Research projects

We prepared different graphene platforms and evaluated their physicochemical properties, including reproducibility of the physical parameters and characterization of the main risks factors in the generation of the materials. None of these materials resulted toxic for macrophages from different origins (murine or human) regardless the pro-inflammatory or anti-inflammatory functional polarization. Graphene matrices and macrophages interact each other and the reactivity of macrophages on the other side is minimally affected in terms of response to extracellular stimuli governing the different polarization phenotypes. These results are relevant for the study of these matrices in CVD, including the infiltration and remodeling process of the heart and, to a different extent, to the management of atheromatous lesions, one of the key issues of the project intended to provide stent containing graphene-based materials. In combination with fabrication processes, special attention has been paid to characterize grain boundaries and defect density by Raman spectroscopy, as these properties are tightly related to chemical stability in liquid media, a matter of relevance in the presence of pro-inflammatory macrophages. This is important, since these cells release continuous and high amounts of reactive oxygen and nitrogen radicals that may affect graphene matrices boundaries.

Regarding the two-terminal and single-terminal device fabrication and deep-UV photolithography for patterning single-cell devices, where the electrical contacts are isolated with biocompatible resist (SU-8), the substrate of choice has been successfully transferred to insulating substrates using automatic methods, as assessed by scanning electron microscopy (SEM) imaging and energy-dispersive X-ray spectroscopy (EDX). These structures were ‘seeded’ with macrophages to characterize the electromechanical properties. Finally, we have described that macrophages display an unusual capacity to phagocyte graphene particles that are retained in specific subcellular microenvironments, but preserving cell viability, although significantly altering the mitochondrial function, study that is still in progress.