Nanostructural analysis of 3T3 mouse fibroblasts cultured on natural silk-based tissue scaffolds in vitro

Objective: to perform a nanostructural analysis of the interaction between mouse 3T3 fibroblasts and natural silk-based tissue scaffolds in vitro using scanning probe nanotomography (SPN). Materials and methods. Two types of natural silk tissue scaffolds were investigated: Fibroplen-Atlas and Fibroplen-Gaz, along with their modified variants, Fibroplen-Atlas 80 and Fibroplen-Gaz 80. Mouse 3T3 fibroblasts were cultured on the scaffolds for 7 days. Following incubation, scaffold–cell constructs were fixed and embedded in epoxy resin. Ultrathin sections were prepared using an ultramicrotome, and the sample surfaces were analyzed by SPN. The acquired data enabled quantitative assessment of key morphological parameters of the cells, the scaffolds, and the interfaces between them. Results. Analysis of the acquired images revealed thinning and fragmentation of microfibers within the strands of the modified scaffolds (Fibroplen-Atlas 80 and Fibroplen-Gaz 80). In contrast to the unmodified scaffolds, fibroblasts in the modified matrices interacted with both the inner and outer surfaces of the microfibers. This enhanced interaction resulted in a marked increase (up to 40%) in the proportion of the cell surface area in contact with the scaffold surface. Conclusion. Nanostructural analysis of mouse 3T3 fibroblasts cultured on natural silk-based tissue scaffolds provided detailed insights into the topological and morphological features of cell–scaffold interactions in both modified and unmodified matrices. Enhanced interaction between cells and microfibers within the modified scaffold strands may promote accelerated scaffold biodegradation. The combined nanostructural findings and in vitro cell culture results indicate that the developed scaffolds effectively support 3T3 cell adhesion and the formation of stable cell–matrix contacts.

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