Phycocyanin-encapsulating hyalurosomes as carrier for skin delivery and protection from oxidative stress damage.

The phycobiliprotein phycocyanin, extracted from Klamath algae, possesses important biological properties but it is characterized by a low bioavailability due to its high molecular weight. To overcome the bioavailability problems, phycocyanin was successfully encapsulated, using an environmentally-friendly method, into hyalurosomes, a new kind of phospholipid vesicles immobilised with hyaluronan sodium salt by the simple addition of drug/sodium hyaluronate water dispersion to phospholipids. Liposomes were used as a comparison. Vesicles were small in size and homogeneously dispersed, being the mean size always smaller than 150 nm and PI never higher than 0.31. Liposomes were unilamellar and spherical, the addition of the polymer slightly modify the vesicular shape which remain spherical, while the addition of PEG improve the lamellarity of vesicles being multilamellar vesicles. In all cases phycocyanin was encapsulated in good amount especially using hyalurosomes and PEG hyalurosomes (65 and 61% respectively). In vitro penetration studies suggested that hyalurosomes favoured the phycocyanin deposition in the deeper skin layers probably thanks to their peculiar hyaluronan-phospholipid structure. Moreover, hyalurosomes were highly biocompatible and improved phycocyanin antioxidant activity on stressed human keratinocytes respect to the drug solution.