Synthesis and evaluation of sodium alginate/borate glass–copper oxide nanocomposite films for dual antimicrobial and anti-osteosarcoma applications

Silver doped amorphous silica nanocomposite with dual antibacterial and osteoconductive properties for bone tissue regeneration

Bone tissue regeneration remains a major clinical challenge due to limitations of conventional grafts and synthetic scaffolds, including poor bioactivity and infection risks. To address these issues, silver-doped amorphous silica (Ag-aSiO2) nanocomposites were synthesized via a sol-gel method and systematically characterized. Structural and morphological features were confirmed using FTIR, XRD, SEM, and nitrogen adsorption analysis, revealing successful silver incorporation within the silica matrix while preserving its amorphous structure and high surface area. Antibacterial efficacy was evaluated against S. aureus using the disc diffusion assay, where 10 wt.% Ag-aSiO2 exhibited a clear inhibition zone (8.06 ± 0.04 mm), confirming strong antimicrobial activity absent in pure silica. Bioactivity studies in simulated body fluid (SBF) demonstrated robust hydroxyapatite (HA) formation, verified by SEM, EDX, and XRD, indicating excellent osteoconductive properties. The synergistic combination of amorphous silica’s high surface area and silver’s antibacterial action resulted in a multifunctional scaffold with dual benefits, which are effective infection control and enhanced mineralization for bone repair. These findings establish Ag-aSiO2 as a promising candidate for bone tissue engineering applications, integrating structural support, osteoconductivity, and antimicrobial protection. Future studies will focus on in vivo validation and clinical translation, with emphasis on optimizing silver release kinetics and long-term biocompatibility. KEY WORDS: Silver, Silica, Nanomaterials, Tissue engineering, Antimicrobial Bull. Chem. Soc. Ethiop. 2026, 40(11), 2473-2487                                         DOI: https://dx.doi.org/10.4314/bcse.v40i11.14

Development of a chitosan/polyethylene oxide/ginger nanocomposite: structural characterization and antibacterial performance

The development of bio-based antibacterial materials using natural additives is a crucial strategy for reducing reliance on hazardous synthetic chemicals. This study investigated the effect of incorporating ginger nanoparticles (GNPs) at varying concentrations (1, 2, 3, and 4 mL) into a chitosan/polyethylene oxide (PEO) blend to enhance its antibacterial properties. XRD analysis revealed that hydrogen bonding between chitosan and PEO produced a broad peak at 23.60°. The addition of the GNPs intensified this peak and introduced a sharper feature at 19.00°, confirming the successful interaction between the nanoparticles and the polymer matrix. FTIR spectroscopy showed new C–O–C vibrational bands at 1107 cm−1 upon blending, with further spectral changes observed after GNP addition, indicating the formation or disappearance of specific functional groups. The incorporation of the GNPs was demonstrated by a new absorption peak at 235 nm, and the semi-crystalline nature of the nanocomposite was confirmed by optical analysis. TEM revealed that the GNPs had diameters of 36.6 ± 13.8 nm, while zeta potential analysis at 25 °C recorded count rates of 106.8, 71.90, and 83.50 kcps for three distinct particle bands, and the mean was −19.33 mV, with a zeta potential deviation of 14.0 mV. The value of the zeta potential indicated the moderate stability of the GNPs. SEM demonstrated that increasing the GNP concentration led to larger, aggregated particle morphologies, with complete coalescence at the highest concentration. The chitosan/PEO blend exhibited higher thermal stability than pure chitosan, while the final polymer nanocomposite showed reduced residue levels at elevated temperatures. Antibacterial testing against Gram-positive (Enterococcus and Staphylococcus aureus) and Gram-negative (Escherichia coli and Klebsiella) bacteria demonstrated that the GNP-loaded nanocomposite exhibited enhanced antimicrobial activity compared with the pure polymer blend. For Gram-negative bacteria, the activity was small or negligible. These results position the chitosan/PEO/GNP nanocomposite as a promising bio-based material for antibacterial applications.

pH-Driven Structural Optimization of Hydroxyapatite/Alginate Composites for Sustained Clindamycin Release and Antibacterial Applications

The bamboo shell-derived HAp/Alg composite produced at pH 10 was a potential candidate for localized antibacterial drug delivery systems in biomedical applications and carried clindamycin efficiently carried on the composite matrix and released in a sustained manner.

Structural and biological evaluation of Ce and Fe doped hydroxyapatite reinforced PLA films for futuristic osteoregenerative applications.

Bioactive strength is crucial for load-bearing biomaterials. Although hydroxyapatite is highly biocompatible, it has brittleness and a lack of dual-ion substitution in polymeric scaffold studies. In this work, Ce/Fe doped HAP was synthesized by chemical precipitation and solvent cast onto PLA films. Phase-pure HAP with no secondary phases and a crystallite size decrease from 2.58-0.85 nm following doping was confirmed by XRD. Its structural integrity was confirmed by FTIR, which showed the distinctive phosphate and hydroxyl bands 550-627, 964.7, 1026, 3441 and 650 cm-1. While EDAX confirmed the distribution of Ca, P, Ce and Fe with Ca/P ratios between 1.64 and 1.67. SEM showed homogeneous morphology. Nanorod structures measuring roughly 50-100 nm in length and 15-20 nm in width were revealed by TEM investigation. Enhanced surface reactivity was indicated by a rise in BET surface area from 89.17-105.82 m2/g and pore-volume from 0.411-0.499 cm3/g. Rapid apatite-nucleation and thick Ca/P-rich layer development were encouraged by in vitro bioactivity in SBF. Because enhanced dispersion stability and decreased particle agglomeration promote cellular interaction and lessen harmful effects, DLS analysis revealed nanosized with stable zeta potential, which correlates with the reported MG-63 cell viability reaching 84%. Excellent hemocompatibility was demonstrated by the fabricated dual ion doped HAP/PLA composite. Microhardness improved by almost 85%, rising from 73 HV to 135 HV. Ce/Fe doped HAP sample possess superior anti-microbial efficiency against both gram (+)'ve and gram (-)'ve strains. These findings demonstrate the complementary effects of polymer reinforcement and dual-ion doping, suggesting great promise for Osteo-regenerative applications.

Multifunctional BiFeO₃ nanoparticles: structure–property investigation and application in pharmaceutical pollutant degradation

Pegylation of Zinc-Doped Copper Ferrite Nanoparticles for Biomedical Applications

Zinc-substituted copper ferrite (Cu1-xZnxFe2O4) nanocomposites were synthesized in a polyethylene glycol (PEG) matrix via a sol–gel auto-combustion method to enhance biocompatibility and functional performance. Structural, optical, morphological, and magnetic properties were systematically investigated using XRD, FTIR, SEM, EDS, UV–Vis spectroscopy, and VSM. XRD confirmed a single-phase inverse spinel cubic structure, with crystallite sizes decreasing from 14.63 nm (pristine) to 9.14, 8.21, and 9.90 nm for x = 0.2, 0.4, and 0.6, respectively, based on the Williamson–Hall method. A slight reduction in bandgap energy (3.56–3.52 eV) was observed with increasing Zn content. FTIR analysis verified PEG functionalization, indicating improved stability and biocompatibility. SEM images revealed agglomerated nanostructures with rough surfaces, promoting reactive oxygen species generation and metal ion (Cu2+/Zn2+) release, which are beneficial for antimicrobial activity. Magnetic measurements demonstrated superparamagnetic behavior with near-zero coercivity, supporting biomedical applicability. The nanocomposites exhibited enhanced antibacterial and antifungal activities compared to standard drugs (cefixime and clotrimazole), with stronger effects against fungal strains. Additionally, notable antioxidant activity was observed. These findings highlight the potential of PEG-assisted Zn-substituted copper ferrite nanocomposites as multifunctional materials for antimicrobial and antioxidant biomedical applications.