Background In recent years, bacterial cellulose (BC), or biocellulose, a natural polymer synthesized by certain bacteria, has attracted great interest in dermatology and cosmetic applications. Several bioactive ingredients are currently loaded into BC masks. However, only a few studies have reported the effectiveness of such delivery systems. Aim The aim of this study was to evaluate the effect on skin parameters of three biocellulose masks formulated to have different cosmetic effects (anti‐aging, lifting, and cell renewal). In particular, skin moisturizing, skin color, skin viscoelastic properties, skin surface smoothness, wrinkle reduction, dermal homogeneity, and stratum corneum renewal were evaluated. Materials and methods The study involved 69 healthy Caucasian female volunteers between 25 and 64 years, who were divided into three different studies. Biocellulose facial masks were applied using the split‐face method three times a week for 4‐8 weeks depending on the study. Results The results obtained from this work highlight that biocellulose masks are very well tolerated. A significant decrease in skin roughness and wrinkle breadth, and an improvement in dermal homogeneity and firmness, was observed after 2 months of treatment with “anti‐aging” masks. A significant improvement in skin firmness and elasticity was observed after 1 month of treatment with “lifting” masks. Furthermore, a 1‐month treatment with “cell renewal” masks promoted the production of new skin cells through a mild exfoliating action. Conclusions This study highlights that biocellulose masks are effective delivery systems to successfully release into the skin several types of active compounds exerting many beneficial effects.

Bacterial cellulose (BC) has become of great interest in recent years, as a delivery system in several areas of application, including food, drugs, and cosmetics, thanks to its exclusive advantages, such as high biocompatibility, water holding capacity, and good gas permeability. The novel approach of the authors has led to a protocol for checking the quality and safety of bacterial cellulose matrices in the manufacture of cosmetic masks. Two non-destructive techniques, near-infrared spectroscopy (NIR) and multiple light scattering (MLS), were used to verify different parameters affecting the quality of BC sheets, allowing cellulose masks to be checked over time. NIR spectroscopy allowed for discovering changes in the water content, depending on filling/packaging procedures, like flat-folding. Multiple light scattering was used to ascertain the stability of solutions in contact with masks. From a clinical standpoint, the cutaneous tolerability of biocellulose masks, and their effect on skin parameters, were evaluated through some specific "in vivo" tests. Also, a safety evaluation during application was conducted through different studies: a short-term one after single application, and a long-term one upon continued use.Cosmetics 2018, 5, 66 2 of 20 surface area per unit mass is demonstrated. This feature, combined with its highly hydrophilic nature, results in a very high liquid-loading capacity. Its water-holding capacity (WHC) is over 100 times (by mass) higher than plant cellulose, and the WHC is 100-200 times its dry weight [1][2][3].The hydrogen bonds between its fibrillar units stabilize the whole structure, and define many of its mechanical properties. Tensile strength, maximum elongation, and elastic modulus, that characterize BC, depend on its own uniform ultrafine-fiber network structure, and the high planar orientation of the ribbon-like fibers, when compressed into sheets, results in good chemical stability [3].Bacterial cellulose shows great biocompatibility, not only because of its non-toxic effects on biological systems but, also, by eliciting an appropriate host response to ensure satisfactory performance during a specific application. Petersen and Gatenholm have pointed out that biocompatibility of BC for tissue engineering applications can be can be due to structure similarities with extracellular matrix components, such as collagen. In fact, collagen and BC nanofibers have similar diameters (around 100 nm), and are extracellularly assembled from precursor molecules into polymer chains [4].Due to its unique structural properties, BC has become of interest in different fields, such as in the textile industry, high quality paper production, food, pharmaceutical and medical devices, electronics, and acoustics [1,2]. In particular, the biomedical field exploits microbial cellulose as a natural, porous, nontoxic material in tissue-like products for both wound care and the regeneration of damaged or diseased organs. Due to its unique nanostructure and properties, BC is a natural candidate for numerou...