Functionalization of ITO electrodes with cell adhesive and osteoimmunomodulatory peptides: towards studying in real time osteogenesis in the context of immune-mediated inflammation

WERNER, JULIETA; MAS-MORUNO CARLES; PALLAROLA, DIEGO

Barcelona

Congreso; XLV Congreso de la Sociedad Ibérica de Biomecánica y Biomateriales; 2023

The immune system plays a key role in bone regeneration. Excessive productionof pro-inflammatory cytokines by immune cells induces bone resorption and affectsosteogenesis, leading to implant failure[1]. Therefore, developing coatings that modulate theinflammatory response to create a beneficial bone immune microenvironment that promotesosteogenesis is crucial. Furthermore, studying in real-time and non-invasively the interaction ofcells with such coatings is essential to gain a detailed understanding of their effect on cellularbehavior. In this regard, electrochemical impedance spectroscopy (EIS) stands out for its uniquesensitivity in studying multiple cellular functions[2]. Accordingly, with the final goal of studyingosteogenesis on real time by EIS, we focused on developing novel multifunctional coatingscombining the adhesive sequence RGD and the osteoimmunomodulatory peptide OGP10-14, theirimmobilization on indium tin oxide (ITO) surfaces, and a preliminary study of mesenchymalstem cells (MSCs) response on the functionalized surfaces.The peptides were synthesized using solid-phase peptide synthesis following theFmoc/tBu strategy. Subsequently, they were purified and characterized by RP-HPLC and MassSpectrometry. These peptides were designed to incorporate 3,4-dihydroxyphenylalanine forhigh-affinity binding to metallic oxides in a one-step process. The functionalization of the ITOsurfaces was characterized using contact angle, XPS and fluorescence measurements.Additionally, the adhesion and morphology of MSCs were studied using immunofluorescence.The peptides (RGD and OGP10-14 sequences) were synthesized in good yields withpurities greater than 95%. Additionally, the physicochemical characterization of the ITOsurfaces demonstrated that the functionalization process was successful as indicated by asignificant change in the wettability of the samples and an increase in the presence of nitrogenin the XPS spectra. In vitro cellular studies revealed that the adhesion (i.e. number of adherentcells) and spreading of MSCs improved on the surfaces coated with the bioactive peptides,individually or mixed at different ratios.Preliminary results indicate that it is possible to create a coating based on theRGD and OGP10-14 peptides capable of improving the interaction of MSCs with ITO surfaces.Our next studies will involve investigating the osteoimmunomodulatory and osteogenicpotential of the coated electrodes by EIS. In this regard, studies focusing on the effect of thecoatings on the response of macrophages are currently in progress.