Protein nanofibers (PNFs) are fundamental buildings blocks in nature. Therefore, they are promising materials for applications in the field of biomedical engineering. PNFs can be used as scaffold material in tissue engineering or drug delivery, as biosensors or as templates for other materials. PNFs consisting of plasma proteins, e.g. fibrinogen, fibronectin, albumin and haemoglobin, are of special importance due to their high biocompatibility. An easy feasible strategy to create these nanofibers is the self-assembly mechanism of protein molecules. The understanding of this little-known mechanism is fundamental.
Here we test the hypothesis that self-assembled hybrid protein nanofibers (PNNF) can consist of two different proteins.
PNNFs were produced by incubating different plasma protein combinations in a mixture of Millipore water and ethanol by elevated temperatures for various time periods. For atomic force microscopy and tip enhanced raman spectroscopy measurements the self-assembled PNNFs were dropped onto activated silicon as well as cleaned and activated glass substrates. Further, immunogold staining was performed to confirm the presence of both proteins. Mechanical and biological properties were analyzed.
In this work we present the self-assembly of different plasma hybrid PNNFs. Further, we show, how the second protein influences the hybrid fiber stability as well as the mechanical properties. For example the incorporation of the second protein leads to a decrease of the rupture force/pull-off force compared to the homogenous PNNFs. Also a possibility to create 3D structures based on these PNNFs is presented.
We demonstrated the possibility to create self-assembled PNNFs in the presence of two different plasma proteins. Further, we confirmed the existence of a novel PNF hybrid. These results lay the foundation for a novel biomaterial based on these PNNF/PNNF hybrids.
This work was part of the project: „Novel functional materials based on self-assembled protein nanofibers: creating and understanding nanofibers”, AOBJ: 609403. We gratefully thank the Deutsche Forschungsgemeinschaft (DFG) for the funding of this project.