Application of MS-based proteomics to study serum protein adsorption/absorption and complement C3 activation on...

Although the interaction between cells and poly(ethylene glycol) (PEG) hydrogels is well documented, there lacks a thorough investigation into the adsorption of blood proteins on these surfaces which dictates the observed cellular and in vivo host response. Thus, a clear understanding of how surface-bound proteins mediate the unique biological property of PEG hydrogels is fundamentally important. The information obtained will also provide insights into future biomaterial design. In this study, several mass-spectrometrybased proteomic tools coupled with complementary immunoassays were employed to survey the complex surface-bound serum proteome. The adsorption of vitronectin, thrombin, fibrinogen and complement component C3 was significantly lower on PEG hydrogels than on tissue culture polystyrene (TCPS). Although PEG hydrogels mediated lower C3 adsorption than TCPS, the extent of C3 activation between the two surfaces was comparable. Adherent monocyte density was also significantly lower on PEG hydrogels as compared to TCPS. Taken together, these results support the critical role of the complement C3 in mediating monocyte adhesion on biomaterials. Thus we conclude that the biocompatibility of PEG hydrogels both in vitro and in vivo can be partly contributed to their limited C3 interaction and monocyte activity.