## 3 Nanomaterials in Anti-Aging Formulations
Vitamins and coenzymes with antioxidant activity include vitamin E (alpha-tocopherol), vitamin C (ascorbic acid), vitamin K, beta-carotene (vitamin A precursor), coenzyme Q, nicotinamide, and lipoic acid. As enzymatic antioxidants, it can be pointed to the glutathione peroxidase, the superoxide dismutase, and catalase [35]. Some substances involved in cell regulation are biological growth factors and, for example, kinetin (a cytokinin, a plant growth hormones), was shown to have potent antioxidant capacity, capable of protecting the skin against the oxidative damage caused by sunlight rays, is commonly used in cosmetic formulations as anti-aging [125]. Growth factors are also included in cosmetics to stimulate collagen and elastin synthesis to repair the dermal extracellular matrix. ; being the most common the epidermal growth factor (EGF), transforming growth factor (TGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), insulin growth factor (IGF) and interleukin [51; 128]. Herbal extracts and essential oils are another source of active cosmetic ingredients used against skin aging [129; 130; 131; 159; 60; 132; 133; 134; 135; 136; 137; 138; 139; 140; 141; 142; 143; 144; 145; 146; 147; 148; 149; 150; 151; 152; 153;  
take into account two principles: assure that the active ingredient reaches the site of action with the right concentration; and that the active cosmetic ingredients are available in the local of action over a certain period of time at the required concentration [142]. Other types of nanomaterials being currently exploited for the delivery of cosmeceuticals and pharmaceuticals are nanolignins and nanocelluloses. Chitin and lignin are by-products of plant biomass and can be used as starting materials for the production of eco-friendly, biocompatible pharmaceuticals and cosmeceuticals. Their high antibacterial, anti-inflammatory, cicatrizing, and anti-aging activities have been described at the nanoscale. [PERSON] et al. have produced microcapsules composed of chitin nanofibrlis (positively charged) and nanolignin (negatively charged) for the loading of glycyrrhetic acid [143]. The obtained microcapsules were shown to downregulate proinflammatory cytokines IL-1-alpha (IL-1\(\alpha\)), IL-1-beta (IL-1\(\beta\)), IL-6, IL-8, and TNF-alpha and upregulate antimicrobial peptide human beta defensin-2. The tested human mesenchymal stromal cell line remained viable while their contact with microcapsules did not modify the osteo-differentiation capability of the cells. The authors postulate that the developed formulation may be useful for the delivery of biomolecules for skin care and regeneration, showing anti-inflammatory activity and cytocompatibility [143]. Within the field of anti-aging, biodegradable non-woven tissues have been recently proposed for the site-specific release of active ingredients into deeper skin layers. [PERSON] et al. have used polysaccharide natural fibers composed of chitin nanofibrils and nanochitin for the production of biofunctional textiles [144]. The developed tissues were shown to mimic the skin extra cellular matrix being suitable for skin repair and for anti-aging and were also proposed for food formulation. Nanocellulose, in particular cellulose nanocrystals and nanofibrilated cellulose, are reported to exhibit attractive properties for use in cosmetic, pharmaceutical, and food products. They are derived from the most widespread and renewable biopolymer-cellulose, showing remarkable chemical and physical properties that can be exploited for the development of new formulations [145]. Chitosan nanocellulose composites have been proposed for both skin tissue engineering and wound dressings as they exhibit biocompatibility, cell adhesion, 3D nanoporous structure, mechanical strength, and high porosity [146], with capacity to load a range of active ingredients. Nanocellulose films have been produced with titanium dioxide nanoparticles for their high refractive index and UV absorbing properties [147].