Mechanical and cell interaction properties of PEG-modified chitosan

In recent studies, chitosan has been found to be a promising base material for a number of tissue engineering applications. However, its mechanical properties are less than ideal for some applications. In this study the authors investigated the effects of grafting monofunctional poly(ethylene glycol) aldehyde (PEG-Aid) side chains onto the chitosan molecule. Cast membranes of modified chitosan were subjected to tensile testing and also evaluated as culture substrates for vascular smooth muscle cells (SMC). Testing results showed that the elastic modulus (E) decreased linearly with increasing PEG content from 6.8 MPa (0% PEG) to 0.8 MPa (52 wt% PEG). Maximum stress also showed a decrease. SMC spreading decreased with increasing PEG content, such that spreading and growth were completely inhibited for chitosan membranes containing 35 wt% PEG and above. The authors concluded that PEG grafting can be used to control the mechanical and cell interaction properties of chitosan