TOWARDS BIOFABRICATION OF RECOMBINANT SPIDER SILK PROTEINS FOR BIOMEDICAL APPLICATIONS
Elise DeSimone, Kristin Schacht, Tamara Aigner, Gregor Lang, Thomas Scheibel
Universitaet Bayreuth, Germany
Traditional tissue engineering, the most widely accepted solution for tissue regeneration or replacement, has yet to be widely applied in the clinical setting. This is due to its many acknowledged disadvantages, for example low seeding density of cells, low control over scaffold architecture and tissue-like constructs are difficult to manufacture. A promising solution is biofabrication, the simultaneous processing of cells and biomaterials. However, there is a critical roadblock to wide-spread use of biofabrication: there is a lack of process-compatible materials. Recombinant spider silk proteins have high biocompatibility, superior mechanical properties, and can be modified with cell adhesion motifs to further enhance their bioactivity. These proteins have thus far been processed into foams, fibers, particles, microcapsules and hydrogels. Additionally, thermally-gelled hydrogels have already been utilized as the biomaterial component of a bioink for 3D bioprinting. Therefore, recombinant spider silk proteins represent a versatile biomaterial for application in biofabrication. However, as with most biopolymers, most of the established processes for producing different scaffold morphologies are not cytocompatible due to extreme physical (e.g. high voltages, high salt concentration) and/or chemical (e.g. toxic solvents) conditions. Additionally, producing scaffolds from cytocompatible processes (e.g. aqueous solvent systems) is attractive due to the ability for safehandling and often the resulting structures are softer, and therefore more tissue-like. The objective of the presented work is to modify and optimize the handling of recombinant spider silk proteins for their use in biofabrication, in particular towards 3D bioprinting and electrospinning. Results in materials characterization as well as cell culture studies indicate that recombinant spider silk proteins are promising to be implemented in biofabrication. It can therefore be concluded that these proteins could provide a valuable tool for various biomedical engineering applications in the future.