Morphology and growth of murine cell lines on model biomaterials

All biomaterial implants are assaulted by the host "foreign body" immune response. Understanding the complex, dynamic relationship between cells, biomaterials and milieu is an important first step towards controlling this reaction. Material surface chemistry dictates protein adsorption, and thus subsequent cell interactions. The cell-implant is a microenvironment involving 1) proteins that coat the surface and 2) cells that interact with these proteins. Macrophages and fibroblasts are two cell types that interact with proteins on biomaterials surfaces and play different related, but equally important, roles in biomaterials rejection and implant failure. Growth characteristics of four murine cell lines on model biomaterials surfaces were examined. Murine monocyte-macrophages (RAW 264.7 and J774A.1), murine macrophage (IC-21) and murine fibroblast (NIH 3T3) cell lines were tested to determine whether differences exist in adhesion, proliferation, differentiation, spreading, and fusion (macrophage lineages only) on these surfaces. Differences were observed in the ability of cells to adhere to and subsequently proliferate on polymer surfaces. (Monocyte-) macrophages grew well on all surfaces tested and growth rates were measured on three representative polymer biomaterials surfaces: tissue culture polystyrene (TCPS), polystyrene, and Teflon-AF. J774A.1 cultures grown on TCPS and treated with exogenous cytokines IL-4 and GM-CSF were observed to contain multinucleate cells with unusual morphologies. Thus, (monocyte-) macrophage cell lines were found to effectively attach to and interrogate each surface presented, with evidence of extensive spreading on Teflon-AF surfaces, particularly in the IC-21 cultures. The J774A.1 line was able to proliferate and/or differentiate to more specialized cell types (multinucleate/dendritic-like cells) in the presence of soluble chemokine cues.