Journal of Biomimetics, Biomaterials and Biomedical Engineering Vol. 71

Abstract: This study focuses on the development of magnesium-zinc (Mg-Zn) matrix alloys enriched with rare earth elements (RE), aiming to evaluate both their structural characteristics and in vitro biological responses. The designed alloys incorporated varying amounts of Zn, Nd, Ce, Gd, Zr, and Ca. Two specific EZ43 alloy compositions were synthesized using an induction-heated furnace under a protective gas atmosphere, differing in their Nd-to-Ce weight ratios (1:2 and 2:1). Following casting, the alloys were homogenized at 400 °C for 24 hours to eliminate dendritic structures and minimize elemental segregation. X-ray fluorescence (XRF) was employed to assess the chemical compositions, while scanning electron microscopy (SEM) provided detailed insight into microstructural features and potential intermetallic phases. Biocompatibility was evaluated through cytotoxicity and genotoxicity tests, conducted in accordance with internationally recognized standards to ensure reliability. Results indicated no genotoxic effects and demonstrated high cell viability up to 142% particularly in Nd-enriched samples. Statistical analysis revealed significant differences in biological behavior between the Nd-rich and Ce-rich alloys, with Nd contributing positively to cellular responses. These findings emphasize the importance of RE composition in influencing biocompatibility and suggest that Nd-enriched Mg-Zn alloys hold strong promise for biomedical applications requiring both structural integrity and favorable biological interaction.

Abstract: Acesulfame, with its oxathiazinone ring and potential coordination sites, acts as a ligand in forming complexes with various metal ions. According to this point, this study includes the synthesis and characterization of novel zinc(II) complexes incorporating acesulfame (acs) with various thione-containing ligands: 2-mercaptobenzothiazole (bztSH), 2-mercapto-benzimidazole (bizmSH), 2-mercaptobenzoxazole (bzoxSH), 1,3-dihydro-2H-imidazole-2-thione (imSH), and 5-(p-tolyl)oxazole-2(3H)-thione (mphtSH). The synthesized complexes, identified as [Zn(acs)₂(bztSH)₂] (1), [Zn(acs)₂(bizmSH)₂] (2), [Zn(acs)₂(bzoxSH)]₂ (3), [Zn(acs)₂(imSH)₂] (4), and [Zn(mphtS)₂] (5), were structurally elucidated using CHN analysis, nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and molar conductivity measurements. Results indicate that the acesulfame ligand coordinates as a monodentate ligand via its nitrogen atom in complexes (1-4). In complex (1), the bztSH ligand coordinates in a monodentate mode through the nitrogen atom of its heterocyclic ring. Conversely, in complexes (2) and (4), bizmSH and imSH coordinate as monodentate ligands via their sulfur atoms. Complex (3) is a binuclear species where bzoxSH coordinates as a bidentate ligand through both its nitrogen and sulfur atoms. Notably, in complex (5) , the mphtSH ligand displaces acesulfame, coordinating as a bidentate ligand through its nitrogen and sulfur atoms. Furthermore, the antibacterial activities of these complexes were evaluated against Staphylococcus aureus and Escherichia coli. Complexes (4) and (1) demonstrated the highest efficacy. The [Zn(acs)₂(imSH)₂] (4) exhibited inhibition efficiencies of 74% and 79% with inhibition zones of 20 mm and 23 mm against S. aureus and E. coli, respectively. Similarly, [Zn(acs)₂(bztSH)₂] (1) showed inhibition efficiencies of 70% and 76% with inhibition zones of 19 mm and 22 mm against S. aureus and E. coli, respectively.

Abstract: The green synthesis of silver nanoparticles (AgNPs) using plant extracts has gained significant attention due to its eco-friendly, cost-effective, and non-toxic approach. This study reports the synthesis of AgNPs using Telfairia occidentalis (fluted pumpkin) leaf extract as a reducing and stabilizing agent. The phytochemical screening of Telfairia occidentalis showed that saponin, tannin, flavonoid, steroid and terpenoid are present in the sample. The synthesized AgNPs were characterized using UV-Vis spectroscopy, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) was used to characterize the developed composites. Furthermore, the bactericidal efficiency of AgNPs-doped epoxy composites was evaluated against Escherichia coli and Staphylococcus aureus to assess their antimicrobial properties. It was observed that the inhibition zone increases with the increase in AgNPs in the composites. The results indicate that the synthesized AgNPs exhibit potent antimicrobial activity, making them suitable for biomedical and industrial applications. Keywords: Green synthesis, Silver nanoparticles, Telfairia occidentalis, Epoxy composite, Antibacterial properties.

Abstract: The first polycaprolactone material experimental and clinical studies were published in 1960-1970, which proved its biocompatibility and determined the absence of toxic properties. At the same time it did not receive widespread use due to insufficient rigidity and strength compared to metal implants. For a long time, relatively solid materials were used to treat injuries to the musculoskeletal system segments. The progress in materials science, development of new sterilization methods has again changed the attitude towards biomaterial implants and has attracted the attention of clinicians. In this regard, the development of predictive modeling methods to determine effective mechanical properties and optimal geometric structure of porous biomedical materials is an important task. Modeling the internal architecture of porous materials and their properties by the finite element method using computed tomography data is as close as possible to the real picture, but it is quite laborious to apply directly to large-sized scaffolds. Properties of such materials largely depend on the technology of their manufacture and processing, the geometric dimensions and cell shape. In this regard, the development and improvement of analytical methods for assessing properties of cellular structures remains relevant. The aim of this study is determining polycaprolactone effective elastic modulus based on modified Gibson-Ashby open-cell model as an implant material and osteochondral defects treatment. A practical analytical method for estimating the elastic modulus of a cellular material regardless of the scaffold volume and shape is proposed. Calculations are performed for polycaprolactone produced using selective laser sintering technology. A comparative analysis of the obtained results with experimental studies of other authors is carried out. The results can be used for evaluation analysis and calculations of medical devices strength and stiffness made of porous polycaprolactone for the bone defects treatment.

Abstract: This study investigates the mechanical performance of hybrid epoxy composites reinforced with natural (jute) and synthetic (carbon and glass) fibers. Two hybrid laminates were fabricated: unidirectional carbon–woven glass (2UCF–2WGF/EPOXY) and unidirectional carbon–woven jute (2UCF–2WJF/EPOXY). Flexural tests revealed that the carbon–jute composite exhibited higher stiffness with a modulus of 69.12 GPa compared to 19.74 GPa for the carbon–glass system. Conversely, the carbon–glass composite demonstrated greater tensile modulus (5.07 GPa vs. 2.23 GPa) and hardness (37.55 HV vs. 20.37 HV), indicating better load transfer and surface resistance. These differences arise from fiber–matrix adhesion, fracture morphology, and energy absorption mechanisms observed in SEM analyses. The results emphasize that selecting suitable fiber combinations allows control over stiffness and strength balance. Such natural–synthetic hybrid composites present an environmentally sustainable approach for advanced structural and biomedical applications requiring optimized mechanical and functional performance.

Abstract: Bone regeneration is a complex physiological process that helps in healing of fractured bone and maintaining skeletal integrity. Chitosan and Hydroxyapatite (HAp) are bio-materials that enhance bone regeneration. The synergistic influence draws the attention of researchers to the use of Chitosan-HAp composite for bone regeneration. However, there is a need to explore more on material properties, fabrication techniques, biological mechanisms and challenges in bone regeneration applications. The biocompatibility, osteoconductivity, and synergistic effects of chitosan and HAp play a vivid role in bone regeneration. This paper explores recent advancements in the development of scaffolds that mimic the extracellular matrix and promote effective bone healing, fabrication techniques such as freeze-drying, 3D printing and nanotechnology, it also explores limitations regarding mechanical properties, scalability, and regulatory hurdles despite the promising attributes of chitosan-HAp composites. The findings show that the use of machine-learning (ML) in forecasting design output and preclinical applications can improve the composite development for effective bone regeneration. Therefore, future research directions should focus on alternative biopolymers, and employ ML techniques to enhance scaffold design and functionality to optimise material properties.

Abstract: The thickness of the residual limb’s soft tissue plays a crucial role in determining the mechanical behavior and stress distribution at the stump–prosthesis interface. Using finite element analysis (FEA), this study investigates the biomechanical effects of different soft tissue thicknesses (30 mm, 50 mm, and 70 mm) on stress distribution. A patient-specific finite element model of the residual limb was developed to simulate realistic anatomical and mechanical conditions. To replicate physiological loading, a static vertical load of 350 N was applied, and the interface between the residual limb and the prosthetic liner was modeled using appropriate contact mechanics. The results revealed that reducing the soft tissue thickness to 3 cm produced higher Von Mises stress concentrations (0.115 MPa) and contact pressure (0.0697 MPa), which may increase discomfort and the risk of tissue damage. Conversely, increasing the thickness to 70 mm reduced stress values (0.016 MPa) and contact pressure (0.0312 MPa) but led to excessive deformations (6.277 mm) that could compromise prosthetic stability. An optimal soft tissue thickness of 5 cm was identified, where Von Mises stress and contact pressure remained at moderate levels, offering a balance between stress distribution and mechanical stability. These findings provide valuable guidance for optimizing prosthetic socket design, as maintaining appropriate soft tissue thickness can enhance comfort, reduce pressure-related injuries, and improve the overall functionality of lower-limb prostheses.

Abstract: Existing technologies for evaluating oxygen delivery efficiency and blood perfusion are limited to complex equipment, whilst accurate diagnosis of compromised microvascular circulation relies on domain-specific mathematical models. Although an ultrasonic flaw detector can be an economical alternative, developing an optimal prediction model for a specific imaging task requires manual fine-tuning and customization. This study aims to introduce an optimization-empowered hybrid spatial-temporal network design framework for rapid and nondestructive blood perfusion status classification using a simple photoacoustic system. To examine this framework, this paper conducted experiments on seventeen volunteers. External intervention was performed to modify the perfusion of the chosen body part; the oxygenation-related photoacoustic (PA) signal was recorded after the chosen site was illuminated with temporally modulated light beams of wavelengths 500 nm and 550 nm. Meanwhile, the network design and training processes used the Particle Swarm Optimization (PSO) method for efficient model convergence on the small PA dataset. Experimental results comparing the designed hybrid model against two benchmark networks trained for the same microcirculatory perfusion disturbance problem confirmed the competitiveness of the proposed model with a superior mean classification accuracy, specificity, precision, and F1 score of 80.8 %, 92.3 %, 89.9 %, and 79.4 %, respectively. This is further supported by the result of the Receiver operating characteristic (ROC) curve, showing a good area under the curve (AUC) of 0.91. These findings offered evidence of hemodynamic fluctuations at the microcirculatory level to compensate for low oxygen under ischemic-hypoxic conditions. This study concluded that the future of this system includes its industrial and medical applications for nondestructive inspections, home use, or bedside microcirculation monitoring to optimize wound and postoperative outcomes.

Abstract: Biosensors have become indispensable tools in modern diagnostics, offering high sensitivity and specificity for the detection of biological and chemical substances. Among various biosensing techniques, optical resonator-based biosensors provide a promising alternative because of their enhanced performance metrics, including high-quality factors and precise wavelength shift detection. This study presents a simulation-based investigation focused on the parametric optimization of optical ring resonator structures for biomedical applications. Although experimental validation with biomolecules has not yet been conducted, the simulated designs demonstrated high quality factors and sensitivity to refractive index changes. These results suggest the potential for integration into compact and efficient biosensing platforms in future implementation in biomedical diagnostics.

Abstract: Training in laparoscopic surgery poses technical challenges due to the minimally invasive nature of the procedure and the need to develop specific psychomotor skills such as bimanual coordination, depth perception, and instrument precision. Although commercial simulators exist, their high-cost limits accessibility in many training environments. To address this need, a modular simulator prototype was developed for the training of basic laparoscopic skills, integrating an automated evaluation system capable of recording objective performance metrics without requiring direct supervision. The development process included the creation of physical training modules using CAD modeling, additive manufacturing with PLA and TPU, silicone-based anatomical elements, and a control unit based on the ESP32-WROOM for real-time data acquisition and processing. The resulting simulator, composed of three functional modules, demonstrated anatomical and technical fidelity and was capable of processing and classifying user performance based on execution time and precision. The evaluation system was structured using adapted criteria from the FLS, OSATS, and GOALS standards, providing methodological robustness. Functional testing confirmed the system’s operability, data integrity, and responsiveness under simulated conditions. The simulator enables objective, formative, and autonomous assessment of psychomotor performance and presents strong potential for implementation in preclinical surgical training programs.