Bioactive scaffolds with surface modification by plasma

Abstract

The growing number of orthopedic procedures for bone repair resulting from increased life expectancy or traumas is a problem that affects all countries. In the U.S., nearly one million bone graft procedures are performed annually, with a growth rate of nearly 13% per year. In this context, new surgical procedures have been developed as well as new materials for bone repair. One of the most prominent alternatives is the development of scaffolds that can be made of metallic, ceramic or polymeric materials and should mimic the natural bone extracellular matrix (architecture, biochemistry and mechanical properties), in order to enable the connection, proliferation and differentiation of cells. One way to obtain scaffolds with appropriate mechanical properties and bioactive behavior is to produce biocompatible/bioabsorbable polymer composites with bioactive ceramic particles such as bioglass, hydroxyapatite (HA), ²-tricalcium phosphate (TCP) and metal oxides (e.g. ZnO). Thus, the biocompatibility and biodegradability characteristics of the polymer and the biocompatibility and bioactivity of these ceramic particles are combined. The addition of Ag or MgO particles to these composites (forming hybrid materials) can also confer bactericidal properties. Conventional techniques to produce polymer composites usually employ high temperatures and shear rates which can result in severe polymer degradation in the presence of certain bioactive fillers. In this project, bioactive and bactericidal particles will be plasma-surface modified to prevent polymer degradation by using organic compounds such as maleic anhydride, glycidyl methacrylate and lactic acid. The scaffolds of PLA/bioactive ceramic composites will be corformed by additive manufacturing technique (3D printing). The surface of scaffods will be modified by plasma in order to improve cell adhesion and growth, aiming to obtain bioactive scaffolds with controlled morphology (pore sizes that mimic bone structure) and that have suitable mechanical properties and permeability to body fluids/proteins for application in bone regeneration. (AU)