Bio-Medical Materials and Engineering - Volume 35, issue 2

Authors: Zhang, Yutao | Du, Shu | Aiyiti, Wurikaixi | Teng, Yong | Jia, Ru | Jiang, Houfeng

Article Type: Research Article

Abstract: BACKGROUND: Intervertebral cages used in clinical applications were often general products with standard specifications, which were challenging to match with the cervical vertebra and prone to cause stress shielding and subsidence. OBJECTIVE: To design and fabricate customized tantalum (Ta) intervertebral fusion cages that meets the biomechanical requirements of the cervical segment. METHODS: The lattice intervertebral cages were customized designed and fabricated by the selective laser melting. The joint and muscle forces of the cervical segment under different movements were analyzed using reverse dynamics method. The stress characteristics of cage, plate, screws and vertebral endplate were analyzed …by finite element analysis. The fluid flow behaviors and permeability of three lattice structures were simulated by computational fluid dynamics. Compression tests were executed to investigate the biomechanical properties of the cages. RESULTS: Compared with the solid cages, the lattice-filled structures significantly reduced the stress of cages and anterior fixation system. In comparison to the octahedroid and quaddiametral lattice-filled cages, the bitriangle lattice-filled cage had a lower stress shielding rate, higher permeability, and superior subsidence resistance ability. CONCLUSION: The inverse dynamics simulation combined with finite element analysis is an effective method to investigate the biomechanical properties of the cervical vertebra during movements. Show more

Keywords: Biomechanical, cervical intervertebral cage, lattice structure, inverse dynamics simulation, finite element analysis

DOI: 10.3233/BME-230154

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 99-124, 2024

Authors: Zhang, Qiao | Fu, Huili | Zhang, Yunfei | Li, Liang | Yan, Guoping

Article Type: Research Article

Abstract: BACKGROUND: Polysaccharide hydrogel is one of the most important materials for the colon target drug release system. However, the degradation time of polysaccharide hydrogel is much longer than the retention time in the colon. The drugs are expelled from the body before being released. OBJECTIVE: In order to match the degradation of drug carriers and their retention time in the colon, a rapidly degradable konjac glucomannan (KGM) hydrogel was designed for colon target drug release. METHODS: A crosslinker containing azo bond, olsalazine, was used to prepare the rapidly degradable KGM hydrogel. The degradation and drug release …of the hydrogels with different crosslinking densities in the normal buffer and the human fecal medium were studied to evaluate the efficiency of colon drug release. RESULTS: More than 50% of the KGM hydrogel by weight was degraded and more than 60% of the 5-fluorouracil (5-Fu) was released within 48 h in 5% w/v human fecal medium. CONCLUSION: The drug was released more rapidly in a simulated colon environment than in a normal buffer. Furthermore, the drug release was controlled by the degradation of the hydrogel. The KGM hydrogel containing azo crosslinker has great potential for colon drug release. Show more

Keywords: Konjac glucomannan, hydrogel, azo bond, colon target, drug release

DOI: 10.3233/BME-230066

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 125-137, 2024

Authors: Nursin, Rohmat | Harun, Masitah Hayati | Mohamad, Dasmawati | Mohd Bakhori, Siti Khadijah | Mahmud, Shahrom

Article Type: Research Article

Abstract: BACKGROUND: Zinc oxide eugenol (ZOE) cement is a popular dental material due mainly to its analgesic, antibacterial and anti-inflammatory effects. The formulation of ZOE cement from nano particle-sized zinc oxide (ZnO) has the potential to increase these properties as well as reduce its adverse effects to the surrounding tissues. OBJECTIVE: This study evaluated the subcutaneous tissue response towards nano ZOE cements (ZOE-A and ZOE-B) in comparison to conventional ZOE (ZOE-K). METHODS: Test materials were implanted into 15 New Zealand white rabbits. Tissue samples were obtained after 7, 14, and 30 days (n = 5 per period) …for histopathological evaluation of inflammatory cell infiltrate, fibrous tissue condensation, and abscess formation. RESULTS: ZOE-A showed the lowest score for the variable macrophage and lymphocyte at day 7. Both ZOE-A and ZOE-B presented lower fibrous tissue condensation and abscess formation compared to conventional ZOE-K. By day 30, ZOE-A exhibited less lymphocytic and neutrophilic infiltrate compared to the other materials, while ZOE-B had the lowest score for macrophages. ZOE-K exerted higher inflammatory cell response at almost all of the experimental periods. All of the materials resulted in thin fiber condensation after 30 days. CONCLUSIONS: Rabbit tissue implanted with ZOE-A and ZOE-B showed better response compared to ZOE-K. Show more

Keywords: Tissue reaction, biocompatibility, nanomaterial, nano zinc oxide eugenol, in vivo

DOI: 10.3233/BME-230118

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 139-151, 2024

Authors: Linfeng, Lai | Xiaowei, Zhou | Xueqin, Chen | Xianfeng, Zhu

Article Type: Research Article

Abstract: BACKGROUND: It is imperative to design a suitable material for bone regeneration that emulates the microstructure and compositional framework of natural bone while mitigating the shortcomings of current repair materials. OBJECTIVE: The aim of the study is to synthesize a 3D aerogel scaffold composed of PLCL/gelatin electro-spun nanofiber loaded with Simvastatin and investigate its biocompatibility as well as its performance in cell proliferation and ossification differentiation. METHODS: PLCL/gelatin nanofibers were fabricated in coaxial electrospinning with simvastatin added. Fibers were fragmented, pipetted into molds, frozen, and dried. The morphology of fibers and contact angles in 4 groups …of PLCL, PLCL@S, 3D-PLCL, and 3D-PLCL@S was observed and compared. MC3T3-E1 cells were planted at the four materials to observe cell growth status, and ALP and ARS tests were conducted to compare the ossification of cells. RESULTS: TEM scanning showed the coaxial fiber of the inner PLCL and outer gelatin. The mean diameter of the PLCL/gelatin fibers is 561 ± 95 nm and 631 ± 103 nm after the drug loading. SEM showed the fibers in the 3D-PLCL@S group were more curled and loose with more space interlaced. The contact angle in this group was 27.1°, the smallest one. Drug release test demonstrated that simvastatin concentration in the 3D-PLCL@S could remain at a relatively high level compared to the control group. The cell proliferation test showed that MC3T3-EI cells could embed into the scaffold deeply and exhibit higher viability in the 3D-PLCL@S group than other groups. The ossification tests of ALP and ARS also inferred that the 3D-PLCL@S scaffold could offer a better osteogenic differentiation matrix. CONCLUSION: The PLCL/gelatin aerogel scaffold, when loaded with Simvastatin, demonstrates a more pronounced potential in enhancing osteoblast proliferation and osteogenic differentiation. We hypothesize that this scaffold could serve as a promising material for addressing bone defects. Show more

Keywords: 3D scaffold, aerogel, bone regeneration, simvastatin

DOI: 10.3233/BME-230068

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 153-163, 2024

Authors: Rongchang, Fu | Kun, Wang | Hui, Wu

Article Type: Research Article

Abstract: BACKGROUND: Sand therapy is a non-pharmacological physiotherapy method that uses the natural environment and resources of Xinjiang to treat through the heat transfer and magnetic effects of sand. OBJECTIVE: Employing the two-phase flow-Casson blood flow model, we investigate the mechanism of atherosclerosis prevention via sand therapy, offering a biomechanical theoretical rationale for the prevention of atherosclerosis through sand therapy via the prism of computational fluid dynamics (CFD). METHODS: Sand therapy experiments were conducted to obtain popliteal artery blood flow velocity, and blood was considered as a two-phase flow composed of plasma and red blood cells, and …CFD method was applied to analyze the hemodynamic effects of Casson’s blood viscosity model before and after sand therapy. RESULTS: (1) The blood flow velocity increased by 0.24 m/s and 0.04 m/s at peak systolic and diastolic phases, respectively, after sand therapy; the axial velocity of blood vessels increased by 28.56% after sand therapy. (2) The average red blood cell viscosity decreased by 0.00014 Pa ⋅ s after sand therapy. (3) The low wall shear stress increased by 1.09 Pa and the high wall shear stress reached 41.47 Pa after sand therapy. (4) The time-averaged wall shear stress, shear oscillation index and relative retention time were reduced after sand therapy. CONCLUSION: The increase of blood flow velocity after sand therapy can reduce the excessive deposition of cholesterol and other substances, the decrease of erythrocyte viscosity is beneficial to the migration of erythrocytes to the vascular center, the increase of low wall shear stress has a positive effect on the prevention of atherosclerosis, and the decrease of time-averaged wall shear stress, shear oscillation index and relative retention time can reduce the occurrence of thrombosis. Show more

Keywords: Sand therapy, two-phase flow, non-Newtonian fluid, atherosclerosis, erythrocytes

DOI: 10.3233/BME-230134

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 165-178, 2024

Authors: Hijikata, Hiroki | Mochizuki, Tomoharu | Maeda, Keisuku | Tanifuji, Osamu | Omori, Go | Yamamoto, Noriaki | Kawashima, Hiroyuki

Article Type: Research Article

Abstract: BACKGROUND: The postoperative varus/valgus stability assessment in stress X-rays has been established as an evaluation index. However, it is performed by the two-dimensional (2D) method rather than the three-dimensional (3D) method. OBJECTIVE: This study aimed to identify the precision and reproducibility of measuring varus/valgus stress X-rays three-dimensionally and to examine varus/valgus stability under anesthesia in imageless robotic assisted total knee arthroplasty (rTKA). METHODS: This prospective study analyzed 52 consecutive rTKAs (five males, 67 ± 5.3 years; 47 females, 74 ± 5.9 years). Postoperative varus/valgus stress X-rays in knee extension under anesthesia at manual maximum stress were …three-dimensionally assessed by 2D–3D image matching technique using the 3D bone and component models. Varus/valgus angle between components (VV angle) in no stress, valgus stress, varus stress, medial joint opening (MJO), and lateral joint opening (LJO) were evaluated, clarifying this method’s precision and reproducibility and valgus/varus stability. RESULTS: All parameters’ precision and reproducibility had <1° mean differences and high intra- and inter-class correlation coefficients. Bland–Altman plots showed no fixed and proportional bias. Non-stress VV angle, valgus VV angle, varus VV angle, MJO, and LJO were 3.6 ± 1.2°, 1.0 ± 1.4°, 7.1 ± 1.9°, 1.5 ± 1.0 mm, and 2.8 ± 2.7 mm, respectively. CONCLUSION: This prospective study demonstrated that (1) the three-dimensional measurement method provided sufficient precision and reproducibility, and (2) the rTKAs could achieve good postoperative varus/valgus stability with a small standard deviation. Show more

Keywords: Robotic total knee arthroplasty, stress X ray, 2D–3D image matching technique, precision, reproducibility

DOI: 10.3233/BME-230146

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 179-189, 2024

Authors: Samy, Prakas Gopal | Kanesan, Jeevan | Badruddin, Irfan Anjum | Kamangar, Sarfaraz | Ahammad, N. Ameer

Article Type: Research Article

Abstract: BACKGROUND: This study explores the dynamics of a mathematical model, utilizing ordinary differential equations (ODE), to depict the interplay between cancer cells and effector cells under chemotherapy. The stability of the equilibrium points in the model is analysed using the Jacobian matrix and eigenvalues. Additionally, bifurcation analysis is conducted to determine the optimal values for the control parameters. OBJECTIVE: To evaluate the performance of the model and control strategies, benchmarking simulations are performed using the PlatEMO platform. METHODS: The Pure Multi-objective Optimal Control Problem (PMOCP) and the Hybrid Multi-objective Optimal Control Problem (HMOCP) are two different …forms of optimal control problems that are solved using revolutionary metaheuristic optimisation algorithms. The utilization of the Hypervolume (HV) performance indicator allows for the comparison of various metaheuristic optimization algorithms in their efficacy for solving the PMOCP and HMOCP. RESULTS: Results indicate that the MOPSO algorithm excels in solving the HMOCP, with M-MOPSO outperforming for PMOCP in HV analysis. CONCLUSION: Despite not directly addressing immediate clinical concerns, these findings indicates that the stability shifts at critical thresholds may impact treatment efficacy. Show more

Keywords: Multi-objective optimal control problem, metaheuristic optimization algorithms, bifurcation analysis, stability analysis

DOI: 10.3233/BME-230149

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 191-204, 2024

Authors: Tang, Haibin | Wu, Dimeng | Liu, Zheng | Liu, Xi | Yuan, Heng | Jin, Xiaosong | Gao, Shuai | Chen, Gang

Article Type: Research Article

Abstract: BACKGROUND: Ureteral stents are commonly used in urology. However, complications such as encrustation and infection on the surface of the stent, and injury to the ureteral mucosa can occur after implantation, causing discomfort for patients. OBJECTIVE: We intend to confirm the biosafety of polyvinylpyrrolidone (PVP) hydrophilic coating and its lubrication properties for surface modification of ureteral stents to reduce friction and improve patient comfort. METHODS: Based on our previous studies, we have developed a PVP hydrophilic coating for surface modification of ureteral stents. We firstly investigated the cytotoxicity, intradermal irritation, delayed type hypersensitivity, and acute systemic …reactions of stent coating extracts. We further characterized the break strength, retention strength, and dynamic friction of the stent. RESULTS: The cell survival rate of all experimental groups was greater than 70%. No hypersensitivity reaction, systemic toxicity reaction, or obvious intradermal reaction were observed. The above results indicate that the test results of the modified stent meet the requirements of ISO 10993-5: 2009 (Cytotoxicity); ISO 10993-10:2021 (Sensitization and Irritation); ISO 10993-11:2017 (Acute Systemic Toxicity). After soaking in artificial urine for an extended period, there was no obvious change in its super-slip performance. CONCLUSION: Our results confirm the safety and lubrication characteristics of PVP hydrophilic coating for ureteral stent surface modification. The performance of this coating has the potential to reduce complications after stent implantation, thereby improving patient comfort, reducing medical burden, and has a good clinical application prospect. Show more

Keywords: Polyvinylpyrrolidone, hydrogel coating, ureteral stent, biocompatibility, ureteral stent modification

DOI: 10.3233/BME-230179

Citation: Bio-Medical Materials and Engineering, vol. 35, no. 2, pp. 205-217, 2024