Development of curcumin loaded sodium hyaluronate immobilized vesicles (hyalurosomes) and their potential on skin inflammation and wound restoring.

In the present work new highly biocompatible nanovesicles were developed using polyanion sodium hyaluronate to form polymer immobilized vesicles, so called hyalurosomes. Curcumin, at high concentration was loaded into hyalurosomes and physico-chemical properties and in vitro/in vivo performances of the formulations were compared to those of liposomes having the same lipid and drug content. Vesicles were prepared by direct addition of dispersion containing the polysaccharide sodium hyaluronate and the polyphenol curcumin to a commercial mixture of soy phospholipids, thus avoiding the use of organic solvents. An extensive study was carried out on the physico-chemical features and properties of curcumin-loaded hyalurosomes and liposomes. Cryogenic transmission electron microscopy and small-angle X-ray scattering showed that vesicles were spherical, uni- or oligolamellar and small in size (112-220 nm). The in vitro percutaneous curcumin delivery studies on intact skin showed an improved ability of hyalurosomes to favour a fast drug deposition in the whole skin. Hyalurosomes as well as liposomes were biocompatible, protected in vitro human keratinocytes from oxidative stress damages and promoted tissue remodelling through cellular proliferation and migration. Moreover, in vivo tests underlined a good effectiveness of curcumin-loaded hyalurosomes to counteract 12-O-tetradecanoilphorbol (TPA)-produced inflammation and injuries, diminishing oedema formation, myeloperoxydase activity and providing an extensive skin reepithelization. Thanks to the one-step and environmentally-friendly preparation method, component biocompatibility and safety, good in vitro and in vivo performances, the hyalurosomes appear as promising nanocarriers for cosmetic and pharmaceutical applications.

Regulation of DHP receptor expression by elements in the 5'-flanking sequence.

The alpha(1)-subunit of the cardiac/vascular Ca(2+) channel, which is the dihydropyridine (DHP)-binding site (the DHP receptor), provides the pore structure for Ca(2+) entry. It contains the binding sites for multiple classes of drugs collectively known as Ca(2+) antagonists. As an initial step toward understanding the mechanisms controlling transcription of the rat cardiac alpha(1C)-subunit gene, we have cloned a 2.3-kb fragment containing the 5'-flanking sequences and identified the alpha(1C)-subunit gene transcription start site. The rat alpha(1C)-subunit gene promoter belongs to the TATA-less class of such basal elements. Using deletion analysis of alpha(1C)-subunit promoter-luciferase reporter gene constructs, we have characterized the transcriptional modulating activity of the 5'-flanking region and conducted transient transfections in cultured neonatal rat cardiac ventricular myocytes and vascular smooth muscle cells. Sequence scanning identified several potential regulatory elements, including five consensus sequences for the cardiac-specific transcription factor Nkx2.5, an AP-1 site, a cAMP response element, and a hormone response element. Transient transfection experiments with the promoter-luciferase reporter fusion gene demonstrate that the 2-kb 5'-flanking region confers tissue specificity and hormone responsiveness to expression of the Ca(2+) channel alpha(1C)-subunit gene. Electrophoretic mobility shift assays identified a region of the alpha(1C)-subunit gene promoter that can bind transcription factors and appears to be important for gene expression.