The authors acknowledge the financial support granted to E.G.F from INIA, MINECO, Spain (RTA2012-00028-C02-02), from Agència de Gestió d’Ajuts Universitaris i de Recerca (2014SGR-132) and from the Centro de Investigación Biomédica en Red (CIBER) de Bioingeniería, Biomateriales y Nanomedicina financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.