Biocompatibility tests performed on nanoporous aluminum oxide coated with polyethyleneglycol and titanium dioxide

Abstract: Anodized aluminium oxide may be chemically treated to yield a uniform self-organized distribution of pores with a specific pore diameter. The thickness of in-house anodized alumina and its pore size can be modified by changing the electrolyte, the temperature of the electrolyte, the time of anodization and the potential over the anodized plates.  In this thesis, a method for anodized aluminium oxide (AAO) was optimized for creating custom-made porous alumina membranes and coating them with TiO2 and polyethylene glycol (PEG). The purpose of finding a method to create porous alumina oxide with specific pore diameters was to eventually use these membranes for use in contact with human living tissue, allowing wanted nutrients and fluid to pass in and out.      SEM images showed that a reproducible method has been established for the membrane production, where the pore diameter is ~ 300nm and the thickness of the oxide is approximately 100µm. The SEM images also showed that the pores are stable and uniform over the entire aluminum plate where they are initially produced.      As a test for biocompatibility, the membranes were implanted into the hipbone of pigs. The histology test showed fibrosis around the location where the membranes were placed. An observation during the extraction was swollenness in the surrounding tissue, which indicates inflammation around the implant. In this respect, the membranes cannot be used for the purpose intended.