Bioactive and bactericidal scaffolds for bone regeneration via 3D printing

Abstract

3D printing has revolutionized the medical field, especially the manufacture of orthopedic prostheses, due to the versatility of adaptation of the prosthesis to a certain defect/person, the low cost, the speed to print the desired material and the possibility of accelerating osseointegration due to the porous structure of the scaffolds, decreasing the recovery time of the patient and the need for additional surgical interventions. Bioactive and biodegradable scaffolds that mimic the natural extracellular matrix of bone (architecture, biochemistry and mechanical properties) act as temporary molds to guide the growth of new tissue. This project aims to produce scaffolds composed of poly(lactic acid) (PLA)-beta tricalcium phosphate (²-TCP) modified by (i) elements to promote the differentiation of mesenchymal stem cells into osteoblasts such as Mg, Sr and Si, and (ii) bactericidal agents such as Ag, Se and Ce nanoparticles. Contamination by bacteria can lead to severe infections and even the need for implant replacement, and therefore a special focus will be given to the bactericidal property of the developed materials. The composites will be used as filaments for 3D printing by fused deposition modeling (FDM), to obtain scaffolds with adequate mechanical properties, controlled morphology (pore sizes that mimic the bone structure), bioactive behavior, and permeability to sufficient body fluids/proteins for application in bone regeneration. The rheological, structural, thermal and mechanical properties of the scaffolds will be analyzed with a wide range of techniques available at Department of Materials Engineering (DEMa), and in vitro cell and bacterial studies will be conducted at Laboratory of Biochemistry and Molecular Biology (LBBM), located in the Department of Physiological Sciences of UFSCar and in a research internship abroad (BEPE).