Accelerated formation of multicellular 3-D structures by cell-to-cell cross-linking.

The three-dimensional (3-D) arrangement of cells within tissues is integral to their development and function. Advances in stem cell science and regenerative medicine have stimulated interest in the replication of this architecture in vitro. We have developed a versatile method for controlling short-term cell-cell and cell-matrix interactions via a facile cell surface engineering process that enables the rapid formation of specific 3-D interactions for a range of cell types. We demonstrate that chemical modification of cell surfaces and matrix proteins can artificially accelerate the cell adhesion process and confirm the ability to control the formation of multicellular aggregates with defined architectures and heterotypic cell types. Direct comparison with a natural aggregation process seen during differentiation of embryonic stem (ES) cells revealed increased expression of developmental regulatory proteins and a concomitant enhancement of ES cell differentiation. Furthermore, this new methodology has numerous applications in generating layered structures. For example, we demonstrate improved transfer of therapeutic human keratinocytes onto a dermal layer in a skin repair model. (c) 2007 Wiley Periodicals, Inc.