Preparation of heterodifunctional polyethyleneglycols: network formation, characterization, and cell culture analysis

Polyethyleneglycols (PEG) are employed extensively in the development of biomaterials; however, the hydroxyl groups in PEG-diols have very limited chemical activity. We developed a synthesis scheme for a library of heterodifunctional PEG (hPEG) with two distinct terminal moieties to improve the reactivity and physicochemical properties of PEG. hPEG were employed in the formulation of polymer networks with various surface physicochemical properties and utilized to study cell-material interaction. Extensive NMR and HPLC analyses confirmed the chemical structure of hPEG. The hydrophilicity of the polymer network was predominantly dependent on the hPEG concentration with the molecular weight and terminal functional group playing lesser roles. Adherent human fibroblast density on the network remained constant with increasing hPEG concentration in the network formulation but decreased rapidly on networks containing 0.8-1.25 g ml(-1) of hPEG. This trend was independent of the hPEG terminal moiety and molecular weight. No adherent cell was observed on all films containing 2.5 g ml(-1) or more of hPEG.