Bio-Medical Materials and Engineering - Volume 32, issue 2

Authors: Yamabe, Akane | Irisawa, Atsushi | Kunogi, Yasuhito | Kashima, Ken | Nagashima, Kazunori | Minaguchi, Takahito | Yamamiya, Akira | Izawa, Naoya | Takimoto, Yoichi | Hoshi, Koki | Nonaka, Lisa | Masuda, Michiaki | Tominaga, Keiichi | Goda, Kenichi | Iijima, Makoto

Article Type: Review Article

Abstract: BACKGROUND: Endoscopic transpapillary stenting is commonly performed in patients with obstructive jaundice caused by a biliary stricture. Although the plastic stent (PS) is widely used for biliary drainage because of the low-cost and easy procedure, patency is short after placement in the bile duct because of the small diameter. Dysfunction of PS is primarily caused by biliary sludge that forms as a result of bacterial adhesion and subsequent biofilm formation on the inner surface of the stent. It is well known that silver ions have excellent antibacterial activity against a wide range of microorganisms. OBJECTIVE: This review provides …an overview and perspective of the significance of silver-coated biliary stents. METHODS: We collected literature regarding silver-coated biliary stents, reviewed the current research/development status and discussed their possible usefulness. RESULTS: To date, several in vivo/vitro studies evaluated the patency of silver-blended or silver-coated biliary stents. These studies suggested that the silver coating on a PS was likely to prolong the patency period. CONCLUSION: The development of biliary stents using silver is expected to prolong stent patency and prevent frequent stent replacement. Show more

Keywords: Biliary stent, silver coating, biliary obstruction, biofilm

DOI: 10.3233/BME-201163

Citation: Bio-Medical Materials and Engineering, vol. 32, no. 2, pp. 63-71, 2021

Authors: Sedira, Sofiane | Mendaci, Bilel

Article Type: Research Article

Abstract: BACKGROUND: Titanium nitride (TiN), titanium carbide (TiC) and titanium carbonitride (TiNC) thin films show promising practical applications due to their photoelectric properties and corrosion behaviour. OBJECTIVE: In this work, we investigated the factors which may affect the optical properties and the corrosion behaviour of these coatings. METHODS: The titanium coatings were carried out by sputtering using the target of Ti6Al4V (purity 99.96%) with different N2 , CH4 and Ar partial pressures. XRD, FTIR, Raman and SEM with EDX studies show the formation of titanium nitride, titanium carbide coatings. Uv-vis spectroscopy was carried out to estimate …the optical properties using the numerical Swanepoel method. Potentiodynamic polarization studies in Hank’s solution show that the corrosion resistance is found to be in the order of C-TiN(2) > C-TiN(1) > TiN > TiC. RESULTS: A high protective efficiency was determined (60%) when comparing TiNC(2) and TiC corrosion current densities, which confirms the lower corrosion velocity and the higher passivation stability of the coatings composed with TiN and TiC phases. Electrochemical impedance spectroscopy studies show that the Rct increases in the following order: TiC < TiN < C-TiN(1) < C-TiN(2), highlighting the fact that C-TiN(2) coating has the higher corrosion resistance. Show more

Keywords: Titanium coatings, optical properties, Swanepoel method, biomedical applications, corrosion resistance

DOI: 10.3233/BME-201134

Citation: Bio-Medical Materials and Engineering, vol. 32, no. 2, pp. 73-83, 2021

Authors: Mori, Takahiro | Mochizuki, Tomoharu | Koga, Yoshio | Koga, Hiroshi | Kobayashi, Koichi | Katsumi, Ryota | Sakamoto, Makoto | Omori, Go | Tanabe, Yuji

Article Type: Research Article

Abstract: BACKGROUND: Identifying the time course of rotational knee alignment is crucial for elucidating the etiology in knee osteoarthritis. OBJECTIVE: The aim of this study was to propose new rotational indices for calculating the change in relative rotational angles between the femur and tibia in standing anteroposterior (AP) radiographs. METHODS: Forty healthy elderly volunteers (20 women and 20 men; mean age, 70 ± 6 years) were assessed. The evaluation parameters were as follows: (1) femoral rotational index: the distance between the sphere center of the medial posterior femoral condyle and the lateral edge of the patella, and …(2) tibial rotational index: the distance between the medial eminence of the tibia and the lateral edge of the fibula head. The indices were standardized by the diameter of the sphere of the medial posterior femoral condyle. This study (1) identified the relationship between changes in rotational indices and the simulated rotational knee angles in the standing position, (2) proposed a regression equation for the change in relative rotational angles between the femur and tibia in standing AP radiographs, and (3) verified the accuracy of the regression equation. RESULTS: The rotational indices increased in direct proportion to simulated rotational knee angles (femoral index: r  > 0.9,p < 0.0001; tibial index: r > 0.9, p < 0.0001). Based on the results, the regression equation with the accuracy of 0.45 ± 0.26° was determined. CONCLUSIONS: The proposed regression equations can potentially predict the change in relative rotational angles between the femur and tibia in a pair of standing AP radiographs taken at different dates in longitudinal studies. Show more

Keywords: Anteroposterior radiograph, rotational index, 3D–2D image registration technique, digital reconstructed radiography, knee rotational angle

DOI: 10.3233/BME-201138

Citation: Bio-Medical Materials and Engineering, vol. 32, no. 2, pp. 85-99, 2021

Authors: Sönmezer, Dilek | Lati̇foğlu, Fatma | Toprak, Güler | Düzler, Ayhan | İşoğlu, İsmail Alper

Article Type: Research Article

Abstract: BACKGROUND: The heart is surrounded by a membrane called pericardium or pericardial cavity. OBJECTIVE: In this study, we investigated the pericardial fluid (PF) for coating polycaprolactone (PCL) scaffolds. PFS, which is a PF component, was used for the coating material. In addition to using PFS for surface coating, MED and fetal bovine serum (FBS) were also used for comparison. METHODS: Pericardial fluid cells (PFSc) isolated from PF were cultured on coated PCL scaffolds for 1, 3, and 5 days. Cell viability was determined using 3-(4, 5-di-methylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The MTT …assay results showed that the viability of cells on PCL scaffold coated with PFS increased over time (P < 0.005), and cell viability was significantly different between PCL scaffolds coated with PFS and non-coated PCL scaffolds. However, cell viability was significantly higher in the PCL scaffolds coated with PFS than non-coated and coated with FBS, MED, and PCL scaffolds. Scanning electron microscopy (SEM) microscopy images and MTT assay indicated that PFSc are attached, proliferated, and spread on PCL scaffolds, especially on PCL scaffolds coated with PFS. CONCLUSIONS: These results suggest that PFS is a biocompatible material for surface modification of PCL scaffolds, which can be used as a suitable material for tissue engineering applications. Show more

Keywords: Pericardial fluid (PF), polycaprolactone (PCL), pericardial fluid structure, tissue engineering

DOI: 10.3233/BME-196014

Citation: Bio-Medical Materials and Engineering, vol. 32, no. 2, pp. 101-113, 2021

Authors: Horiguchi-Babamoto, Emi | Otsuka, Makoto

Article Type: Research Article

Abstract: BACKGROUND: Warfarin potassium (Wf) commercial tablets originally formulated for adults are ground before administration to pediatric patients and elderly patients with dysphagia. OBJECTIVE: The present study investigated the effect of tablet grinding on the photostability of four types of commercial Wf tablets and predicted the photostability of the tablet powders by chemometric analysis. METHODS: The photodegradation of Wf content was evaluated by reversed-phase column high-performance liquid chromatography with ultraviolet (HPLC-UV). RESULTS: The bulk Wf powder was relatively photostable, whereas ground Wf tablets underwent substantial photodegradation. The photostability of the ground powders of a brand-name …Wf commercial tablet and three generic Wf commercial tablets was quantitatively assessed and compared. In certain cases, the Wf in all the three ground generic tablets was less photostable than in the ground brand-name tablets. After 28 days of light irradiation, the Wf content decreased to 69.79% in the brand-name tablets, while it was 31.90% in some generic tablets. To clarify the factors influencing the relative photostability in various Wf formulations, we analyzed the intermolecular interactions between the active ingredient and the excipients by partial least-squares regression analysis based on photostability screening for each additive. CONCLUSION: The results suggested that the additives light anhydrous silicic acid and povidone adversely affect the stability of Wf tablets. In addition, the light stability of ground tablets was affected considerably by their formulation. Show more

Keywords: Photostability, crushed tablets, chemometric analysis, warfarin potassium, high-performance liquid chromatography-ultraviolet (HPLC-UV)

DOI: 10.3233/BME-201167

Citation: Bio-Medical Materials and Engineering, vol. 32, no. 2, pp. 115-129, 2021