Biological response of biomaterials loaded with copper ions for dental implants rehabilitation

Abstract

Dental implants and membranes for guided bone regeneration (GBR) in current clinical use have no direct effect on the regulation of bone cells. Thus, the need to develop biomaterials that could assist in recruiting endogenous stem cells and support, guide and stimulate the innate bone regeneration is still ongoing. Copper (Cu) ions have been used to functionalize biomaterials due to its antibacterial activity and capacity to stimulate bone regeneration and angiogenesis. Few studies have incorporated Cu to implants materials using plasma electrolytic oxidation (PEO) and to GBR membranes by means of electrospinning. However, it is still unclear the efficacy and safety of incorporating Cu to these biomaterials aiming to achieve greater osseointegration and bone regeneration. In view of this, we here aim to evaluate the biological response of biomaterials loaded with copper ions for dental implants rehabilitation. Our specific aims are: (1) to evaluate the cellular response of Cu-bioactive surfaces produced by PEO on titanium discs (Ti) using platelets and monocytes/macrophages culture, and a 3D spheroid culture model with human umbilical vein endothelial cells (HUVEC); and (2) to synthetize and evaluate the morphologic, structural, chemical and biological properties of copper ion-loaded membranes for guided bone regeneration (GBR) formed by means of electrospinning technique. PEO treatment will be performed by a pulsed DC power supply using electrolytes with and without Cu. Polished Ti discs will be used as control. A 3D HUVEC spheroid culture model will be performed onto discs to mimic the natural environment found in vivo. Platelets adhesion and monocytes/macrophages morphology, proliferation, cytokine secretion, and polarization will be evaluated for Ti surfaces to verify its effects on the initial cascade of events after implant installation. The membranes will be produced using a commercially available coaxial electrospinning set-up. Polymer-based solutions without and with different Cu concentrations will be prepared for electrospinning. Morphological, structural and chemical properties of the electrospun membranes will be characterized by several techniques. The antibacterial activity of the membranes will be assessed by means of zone of inhibition test and a modified direct contact test. The cytotoxicity, osteostimulatory and anti-inflammatory potential will be determined by in vitro culture of the membranes with human gingival fibroblasts, human monocytic cell line, human umbilical vein endothelial cells (HUVEC), and bone marrow stromal cells.