Chitin nanofibril-hyaluronan block polymer characterised

The primary barrier to transdermal delivery is the stratum corneum composed of corneocytes embedded and surrounded by a semi-continous matrix of lipids. Nanoparticles made of chitin-hyaluronic acid (CN-HA) block polymers, produced by the gelation method and published elsewere by our group, have shown to promote paracellular and transcellular permeability, significantly impacting all the topical skin treatments, because of their ability to mimic the native state of extracellular matrix macromolecules. This paper describes the physico-chemical characterisation of CN-HA controlled by SEM.

 A vast number of pharmaceutical and cosmetic products target skin tissue, aiming to treat the diseases, the dysfunctions and/or the damages even mechanical ones, affecting this organ. Moreover, they have also to preserve the skin from age-related consequences or, in particular, to protect it as much possible from consequences of premature ageing, because skin ageing prevention has become more important for the general population, year by year. The mainstay of skin protective strategies is photo protection and, as a practical consequence, UV filters are no longer used solely in sunscreens, but are increasingly present as relevant concentrations in cosmetic products for daily use also.1 However, photo protection provided by UV filters is not 100% perfect and thus, there is room for improvement. This is the reason why nanotechnology has been identified as a key enabling technology (KET) providing the basis for further innovation and new products.2 Therefore, many research studies are looking for innovative active molecules which provide photo protection through mechanisms which are not only based on absorption or reflection of UV rays, but are also capable of enhancing skin transformation and regeneration, having wound healing properties, and, of course, possess antiwrinkle activity. In recent years the study and development of materials at the nanometric level had the attention of the scientific community due to its enormous potential in creating innovative ingredients with high performance for advanced applications in many different disciplines, such as electronics, polymer engineering, surface treatments, medical science, etc. Therefore, the benefits of nano-materials and new uses are being developed rapidly, so that the group of nano-titanium dioxide and nano-zinc oxide are molecules with a fast increasing variety of uses, for example, in the cosmetic/pharmaceutical fields. Moreover, the necessity to have efficacious vehicles able to easily penetrate the skin barrier, has also gained much interest in tissue engineering applications. Thus, fabrication and design of complex structural colloidal architectures (scaffolds) has been realised. Because of their ability to geometrically and typologically mimic the native state of extracellular matrix macromolecules in living tissue (i.e. collagen, hyaluronic acid, glycosaminoglycan, etc.), scaffolds of natural polymers, such as chitin and chitosan, have been produced, demonstrating their effectiveness as substrates for cell growth and as drug/cosmetic delivery vehicles.3–7 In any way, the benefits of these innovative materials range from saving lives, breakthroughs enabling new applications, to perform new functions for every day commodity products. For all these reasons, products underpinned by nanotechnology are forecast to grow from a volume of e200 billion to e2 trillion by 2015.8 According to the EU figures,9 these applications will be essential for the competitiveness of a wide area of EU products in the global market. Thus, current direct employment in nanotechnology is estimated at 300,000 to 400,000 jobs with an increasing trend.10 Many other nanomaterials are used, in fact, in innovative applications, as catalysts, electronics, solar panels, batteries, water recovery and desalination, and biomedical applications, including specialised bio-textiles, diagnostics and tumour therapies. At this purpose, in its communication the EU Commission has outlined a single strategy for KETs, including nanotechnology, built upon three pillars: Technological Research, Products Demonstration and Competitive Manufacturing Activities.11

Chitin nanofibrils