Figure 1. Schematic of the ‘bacteria-instructed synthesis’ process.

In (a) bacteria induce polymerisation in monomer / catalyst suspensions to generate a synthetic extra-cellular matrix of polymers (b). Recovery of polymers from the suspensions leads to two fractions (c), with polymer obtained from the aqueous phase suspension around the bacteria denoted as ‘non-templated’ and a second fraction obtained from a wash of the cell surfaces denoted as ‘templated’. Incubation of polymers with bacteria results in low binding of cells for which the polymer is non-templated (d), or where a polymer templated with one cell type (shown in orange) is incubated with a cell (shown in green) of another type (e). Addition of a polymer, templated by one cell type, with its own ‘matched’ cell population results in the formation of large polymer – cell clusters (g), as the templated polymers sequester the bacteria which ‘instructed’ their formation with high affinity. The same reducing environment at bacterial surfaces which aids the polymer synthesis can also be used to label the cells in situ (g) via pro-fluorescent markers, which react with cell-surface bound polymers containing ‘clickable’ residues.