In vivo characterization of the integration and vascularization of a silk-derived surgical scaffold

BACKGROUND The application of acellular matrices, biomaterials, and polymeric scaffolds in reconstructive surgery facilitates postsurgical tissue remodeling and is increasingly used clinically in order to improve tissue healing and implant coverage. This study presents an in vivo investigation of the integration of the knitted, silk-derived surgical scaffold, SERI(®) with regard to angiogenesis and wound healing. METHODS SERI(®) Surgical Scaffold was implanted into a full-thickness skin defect in male C57BL/6J mice (n = 45) via the dorsal skinfold chamber (DSC). Skin tissue samples were collected for histology on days 2, 5, 7, 10, 14, and 21 (n = 5 per time point) post implantation. Immunohistochemistry was performed for various angiogenic and inflammatory markers, as well as collagen deposition (CD31, VEGF, CD3, CD45, Desmin, and Sirius red). Vascular corrosion casting was used to assess the neovasculature within the silk and was visualized with scanning electron microscopy. RESULTS We observed both early and late stages of inflammation during the healing process characterized by the infiltration of regenerating tissue by different subsets of leukocytes. Histological analysis displayed capillary-containing granulation tissue with full scaffold integration. In addition, collagen deposition within the scaffold and full skin defect was significantly increased over time. Qualitative analysis of the regenerated vasculature through corrosion casting and scanning electron microscopy revealed a complex, angiogenic network of capillaries originating from the wound bed. CONCLUSIONS Based on these findings, SERI(®) displays the potential to be a promising resorbable bioengineered material for use in reconstructive surgery

Surface-Structured Bacterial Cellulose with Guided Assembly-Based Biolithography (GAB)

A powerful replica molding methodology to transfer on-demand functional topographies to the surface of bacterial cellulose nanofiber textures is presented. With this method, termed guided assembly-based biolithography (GAB), a surface-structured polydimethylsiloxane (PDMS) mold is introduced at the gas-liquid interface of an Acetobacter xylinum culture. Upon bacterial fermentation, the generated bacterial cellulose nanofibers are assembled in a three-dimensional network reproducing the geometric shape imposed by the mold. Additionally, GAB yields directional alignment of individual nanofibers and memory of the transferred geometrical features upon dehydration and rehydration of the substrates. Scanning electron and atomic force microscopy are used to establish the good fidelity of this facile and affordable method. Interaction of surface-structured bacterial cellulose substrates with human fibroblasts and keratinocytes illustrates the efficient control of cellular activities which are fundamental in skin wound healing and tissue regeneration. The deployment of surface-structured bacterial cellulose substrates in model animals as skin wound dressing or body implant further proves the high durability and low inflammatory response to the material over a period of 21 days, demonstrating beneficial effects of surface structure on skin regeneration

Surface-Structured Bacterial Cellulose with Guided Assembly-Based Biolithography (GAB)

A powerful replica molding methodology to transfer on-demand functional topographies to the surface of bacterial cellulose nanofiber textures is presented. With this method, termed guided assembly-based biolithography (GAB), a surface-structured polydimethylsiloxane (PDMS) mold is introduced at the gas–liquid interface of an <i>Acetobacter xylinum</i> culture. Upon bacterial fermentation, the generated bacterial cellulose nanofibers are assembled in a three-dimensional network reproducing the geometric shape imposed by the mold. Additionally, GAB yields directional alignment of individual nanofibers and memory of the transferred geometrical features upon dehydration and rehydration of the substrates. Scanning electron and atomic force microscopy are used to establish the good fidelity of this facile and affordable method. Interaction of surface-structured bacterial cellulose substrates with human fibroblasts and keratinocytes illustrates the efficient control of cellular activities which are fundamental in skin wound healing and tissue regeneration. The deployment of surface-structured bacterial cellulose substrates in model animals as skin wound dressing or body implant further proves the high durability and low inflammatory response to the material over a period of 21 days, demonstrating beneficial effects of surface structure on skin regeneration

Surface-Structured Bacterial Cellulose with Guided Assembly-Based Biolithography (GAB)

A powerful replica molding methodology to transfer on-demand functional topographies to the surface of bacterial cellulose nanofiber textures is presented. With this method, termed guided assembly-based biolithography (GAB), a surface-structured polydimethylsiloxane (PDMS) mold is introduced at the gas–liquid interface of an <i>Acetobacter xylinum</i> culture. Upon bacterial fermentation, the generated bacterial cellulose nanofibers are assembled in a three-dimensional network reproducing the geometric shape imposed by the mold. Additionally, GAB yields directional alignment of individual nanofibers and memory of the transferred geometrical features upon dehydration and rehydration of the substrates. Scanning electron and atomic force microscopy are used to establish the good fidelity of this facile and affordable method. Interaction of surface-structured bacterial cellulose substrates with human fibroblasts and keratinocytes illustrates the efficient control of cellular activities which are fundamental in skin wound healing and tissue regeneration. The deployment of surface-structured bacterial cellulose substrates in model animals as skin wound dressing or body implant further proves the high durability and low inflammatory response to the material over a period of 21 days, demonstrating beneficial effects of surface structure on skin regeneration