Evaluate Histone adsorption of TiC nanotube arrays to improve its antibacterial activity

  • 柯 志融

Student thesis: Doctoral Thesis

Abstract

As a result of the excellent mechanical properties anti-corrosion and fatigue strength of titanium metal it is broadly used in dental and orthopedic field We focus on improving the osseointegration ability by different surface modification treatments and one of them is anodization titanium oxide (ATO) method The feature of ATO method is of the highly ordered and controllable nanopore or nanotube structure Further this kind of nano-structure has been proved with the function to accelerate the differentiation of bone marrow stem cells Nevertheless the lack of sufficient mechanical property of this bioactive titanium oxide coating will be easily ruptured during the surgical procedure inducing adverse effect of surrounding tissues In our study we prepared titanium carbide (TiC) nanotube arrays to perform better mechanical strength of surface structure In addition our research used Histone (type 2A) as the cationic antimicrobial reagent The feature of Histone is the positively charged protein and it has the tendency to combine with negatively charged bacteria membrane entering the bacteria body to disrupt the DNA formation or breaking bacteria membrane from outside Hence we evaluated the effect of different nanotube structure with Histone adsorption to inhibit the bacteria growth In this study we used ATO method to prepared titanium oxide (TiO2) nanotube arrays and replaced the oxygen with carbon to proceed TiC nanotubes by vacuum heat treatment (VHT) Next the TiC samples will be processed with the RF oxygen plasma treatment and self-assembled monolayer (SAMs) to acquire special surface via surface chemical modification which could be improved the Histone adsorption of TiC nanotubes First part of my research is empathized on adjusting ATO applied voltage to find the optimal Histone adsorption concentration and compared to TiC nanotube Second part begins with surface grafting of SAMs and their terminal group is –NH2 and –COOH respectively These two terminal groups presented positive and negative functional groups With the attractive electric force which will improve the adsorption of TiC nanotube and also provide stronger chemical bindings The bacteria strains we used in vitro were Escherichia coli (E coli) and Staphylococcus aureus (S aureus) Based on time killing curve for 3 hours the MIC of E coli is 80 μg/mL and S aureus is 160 μg/mL We also evaluated the bacteria morphology and viability of Histone adsorption samples The results showed the bacteria numbers decreased with significance difference At last this study used cell adhesion cell proliferation and cell differentiation to evaluate different diameter of TiO2 and TiC nanotube surface The above data confirmed that we successfully prepared the surface modification with both antibacterial activity and cell activity
Date of Award2020
Original languageEnglish
SupervisorTzer-Min Lee (Supervisor)

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