Processing and characterization of UHMWPE-TiO2 nanocomposites for the development of a zygomatic bone prosthesis manufactured by SPIF

Abstract

In the past years the use of nanotechnology for the development of new composite materials had become one of the most trending topics in the scientific community. Researchers around the world are working hard to prove that the addition of small quantities of nanoparticles (NPs) can be the differentiator that might change completely the way materials are seen nowadays. This master’s program thesis focuses on bringing to medical disposition a novel material for craniofacial prosthesis capable of satisfying several of the biggest medical issues reported today in hospitals all over the world. In particular, the use of the developed UHMWPE-TiO2 nanocomposite is, but not exclusively, aimed to be the principal material in the manufacture of a functional zygomatic bone prosthesis. For achieving this goal, UHMWPE-TiO2 sheet nanocomposites were prepared using incipient wetting and compression molding processes at different concentrations (0.25 wt. %, 0.5 wt. %, 0.75 wt. % and 1 wt. %). Positive results were obtained through the dispersion of the TiO2 NPs in a liquid solution observed at low concentrations (<0.75 wt. %). At higher concentrations, micro scaled agglomerations of NPs were seen with the use of SEM images which exhibit that the saturation point of TiO2 NPs inside the polymeric matrix is situated between 0.75 wt. % and 1 wt. %. The degree of crystallinity and structural properties of the developed nanocomposites were investigated by X-ray diffraction and differential scanning calorimetry, the results presumes that the compression molding manufacturing procedure inhibits the normal crystallization phenomena of UHMWPE. It was observed the reduction in symmetry for the orthorhombic unit cells, found in(110) and (200), to monoclinic structures (001). Furthermore, FT-IR revealed the appearance of carbon-oxygen vibrational modes at 1740cm−1 (C=O) and 1250cm−1 (C-O) assuring a positive dispersion of TiO2 NPs inside the polymeric matrix. Tensile tests and single point incremental forming processes were carried out indicating the enhance of the mechanical properties of the UHMWPE-TiO2 nanocomposite superior to recent publications. Biological activity was analyzed using LIVE/DEAD Cell viability assays with favorable results showing almost null cytotoxicity. Finally a personalized, bio compatible, inert, resistant, cheap and light weighted zygomatic bone graft was crafted and mounted in a real partially damaged skull.