, oral, ocular, and rectal for administering proteins and peptides. Unfortunately, the widespread use of proteins and peptides as drugs is still faced by many obstacles such as low bioavailability, short half-life in the blood stream, in vivo instability and numerous other problems. In order to overcome these hurdled and improve protein/peptide drug efficacy, various strategies have been developed such as permeability enhancement, enzyme inhibition, protein structure modification and protection by encapsulation. This review provides a detailed description of all the previous points in order to highlight the importance and potential of proteins and peptides as drugs.
An ideal stimuli-responsive magnetic system possibilities the monitoring of the medication in the organism followed by the treatment using local drug delivery or hyperthermia.
In recent years, ...magnetic nanoparticles have been studied due to their potential applications as magnetic carriers in biomedical area. These materials have been increasingly exploited as efficient delivery vectors, leading to opportunities of use as magnetic resonance imaging (MRI) agents, mediators of hyperthermia cancer treatment and in targeted therapies. Much attention has been also focused on “smart” polymers, which are able to respond to environmental changes, such as changes in the temperature and pH. In this context, this article reviews the state-of-the art in stimuli-responsive magnetic systems for biomedical applications. The paper describes different types of stimuli-sensitive systems, mainly temperature- and pH sensitive polymers, the combination of this characteristic with magnetic properties and, finally, it gives an account of their preparation methods. The article also discusses the main in vivo biomedical applications of such materials. A survey of the recent literature on various stimuli-responsive magnetic gels in biomedical applications is also included.
Solvent displacement and emulsification-diffusion are the methods used most often for preparing biodegradable submicron particles. The major difference between them is the procedure, which results ...from the total or partial water miscibility of the organic solvents used. This review is devoted to a critical and a comparative analysis based on the mechanistic aspects of particle formation and reported data on the influence of operating conditions, polymers, stabilizing agents and solvents on the size and zeta-potential of particles. In addition, a systematic study was carried out experimentally in order to obtain experimental data not previously reported and compare the data pertaining to the different methods. Thus the discussion of the behaviors reported in the light of the results obtained from the literature takes into account a wide range of theoretical and practical information. This leads to discussion on the formation mechanism of the particles and provides criteria for selecting the adequate method and raw materials for satisfying specific objectives in submicron particle design.
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•Description of a new liposome preparation technique.•Comparison with a conventional method: ethanol injection.•Assessment of scaling-up performances.
Here, we propose a new method ...for lipid vesicles preparation: double solvent displacement. Influence of various parameters on colloidal properties was studied to assess scale-up performances in comparison with ethanol injection. Lipid vesicles were prepared by double solvent displacement (DSD). The first one was performed in non-aqueous media, only with an ethanol phase containing phospholipids dispersed in PEG400. The second one consisted of a dispersion of the previous mixture in an aqueous phase containing glycerin. Our results showed that double solvent displacement could be able to produce large amount of small and homogeneous lipid vesicles. With such method, we could use higher phospholipids concentrations without significantly affecting vesicle colloidal properties compared to ethanol injection. Indeed, for concentrations higher than 12.5mg/ml, we observed a continuous size increase (from 129±54nm to 318±220nm) associated with a higher heterogeneity of the population whereas results remained stable for the DSD technique (size between 123±57nm and 141±67nm, respectively). DSD technique allowed preserving colloidal properties over a large range of solvent/non solvent (S/NS) ratios. Scale-up studies showed more pronounced impact with ethanol injection technique for which colloidal properties were more altered. Indeed, size decreased significantly by 11.8% compared to DSD for which the increase was just about 3.5%. The latter appeared to be more easily scalable than ethanol injection. The simplicity and the rapidity of this new technique enable us to produce liposomes with good proficiency of the process offering high yield while keeping economically attractive.
In the first step, inner aqueous phase (W1) was added to dichloromethane (DCM) containing polycaprolactone (PCL) polymer and homogenized to form primary emulsion (W1/O). In the second step, the ...primary emulsion was emulsified in the outer aqueous phase (W2) containing polyvinyl alcohol (PVA) as stabilizer using ultra-turrax to have double emulsion (W1/O/W2). SEM microgram shows the particles morphology.
•Formulation of polymeric particles through double emulsion like process.•Effects of process parameters on particles colloidal properties.•Both agitation time and speed affect the final average particles size.•The use of high amount of polycaprolactone leads to large particles size.
Preparation of polycaprolactone (PCL) based microparticles by double emulsion solvent diffusion like process was studied in this work. The double emulsion was prepared in two steps. In first step, the inner aqueous phase (W1) was added to dichloromethane (DCM) solution containing PCL and homogenized to form primary emulsion (W1/O). In the second step, the primary emulsion (W1/O) was emulsified with the outer aqueous phase (W2) containing polyvinyl alcohol (PVA) as stabilizer using ultra-turrax at a specific speed and time in order to achieve the double emulsion (W1/O/W2). Effects of various parameters such as stirring time and speed, polymer amount and the volume fraction of each phase on hydrodynamic particle size, size distribution and zeta potential were investigated.
As a general tendency, zeta potential of all prepared particles was found to be constant irrespective of investigated parameter. Whereas, the increase in polymer amount leads to large particles size and lowest sizes were obtained when high stirring speed was used during the second emulsification step.
Carriers are largely used to enhance therapy efficiency via the encapsulation of active molecules. The encapsulation enhances the stability of drug molecules, improves the targeting properties and ...prolongs pharmacological activity via continuous local release of active molecules. The aim of this review is to report the carrier systems used in osteoporosis therapy. This state of the art research has mainly focused on describing all types of carriers used in this area, their elaboration and properties, the drug characteristics used in such specific application, and drug release and efficiency. In this field, various processes have been used in order to obtain well-defined capsules, spheres and more complex carriers. In this exhaustive review, each process is described, illustrated and discussed.
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