"Introduction: Spider silk (SPSI) as one of nature’s most fascinating materials has attracted vivid attention due to its remarkable performance in tissue regenerative applications by supporting nerve growth and nerve regeneration. Particularly for supporting the regeneration of large nerve defects, the biomaterial has proven to be incomparably successful. The material’s variability and the difficulty to harvest it in large quantities constitute major limitations in translating the fiber into clinical practice. For this reason, the search for possible SPSI analogues for applicability in human medicine is of tremendous scientific and clinical interest. To pave the way toward this, an investigation of structural, morphological and chemical properties of different SPSIs together with an assessment of their nerve regenerative potentials is necessary.
Methodology: This systematic study correlates varying in vitro performances of different SPSI to the silk’s material properties. Therefore, primary rat Schwann cells (rSCs) were cultured on SPSI of various species and live cell imaging was performed to assess the migratory potential of cells by tracking them using ImageJ. The extent of culture’s purity and proliferation was examined by multicolor immunofluorescence stainings. Liquid chromatography - mass spectrometry and atomic force microscopy were employed to elucidate SPSI’s primary protein structure and its morphology, respectively.
Results: The results showed that rSCs can adhere and migrate along SPSI, with deviating velocity depending on SPSI type. Multicolor images of rSCs stained for Sox10 and S100 in combination with DAPI indicated a rSC culture purity over 95%. Furthermore, the proliferation of rSCs on SPSI was evaluated with an EdU staining. These differences in the cell behavior on SPSI were correlated to the silk’s morphology and primary protein structure.
Conclusion: So far, very little is known about the interactions between SCs and SPSI, rendering the well-aimed and targeted improvements of the natural silk and replacement with customed artificial fibers, tailored to specific applications, challenging. Our results demonstrated variations in the regenerative potentials of SPSI and showed that it is possible to use the natural differences between the native silks of diverse spider species to better understand the interactions between silk and cells."