Institute of Fundamental Technological Research

The disruption of homeostasis in the tissue microenvironment following skin injury necessitates the provision of a supportive niche for cells to facilitate the restoration of functional tissue. A meticulously engineered cell-scaffold biointerface is essential for eliciting the desired cellular responses that underpin therapeutic efficacy. To address this, we fabricated an electrospun poly-(L-lactide) (PLLA) cell scaffold enriched with graphene oxide (GO) and gold nanoparticles (AuNPs). Comprehensive characterization assessed the scaffolds’ microstructural, elemental, thermal, and mechanical properties. In vitro investigations evaluated the biocompatibility, adhesive and regenerative capabilities of the scaffolds utilizing human keratinocytes (HEKa), fibroblasts (HFFF2), and reconstructed epidermis (EpiDerm™) models. The results demonstrated that the incorporation of the GO-Au composite substantially altered the nanotopography and mechanical properties of the PLLA fibers. Cells effectively colonized the PLLA + GO-Au scaffold while preserving their structural morphology. Furthermore, PLLA + GO-Au treatment resulted in increased epidermal thickness and reduced tissue porosity. The scaffold exerted a significant influence on actin cytoskeleton architecture, facilitating cell adhesion through the upregulation of integrins, E-cadherin, and β-catenin. Keratinocytes exhibited enhanced secretion of growth factors (AREG, bFGF, EGF, EGF R), while fibroblast secretion remained stable. These findings endorse the scaffold’s potential for regulating cellular fate and preventing hypertrophic tissue formation in skin tissue engineering.

Wound healing, Electrospun fibers, Graphene oxide, Gold nanoparticles, Proregenerative cell scaffold

Hydrogels with multifunctional properties activated at specific times have gained significant attention in the biomedical field. As bacterial infections can cause severe complications that negatively impact wound repair, herein, we present the development of a stimuli-responsive, injectable, and in situ-forming hydrogel with antibacterial, self-healing, and drug-delivery properties. In this study, we prepared a Pluronic F-127 (PF127) and sodium alginate (SA)-based hydrogel that can be targeted to a specific tissue via injection. The PF127/SA hydrogel was incorporated with polymeric short-filaments (SFs) containing an anti-inflammatory drug – ketoprofen, and stimuli-responsive polydopamine (PDA) particles. The hydrogel, after injection, could be in situ gelated at the body temperature, showing great in vitro stability and self-healing ability after 4 h of incubation. The SFs and PDA improved the hydrogel injectability and compressive strength. The introduction of PDA significantly accelerated the KET release under near-infrared light exposure and extended its release validity period. The excellent composites’ photo-thermal performance led to antibacterial activity against representative Gram-positive and Gram-negative bacteria, resulting in 99.9% E. coli and S. aureus eradication after 10 min of NIR light irradiation. In vitro, fibroblast L929 cell studies confirmed the materials’ biocompatibility and paved the way toward further in vivo and clinical application of the system for chronic wound treatments.

Nanostructuring is a process involving surface manipulation at the nanometric level, which improves the mechanical and biological properties of biomaterials. Specifically, it affects the mechanotransductive perception of the microenvironment of cells. Mechanical force conversion into an electrical or chemical signal contributes to the induction of a specific cellular response. The relationship between the cells and growth surface induces a biointerface-modifying cytophysiology and consequently a therapeutic effect. In this study, we present the fabrication of graphene oxide (GO)-based nanofilms decorated with metallic nanoparticles (NPs) as potential coatings for biomaterials. Our investigation showed the effect of decorating GO with metallic NPs for the modification of the physicochemical properties of nanostructures in the form of nanoflakes and nanofilms. A comprehensive biocompatibility screening panel revealed no disturbance in the metabolic activity of human fibroblasts (HFFF2) and bone marrow stroma cells (HS-5) cultivated on the GO nanofilms decorated with gold and copper NPs, whereas a significant cytotoxic effect of the GO nanocomplex decorated with silver NPs was demonstrated. The GO nanofilm decorated with gold NPs beneficially managed early cell adhesion as a result of the transient upregulation of α1β5 integrin expression, acceleration of cellspreading, and formation of elongated filopodia. Additionally, the cells, sensing the substrate derived from the nanocomplex enriched with gold NPs, showed reduced elasticity and altered levels of vimentin expression. In the future, GO nanocomplexes decorated with gold NPs can be incorporated in the structure of architecturally designed biomimetic biomaterials as biocompatible nanostructuring agents with proadhesive properties.