Build‐up of Polypeptide Multilayer Coatings with Anti‐Inflammatory Properties Based on the Embedding of Piroxicam–Cyclodextrin Complexes

We describe the build‐up of biomaterial coatings based on polypeptide multilayers possessing anti‐inflammatory properties. Poly(L ‐lysine) (PLL) and poly(L ‐glutamic acid) (PGA) are used as polypeptides, and piroxicam (Px) is used as the anti‐inflammatory agent. In order to embed high enough amounts of Px, the drug is incorporated in the films in the form of complexes with a charged 6^A‐carboxymethylthio‐β‐cyclodextrin (cCD). It is shown that this cyclodextrin can solubilize higher amounts of Px than the cyclodextrins used commercially. The anti‐inflammatory properties are evaluated by determining the inhibition of TNFα production by human monocytic THP‐1 cells stimulated with lipopolysaccharide (LPS) bacterial endotoxin. Using Fourier‐transform (FT) Raman spectroscopy, we show that Px is mainly in the neutral form in cCD–Px complexes in solution, and that it remains biologically active under this form, whereas up to now only the zwitterionic form was reported to possess anti‐inflammatory properties. When incorporated in PLL/PGA multilayers, Px in the cCD–Px complexes changes from the neutral to the zwitterionic form. It is shown that these films present anti‐inflammatory properties, which can be delayed, and whose duration can be tuned by changing the film architecture.