The Authors state that this manuscript has not been published previously and is not currently being assessed for publication by any journal other than The InternationalJournal of Artificial Organs.Each Author has contributed substantially to the research, preparation and production of the paper and approves of its submission to the Journal. FINANCIAL SUPPORT CONFLICT OF INTERESTThe authors state they do not have proprietary interest. MEETING PRESENTATIONThis study has been partially presented at the following meeting: ABSTRACT Purpose: Tissue engineering techniques were used to study cartilage repair over 12-month period in a rabbit model. Methods:A full-depth chondral defect along with subchondral bone injury were originated in the knee joint, where a biostable porous scaffold was implanted, synthesized of poly(ethyl acrylate-co-hydroxyethyl acrylate) copolymer. Morphological evolution of cartilage repair was studied 1 and 2 weeks, and 1, 3 and 12 months after implantation by histological techniques. Three-month group was chosen to compare cartilage repair to an additional group where scaffolds were preseeded with allogeneic chondrocytes before implantation, and also to controls, who underwent the same surgery procedure, with no scaffold implantation.

survival was demonstrated in all the membranes after three months follow-up. A slight reduction in the extrusion rate of h-ADASC colonized materials was observed. No significant differences between the groups with and without h-ADASC were detected respect to transparency or neovascularization. We propose PEA with low hydroxylation as a scaffold for the anchoring ring of future keratoprosthesis.

2 AbstractThe aim of this paper is to quantify the adhered fibronectin (by adsorption and/or grafting) and the exposure of its cell adhesive motifs (RGD and FNIII7-10) on poly (ethyl acrylate) copolymers whose chemical composition has been designed to increase wettability and to introduce acid functional groups. Fibronectin was adsorbed to poly (ethyl acrylate), poly (ethyl acrylate-co-hydroxyethyl acrylate), poly (ethyl acrylate-co-acrylic acid) and poly (ethyl acrylate-co-methacrylic acid) copolymers and covalently cross-linked to poly (ethyl acrylateco-acrylic acid) and poly (ethyl acrylate-co-methacrylic acid) copolymers. Amount of adhered fibronectin and exhibition of RGD and FNIII7-10 fragments involved in cell adhesion were quantified with ELISA tests.Even copolymers with a lower content of the hydrophilic component showed a decrease in water contact angle. In addition, fibronectin was successfully fixed on all surfaces, especially on the hydrophobic surfaces. However, it was demonstrated that exposure of its cell adhesion sequences, which is the key factor in cell adhesion and proliferation, was higher for hydrophilic surfaces.

Corneal ectatic disorders are characterized by a progressive weakening of the tissue due to biomechanical alterations of the corneal collagen fibers. Carbon nanostructures, mainly carbon nanotubes (CNTs) and graphene, are nanomaterials that offer extraordinary mechanical properties and are used to increase the rigidity of different materials and biomolecules such as collagen fibers. We conducted an experimental investigation where New Zealand rabbits were treated with a composition of CNTs suspended in balanced saline solution which was applied in the corneal tissue. Biocompatibility of the composition was assessed by means of histopathology analysis and mechanical properties by stress-strain measurements. Histopathology samples stained with blue Alcian showed that there were no fibrous scaring and no alterations in the mucopolysaccharides of the stroma. It also showed that there were no signs of active inflammation. These were confirmed when Masson trichrome staining was performed. Biomechanical evaluation assessed by means of tensile test showed that there is a trend to obtain higher levels of rigidity in those corneas implanted with CNTs, although these changes are not statistically significant (p > 0.05). Implanting CNTs is biocompatible and safe procedure for the corneal stroma which can lead to an increase in the rigidity of the collagen fibers.

Cartilage regeneration depends mainly on the properties of the scaffold, such as stiffness and hydrophilicity, whereas little difference was observed between preseeded and non-preseeded scaffolds.