Investigation of physical and chemical properties of anodic aluminium oxide membranes for tissue engineering and biosensors applications

Anodic aluminum oxide (AAO) membranes are a ceramic material group which comes into prominence due to their physical and chemical advantages in various fields of biomedical engineering. In the thesis scope, AAO membranes were contextualized regarding their potential tissue engineering and biosensor applications. In the first part of the thesis, the potential of AAO membranes as a neuro-electrode was investigated. The results showed that conductive 100 nm AAO (CAAO) membranes triggers neuron growing and differentiation compared to 250 nm AAO membranes. Moreover, 100 nm AAO membranes has a potential to be neuron electrode surface if controlled release parameters of nerve growth factors on the membranes. Additionally, the membranes were used as a mold to fabricate Raman active substrates which were utilized for detecting of Alzheimer`s proteins. The results demonstrated that 20 nm Au coated multibranched substrates (Au@MDS) provides detecting amyloid β 1-42 (Aβ 1-42) proteins by 0,5 pg/ ml concentration. Furthermore, signal reproducibility (RSD%: 17%) and selectivity (aganist to myglobin) of surfaces were tested. Overall, results indicated that Au@MDSs triggers hot spot formation due to their pyhsical structures. Moreover, nano-designed and/or epidermal growth factor doped chitosan:gelatin (C:G) films were synthesized with the drop casting technique and the potential of the films as an implant coating or wound patch model (melanogenesis perspective) were followed under in vitro / in vivo conditions. Nano C:G films has potential to differentiate mesenchymal stem cells to bone cells compared to flat films and TCPS control group. Additionally, the same analyses were repeated for mature bone cells and same results were obtained. Skin tissue enngineering studies were presented protein and gene based analysis under in vitro and in vivo conditions. Although epidermal growth factor (EGF) has no significant effect on melanogenesis, it has been shown to improve wound closure performance. The results were confimed by histology staining. However, it is established that nanotopography effect has taken active role on melanogenesis. When all results are evaluated together, it is thought that nano films can be a good wound patch model in the presence of EGF. The results showed that the controllable parameters of AAO membranes have a potential to trigger cellular activity and hot spot formation in optic sensors, directly or indirectly (mold).