The role of the conformational profile of polysaccharides on skin penetration: the case of hyaluronan and its sulfates.
The literature data suggest the capacity of biomacromolecules to permeate the human skin, even though such a transdermal permeation appears to be governed by physicochemical parameters which are significantly different compared to those ruling the skin permeation of small molecules. On these grounds, the present study was undertaken to investigate the in vitro diffusion properties through the human epidermis of hyaluronic acid and their sulfates. Low- and medium-molecular-weight hyaluronic acids and the corresponding derivatives at two degrees of sulfation were then tested. In vitro studies evidenced that the sulfated polymers permeate better than the corresponding hyaluronic acid, despite their vastly greater polarity, while the observed permeation markedly decreases when increasing the polymer's molecular weight regardless of the sulfation degree. Using a fluorescent-labeled polysaccharide, it was also evidenced that hyaluronans have a great affinity for corneocytes and likely cross the stratum corneum mainly through a transcellular route. The molecular-dynamics study revealed how the observed permeations for the investigated polysaccharides can be rationalized by monitoring their conformational profiles, since the permeation was found to be directly related to their capacity to assume extended and flexible conformations.
Università degli Studi di Milano, Department of Pharmaceutical Sciences, via G. Colombo, 71, I-0133 Milano (phone: +39-02-50324635; fax: +39-02-50324657). francesco.cilurzo@unimi.it.
Francesco
F
Cilurzo
Giulio
G
Vistoli
Chiara G M
CG
Gennari
Francesca
F
Selmin
Fabrizio
F
Gardoni
Silvia
S
Franzè
Monica
M
Campisi
Paola
P
Minghetti
D000279:Administration, Cutaneous; D002236:Carbohydrate Conformation; D003198:Computer Simulation; D004817:Epidermis / Q000187:drug effects; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D018613:Microscopy, Confocal; D056004:Molecular Dynamics Simulation; D008970:Molecular Weight; D012867:Skin / Q000187:drug effects*; D013431:Sulfates
D013431:Sulfates; D006820:Hyaluronic Acid
Hyaluronan; Molecular dynamics; Radius of gyration; Skin permeation