Bio-Medical Materials and Engineering - Volume 30, issue 5-6

Authors: Ohara, Masato | Itoh, Soichiro | Fujiwara, Hiroyoshi | Oda, Ryo | Tsuchida, Shinji | Kohata, Kazuhiro | Yamashita, Kimihiro | Kubo, Toshikazu

Article Type: Research Article

Abstract: BACKGROUND: We have developed a technology to electrically polarize living bone. OBJECTIVE: The effects of stored electrical charge in electrical polarized bone on the facilitation of new bone formation were assayed. METHODS: Stimulated depolarized current measurement was performed in electrically polarized and nonpolarized femora of SD rats. These bone specimens were implanted into bone defects of the rat femora and fixed with a custom-made external fixator. X-ray imaging of the implant was performed every week. After 3 weeks, micro-CT scanning was performed to evaluate the displacement rate. Histological observation was performed, and the occupancy ratio of …the newly formed bone was calculated from tissue specimens stained with Villanueva’s Goldner method. RESULTS: There was a tendency for the displacement rate of the implant to be smaller and the occupancy ratio of the newly formed bone to be larger, especially at the distal end, in the polarized group compared with the nonpolarized group. The time of callus appearance was significantly earlier in the polarized group than in the nonpolarized group, and bridging callus grew from the distal to the proximal end. CONCLUSIONS: Bone specimens can be electrically polarized, and the stored electrical charge can work effectively to facilitate new bone formation. Show more

Keywords: Electrical polarization, electrical charge, living bone, rat femoral bone defect model, external fixator

DOI: 10.3233/BME-191068

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 475-486, 2019

Authors: Ali, Saqib | Farooq, Imran | Al-Thobity, Ahmad M. | Al-Khalifa, Khalifa S. | Alhooshani, Khalid | Sauro, Salvatore

Article Type: Research Article

Abstract: BACKGROUND: Many novel biomaterials have been incorporated in toothpastes to promote remineralization of tooth structure. OBJECTIVES: This study was carried out to compare the discrepancies between declared and actual total fluoride (TF) or total soluble fluoride (TSF) concentration of two modern toothpastes containing bioactive glasses; these were also assessed for their remineralization potential. MATERIALS AND METHODS: The TF and TSF concentration were assessed using a fluoride ion selective electrode. Enamel remineralization was evaluated through micro-hardness analysis. Eighteen enamel blocks were divided into three groups: 1 (n = 6; control), 2 (n = 6; Novamin® toothpaste), …and 3 (n = 6; BiominF® toothpaste). The specimens were demineralized by 6 wt% citric acid (pH = 2.2). Subsequently, the specimens in group 1 were kept in artificial saliva (AS), while the specimens in groups 2 and 3 were stored in AS + Novamin® and AS + Biomin® , respectively. RESULTS: Both Novamin® or BiominF® showed less TF concentration than their label claims. BiominF® had more TF and TSF compared to Novamin® (p < 0.05). The BiominF® toothpaste presented higher micro-hardness values on remineralization. CONCLUSION: BiominF® toothpaste demonstrated more fluoride content and greater potential to promote remineralization of demineralized human enamel compared to Novamin® . Show more

Keywords: Bioactive glass, demineralization, enamel, fluoride, remineralization

DOI: 10.3233/BME-191069

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 487-496, 2019

Authors: Shim, Shinyong | Yun, Seunghyeon | Kim, Sunhyo | Choi, Gwang Jin | Baek, Changhoon | Jang, Jungwoo | Jung, Younginha | Sung, Jaehoon | Park, Jeong Hoan | Seo, Kangmoon | Seo, Jong-mo | Song, Yoon-Kyu | Kim, Sung June

Article Type: Research Article

Abstract: BACKGROUND: Animal learning based on brain stimulation is an application in a brain-computer interface. Especially for birds, such a stimulation system should be sufficiently light without interfering with movements of wings. OBJECTIVE: We proposed a fully-implantable system for wirelessly navigating a pigeon. In this paper, we report a handheld neural stimulation controller for this avian navigation guided by remote control. METHODS: The handheld controller employs ZigBee to control pigeon’s behaviors through brain stimulation. ZigBee can manipulate brain stimulation remotely while powered by batteries. Additionally, simple switches enable users to customize parameters of stimuli like a gamepad. …These handheld and user-friendly interfaces make it easy to use the controller while a pigeon flies in open areas. RESULTS: An electrode was inserted into a nucleus (formatio reticularis medialis mesencephalic) of a pigeon and connected to a stimulator fully-implanted in the pigeon’s back. Receiving signals sent from the controller, the stimulator supplied biphasic pulses with a duration of 0.080 ms and an amplitude of 0.400 mA to the nucleus. When the nucleus was stimulated, a 180-degree turning-left behavior of the pigeon was consistently observed. CONCLUSIONS: The feasibility of remote avian navigation using the controller was successfully verified. Show more

Keywords: Avian navigation, remote control, handheld controller, neural stimulation, brain-computer interface

DOI: 10.3233/BME-191070

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 497-507, 2019

Authors: Saito, Shuji | Hattori, Yusuke | Sakamoto, Tomoaki | Otsuka, Makoto

Article Type: Research Article

Abstract: BACKGROUND: Real-time monitoring is required for the pharmaceutical manufacturing process to produce high-quality pharmaceutical products. OBJECTIVE: Changes in the critical tableting process parameters of single-punch tableting machine due to variability in the moisture content of the raw powders were monitored by hybrid tableting pressure–time profiles. METHODS: After mixing of the raw powders, which consisted of theophylline, anhydrous lactose, potato starch and crystalline cellulose, they were stored at 0%, 45%, or 75% relative humidity (RH) for 24 h, respectively. Continuous tablet productions were carried out using the mixed powder samples at 10%, 45%, or 75% RH, respectively. …The critical process parameters, such as upper and lower puncture pressures, die wall pressures, and inter-punch distances were recoded with the tableting machine, and then, tablet hardness (H), weight (W) and disintegration time (DT) of the tablets were measured. RESULTS: Hybrid tableting pressure–time profiles were obtained from various critical process parameters, and calibration models to predict pharmaceutical properties were calculated based on the hybrid profiles using a partial-least-squares regression (PLSR) method. In addition, the consistency of the calibration models were verified by constructing robust calibration models. CONCLUSION: Informetrical analysis for tablets based on hybrid tableting pressure–time profiles could evaluate the change of tablet properties dependent on the moisture content in the raw powders during the tableting process. The changes of tableting properties and elasticity were caused by agglomeration of powder particles at moisture content. Show more

Keywords: Tableting compression, effect of moisture content, process analytical technology, hybrid tableting pressure–time profiles, tablet hardness, tablet disintegration time, partial-least-squares-regression

DOI: 10.3233/BME-191071

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 509-524, 2019

Authors: Lakzian, E. | Akbarzadeh, P.

Article Type: Research Article

Abstract: A numerical investigation of Newtonian/non-Newtonian unsteady pulsatile entry blood flow inside a 3D curved stenosed artery is presented. For considering the non-Newtonian effect (shear thinning or shear thickening behavior), the blood viscosity is characterized by the power-law model (Ostwald de Waele Equation). At the inlet of the artery, a realistic pulsatile waveform is utilized according to the experimental data reported by other researchers. This study belongs to the analysis of the curvature ratios, percentage and length ratio of stenosis, and blood thickening on hemodynamic characteristics of the flow. The results emphasize that the maximum wall shear stress happens near the …stenosis neck and as expected, by decreasing the stenosis length, the maximum value of wall shear stress increases. In addition, the results indicate that the shear thickening fluid shows a more stable velocity profile rather than the shear thinning fluid flow. Show more

Keywords: Pulsatile blood flow, curved stenosed artery, non-Newtonian power-law model, curvature ratios, stenosis length ratio

DOI: 10.3233/BME-191072

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 525-540, 2019

Authors: Robau-Porrua, Amanda | Pérez-Rodríguez, Yoan | Soris-Rodríguez, Laura M. | Pérez-Acosta, Osmel | González, Jesús E.

Article Type: Research Article

Abstract: This study investigated the effect of three different parameters of a dental implant on stress and strain values in the peri-implant bone by finite element analysis. In this work, the effect of diameter, length and elastic modulus on the biomechanical behavior of a new dental implant was simulated using the finite element method. A three-dimensional model of a mandible segment corresponding to the premolar region and twelve dental implant models were obtained. Loads in three directions were distributed on the surface of the coronal area of the dental implants. The dental implant models were obtained in the FreeCAD 0.16 software …and the simulations were made using the Abaqus/CAE software. In all cases, higher stress concentrations were obtained in the peri-implant cortical bone between 40.6 and 62.8 MPa, while the highest levels of strain were observed in the peri-implant trabecular bone between 0.002544 and 0.003873. In general, the highest von Mises equivalent stress values were observed in the peri-implant cortical bone. However, in this bone, both the maximum von Mises equivalent stress values and the von Mises strain are similar or inferior to those reported in different studies by finite element for other models of dental implants under immediate loading. Maximum von Mises strain values were observed in peri-implant trabecular bone. However, in this bone strains levels were obtained that maintain bone density or increase it. The effect of the three simulated variables (implant diameter, length, and elastic modulus) have a statistically significant influence on the von Mises equivalent stress and in von Mises strain values. Show more

Keywords: Dental implant, elastic modulus, finite element method, strain, stress

DOI: 10.3233/BME-191073

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 541-558, 2020

Authors: Kaga, Naoyuki | Akasaka, Tsukasa | Matsuura, Takashi | Yokoyama, Atsuro | Yoshida, Yasuhiro

Article Type: Research Article

Abstract: BACKGROUND: Surface nanostructures in titanium (Ti) oral implants are critical for rapid osseointegration. OBJECTIVE: The purpose of this study was to evaluate the growth of osteoblast-like (Saos-2) and epithelial-like (Ca9-22) cells on nanopatterned Ti films. METHODS: Ti films with 500 nm grooves and pillars were fabricated by nanoimprinting, and seeded with Saos-2 and Ca9-22 cells. Cell viability and morphology were assessed by cell proliferation assay and scanning electron microscopy, respectively. RESULTS: As assessed after 1 hour, proliferation of Saos-2 cells was most robust on grooved films than on pillared and smooth films, in this order. …These cells approximately doubled on grooved and pillared substrates in 24 hours and after 5 days, but not on smooth surfaces. In contrast, Ca9-22 cells favored smooth surfaces, followed by grooved and pillared films. Indeed, cells sparsely adhered to pillared films over 5 days of incubation (p < 0.05). CONCLUSIONS: The data show that Saos-2 and Ca9-22 cells respond differently to different nanostructures, and highlight the potential use of nanopatterns to promote bone regeneration or to prevent epithelial downgrowth at the implant-bone interface. Show more

Keywords: Saos-2, Ca9-22, grooved implant, pillared implant, titanium, nanopatterning, cell proliferation

DOI: 10.3233/BME-191074

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 5-6, pp. 559-567, 2020