Phosphorylcholine-containing polyurethanes for the control of protein adsorption and cell attachment via photoimmobilized laminin oligopeptides

In this study, we synthesized a biomaterial whose surface inhibits non-spec ific protein and cell attachment. The polymer was designed to mimic the ext ernal cell plasma membrane properties through the introduction of particula r chemical constituents of the cell membrane: phospholipid polar headgroups . This was done by copolymerizing phosphorylcholine (PC) groups into a poly urethane polymer backbone (PCPUR). Peptides known to induce specific cell a ttachment were subsequently bound to the surface of this copolymer in a pho toadressible manner to obtain surfaces that allowed the attachment of cells in a specific pattern. Two polymers with different phosphorylcholine conce ntrations were synthesized and their bulk and surface properties were chara cterized through differential scanning calorimetry. wettability measurement s, angle-resolved X-ray photoelectron spectroscopy and time-of-flight secon dary ion mass spectrometry. Protein and lipid adsorption investigation usin g optical waveguide light mode spectroscopy showed that the irreversible ad sorption of both proteins and lipids is drastically reduced as a result of simultaneous contributions of the PC groups, molecular mobility and strong hydrophilicity of the polymers. Consequently, this leads to a marked reduct ion in the cellular attachment response, which further decreases with incre asing PC concentration, Finally, when the polymer surface was photo-derivat ized, attachment of the neural NG108-15 cell line occurred only on the area s of the PCPUR where the laminin CDPGYIGSR peptide sequence was photoimmobi lized. Cell attachment was nevertheless found to be non-specific with respe ct to the peptide sequence used and reasons for such results are therefore discussed.