Effects of extracellular matrix protein functionalized fluid membrane on cell adhesion and matrix remodeling

In order to study cellular responses and extracellular matrix protein remodeling mediated by biomaterials coating, we proposed a biomimetic construct containing protein-conjugated supported lipid bilayers (SLBs) as a cell culture platform. Single or multi-component proteins-bound SLBs were fabricated by conjugating type I collagen and/or fibronectin on the N-hydroxysulfosuccinimide-functionalized SLBs. The proposed protein-conjugated systems were quantitatively characterized by the quartz crystal microbalance with dissipation. NIH 3T3 fibroblasts were cultured on the model constructs and on oxygen plasma pretreated polystyrene (PSo) for parallel comparison. The retards of mobility of SLB after protein conjugation and cell culture were estimated by fluorescence recovery after photobleaching. The resulting cell morphology, adsorption kinetics and somatic dynamics were examined microscopically. We found that, on the SLB based cultures, the largest spreading size and cell number counts of 3T3 fibroblasts were found on the fibronectin containing surfaces. However, on the protein-coated PSo surfaces, no such distinguishable differences can be observed on all protein contents. Immunofluorescent staining results revealed that adsorption of endogenously produced fibronectin by 3T3 cells on PSo based surfaces is significantly more than that on SLB based surfaces. This suggests that the anti-fouling nature of underneath SLBs have played an important role in preventing 3T3 cells from effectively remodeling their microenvironment, whereas cells can easily remodel the nonspecific adsorption prone surfaces such as PSo based platforms. In summary, the protein conjugated SLB surfaces can serve as a platform for determining and regulating cell specific binding and subsequent signaling events with extracellular environments.