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Journal of Long-Term Effects of Medical Implants
SJR: 0.332 SNIP: 0.491 CiteScore™: 0.89

ISSN Print: 1050-6934
ISSN Online: 1940-4379

Journal of Long-Term Effects of Medical Implants

DOI: 10.1615/JLongTermEffMedImplants.2015011716
pages 95-103

Graphene Nanoplatelet-Reinforced Silicone for the Valvular Prosthesis Application

Makensley Lordeus
Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA
Angie Estrada
Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA
Danique Stewart
Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA
Rupak Dua
Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA
Cheng Zhang
Department of Mechanical and Materials Engineering, Florida International University, Miami, FL, USA
Arvind Agarwal
Nanomechanics and Nanotribology Laboratory, Mechanical and Materials Engineering Department, Florida International University, Miami, FL, USA
Sharan Ramaswamy
Department of Biomedical Engineering, Florida International University Miami, Florida, USA

ABSTRACT

Newly developed elastomer heart valves have been shown to better re-create the flow physics of native heart valves, resulting in preferable hemodynamic responses. This emergence has been motivated in part by the recent introduction of percutaneous valve approaches in the clinic. Unfortunately, elastomers such as silicone are prone to structural failure, which drastically limits their applicability the development of a valve prosthesis. To produce a mechanically more robust silicone substrate, we reinforced it with graphene nanoplatelets (GNPs). The nanoplatelets were introduced into a two-part silicone mixture and allowed to cure. Cytotoxicity and hemocompatibility tests revealed that the incorporation of GNPs did not adversely affect cell proliferation or augment adhesion of platelets on the surface of the composite materials. Static mechanical characterization by loading in the tensile direction subsequently showed no observable effect when graphene was utilized. However, cyclic tensile testing (0.05 Hz) demonstrated that silicone samples containing 250 mg graphene/L of uncured silicone significantly improved (p<0.05) material fatigue properties compared with silicone-only controls. This finding suggests that for the silicone−graphene composite, static loads were principally transferred onto the matrix. On the other hand, in cyclic loading conditions, the GNPs were recruited effectively to delay failure of the bulk material. We conclude that application of GNPs to extend silicone durability is useful and warrants further evaluation at the trileaflet valve configuration.