A microfluidic coculture system for cell-cell interaction study

A novel microfluidic coculture system was developed for more accurately modelling the interaction of macrophages and osteoblasts. The microfluidic coculture chip was fabricated by CO/sub 2/ laser direct-writing on poly(methyl methacrylate) (PIMMA) and was designed to separate two cell types by a microchannel, while permitting cellular media to transfer. The released inflammatory cytokines (ex: IL-I/spl beta/, TNF-/spl alpha/ activated in upstream macrophages flow through a microfluidic system and generate linear concentration gradients in down-stream wells and induce down-stream osteoblasts to release prostaglandin E2 (PGE2), which is well-known as a bone resorption marker. Colorimetric MTT assay was used to examine the osteoblast viability. This system can be used to evaluate the cell-cell interaction while physically separate the interacting cells.