# Grape By-Products in Sustainable Cosmetics: Nanoencapsulation and Market Trends
## 6 Nanoencapsulation Trends
### Liposomes and Nanovesicles  
A liposome, Figure 3, consists of a spherical nanovesicle composed primarily of phospholipids that form a bilayer structure when dispersed in water [82]. [PERSON] et al. [34] developed liposomes and phospholipid-based nanovesicles, modified with glycerol, or Montanov 82\({}^{\text{\text{\text  
significant physical alterations (e.g., mean particle size) and no significant vesicle migration and aggregation were observed, and there was a constancy of the PI (polydispersity index) [85]. Moreover, [PERSON] et al. [86] combined a grape pomace extract (4 or 5% (\(w/v\))) in small-sized sodium alginate (SA)- or arabic gum (AG)-based liposomes with good encapsulation efficiency, potentiating its applicability in the nutraceutical industry. Depending on the used extract concentration, the encapsulation efficiencies were 91 and 53% when using SA, and 84 and 52% when using AG, for 4 and 5% concentration, respectively. [PERSON] et al. [87] evaluated an integrated resveratrol- and quercetin-loaded liposomal formulation, made from Lipoid S75, oleic acid, and ATX Tris buffer, in an animal model of cancer-mediated skin tissue injury, leading to the enhancement of human dermal fibroblasts viability (from 20 to 60% at 400 uM), presumably via reducing intracellular reactive oxygen species (ROS) levels. In 2008, [PERSON] et al. [88] developed resveratrol-loaded liposomes, made from enriched soy phosphatidylcholine (P90G), diacetyl phosphate (DCP), cholesterol, or lecithin alone, stable up to 60 days, without significative differences in particle size, zeta potential, loaded resveratrol quantity and no signs of _trans/cis_-isomerisation, thus increasing the efficacy of the treatment and prevention of skin disorders caused by excessive UV radiation exposure. [PERSON] [89] created an in vitro formulation of propylene glycol liposomes and simple liposomes, both stabilised with grape-silver nanoparticles and loaded with grape pomace extract. The mixture was shown to be effective in removing several pathogens (_Staphylococcus aureus_ and _Pseudomonas aeruginosa_) and free radicals, as well as in protecting fibroblasts and keratinocytes against oxidative stress, suggesting a suitable formulation for topical treatment of skin lesions. In agreement with the last study, [PERSON] et al. [90] showed that resveratrol and gallic acid co-loaded (0.5% (\(w/v\)) each) into phospholipid liposomes were able to protect fibroblasts and keratinocytes from oxidative stress and from pathogenicity (antimicrobial activity boost). Another study focused on ultra-deformable liposomes (UDL), composed of 36-[N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol hydrochloride (DC-Chol), cholesterol, and sodium deoxy malate (SDC), and loaded with resveratrol and psoralen (from 2.5% to 10% (\(w/w\)), with respect to the lipids weight), highlighted their potential for utiligo treatment. The procedure consisted of the administration of two doses of the liposomes, significantly increasing tyrosinase activity ca. 1.70-fold for both doses, and melanin concentration by 1.69 and 2.12 for first and second drug delivery moments, respectively. Interestingly, liposomes loaded only with resveratrol did not show significant improvements for these parameters [91].  
Figure 3: Nanoencapsulation techniques and their respective advantages.