No abstract

Vascularization is a key process in tissue engineering and regeneration and represents one of the most important issues in the field of regenerative medicine. Thus, several strategies to improve vascularization are currently under clinical evaluation. In this study, stem cells derived from human sweat glands were isolated, characterized, seeded in collagen scaffolds, and engrafted in a mouse full skin defect model for dermal regeneration. Results showed that these cells exhibit high proliferation rates and express stem cell and differentiation markers. Moreover, cells responded to angiogenic environments by increasing their migration (P<0.001) and proliferation (P<0.05) capacity and forming capillary-like structures. After seeding in the scaffolds, cells distributed homogeneously, interacting directly with the scaffold, and released bioactive molecules involved in angiogenesis, immune response, and tissue remodeling. In vivo, scaffolds containing cells were used to induce dermal regeneration. Here we have found that the presence of the cells significantly improved vascularization (P<0.001). As autologous sweat gland-derived stem cells are easy to obtain, exhibit a good proliferation capacity, and improve vascularization during dermal regeneration, we suggest that the combined use of sweat gland-derived stem cells and scaffolds for dermal regeneration might improve dermal regeneration in future clinical settings.

Delayed wound healing and scar formation are among the most frequent complications after surgical interventions. Although biodegradable surgical sutures present an excellent drug delivery opportunity, their primary function is tissue fixation. Mesenchymal stem cells (MSC) act as trophic mediators and are successful in activating biomaterials. Here biodegradable sutures were filled with adipose-derived mesenchymal stem cells (ASC) to provide a pro-regenerative environment at the injured site. Results showed that after filling, ASCs attach to the suture material, distribute equally throughout the filaments, and remain viable in the suture. Among a broad panel of cytokines, cell-filled sutures constantly release vascular endothelial growth factor to supernatants. Such conditioned media was evaluated in an in vitro wound healing assay and showed a significant decrease in the open wound area compared to controls. After suturing in an ex vivo wound model, cells remained in the suture and maintained their metabolic activity. Furthermore, cell-filled sutures can be cryopreserved without losing their viability. This study presents an innovative approach to equip surgical sutures with pro-regenerative features and allows the treatment and fixation of wounds in one step, therefore representing a promising tool to promote wound healing after injury.