Optimization of Novel Spider Silk Materials to Attain Cell-Specific Effects

Materials made from spider silk can be specifically modified or processed in such a way that living cells of a particular species adhere to, grow and reproduce. This was discovered by researchers at the University of Bayreuth under the supervision of Professor Dr. Thomas Schäipel.

The cell-specific effects of the materials can be created by biochemical modifications of the silk proteins, but also by the surface structure of the spider silk coating. Search results published in Advanced healthcare materials And Advanced Material InterfacesPioneers of regenerative medicine and synthetic tissue production.

Spider silk promotes normal tissue formation in a cell-specific way

In many cases, biomedical restoration of damaged or destroyed tissue relies on stimulating and controlling the growth of specific cells. Different types of cells, such as skin, muscle, and nerve cells, must be involved in order to create a functioning cellular network. A scaffold of spider silk implanted in the body, to which an increasing number of newly developing cells adhere, provides important prerequisites for this natural rebuilding process: spider silk proteins are biodegradable and generally compatible with cells in the organism.

Bayreuth’s research results obtained in the Biomaterials Chair now show how such a spider silk scaffold could be improved. For spatially different sections of the scaffold, materials can be used in the future that are well suited for the targeted attachment, growth and proliferation of cells of the desired cell type.

As a result, a body-grown spider silk scaffold is ideally suited for the production of large normal tissue structures that include different types of cells. It gradually degrades in a natural way as tissue regeneration progresses.

Spider silk implant coatings prevent rejection reactions

The results of the two studies will also inform the improvement of implants that are intended to permanently replace normal tissue and remain in the body. This requires materials that ensure that implants are not rejected due to infection or sensitivity.

The spider silk coating, which perfectly adapts to the respective cell types in the surrounding tissues and enhances their attachment, helps to avoid these rejection reactions, and thus contributes to the smooth integration of the implant into normal tissues.

Cell-specific effects through biochemical modifications

As the Bayreuth researchers show, the cell-specific effects of spider silk materials can be produced by functionally modifying silk proteins through the incorporation of peptides, which are short-chain polyamino acids. Cell-interacting peptides (cell-adhesive peptides) are found in the extracellular matrix (ECM) of normal tissues: this is a network-like molecular structure that fills the spaces between neighboring cells in tissues and stabilizes their spatial arrangement.

The Bayreuth researchers grafted some cell-adhesive peptides found in the ECM of many organisms — including humans — into several different types of silk protein derived from garden spider silk via a spider. As a result of biochemical modification, some of these altered silk proteins were found to be generally cell-adhesive, while others showed a more general cell-repelling behaviour.

However, in some cases, cell-specific interactions were observed in addition. Particularly striking were the effects of the KGD peptide: it specifically promotes the attachment and growth of muscle cells. These are embryonic muscle cells that can develop into muscle fibres.

“Our findings point to a new pathway leading to cell-specific applications for spider silk materials — whether in designing scaffolds to enhance natural regenerative processes, in coating implants, or even in 3D printing of encapsulated hydrogels,” said Vanessa Trosman MA, lead author of the published study. in Advanced healthcare materials.

Cell-specific effects through the surface structure of spider silk coatings

The study published in Advanced Material Interfaces, presents a different method for improving spider silk ores. Coatings made with a single silk protein derived directly from garden spider silk do not exhibit cell adhesion behavior on their own – without biochemical modification.

The research team led by Professor Dr Thomas Schieble has now used a lithography process to structure the surface of these coatings in a way that specifically stimulates the attachment and growth of cells of a particular type. Different cell interactions on the shape and size of surface-imprinted geometric structures depend strongly on the cell type involved, among other parameters, as extensive testing has shown.

“Based on the results of our research, it will be possible to improve lithographic coatings made of silk proteins or other biocompatible materials in a way that stimulates and drives the natural renewal of complex tissue structures in a cell-specific manner,” says Schieble.