Smooth muscle cell growth in photopolymerized hydrogels with cell adhesiveand proteolytically degradable domains: synthetic ECM analogs for tissue engineering

Photopolymerizable polyethylene glycol (PEG) derivatives have been investig ated as hydrogel tissue engineering scaffolds. These materials have been mo dified with bioactive peptides in order to create materials that mimic some of the properties of the natural extracellular matrix (ECM). The PEG deriv atives with proteolytically degradable peptides in their backbone have been used to form hydrogels that are degraded by enzymes involved in cell migra tion, such as collagenase and elastase. Cell adhesive peptides, such as the peptide RGD, have been grafted into photo polymerized hydrogels to achieve biospecific cell adhesion. Cells seeded homogeneously in the hydrogels dur ing photopolymerization remain viable, proliferate. and produce ECM protein s. Cells can also migrate through hydrogels that contain both proteolytical ly degradable and cell adhesive peptides. The biological activities of thes e materials can be tailored to meet the requirements of a given tissue engi neering application by creating a mixture of various bioactive PEG derivati ves prior to photopolymerization. (C) 2001 Elsevier Science Ltd. All rights reserved.