Tribomechanical Properties of PVA/Nomex<sup>®</sup> Composite Hydrogels for Articular Cartilage Repair
Francisco Santos,
Carolina Marto-Costa,
Ana Catarina Branco,
Andreia Sofia Oliveira,
Rui Galhano dos Santos,
Madalena Salema-Oom,
Roberto Leonardo Diaz,
Sophie Williams,
Rogério Colaço,
Célio Figueiredo-Pina,
Ana Paula Serro
Affiliations
Francisco Santos
Centro de Química Estrutural (CQE), Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Carolina Marto-Costa
Centro de Química Estrutural (CQE), Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Ana Catarina Branco
Centro de Química Estrutural (CQE), Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Andreia Sofia Oliveira
Centro de Química Estrutural (CQE), Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Rui Galhano dos Santos
CERENA—Centre for Natural Resources and the Environment, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
Madalena Salema-Oom
Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, Monte da Caparica, 2829-511 Almada, Portugal
Roberto Leonardo Diaz
Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Woodhouse, Leeds LS2 9JT, UK
Sophie Williams
Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Woodhouse, Leeds LS2 9JT, UK
Rogério Colaço
Instituto de Engenharia Mecânica (IDMEC), Department of Mechanical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Célio Figueiredo-Pina
Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, Monte da Caparica, 2829-511 Almada, Portugal
Ana Paula Serro
Centro de Química Estrutural (CQE), Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Due to the increasing prevalence of articular cartilage diseases and limitations faced by current therapeutic methodologies, there is an unmet need for new materials to replace damaged cartilage. In this work, poly(vinyl alcohol) (PVA) hydrogels were reinforced with different amounts of Nomex® (known for its high mechanical toughness, flexibility, and resilience) and sterilized by gamma irradiation. Samples were studied concerning morphology, chemical structure, thermal behavior, water content, wettability, mechanical properties, and rheological and tribological behavior. Overall, it was found that the incorporation of aramid nanostructures improved the hydrogel’s mechanical performance, likely due to the reinforcement’s intrinsic strength and hydrogen bonding to PVA chains. Additionally, the sterilization of the materials also led to superior mechanical properties, possibly related to the increased crosslinking density through the hydrogen bonding caused by the irradiation. The water content, wettability, and tribological performance of PVA hydrogels were not compromised by either the reinforcement or the sterilization process. The best-performing composite, containing 1.5% wt. of Nomex®, did not induce cytotoxicity in human chondrocytes. Plugs of this hydrogel were inserted in porcine femoral heads and tested in an anatomical hip simulator. No significant changes were observed in the hydrogel or cartilage, demonstrating the material’s potential to be used in cartilage replacement.
