Journal of Biomimetics, Biomaterials and Biomedical Engineering Vol. 69

Abstract: Tissue engineering provides a promising approach to addressing the global shortage of organ and tissue donors by developing biological substitutes that can restore or enhance tissue function. This study presents the development and characterization of PEG-PVA biodegradable hydrogels, synthesized through chemical crosslinking with varying concentrations of glutaraldehyde, for tissue engineering applications. Mechanical, thermal, and structural properties were systematically analyzed to determine the optimal formulation for different applications. Hydrogels synthesized with 0.10g and 0.15g of glutaraldehyde were selected for detailed evaluation. The hydrogel with 0.10g glutaraldehyde exhibited a tensile strength of 1200 MPa, a glass transition temperature (Tg) of ～50°C, and a swelling ratio of 7.65, demonstrating superior mechanical robustness and thermal stability for load-bearing applications such as bone and cartilage regeneration. In contrast, the hydrogel with 0.15g glutaraldehyde, with a tensile strength of 1000 MPa, a Tg of 45°C, and a swelling ratio of 4.49, showed greater flexibility and a denser microstructure, making it more suitable for soft tissue applications requiring controlled degradation. These results underscore the importance of tailoring crosslinking density to optimize hydrogel performance for specific biomedical applications. Future studies should explore the behavior of these hydrogels in biologically relevant environments, including enzymatic degradation and in vivo testing. With further development, PEG-PVA hydrogels could play a key role in regenerative medicine, offering customizable mechanical and degradation properties for diverse clinical applications.

Abstract: Catechins, naturally derived from green tea leaves, are potent antioxidants known for their anti-inflammatory, antimicrobial, anticancer, cardiovascular, and antidiabetic properties. In this study, green tea catechin was successfully encapsulated within a zeolitic imidazolate framework-8 (cate@ZIF-8) and further incorporated into a calcium alginate hydrogel to improve its stability and bioavailability. The system's encapsulation efficiency, structural properties, and release behavior were comprehensively analyzed. X-ray diffraction (XRD) confirmed that the crystalline structure of ZIF-8 remained intact after catechin encapsulation, while Fourier transform infrared spectroscopy (FT-IR) indicated specific interactions between catechin molecules and the ZIF-8 framework. Scanning electron microscopy (SEM) was employed to examine the morphology of the cate@ZIF-8 particles within the alginate hydrogel matrix. Catechin release studies under different pH conditions demonstrated a controlled release profile, especially in acidic environments. These findings underscore the potential of alginate-embedded cate@ZIF-8 hydrogels as an effective platform for sustained catechin delivery in therapeutic applications.

Abstract: “Gbogbonise” Polyherb (GP) is one of the traditional medicines used in Nigeria to cure various ailments as professed by Nigerian folks. However, no scientific work, including laboratory-proof-of-concept experiment, has been documented in the literature regarding total phenolic content of extract recovery from GP. Therefore, this study reports High-Performance-Liquid-Chromatography (HPLC) finger-profiling, process modelling, scale-up process simulation and manufacturing cost of phenolic extract production from GP. The poly-herbal extraction experiment and analyses were performed using Response Surface Methodology (RSM) at extraction time (2.79-4.21hours), extraction temperature (33.79-76.21°C), and solid-liquid ratio (0.007929- 0.018355 g/ml) with yield, Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Antioxidant Activity (AA) as dependent variables. RSM models compared with the developed Adaptive Neuro-Fuzzy Inference System (ANFIS) models in Matlab software. ASPEN software was used for process simulation and cost of manufacturing. RSM and ANFIS models for predicting the extraction responses showed coefficients of determination (R²) of 0.99152 (RSM) and 0.999 (ANFIS) for yield, 0.981766 (RSM) and 0.9999 (ANFIS) for TFC, 0.986031 (RSM) and 0.999 (ANFIS) for AA, 0.842463 (RSM) and 0.999 (ANFIS) for TPC. HPLC results showed presence of betulinic acid (0.028 µg/g.dw), gallic acid (0.034 µg/g.dw), caffeic acid (0.051 µg/g.dw), erulic (0.0826 µg/g.dw) and ellagic acid (0.064 µg/g.dw) in the extract. The scale-up simulation results gave batch size (3.99 kg/batch) and number of batches (1,751 batches) for the annual production target (7,000 kg); while 339.1 USD/kg was obtained as product cost of manufacturing. The technical-economic-parameters obtained from this study are precursors to poly-herbal extraction plant design construction.

Abstract: This work employed biocompatible and antibacterial materials to coat a commercial pure titanium (Cp-Ti) substrate for orthopedic implants applications. Three sorts of coatings were utilized using the electrophoretic deposition (EPD) technique: collagen, yttria-partially stabilized zirconia (YPSZ), and a composite of collagen/YPSZ (denoted as CZ). Surface microstructure before and after coating was examined using scanning electron microscopy (SEM). Results presented that homogeneous and uniform coating layers were successfully deposited on all samples’ surface. A relatively low pores density was observed in the surface microstructure of composite-coated sample (CZ). The chemical composition of coatings was evaluated via energy-dispersive X-ray spectroscopy (EDX), confirming that all spectra matched those of standard materials, with no signs of contaminations. Adhesion strength of coatings was evaluated using a tape test. CZ-coated sample exhibited the smallest removal area at 11.81%, demonstrating superior adhesion strength. Wettability tests were conducted on the Cp-Ti substrate before and after coating. The results showed that the application of the collagen/YPSZ composite coatings significantly enhanced surface wettability by diminishing the contact angle, making the samples surface more hydrophilic. Post-deposition antibacterial activity was estimated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) pathogenic bacteria. All coated samples demonstrated improved antibacterial performance compared to the uncoated Cp-Ti, with the CZ-coated sample exhibiting the largest inhibition zone of 32 mm and 37 mm against both E. coli and S.aureus bacteria respectively.

Abstract: Unidirectional composite structures are increasingly utilized in structural design due to their excellent compressive strength. The present study provides an evaluation of the fatigue performance of materials commonly used in hip prostheses such as Ti-6Al-4V, Co-Cr alloys, UHMWPE, and a silicon matrix composite reinforced with unidirectional carbon fibers in three different fiber volume fractions. Using Bergmann's loading factors, stress calculations were conducted for an 80 kg individual. The Goodman criterion and S-N curves were applied to assess fatigue life. Results show the unidirectional composite with 70% fiber volume fraction has the highest fatigue resistance, making it most suitable for high-stress applications. In contrast, Ti-6Al-4V and Co-Cr alloys showed moderate performance, while UHMWPE was found to be suitable for low-stress applications. These results underscore the necessity of selecting the ideal composition to maximize durability and fatigue resistance in essential mechanical applications. This finding suggests a promising alternative for improving the design and performance of femoral neck implants. This suggests a promising alternative for improving the design and performance of femoral neck implants.

Abstract: This paper explores the application of Abrasive Flow Machining (AFM) as an innovative technique to enhance the finishing process of fracture plate implants. The study aims to deepen the understanding of AFM machining dynamics, optimize process parameters, and assess the effectiveness of AFM through advanced modeling and simulation. The major contributions include detailed simulation frameworks and validation through practical applications on SS316L implants, highlighting AFM’s effectiveness in achieving high-precision finishes essential for biomedical applications.

Abstract: The nervous system plays a vital role in maintaining overall health. Recent nanotechnology advances enable precise control of neuronal activity using metal nanoparticles, which convert external stimuli into electrical, mechanical, or thermal signals to modulate excitability. This review explores three primary neuromodulation strategies (e.g., electrical, magnetic, and optothermal stimulation) where magnetic methods create magnetothermal and magnetomechanical effects, optothermal techniques use surface plasmon resonance to activate heat-sensitive ion channels, and electrical approaches alter membrane potential via the high conductivity of nanoparticles. These methods hold significant potential for treating neurological disorders such as chronic pain, epilepsy, and Parkinson’s disease, though challenges like biocompatibility, metal ion toxicity, and efficient nanoparticle clearance must be addressed. To overcome these barriers, ongoing research focuses on coating nanoparticles with protective layers, modifying their surfaces to improve safety, and designing them in ways that help the body clear them more easily. Incorporating targeted delivery systems, biodegradable materials, and stimuli-responsive coatings into nanoparticle design could further improve safety, enhance personalization, and enable precise, reversible control of brain circuits, opening new avenues for treating neurological conditions.

Abstract: Microfluidic systems are transforming chemical and biological research by enabling precise control and analysis of fluids on a microscale. This study presents the design and computational simulation of a microfluidic system for the in vitro maintenance of pancreatic islets, critical endocrine structures of the pancreas involved in glucose regulation. Three chamber geometries-ellipsoidal, hexagonal, and rectangular-were proposed, each combined with three irrigation patterns: periphery-to-center, pole-to-pole, and a hybrid model. A total of 18 design configurations were analyzed. The irrigation channels, with a diameter of 30 µm and a bifurcation angle of 43°, were designed to mimic physiological conditions, facilitating efficient nutrient exchange. Computational fluid dynamics (CFD) simulations using ANSYS Fluent demonstrated that most designs achieved a flow rate of 14.56 nL/s, closely matching theoretical values and meeting the physiological requirements of islets. Among the proposed models, the hexagonal chamber with peripheral irrigation (single-cell configuration) and the ellipsoidal chamber with periphery-to-center irrigation (dual-cell configuration) showed optimal performance, with stable laminar flow and minimal pressure drop. These results highlight the potential of this microfluidic system as an innovative tool for diabetes research, enabling the study of islet biology, drug testing, and disease modeling under controlled conditions. Future work will focus on experimental validation and optimization of the proposed designs.

Abstract: Over the past 30 years, the medical sector has increasingly used 3D printing to offer personalized and fast solutions for patients. The lack of biocompatible and biomechanically efficient polymers, hydrogels, biomaterials and bioinks is a major barrier to the widespread adoption of 3D printing in biomedical manufacturing. For this aim, a variety of synthetic and biological polymers can be employed. Combining biological and synthetic materials can enhance their physicochemical and biological qualities, as each has advantages and downsides. This paper discusses the types of synthetic, natural and hybrid materials that can be used for medical purpose 3D printing.

Abstract: This paper presents the outcomes of the project for applications of 3D printing technology in healthcare. The anatomical 3D modelling was carried out, and the 3D digital anatomical models were developed from the CT scan medical images, through medical images acquisition, segmentation, preparation, 3D printing and post-processing processes. Furthermore, the 3D digital models were converted into 3D physical models through Fused Deposition Modeling (FDM) and Stereolithography (SLA) 3D printing technologies. The segmentation and preparation processes were performed by employing 3D Slicer V5.8.0 and Meshmixer Autodesk V3.5software, respectively. The 3D digital models were prepared for printing using GrabCAD print V1.88 and Preform V3.36.0 software for FDM and SLA 3D printing technologies, respectively. During the models’ printing preparations, the printing parameters’ settings were performed, and the G-Codes were generated, which then sent to the printers. The printed models are to be used for training and research at University of Namibia. In addition to manual segmentation, AI-based segmentation which is an automated segmentation was also performed, and the models generated from the two segmentation methods were compared.