Bio-Medical Materials and Engineering - Volume 29, issue 6

Authors: Luo, Yue | Li, Donghai | Zhao, Jinhai | Yang, Zhouyuan | Kang, PengDe

Article Type: Research Article

Abstract: Hydroxyapatite (HA) possesses similar mineral components to bone and possesses good physicochemical properties. Even though pure HA scaffold is brittle, it is insufficient in promoting vascularization and osteoinductivity. This study was conducted to assess whether lithium (Li) incorporated into HA could improve the scaffolds’ inherent shortcomings. In the experiments, Li-hydroxyapatite scaffolds’ mechanical strength, biocompatibility, and biodegradability were researched primarily. In vivo studies, the Li hydroxyapatite scaffolds were implanted into an animal model to repair the bone defects. Meanwhile, we also evaluated the expression of angiogenic and osteogenic factors. For comparison, autologous bone, hydroxyapatite, and blank control groups were designed. …According to the results, Li incorporated with hydroxyapatite did not significantly change the scaffold’s degradation velocity, but it obtained higher compress mechanical strength. After Li was doped, bone regeneration was further enhanced but the angiogenic effect was not improved significantly. The in vivo study, Li-HA scaffolds improved new bone formation with GSK-3𝛽 decreased and 𝛽-catenin increased. In conclusion, doped Li into hydroxyapatite was an alternative strategy for improving hydroxyapatite’s mechanical property and promoting the osteogenesis potential. This method is highly recommended for clinical application based on this study alone. Show more

Keywords: Scaffold, hydroxyapatite, lithium, bone defect repair

DOI: 10.3233/BME-181018

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 699-721, 2018

Authors: Kalayarasan, M. | Shankar, S. | Manikandan, M. | Adithan, K.

Article Type: Research Article

Abstract: The selection of best material pair in the hip prosthetics design for improved performance and life relies on the estimation of hip joint contact stresses and contact pressure distribution during various dynamic loading cycles: Climbing Upstairs, Climbing downstairs and Knee bending. The maximum Von Mises stress, contact pressure and deformation are considered factors in selecting the material pair in this current study. This is done by analysis of a three-dimensional finite element model of the acetabular component during the different dynamics cycles using ANSYS® . The different material combination of bearing couples considered for this analysis are metal in contact …with plastic, metal on metal, metal on ceramic, ceramic on plastic, ceramic on metal and ceramic on ceramic. The numerical results were validated by comparing them with the FEA results of Hai-Bo Jiang et al. for the existing material combinations and a high correlation of 92% was observed. We found that the Alumina femoral head paired with ultra-high molecular weight polyethylene (UHMWPE) cup reduces the maximum Von Mises stress and maximum contact pressure developed at the interface amongst other material pairs. Show more

Keywords: Hip prosthesis, materials, finite element method, dynamic loading cycle, bearing couples

DOI: 10.3233/BME-181019

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 723-737, 2018

Authors: Ramu, M. | Ananthasubramanian, M. | Kumaresan, T. | Gandhinathan, R. | Jothi, Sathiskumar

Article Type: Research Article

Abstract: Numerous biomaterials are used to fabricate bone scaffolds to repair the bones subjected to trauma. The scaffolds are fabricated with interconnected pores with 40–70% porosity to facilitate the entry of the cells that ensures rapid bone formation. In addition, the interconnected pores also serve as a channel for the exchange of nutrients and waste materials. Rapid prototyping techniques use the CAD model of the scaffold to be fabricated which facilitates fabrication of components with complex architecture easily. This research deals with the design, fabrication and analysis of porous scaffold models with different configurations. Apart from the conventional pore geometry like …cubical, spherical shaped pores, their shifted arrangements were also considered for this study. The minimum pore size used for the study is 400 μm and the porosity ranges from 40–70%. Based on the results of finite element analysis, the best scaffold configuration is identified and was fabricated with different build orientation using Selective Laser Sintering (SLS) process with different mix of Polyamide and Hydroxyapatite. The fabricated test specimens were evaluated based on mechanical tests for its strength and in vitro studies with human osteosarcoma cell line for cell growth studies. The mechanical tests witnesses good physical properties than the earlier reported research. The suitability of the porous scaffolds for bone repair is also ensured using finite element analysis of a human femur bone under various physical activities. Show more

Keywords: Femur bone, Polyamide (PA), Hydroxyapatite (HA), Selective Laser Sintering (SLS), finite element analysis (FEA), porous scaffold

DOI: 10.3233/BME-181020

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 739-755, 2018

Authors: Wang, Bo | Wu, Yong | Yu, Hongbo | Jiang, Lingyong | Fang, Bing | Guo, Qiuman

Article Type: Research Article

Abstract: INTRODUCTION: Exogenous Nel-like molecule type 1 (NELL1) represents a potentially attractive clinical treatment option in the orthodontic and other settings because of its osteoinductive and vasculogenic properties. AIMS: To explore effects of NELL1on corticotomy-assisted tooth movement and osteogenesis in a rat model. METHODS: Thirty Sprague-Dawley rats were divided into 6 groups: Control, Sham, Tooth movement only, Vehicle, NELL1-LD (low-dose NELL), NELL1-HD (high-dose NELL). Human recombinant NELL1 protein was applied locally (Groups NELL1-LD and NELL1-HD) into buccal mucosa region of left first upper molar. Then the distance and velocity of tooth movement was measured, animals at 6 …weeks after surgery were sacrificed, and was followed by computed tomography and histochemical staining. RESULTS: Both NELL1 groups had higher bone mineral density, greater tooth movement distance and velocity in comparison to the Vehicle group. Proximally and distally, periodontal ligament width was significantly increased in the NELL1-LD and NELL1-HD groups. Decortication enhances remodeling, however, rapid bone formation by high-dose NELL1 may affect bone absorption. CONCLUSION: Appropriate dose of NELL1 can be administrated to reduce the total time for tooth movement, and may shorten the treatment time in select populations. Show more

Keywords: Nel-like molecule type 1, corticotomy, tooth movement, osteogenesis, orthodontics, rat

DOI: 10.3233/BME-181021

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 757-771, 2018

Authors: Wu, I.-Ting | Chiang, Ting-Yi | Chen, Chun-Cheng | Chen, Yung-Chang | Ding, Shinn-Jyh

Article Type: Research Article

Abstract: BACKGROUND: To enhance calcium silicate cements (CSCs) towards a specific clinical application of endodontics and vertebroplasty, the addition of oxide dopants (Bi2 O3 , SrO, ZnO, ZrO2 ) as radiopacifiers allows for tailoring of material properties. OBJECTIVE: Effects of oxide dopants on the in vitro physicochemical properties and osetogenic activity of CSCs were investigated. METHODS: The setting time, compressive strength, radiopacity, and osteogenic ability of the cements were evaluated. The ability of cement samples to support MG63 attachment, proliferation, differentiation, and mineralization was assessed. RESULTS: The greater the oxide amount, the higher the …setting time and radiopacity were in the cement. The effect of the oxide dopants on radiopacity followed the order Bi2 O3 > ZrO2 > SrO > ZnO, which were greater than 3 mm of Al recommended by ISO 6876: 2001 standards. ZrO2 could reinforce compressive strength of the control cement, while ZnO remarkably reduced the strength. The adverse effect of Bi2 O3 and ZrO2 was found on cell number, alkaline phosphatase (ALP) activity and mineralization of MG63 cells. SrO supported cell attachment, proliferation and differentiation, and significantly increased cellular mineralization compared to the control. CONCLUSIONS: The 20 wt% SrO-containing CSCs may be applied to endodontic treatment and vertebroplasty surgery. Show more

Keywords: Calcium silicate, bone cement, radiopacifier, osterogenesis

DOI: 10.3233/BME-181022

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 773-785, 2018

Authors: Swapna, M.S. | Shinker, S.S. | Suresh, S. | Sankararaman, S.

Article Type: Research Article

Abstract: BACKGROUND: The limitations of the existing techniques for the early detection of dengue fever necessitate the development of a powerful optical technique. OBJECTIVE: The present work is a study of Raman spectral modifications of blood on dengue infection and thereby to develop a spectroscopic method for its early detection. The images of the samples are subjected to fractal analysis to find the variation of fractal dimensions on dengue infection. METHODS: Correlation of platelet counts of dengue infected blood with Raman spectrum modification and fractal dimension. The effect of lowering of blood platelet count due to dengue …infection is found to show some interesting changes in the spectrum. RESULTS: The full width at half maximum (FWHM) of the two bands in the region 950–1200 cm−1 increase with the decrease of blood platelet count. The increase in fractal dimension gives an indication of the decrease of platelet count and hence the dengue infection. CONCLUSIONS: Raman spectrum and fractal analysis can effectively be used as potential techniques for the early detection of dengue infection. Show more

Keywords: Raman spectroscopy, dengue fever, platelet, blood, fractals

DOI: 10.3233/BME-181023

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 787-797, 2018

Authors: Afnan, Michael Anis Mihdi | Saxena, Amulya Kumar

Article Type: Research Article

Abstract: BACKGROUND: There has been increased interest in the use of biomaterials that resorb completely leaving only the patient’s native tissue. Synthetic materials are advantageous for tissue repair because they are highly customisable. The infection rate of using resorbable natural materials in paediatric surgery has recently been outlined, but there has not yet been a review of the use of synthetic resorbable materials in paediatric surgery. OBJECTIVES: This systematic review analyses the risk of infection after implantation of fully resorbable synthetic biomaterials in paediatric cases. METHODS: The literature was searched from January 1970 to January 2018 (inclusive), …specifically searching for paediatric cases (0–18 years old), use of synthetic resorbable materials and infection. RESULTS: The infection rate in 3573 cases of synthetic resorbable material implantation was 1.1% (41 cases). A Chi-squared test for independence found infection rate to vary among materials. Of the many biomaterials identified in this review, the highest infection rates were seen in Suprathel’s use in burns injuries (12.1%). CONCLUSIONS: This review found a low infection rate in synthetic resorbable materials used in paediatric surgery, with particularly strong evidence for low infection risk in LactoSorb®  use. Show more

Keywords: Synthetic, pediatrics, infection, outcome, biomaterial

DOI: 10.3233/BME-181024

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 799-808, 2018

Authors: Al-Harbi, F.F. | Alkhalifah, Dalal H.M. | Elqahtani, Zainab M. | Ali, Fadel M. | Mohamed, Shaimaa A. | Abdelbacki, A.M.M.

Article Type: Research Article

Abstract: BACKGROUND: Escherichia coli (E. coli)  bacteria normally live in the intestines of people and animals. Most E. coli  are harmless and the treatment of the infection could be achieved by using antibiotics, however the effectiveness is still debatable and needs more investigation. OBJECTIVE: Researching the inhibition resonance frequency of square amplitude modulating waves (QAMW) that can inhibit the growth activity of E. coli and its ability to make division. METHODS: A range of different extremely low frequencies of square amplitude modulated waves (QAMW) from 0.1 to 1.0 Hz from two generators with a constant carrier frequency of …10 MHz, amplitude of 10 Vpp, modulating depth ± 2 Vpp and constant field strength 200 V/m were used to treat E. coli cells at 37 °C. RESULTS: The exposure of E. coli to 0.3 Hz QAMW for 90 min was the most inhibited frequency where the bacterial growth inhibited by 42.3%. Furthermore, a significant increase in antibiotic susceptibility to protein and cell wall inhibitors was investigated. Also, results of the chromosomal DNA sequences, dielectric relaxation and TEM indicated highly significant molecular and morphological changes after the exposure. CONCLUSIONS: We concluded that the exposure of E. coli to QAMW at the inhibiting frequency interfered with the bioelectric signals generated from the bacteria during the cell division and changed the cellular activity and DNA sequences, and these changes lead to a significant inhibition of the bacterial growth. This is a new promising technique that aids to avoid the repetitive use of antibiotics against the bacterial pathogens. Show more

Keywords: Escherichia coli infection, electromagnetic inhibition, resonance frequency, amplitude modulated waves

DOI: 10.3233/BME-181025

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 809-820, 2018

Authors: Razavi, Seyed Esmail | Jouybar, Mohammad

Article Type: Research Article

Abstract: Two common abnormalities in ureters include primary refluxing megaureter (PRM) and primary obstructed megaureter (POM). The aim of this study was to represent the numerical simulation of the urine flow at the end of the ureter with vesicoureteral reflux (VUR) and POM during peristalsis. Methodologically, the peristalsis in the ureter wall was created using Gaussian distribution. Fluid-structure interaction (FSI) was applied to simulate urine-elastic wall interactions; and governing equations were solved using the arbitrary Lagrangian-Eulerian method. Theories such as wall elasticity, Newtonian fluid, and incompressible Navier-Stokes equations were used. Velocity fields, viscous stresses and volumetric outflow rate profiles were obtained …through the simulation of the ureter with VUR and POM during peristalsis. In addition, the effect of urine viscosity on flow rate was investigated. When the bladder pressure increased, VUR occurred because of the ureterovesical junction (UVJ) dysfunction, leading to high stresses on the wall. In the POM, the outflow rate was ultimately zero, and stresses on the wall were severe in the obstructed section. Comparing the results demonstrated that the peristalsis leads to even further dilation of the prestenosis portion. It was also observed that the reflux occurs in the ureter with VUR when the bladder pressure is high. Additionally, the urine velocity during the peristalsis was higher than the non-peristaltic ureter. Show more

Keywords: Primary obstructed megaureter, ureterovesical reflux, Arbitrary Lagrangian-Eulerian, fluid-structure interaction, Navier-Stokes equations, moving mesh

DOI: 10.3233/BME-181026

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 821-837, 2018

Authors: Sakurai, Toshiyuki | Fujimori, Shunji | Hayashida, Mari | Hanada, Ryuzo | Akiyama, Junichi | Sakamoto, Choitsu

Article Type: Research Article

Abstract: BACKGROUND: There are no reports to prove the repeatability of gastric transit time (GTT) and small bowel transit time (SBTT) in capsule endoscopy (CE). OBJECTIVE: To clarify the repeatability and factors that affect GTT/SBTT in CE. METHODS: We analyzed the data of 150 healthy subjects from our previous randomized controlled trial that compared small intestinal injuries between two 14-day treatment groups: 1) celecoxib and 2) loxoprofen + lansoprazole. Correlation of GTT/SBTT with pre- and post-treatment CE was analyzed. In addition, the associations of pre-treatment CE SBTT with physical factors, post-treatment CE SBTT and the presence of …small intestinal mucosal injuries were analyzed. RESULTS: Analyses of 148 subjects pre-treatment CE and 146 subjects post-treatment CE were performed. There were no significant differences between mean GTT and SBTT before and after treatment. Both GTT (𝜌 = 0.22, p < 0.01) and SBTT (𝜌 = 0.47, p < 0.0001) showed positive correlations between pre- and post-treatment CE. In pre-treatment CE, physical factors and the presence of small intestinal mucosal injury had no associations with SBTT. CONCLUSIONS: Moderate correlation in SBTT and slight correlation in GTT were shown on repeated CE. The factors affecting SBTT were not clarified in this analysis. Show more

Keywords: Small bowel transit time, gastric transit time, repeatability, factors, capsule endoscopy

DOI: 10.3233/BME-181027

Citation: Bio-Medical Materials and Engineering, vol. 29, no. 6, pp. 839-848, 2018