Evaluation techniques of metallic biomaterials in vitro

Metals and alloys are widely used as biomedical materials and are important in medicine and they cannot be replaced with ceramics or polymers at present mainly because of their high strength and toughness. Since safety is the most important property of biomaterials, corrosion-resistant materials such as stainless steel, Co–Cr–Mo alloy, commercially pure titanium, and titanium alloys are employed as biomaterials. Evaluation techniques for corrosion with culturing cells, the characterization of reconstruction of surface oxide film, fretting fatigue, cytotoxicity, and biocompatibility are reviewed in this paper. These techniques are original and characteristics in the field of biomaterials that should contribute to the proper evaluations of biomaterials in vitro.     

Analytical decision model for the cost-effective management of solitary pulmonary nodules

PURPOSE AND METHODS: Multiple strategies are currently being used to manage patients who present with indeterminate solitary pulmonary nodules (SPN). We have used decision-analysis models to assess the cost-effectiveness of various strategies for the diagnosis and management of SPN. Four decision strategies were compared: a wait and watch strategy, a surgery strategy, a computed tomography (CT)-based strategy, and a CT-plus-positron emission tomography (PET) strategy. An incremental cost-effectiveness ratio (ICER) was used to compare all strategies to the wait and watch strategy. RESULTS: A CT-plus-PET strategy was the most cost-effective over a large pretest likelihood (probability of having a malignant nodule), with a range of 0.12 to 0.69. Furthermore, within this likelihood range, the potential cost savings of using the CT-plus-PET strategy over the CT strategy ranged from $91 to $2,200 per patient. This translates to a yearly national savings of approximately $62.7 million. CONCLUSION: Decision-analysis modeling indicates the potential cost-effectiveness of [18F]2-fluoro-2-deoxy-D-glucose (FDG)-PET in the management of SPN. Furthermore, the decision trees developed can be used to model various features of the management of SPN, including modeling the cost-effectiveness of other newly emerging technologies.     

Removal of endocrine disruptors in milk by circulation through polydimethylsiloxane tubing

A simple circulating system was developed, in which an aqueous solution, cow milk, or human milk was circulated through hydrophobic polymeric tubing to remove the endocrine disruptors from the solution by sorption into the tubing. The effect of circulating parameters, such as tube length, circulating time, and flow rate, against the removal ratio (R) of endocrine disruptors was investigated. R of 1,2,3,4,5,6‐hexachlorocyclohexane (γ‐HCH, lindane) increased with the length of the hydrophobic polymeric tubing, circulating time, and flow rate when cow milk containing 1 ppm γ‐HCH was circulated through polydimethylsiloxane tubing. The R values of several endocrine disruptors with different octanol–water distribution coefficients (log P_ow) was investigated for γ‐HCH and dichlorodiphenyltrichloroethane in an aqueous solution, cow milk, and human milk. A similar trend for R versus log P_ow of the human milk to that of the aqueous solution and cow milk was observed. The R values of the endocrine disruptors decreased in the following order: Aqueous solution > Human milk > Cow milk. Stable micelles in cow milk disturbed the shift of the endocrine disruptors from the milk micelles into the hydrophobic tubing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3634–3640, 2006     

Development of electrolytic cell with cell-culture for metallic biomaterials

The interface reactions between materials and tissues must be understood to improve the corrosion resistance in vivo and biocompatibility of the materials. Then, we have developed a new electrolytic cell by which electrochemical measurement can be performed during culturing cells on specimen. Open-circuit potential (E_open) and AC impedance of commercially pure titanium at E_open were measured in a cell-culture medium with and without culturing murine fibroblasts L929 and in the medium without proteins. The biomolecule adsorption layer containing proteins and cells was formed on titanium oxide film and worked as a capacitor by preventing the diffusion of molecules. The cell enhanced this prevention.     

Crystal structures of 2-aminotropone, n,n'-di(tropon-2-yl)piperazine, and 5-(4-ethoxyphenylazo)tropolone

Crystal structures of 2-aminotropone (1), N,N'-di(tropon-2-yl)piperazine (2), and 5-(4-ethoxyphenylazo)tropolone (3) have been elucidated by X-crystallographic analysis. 2-Aminotropone (1) contains three crystallographically independent molecules in the crystal lattice. The NH2 groups of 2-aminotropone unit of 1 participate in the N-H...O intermolecular hydrogen bonds. Two tropone units of N,N'-di(tropon-2-yl)piperazine (2) have an anti orientation to the piperazine ring. The crystal packing of 2 is consolidated by pi...pi, C-H...pi, and C-H...O interactions. 5-(4-Ethoxyphenylazo)tropolone (3) forms O-H...O hydrogen bond dimmers about inversion centres, involving the OH group and an intermolecular carbonyl O acceptor.     

Calcium phosphate formation on titanium by low-voltage electrolytic treatments

Electrochemical treatments are expected to be effective for the coating of calcium phosphate ceramics to a titanium substrate. In the present study, two types of chronoamperometry with a step potential and a cyclic wave potential at low voltage (up to 2.0 V) and low current density were performed in Hanks’ solution to modify the surface characteristics of titanium. Titanium oxide film formed by self-passivation, that formed as reconstructed film during electrochemical treatments, and a calcium phosphate layer precipitated through treatments were characterised by X-ray photoelectron spectroscopy. The thickness and compositions of the surface films and layers were quantified from the XPS results. Calcium phosphate formation during immersion in Hanks’ solution for 1.0 Ms was evaluated by scanning electron microscopy with energy-dispersive X-ray spectrometry. The results confirmed that the electrolytic treatments in this study were effective to accelerate calcium phosphate formation on titanium in Hanks’ solution in spite of their lower voltage than conventional methods. The results also suggested that the hydroxyl group in the surface oxide film might contribute to the formation of calcium phosphate. This technique is a promising process for the treatment of thin titanium materials.     

The effect of UV irradiation on the electrospun PCL/TiO2 composites fibers

The effect of UV irradiation and micro‐ and nano‐TiO₂ as well as titanate nanotubes (TiNT) on the phase morphology and thermal properties of the electrospun PCL composite fibers was investigated. Polycaprolactone (PCL)/TiO₂ (micro‐ and nano‐TiO₂ as well as titanate nanotubes) composite fibers were prepared by electrospinning a polymer solution. The PCL and PCL/TiO₂ composite fibers were exposed to UV light at irradiation times of 5 and 10 days. After UV irradiation the crystallinity of the electrospun PCL/TiNTcomposite fibers increased because of the large specific surface area of TiNT. The thermal stability of the PCL/TiNT electrospun composite fibers increased due to the formation of crosslinking structure after UV irradiation. The SEM analysis suggests that after UV radiation the fibers showed high degree of degradation due to the high number of fibers breakages and fibers surface voids. The results of FTIR spectroscopy confirmed that the TiO₂ particles enhance the degradation process because of their photocatalytic activity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43539.     

Titanium Containing High Strength Sulfuric Acid Corrosion Resistant Steel

Ti containing low alloy steel free of Sb is found to have higher strength than and equivalent sulfuric acid corrosion (SAC) resistance to traditional SAC resistant steels in Cu? Cr? Sb system. SAC resistance of the Ti containing steel was investigated with potentiodynamic polarization, linear polarization resistance, electrochemical impedance spectroscopy, and weight loss measurements in a solution of 20 wt% H₂SO₄ at 20°C. All measurements confirm that Ti addition is suitable for designing high strength SAC resistant steels.     

Patidegib in Dermatology: A Current Review

Background: Basal cell carcinoma is one of the most common types of non-melanoma skin cancers, which can be locally destructive despite low-rate metastasis. Surgery is the treatment of choice, but it lacks of efficacy on advanced cases. Hedgehog pathway inhibitors are a class of drugs providing a new therapeutic option for patients affected by advanced disease. Besides systemic therapy, such as vismodegib and sonidegib, also topical inhibitors have been developed. Patidegib is able to decrease tumor burden, reducing the adverse effects induced by systemic targeted therapies. Methods: We performed comprehensive research to summarize the use of patidegib in advanced and recurrent aggressive basal cell carcinomas. Only English language human studies were included in the search. Results: Seven trials reported the application of patidegib. Both topical and systemic patidegib demonstrated safety, tolerability, and efficacy in naïve patients with stage II and III basal cell carcinomas, while stage IV disease and not-naïve patients did not show any benefit. Conclusion: Unlike systemic Hedgehog pathway inhibitors, patidegib 2% gel is not associated with systemic adverse effects and allows a better patient management. Considering the multidisciplinary management of neoplasia, in the era of precision medicine, it is mandatory to confide in pharmacogenomics to obtain personalized combined or sequential therapies.