Soo-Hyuk Uhm

Tailoring of antibacterial Ag nanostructures on TiO2 nanotube layers by magnetron sputtering

To reduce the incidence of postsurgical bacterial infection that may cause implantation failure at the implant-bone interface, surface treatment of titanium implants with antibiotic materials such as silver (Ag) has been proposed. The purpose of this work was to create TiO2 nanotubes using plasma electrolytic oxidation (PEO), followed by formation of an antibacterial Ag nanostructure coating on the TiO2 nanotube layer using a magnetron sputtering system. PEO was performed on commercially pure Ti sheets. The Ag nanostructure was added onto the resulting TiO2 nanotube using magnetron sputtering at varying deposition rates. Field emission scanning electron microscopy and transmission electron microscopy were used to characterize the surface, and Ag content on the TiO2 nanotube layer was analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. Scanning probe microscopy for surface roughness and contact angle measurement were used to indirectly confirm enhanced TiO2 nanotube hydrophilicity. Antibacterial activity of Ag ions in solution was determined by inductively coupled plasma mass spectrometry and antibacterial testing against Staphylococcus aureus (S. aureus). In vitro, TiO2 nanotubes coated with sputtered Ag resulted in significantly reduced S. aureus. Cell viability assays showed no toxicity for the lowest sputtering time group in the osteoblastic cell line MC3T3-E1. These results suggest that a multinanostructured layer with a biocompatible TiO2 nanotube and antimicrobial Ag coating is a promising biomaterial that can be tailored with magnetron sputtering for optimal performance.

The effect of non-thermal atmospheric pressure microwave-pulsed plasma on staphylococcus aureus and fibroblast L929 cells

Using non-thermal atmospheric pressure plasma (NTAP) has been studied for killing various bacteria, cell differentiation, cancer cell treatment and so on. Bacteria and cells were co-located in our oral environment, so NTAP could be influenced for both bacteria and cells. In this study, we studied the effect of radio-frequency microwave-pulsed non-thermal atmospheric pressure plasma (MWP-NTAP) for killing Staphylococcus aureus (S.aureus) which is a common oral bacteria, and at the same time we observed cellular response of fibroblast cell line L929 cells.

Applications of non-thermal atmospheric pressure plasma in prevention and regeneration of oral diseases

Since the introduction of non-thermal atmospheric pressure plasmas in the field of the dentistry, numerous applications have been investigated. Especially with its advantages over existing vacuum plasma in terms of portability, low cost, and non-thermal damage, it can be directly applied in the oral cavity, giving number of potentials for dental application.

Time-dependent growth of titania nanotubes from sputtered titanium thin films for bio-application

Summary form only given. TiO 2 nanotubes are biocompatible and many studies have been carried out for their biotechnological applications, especially in relation to drug carriers. The purpose of this study is to apply TiO 2 film on the variety of metal substrates that could be used as biomaterials, and by forming various depth of nanotubes on the films, biocompatibility of the TiO 2 nanotube and its ability as a carrier is applied to variety of materials according to various purposes. In this work, we present the fabrication of self-organized TiO 2 nanotubes layer that was grown from flat and thin sputter-deposited titanium (Ti) films on Si (100) wafer.

Conservative the effect of heat treatment on osteogenic property of sputtered antibacterial silver-titanium oxide nanocomposite films

Summary form only given. Silver-containing titanium oxide (Ag-TiOx) nanocomposite thin films were deposited on cp-Ti substrate using DC reactive magnetron sputtering system. After deposition, heat treatment process was performed under 600°C for 1 hour. It is well known fact that the success of dental implant surgery is dependent on the bone-implant osseointegration. Also, longterm success rate is dependent on the absence of bacteria surrounding the implants which can induce the bio-film formation. In this study, effect of heat treatment on osseointegration and mechanical behavior of the antibacterial sputtered films was investigated.

Antimicrobial efficacy of non-thermal atmospheric pressure plasma jet on oral micro-organisms

Summary form only given. Non-thermal pressure atmospheric plasma jets are being intensively studied with respect to potential applications in medicine due to their advantage of avoiding harmful thermal damage on human body. Recent researches have revealed their several important applications as medical devices as the possible selective inactivation of bacteria, fungi, parasites and viruses in and on living tissue, without causing damage to human cell. However, despite of the many investigations, details of the mechanisms related to how non-thermal plasma has effects on bacteria are still largely unknown.

Enhanced funtion of human periodontal ligament cells cultured on nanoporous titanium surfaces

Summary form only given. Biological integration of implant to surrounding tissue is important process as it determines its clinical success and attraction of bone cells. Also, in order to reduce the problems of implant-related infections, many kinds of the surface treatment on titanium have been proposed. The formations of TiO 2 nanotubes on the titanium have been widely studied to improve the biocompatibility of the surface, and silver nanoparticles have been known to exhibit the antibacterial efficacy. The purpose of this study was to carry out surface treatment on titanium and observe response of human periodontal ligament (hPDL) cells using combination of nanotube formation and silver nanoparticles treatment.

Effect of non-thermal atmospheric pressure plasma jet on hydrophilicity and cellular activity of SLA-treated titanium surface

Summary form only given. Along the many surface treatment of titanium (Ti) for dental implant, sandblasted with large-grit corundum and acid etched (SLA) treatment on titanium is one of the most popular choices of surface treatment in recent years due to its excellent ability in osseointegration. However, despite such popularity, poor surface wettability of SLA treated titanium has been the main downside and many attempts were carried out to resolve this problem.