Functionalization of a poly(D,L)lactic acid surface with galactose to improve human keratinocyte behavior for artificial epidermis

The production of artificial epidermis using reabsorbable polymeric matrices is one of possible goals; one of most used strategies in this field is the polymer substrate functionalitation using specific growth factors, in order to accelerate and improve keratinocyte adhesion and proliferation. In this study films of poly(D,L)lactide (P(D,L)LA), have been functionalized with various concentrations of galactose (GAL, 1-5-10%, w/v) conjugated with poly-L-lysine (PLL) using 1-etil-3-(3-diaminopropil) carbodiimide (EDC) as a coupling agent. GAL is a disaccharide present in the extra-cellular matrix (ECM) and it is bind by Galectines, a family of cell receptors whose activation regulate the cell-matrix interaction and cell growth and apoptosis. One of these receptors, Galectin-7 (Gal-7), is selectively expressed by human keratinocytes. Spontaneously immortalized human keratinocytes (HaCaT) that express high level of Gal-7 were allowed to adhere for 4 h in serum free condition on control P(D,L)LA (PLA), and on PLA-GAL and cell proliferation; the production of matrix metalloproteinases (MMP-2, MMP-9, and MMP-28), involved in cellular migration and tissue homeostasis have been analyzed after 24 h. The presence of GAL onto the polymer surface increased both cell adhesion, spreading and proliferation along with MMP-9 and MMP-28 production, suggesting that polymer functionalization using GAL could be an useful tool for the production of an artificial epidermis.