Liposomes augment biological benefits of curcumin for multitargeted skin therapy.

Curcumin, a multi-targeting pharmacologically active compound, is a promising molecule for the treatment of skin inflammation and infection in chronic wounds. However, its hydrophobic nature remains to be a challenge in development of its pharmaceutical products, including dermatopharmaceuticals. Here we propose deformable liposomes (DLs) as a mean to overcome the curcumin limitations in skin treatment. We explored the properties and biological effects of curcumin containing DLs (curcumin-DLs) with varying surface charge by preparing the neutral (NDLs), cationic (CDLs) and anionic (ADLs) nanocarriers. The vesicles of mean diameter 200-300 nm incorporated high curcumin load mirroring the type of employed surfactant. Curcumin-CDLs provided the most sustained ex vivo penetration of curcumin through the full thickness human skin. Although the curcumin-CDLs were the most potent regarding the in vitro anti-inflammatory activity, all curcumin-DLs were superior to curcumin in solution (control). No cytotoxicity in human skin fibroblasts was detected. All DLs significantly inhibited bacterial Staphylococcus aureus and Streptococcus pyogenes growth in vitro. The curcumin-CDLs were found superior to other DLs. The incorporation of curcumin in DLs enabled both its sustained skin penetration and enhancement of its biological properties. Cationic nanocarriers enhanced the activities of curcumin to the greatest extent.

Mucus-PVPA (mucus Phospholipid Vesicle-based Permeation Assay): An artificial permeability tool for drug screening and formulation development.

The mucus layer covering all mucosal surfaces in our body is the first barrier encountered by drugs before their potential absorption through epithelial tissues, and could thus affect the drugs' permeability and their effectiveness. Therefore, it is of key importance to have in vitro permeability models that can mimic this specific environment. For this purpose, the novel mucus phospholipid vesicle-based permeation assay (mucus-PVPA) has been developed and used for permeability screening of drugs and formulations. The model proved to be stable under the chosen conditions and demonstrated the ability to discriminate between compounds with different chemical structures and properties. Overall, a decrease in drug permeability was found in the presence of mucus on top of the PVPA barriers, as expected. Moreover, mucoadhesive (chitosan-coated) and mucopenetrating (PEGylated) liposomes were investigated in the newly developed model. The mucus-PVPA was able to distinguish between the different liposomal formulations, confirming the penetration potential of the tested formulations and the related drug permeability. The mucus-PVPA model appears to be a promising in vitro tool able to mimic the environment of mucosal tissues, and could therefore be used for further drug permeability screening and formulation development.