Nanocomplex of quaternized cyclodextrin grafted chitosan and hyaluronic acid for a skin delivery

Water soluble quaternized cyclodexrin grafted chitosan (QCD-g-CS) was synthesized by combining both beneficial properties of β-cyclodextrin (β-CD) and the chitosan (CS) backbone. The chitosan backbone exhibits positive charges, while the β-CD moieties are available to include hydrophobic guest molecules into the cavity. The present work demonstrates a formation of nanocomplexes by simple mixing of the cationic QCD-g-CS with three different molecular weights of anionic Hyaluronic acid (low, medium and high HA; LHA, MHA and HHA, respectively). The HA is well-known on providing hydration to the skin and normalize keratinization. However, its strong hydrophilicity limits skin absorption. The polyelectrolyte nanocomplexes between QCD-g-CS and HA formed through the electrostatic interactions were confirmed by FTIR. Particle size of HA nanocomplexes were greater than that of free QCD-g-CS and increased with an increase in HA content. The complex of LHA and MHA improve the water retention capacity as well as ability to control the release of HA to be slower than the original HA. The release of both LHA and MHA from their complexes were both limited diffusion kinetics. Pronounced effect of small particle sizes of LHA complexes was found to benefit skin penetration. Clinical study indicated that LHA complexes improved skin texture and elasticity due to an increase in skin hydration. It is suggested that the QCD-g-CS in combination with anionic hydrophilic HA can be used as a promising polysaccharide-based skin delivery system.