Surface Modification of Polymeric Biomaterials Using Recombinant Spider Silk Proteins

The performance of biomaterials largely depends on the materials biocompatibility, which is directly related to unwanted side effects like foreign body responses and inflammation, and the potential of interaction of cells with its surface, for example, cell adhesion. In the distinct application of catheters, low or even no cell adhesion is eligible. To influence the properties of existing and commonly used biomaterials and to further increase their biocompatibility, a coating with a recombinantly produced spider silk protein as outer layer was applied on three selected catheter polymers (polyurethane, polytetrafluoroethylene, silicone) and evaluated based on cell adhesion. The tested cell types, HaCaT keratinocytes (epidermal cells), B50 neuronal cells, C2C12 myoblasts (muscle cells) and BALB/3T3 fibroblasts (connective tissue), exhibited low or no adhesion on the silk-coated materials. In combination with the lack of toxicity, the good biocompatibility, and the low body response, it could be shown that silk coatings have a high potential as a biomedical coating material, e.g., for catheters

<i>In Vivo</i> Coating of Bacterial Magnetic Nanoparticles by Magnetosome Expression of Spider Silk-Inspired Peptides

Magnetosomes are natural magnetic nanoparticles with exceptional properties that are synthesized in magnetotactic bacteria by a highly regulated biomineralization process. Their usability in many applications could be further improved by encapsulation in biocompatible polymers. In this study, we explored the production of spider silk-inspired peptides on magnetosomes of the alphaproteobacterium Magnetospirillum gryphiswaldense. Genetic fusion of different silk sequence-like variants to abundant magnetosome membrane proteins enhanced magnetite biomineralization and caused the formation of a proteinaceous capsule, which increased the colloidal stability of isolated particles. Furthermore, we show that spider silk peptides fused to a magnetosome membrane protein can be used as seeds for silk fibril growth on the magnetosome surface. In summary, we demonstrate that the combination of two different biogenic materials generates a genetically encoded hybrid composite with engineerable new properties and enhanced potential for various applications

<i>In Vivo</i> Coating of Bacterial Magnetic Nanoparticles by Magnetosome Expression of Spider Silk-Inspired Peptides

Magnetosomes are natural magnetic nanoparticles with exceptional properties that are synthesized in magnetotactic bacteria by a highly regulated biomineralization process. Their usability in many applications could be further improved by encapsulation in biocompatible polymers. In this study, we explored the production of spider silk-inspired peptides on magnetosomes of the alphaproteobacterium Magnetospirillum gryphiswaldense. Genetic fusion of different silk sequence-like variants to abundant magnetosome membrane proteins enhanced magnetite biomineralization and caused the formation of a proteinaceous capsule, which increased the colloidal stability of isolated particles. Furthermore, we show that spider silk peptides fused to a magnetosome membrane protein can be used as seeds for silk fibril growth on the magnetosome surface. In summary, we demonstrate that the combination of two different biogenic materials generates a genetically encoded hybrid composite with engineerable new properties and enhanced potential for various applications