Ming-Ying Lan

Both Enhanced Biocompatibility and Antibacterial Activity in Ag-Decorated TiO2 Nanotubes

In this study, Ag is electron-beam evaporated to modify the topography of anodic TiO2 nanotubes of different diameters to obtain an implant with enhanced antibacterial activity and biocompatibility. We found that highly hydrophilic as-grown TiO2 nanotubes became poorly hydrophilic with Ag incorporation; however they could effectively recover their wettability to some extent under ultraviolet light irradiation. The results obtained from antibacterial tests suggested that the Ag-decorated TiO2 nanotubes could greatly inhibit the growth of Staphylococcus aureus. In vitro biocompatibility evaluation indicated that fibroblast cells exhibited an obvious diameter-dependent behavior on both as-grown and Ag-decorated TiO2 nanotubes. Most importantly, of all samples, the smallest diameter (25-nm-diameter) Ag-decorated nanotubes exhibited the most obvious biological activity in promoting adhesion and proliferation of human fibroblasts, and this activity could be attributed to the highly irregular topography on a nanometric scale of the Ag-decorated nanotube surface. These experimental results demonstrate that by properly controlling the structural parameters of Ag-decorated TiO2 nanotubes, an implant surface can be produced that enhances biocompatibility and simultaneously boosts antibacterial activity.

Diameter-sensitive biocompatibility of anodic TiO2 nanotubes treated with supercritical CO2 fluid.

This work reports on the diameter-sensitive biocompatibility of anodic TiO2 nanotubes with different nanotube diameters grown by a self-ordering process and subsequently treated with supercritical CO2 (ScCO2) fluid. We find that highly hydrophilic as-grown TiO2 nanotubes become hydrophobic after the ScCO2 treatment but can effectively recover their surface wettability under UV light irradiation as a result of photo-oxidation of C-H functional groups formed on the nanotube surface. It is demonstrated that human fibroblast cells show more obvious diameter-specific behavior on the ScCO2-treated TiO2 nanotubes than on the as-grown ones in the range of diameters of 15 to 100 nm. This result can be attributed to the removal of disordered Ti(OH)4 precipitates from the nanotube surface by the ScCO2 fluid, thus resulting in purer nanotube topography and stronger diameter dependence of cell activity. Furthermore, for the smallest diameter of 15 nm, ScCO2-treated TiO2 nanotubes reveal higher biocompatibility than the as-grown sample.

Induction of apoptosis by high-dose gold nanoparticles in nasopharyngeal carcinoma cells

OBJECTIVE Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world, but is a common cancer in southern Asia. Local recurrent disease and distant metastasis of NPC are still the unsolved problems. Recently, gold nanoparticles (AuNPs) have been developed as potential in vivo diagnostic and therapeutic agents. However, their role on nasopharyngeal cancer remains unknown. The object of this study is to investigate if AuNPs can be used as a new therapeutic agent for NPC by evaluating their anti-tumor effect in vitro. METHODS The AuNPs were prepared by the reduction of chloroauric acid to neutral gold. Their size distribution and microstructures were characterized by transmission electron microscopy (TEM). To evaluate their cytotoxic effect, NPC cell line TW01 and Human Nasal Epithelial Cells (HNEpC) were cultured in various concentrations of AuNPs for 3 days. Cell viability was evaluated by Trypan Blue viability assay while morphologic findings were observed via light microscopy. Terminal deoxynucleotidyltransferase-mediated dUPT nick end labeling (TUNEL) assay was used to detect apoptosis. RESULTS AuNPs prepared in this study had an average diameter of 20.5nm and they were observed under light microscopy as dark material aggregated in the cells after treatment. Contrary to the HNEpC, the AuNPs reduced cell viability of NPC cell in a concentration-dependant manner by Trypan Blue assay, especially at high concentration. Besides, cell apoptosis was demonstrated by positive TUNEL assay. CONCLUSIONS The AuNP possesses specific imaging properties and is cytotoxic to NPC cells at high concentrations.

Using computational strategies to predict potential drugs for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a unique cancer. Refinement of current therapy by discovering potential drugs may be approached by several computational strategies.

Evaluating the Autonomic Nervous System in Patients with Laryngopharyngeal Reflux

Objectives The pathogenesis of laryngopharyngeal reflux (LPR) remains unclear. It is linked to but distinct from gastroesophageal reflux disease (GERD), which has been shown to be related to disturbed autonomic regulation. The aim of this study is to investigate whether autonomic dysfunction also plays a role in the pathogenesis of LPR. Study Design Case-control study. Setting Tertiary care center. Subjects and Methods Seventeen patients with LPR and 19 healthy controls, aged between 19 and 50 years, were enrolled in the study. The patients were diagnosed with LPR if they had a reflux symptom index (RSI) ≥13 and a reflux finding score (RFS) ≥7. Spectral analysis of heart rate variability (HRV) analysis was used to assess autonomic function. Anxiety and depression levels measured by the Beck Anxiety Inventory (BAI) and Beck Depression Inventory II (BDI-II) were also conducted. Results In HRV analysis, high frequency (HF) represents the parasympathetic activity of the autonomic nervous system, whereas low frequency (LF) represents the total autonomic activity. There were no significant differences in the LF power and HF power between the 2 groups. However, significantly lower HF% (P = .003) and a higher LF/HF ratio (P = .012) were found in patients with LPR, who demonstrated poor autonomic modulation and higher sympathetic activity. Anxiety was also frequently observed in the patient group. Conclusion The study suggests that autonomic dysfunction seems to be involved in the pathogenesis of LPR. The potential beneficial effect of autonomic nervous system modulation as a therapeutic modality for LPR merits further investigation.

The predictive value of drug-induced sleep endoscopy for CPAP titration in OSA patients

PurposeThe aim of this study was to identify possible upper airway obstructions causing a higher continuous positive airway pressure (CPAP) titration level, utilizing drug-induced sleep endoscopy (DISE).MethodsA total of 76 patients with obstructive sleep apnea (OSA) underwent CPAP titration and DISE. DISE findings were recorded using the VOTE classification system. Polysomnographic (PSG) data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with CPAP titration levels.ResultsA significant association was found between the CPAP titration level and BMI, oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and neck circumference (NC) (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, by Spearman correlation). Patients with concentric collapse of the velum or lateral oropharyngeal collapse were associated with a significantly higher CPAP titration level (P < 0.001 and P = 0.043, respectively, by nonparametric Mann-Whitney U test; P < 0.001 and P = 0.004, respectively, by Spearman correlation). No significant association was found between the CPAP titration level and any other collapse at the tongue base or epiglottis.ConclusionsBy analyzing PSG data, anthropometric variables, and DISE results with CPAP titration levels, we can better understand possible mechanisms resulting in a higher CPAP titration level. We believe that the role of DISE can be expanded as a tool to identify the possible anatomical structures that may be corrected by oral appliance therapy or surgical intervention to improve CPAP compliance.

Enhanced Biocompatibility in Anodic TaO x Nanotube Arrays

This study first investigates the biocompatibility of self-organized TaOx nanotube arrays with different nanotube diameters fabricated by electrochemical anodization. All as-anodized TaOx nanotubes were identified to be an amorphous phase. The transition in surface wettability with TaOx nanotube diameters can be explained based on Wenzel’s model in terms of geometric roughness. In vitro biocompatibility evaluation further indicates that fibroblast cells exhibit an obvious wettability-dependent behavior on the TaOx nanotubes. The 35-nm-diameter TaOx nanotube arrays reveal the highest biocompatibility among all samples. This enhancement could be attributed to highly dense focal points provided by TaOx nanotubes due to higher surface hydrophilicity. This work demonstrates that the biocompatibility in Ta can be improved by forming TaOx nanotube arrays on the surface with appropriate nanotube diameter and geometric roughness.

The Relationship Between Modified Mallampati Score, Müller’s Maneuver and Drug-Induced Sleep Endoscopy Regarding Retrolingual Obstruction

Objectives: This study explored the correlation between clinical explorations, including modified Mallampati score and Müller’s maneuver, with drug-induced sleep endoscopy (DISE) findings regarding retrolingual obstruction. Methods: One hundred forty-two obstructive sleep apnea patients were enrolled in this prospective study. All of the patients received clinical explorations including modified Mallampati scoring and Müller’s maneuver in the clinic. Drug-induced sleep endoscopy was further evaluated in the operating room. Results: A significant relationship was noted between modified Mallampati score and retrolingual obstruction during DISE. In contrast, no significant relationship was noted between Müller’s maneuver and DISE findings regarding retrolingual obstruction. Conclusions: A significant discrepancy existed between retrolingual airway collapse evaluated by modified Mallampati score and Müller’s maneuver. Modified Mallampati score is more correlated with DISE regarding retrolingual obstruction compared to Müller’s maneuver. It should therefore be used as an initial evaluation of retrolingual obstruction when DISE is unavailable.

Application of nitrogen plasma immersion ion implantation to titanium nasal implants with nanonetwork surface structure

In nasal reconstruction, the response of cells to titanium (Ti) implants is mainly determined by surface features of the implant. In a pilot study, the authors applied electrochemical anodization to Ti surfaces in an alkaline solution to create a network of nanoscale surface structures. This nanonetwork was intended to enhance the responses of primary human nasal epithelial cell (HNEpC) to the Ti surface. In this study, the authors then treated the anodized, nanonetwork-structured Ti surface using nitrogen plasma immersion ion implantation (NPIII) in order to further improve the HNEpC response to the Ti surface. Subsequently, surface characterization was performed to elucidate morphology, roughness, wettability, and chemistry of specimens. Cytotoxicity, blood, and HNEpC responses were also evaluated. Our results demonstrate that NPIII treatment led to the formation of a noncytotoxic TiN-containing thin film (thickness <100 nm) on the electrochemically anodized Ti surface with a nanonetwork-structure. NPII...

Nasopharyngeal cancer cell death induced by high-dose gold nanoparticles

This study investigated if gold nanoparticles (AuNPs) could be used as a new therapeutic agent for NPC by evaluating their anti-tumor effect in vitro. AuNPs prepared in this study had an average diameter of 20.5 nm and they were observed under light microscopy as dark material aggregated in the cells after treatment. The AuNPs reduced cell viability in a concentration-dependant manner by Trypan Blue assay: 74.7% at 50 μM, 39.0% at 100μM, and 7.1% at 200 μM, respectively. TUNEL stain was positive in AuNP-treated cells. The AuNP possess specific imaging properties and is cytotoxic to NPC cells at high concentrations.