CDC researchers have developed a fabrication process to create bifunctional microparticles displaying two distinct proteins that are spatially segregated onto a single hemispheric surface. At present, there is no described way of producing biological microparticles with two distinct types of separated proteins. Bifunctional Janus particles generated by the CDC approach possess biologically relevant, native conformation proteins attached to a biologically unreactive and safe substrate. They also display high densities of each type of proteins that may enable a range of capabilities that monofunctional particles cannot, such as improved drug targeting and bioimaging agents.

The possible uses of these particles are limited only by the biological functions of proteins. For example, two recognition proteins could be used to bring different biological effectors together for enzymatic activation or breakdown. A recognition protein plus an activation molecule could simultaneously bind a cell and stimulate the immune system or facilitate the breakdown of toxic products. Alternatively, a protein drug plus a targeting and internalization motif could target treatment to a specific subset of cells and reduce nonspecific effects of drugs with severe side effects. Such bifunctional Janus particles can be used to create an entirely novel class of smart particle capable of high avidity targeting to and stimulation of multiple cell types. With these new particles, scientists and biomedical engineers can potentially improve the range, specificity and capabilities of therapeutic interventions and research.