Calcium phosphate cements reinforced with polyvinyl alcohol fibers for bone load-bearing applications

Abstract

The development of bioceramics for regeneration of bone tissue has been widely explored as reflected by its high application frequency resulting from problems associated with congenital defects, bone diseases or trauma. In this context, since 1980 that calcium phosphate cements has played an important role as bone filler or as scaffolds for bone regeneration, presenting good properties in terms of biocompatibility and bioactivity. However, the mechanical properties of this class of bioceramicshave limitations regarding to brittleness and low flexural strength. Thus, the areas of potential application of these cements are limited to non load bearing areas. The cements reinforced with polymeric fibers, is a solution long been widely explored by civil engineering, in order to improve the mechanical properties of cements, increasing its toughness and ductility. From the same engineering principle, to reinforce composites for medical purposes, polymeric fibers made of natural and synthetic polymers have been studied. Promising results in vitro and in vivo have been achieved, but without translation towards applications in load bearing areas. Polyvinyl alcohol fibers are used for the reinforcement of ceramic composites such as concrete because of their beneficial mechanical properties. In the biomedical context, polyvinyl alcohol fibers are commonly used as a polymer-base for hydrogels, offering good mechanical properties and biocompatibility. In this study was used microsized PVA fibers (Kuralon TM from Kuraray) as reinforcement of calcium phosphate cements for the mechanical properties evaluation, as well as the analysis of the chemical, structural and cytotoxic properties of the fiber. On basis of the results of this study, significant improvements were achieved in the mechanical properties with the inclusion of Kuralon TM fibers compared to cement devoid of fiber. Invitro, the fibers were not cytotoxic to osteoblasts precursor cells.

Date of Award	19 Apr 2017
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Sander Leeuwenburgh (Supervisor) & Sónia L. Schickert (Co-Supervisor)