Role of active nanoliposomes in the surface and bulk mechanical properties of hybrid hydrogels.

Nanoliposomes are widely used as delivery vehicles for active compounds. Nanoliposomes from rapeseed phospholipids were incorporated into interpenetrating polymer network hydrogels of gelatin methacryloyl and alginate. The multiscale physicochemical properties of the hydrogels are studied both on the surface and through the thickness of the 3D network. The obtained composite hydrogels exhibited strong mechanical properties and a highly porous surface. The blend ratio, as well as the concentration of nanoliposomes, affects the properties of the hydrogels. Nanofunctionalized hydrogels induced keratinocyte â€‹growth. These advantageous characteristics may open up many applications of the developed hydrogels in drug delivery and tissue engineering.

Nanoemulsions and topical creams for the safe and effective delivery of lipophilic antioxidant coenzyme Q10.

Emulsion-based delivery systems have been developed to increase the topical bioavailability of lipophilic active compounds within skin membrane. The aim was to develop nanoemulsion from natural sources (rapeseed oil) with the same sources of pure phospholipids (lecithin) rich on mono and polyunsaturated fatty acids for encapsulation of hydrophobic antioxidant (Coenzyme Q10) giving nanoemulsion with double functionality. Nanoemulsions were used for cream preparation using xanthan gum and carboxylmethylcellulose as texturizing agents. The physico-chemical properties, toxicity and biocompatibility were evaluated. Physical stability was followed under different storage temperatures (25; 37 and 50 °C) for one month and revealed stable systems with 150 nm particle size. Anionic thickening addition influenced the electrophoretic mobility but not the size distribution. The addition of polyanionic thickening in nanoemulsions promoted negative surface charge that increased electrostatic repulsive forces between droplets avoiding destabilization phenomena such as coalescence and Ostwald ripening. Moreover, chemical stability evaluation of components confirmed the absence of interactions. FTIR analysis indicated the vibration band position of cis double stretching of unsaturated fatty acids between 3009 and 3006 cm-1, which characterized the non-oxidized oils with same intensities before and after sonication. Antioxidants measurement shown that CMC significantly reduced antioxidant activity due to masking action of CoQ10 functional groups by the carboxylmethylcellulose gum conversely to xanthan gum addition. Finally, in vitro biocompatibility results shown that CoQ10 protected the DNA, and xanthan gum improve glucose metabolism inducing a better cell growth, while carboxymethylcellulose which was not metabolized by fibroblast cell inducing lower growth rate.

Skin delivery of hydrophilic molecules from liposomes and polysaccharide-coated liposomes.

OBJECTIVES: Liposomes are commonly used in cosmetic formulations to increase the bioavailability of active ingredients. We have previously shown that polysaccharide coating of liposomes improves their resistance to surfactants and electrolytes. In the current study, we have assessed the impact of coating on the skin penetration enhancer properties of liposomes. METHODS: The physicochemical properties of coated liposomes (Ionosomes™) were evaluated before and after encapsulation of two different hydrophilic molecules (caffeine and a hexapeptide), and compared to those observed with non-coated liposomes. Moreover, in vitro permeation experiments were performed using Franz™-modified diffusion cells, with normal human skin as membranes. RESULTS: Results showed that both coated and non-coated liposomes significantly improved the bioavailability of hydrophilic active molecules in skin, compared to reference solutions. Although liposome coating slightly reduced entrapment efficiency, the delivery of active molecules was not adversely affected by the process. In conclusion, polysaccharide coating of liposomes allows for better protection of their integrity without compromising the skin bioavailability of the active molecules that they convoy.

Efficiency of emulsifier-free emulsions and emulsions containing rapeseed lecithin as delivery systems for vectorization and release of coenzyme Q10: physico-chemical properties and in vitro evaluation.

To improve the encapsulation and release of coenzyme Q10 (CoQ10), emulsifier-free-emulsions were developed with a new emulsification process using high-frequency ultrasound (HFU) at 1.7MHz. Nano-emulsions containing CoQ10 were prepared with or without rapeseed lecithin as an emulsifier. The emulsions prepared with HFU were compared with an emulsion of CoQ10 containing emulsifier prepared with the same emulsification technique as well as with emulsions prepared with low-frequency ultrasound coupled with high-pressure homogenization (LFU+HPH). The physico-chemical properties of the emulsions were determined by average droplet size measurement with nano-droplet tracking analysis, droplet surface charge with ζ potential measurement, surface tension and rheological behaviour. Emulsions made by LFU+HPH with an emulsifier showed lower droplet sizes due to cavitation generated by the HFU process. Surface tension results showed that there was no significant difference between emulsions containing lecithin emulsifier regardless of the preparation process or the inclusion of CoQ10. In vitro biocompatibility tests were performed on human mesenchymal stem cells in order to show the cytotoxicity of various formulations and the efficiency of CoQ10-loaded emulsions. In vitro tests proved that the vectors were not toxic. Furthermore, CoQ10 facilitated a high rate of cell proliferation and metabolic activity especially when in an emulsifier-free formulation.

Liposome encapsulation of curcumin: physico-chemical characterizations and effects on MCF7 cancer cell proliferation.

The role of curcumin (diferuloylmethane), for cancer treatment has been an area of growing interest. However, due to its low absorption, the poor bioavailability of curcumin limits its clinical use. In this study, we reported an approach of encapsulation a curcumin by nanoliposome to achieve an improved bioavailability of a poorly absorbed hydrophobic compound. We demonstrated that liposomal preparations to deliver curcumin increase its bioavailability. Liposomes composed of salmon's lecithin also improved curcumin bioavailability compared to those constituted of rapeseed and soya lecithins. A real-time label-free cell analysis system based on real-time cell impedance monitoring was used to investigate the in vitro cytotoxicity of liposomal preparations.

Effects of Ar-H2-N2 microwave plasma on chitosan and its nanoliposomes blend thin films designed for tissue engineering applications.

This work addresses the functionalization of chitosan thin films and its nanoliposomes blend films by a microwave-excited Ar/N2/H2 surface-wave plasma treatment which was found an effective tool to modify surface properties. Changes in the film properties (wettability, chemical composition, morphology) induced by the plasma treatment are studied using water contact angle measurements, X-ray photoelectron spectroscopy and scanning probe microscopy. The results suggest that hydrophilicity of the films is improved by plasma treatment in a plasma condition dependency manner. Water contact angle of chitosan films before and after plasma treatment are, respectively, 101° and 27°. Besides chemical changes on the surface, the nanoliposomes incorporation and plasma treatment also induce morphological modifications. Moreover, a correlation is found between the nanoliposomes composition and size, and the effects of plasma treatment. It is shown that the plasma treatment significantly improves the chitosan film functionalization. The effect of N2 content (88% and 100%) in the plasma gas mixture on the film etching is also pointed out.