Poly(vinyl alcohol)-based hydrogels for joint prosthesis

Ana Carolina da Cruz Quartin Borges

Key information

Authors:

Ana Carolina da Cruz Quartin Borges (Ana Carolina da Cruz Quartin Borges)

Supervisors:

Ana Paula Valagão Amadeu do Serro (Ana Paula Valagão Amadeu do Serro); Rogério Anacleto Cordeiro Colaço (Rogério Anacleto Cordeiro Colaço)

Published in

06/05/2018

Abstract

The best treatment currently available for severe joint disease is total replacement. This involves the use of biocompatible metal alloys that articulate against other metals, ceramic or polyethylene coatings. These materials present some limitations, namely the shielding of the bone with regard to the application of forces, which can result in osteoporosis, wear leading to immunogenic debris and eventual dislocation and fracture. The biomechanical design of these implants relies on "hard-on-hard" and "hard-on-soft" interactions. This type of design does not mimic the soft-on-soft interactions that occur in natural cartilage. Hydrogels, namely polyvinyl alcohol-based hydrogels (PVA), have been studied and mentioned as a possible alternative for materials used in hip and knee prostheses because of their biocompatibility, swelling ability and tribological behavior. In this work, different formulations of PVA hydrogels were investigated in terms of their physical properties (swelling, wettability, thermotropic behavior) and mechanical properties (Young's modulus, toughness, ultimate tensile strength and maximum strain). Total replacement of the hip or knee and the results were compared with the natural cartilage and other PVA hydrogels in the literature. It was observed that the swelling and thermotropic behavior of the materials was very similar to those found in the literature. It has also been observed that, mechanically, higher molecular weight hydrogels have characteristics comparable to those of natural cartilages. However, all the gels studied have a higher compressive strength than traction, as opposed to the typical cartilage behavior, which is more resistant to compression.