An ideal implant surface should promote cell attachment and tissue integration while preventing bacterial colonization. Engineering the surface topography of a biomaterial implant to elicit a differential response is a promising approach to dealing with both issues. To achieve this, we integrated Moth-Eye (ME) nanocones with micrometric features such as gratings and pillars in various hierarchical configurations, leading to different responses in bacteria and cells. These hierarchical topographies were tested on different polymers to compare their biological responses. Mesenchymal stem cells (MSCs) were employed as a model system to study cell behavior, given their ability to proliferate, self-renew, and differentiate. The bactericidal effect was tested using gram-negative Escherichia coli and gram-positive Staphylococcus aureus. Results show that these topographies-maintained cell viability and influenced cell morphology, orientation, migration and differentiation, which are crucial processes for regeneration and osseointegration. Finite Element Method (FEM) simulations estimated the traction forces generated by cells on these surfaces. Overall, the hierarchical topographies enhanced the expression of osteogenic markers in the MSCs while retaining the bactericidal properties of the ME nanostructures.

The aim of this study was to test, by an in vitro approach, whether a natural extract derived from eggs of the mollusc Cryptomphalus aspersa (e-CAF) that seems to present regenerative properties, can enhance the mobilization of human hair dermal papilla cells (HHDPCs) and play a role on tissue repair and regeneration. We have tested HHDPCs proliferation by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium-bromide (MTT) assay; cell migration by using a wound healing assay, as well as the modulation of the expression of cytoskeletal (F-actin and vimentin) and cell adhesion to the extracellular matrix (ECM) (vinculin and P-FAK) proteins. We also explored whether e-CAF could lead HHDPCs to keratinocytes and/or fibroblasts by evaluating the expression of specific markers. We have compared these e-CAF effects with those induced by TGFβ₁, implicated in regulation of cell proliferation and migration. e-CAF promotes proliferation and migration of HDDPCs cells in a time- and dose-dependent manner; it also increases the migratory behavior and the expression of adhesion molecules. These results support the fact that e-CAF could play a role on skin regeneration and be used for the prevention or repair of damaged tissue, either due to external causes or as a result of cutaneous aging.