Multi-photon structuring of native polymers: A case study for structuring natural proteins

The trend of mimicking the real biological world has created an intensive search for methods that are able to engineer 3D-structured biological environments using nano- and micro-system technologies. Recently published methods show the design of 3D structures by multi-photon induced polymerization of artificial polymers, such as chemically modified natural polymers. However, limitations of this approach are the long processing time and the fact that no native polymers have been used up to date. In this communication, a case study of multi-photon structuring of unmodified, native proteins (e.g. collagen and fibrinogen) and liquids, such as natural human blood, or cell culture medium supplements, such as fetal calf serum, is presented. Based on a computer-assisted process, the structures are polymerized precisely. Even adhesion and gluing of cells with this technique are possible. These encouraging results open new avenues for further inquiry, which are discussed in the paper.