Injectable in situ forming hydrogels based on natural and synthetic polymers for potential application in cartilage repair

In this work we prepared two new hyaluronic acid (HA) based in situ forming hydrogels for the potential treatment of articular cartilage damages. In particular the amino derivative of HA (HA-EDA) and its graft copolymer with alpha-elastin (HA-EDA-g-alpha-elastin) were crosslinked, in mild physiological conditions via Michael-type addition, with alpha, beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) derivatized with divinylsulfone (DV). The swelling and degradation profile of the obtained hydrogels as well as the metabolic activity of incorporated bovine articular chondrocytes were investigated. Histological analysis and scanning electron microscopy (SEM) were performed to analyze the morphology of cells after scheduled times of incubation. Moreover the influence of the alpha-elastin on the elastic modulus of cell free and cell containing hydrogels has been studied through atomic force microscopy (AFM).