ABSTRACT
Applications .................................................................................................. 218 10.6.1 Functional in vitro Drug Screening Platforms ................................. 218 10.6.2 Engineered Functional Neuronal Networks .....................................220 10.6.3 Accelerated Biocompatibility Studies .............................................. 221
The determination and engineering of the behavior of living cells became a crucial task in several emerging Œelds of tissue engineering and drug screening [1]. The building of complex tissue analogs, the creation of tissue engineered organs, the preparation of stem cells for therapy, the development of high-throughput functional drug screening platforms, or the integration of whole-cell biosensors with siliconbased electronics all require the manipulation of cells and the determination of their placement, interactions, differentiation, and integration [2-5]. Unfortunately, conventional engineering methods may not be suitable to deal with living cells, primarily because the cells are following a self-organizing internal program that we have only limited knowledge about and is usually not our design. Consequently, traditional cell engineering methods do not fulŒll their intended purpose, in particular, mimicking the native cellular environment. Recently, new technologies have been emerging, with the aim of engineering the environment of living cells to control their internal program through extracellular cues [4,6-10]. These extracellular cues could be soluble factors introduced in the culture medium or surface-bound topographical, chemical, or physical signals on the culture surface or incorporated into tissue engineered three-dimensional (3-D) scaffolds. At the same time, new technologies were also developed to create spatial and (in a lesser extent) temporal patterns of these signals [4,6,7,11-17]. Contact interactions are major determinants of cell attachment, proliferation, growth, and differentiation. Cell adhesion and attachment molecules play essential roles in embryonic development, integration of cells into tissues and organs, cell migration, axon guidance, immune response, and tumor development [18-20].
