Silk fibroin has recently gained considerable attention as a promising biomaterial for use in medical and bioengineering technologies due to its biocompatibility and favorable mechanical properties. In this study, composite gel based on silk fibroin microparticles and carboxymethyl cellulose was developed, characterized by a viscous, homogeneous white mass containing uniformly distributed fibroin microparticles ranging from 1 to 20 μm in size. The gel exhibited a kinematic viscosity of 36.5 × 10⁻⁶ St, allowing for convenient application to wounds using a syringe or spatula while preventing uncontrolled spreading. The cytocompatibility of the gel was confirmed using the methylthiazol tetrazolium (MTT) assay, which showed no cytotoxic effects on 3T3 fibroblast cells. Furthermore, the gel remained stable for over one year when stored at 10 °C, in contrast to conventional fibroin solutions, which typically lose stability within a month under similar conditions. In a full-thickness skin wound model in rats, the application of the gel significantly accelerated skin regeneration, with complete wound closure observed by day 15, compared with 30 days in the control group. Histological analysis confirmed the restoration of all skin layers. These findings demonstrate the high potential of the gel for applications in regenerative medicine and tissue engineering.

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.

Objective : To evaluate the in vitro cytotoxicity, adhesion, and proliferation of fibroblasts on film coatings made of Bombyx mori silk fibroin, wild silk (Tussah) fibroin, and their chitosan composites. Materials and methods . Four types of film coatings were investigated: Bombyx mori fibroin, wild silk fibroin, and their respective chitosan composites. The coatings were fabricated by casting aqueous polymer solutions followed by drying. Cytotoxicity was assessed in accordance with GOST R ISO 10993-5 using the extract assay method. NIH 3T3 fibroblast adhesion was evaluated 1 hour after seeding, while proliferation was assessed on days 1, 2, and 3 of culture. Cell quantification was performed following nuclear staining with 4′,6-diamidino-2-phenylindole (DAPI) using fluorescence microscopy combined with automated image analysis. Culture dishes containing sterile medium and medium supplemented with ethylenediaminetetraacetic acid or dimethyl sulfoxide served as control groups. Results . All tested coatings supported fibroblast viability, with metabolic activity levels comparable to those observed on standard culture plastic. Fibroblast adhesion and proliferation were consistently higher on wild silk fibroin coatings compared with Bombyx mori fibroin coatings at all time points. The incorporation of chitosan further enhanced both cell adhesion and proliferation. The most pronounced cellular response was observed on composite coatings based on wild silk fibroin and chitosan. Conclusion . Film coatings based on wild silk fibroin demonstrate an enhanced ability to support fibroblast adhesion and proliferation in vitro – more than twice as high as that of Bombyx mori fibroin with chitosan. Composite systems incorporating chitosan further enhance these properties, making them promising candidates for the development of functional biomedical coatings.