Two novel samples of nanoparticles based on chitosan were greenly synthesized using pomegranate peel extract. The extract served as a nanoparticle precursor, facilitating the precipitation of nanosized chitosan through the ionic gelation method. Additionally, by mixing the green chitosan nanoparticles with copper ions, a nanoscale composite of chitosan and copper oxide was also produced. Structural and morphological investigations (FTIR, XRD, SEM, EDX, and TGA analyses) were performed for greenly synthesized chitosan nanoparticles and their copper oxide composite to determine all the significant characteristics of those nanoparticles. In addition, both samples were tested using some biological investigations, such as antimicrobial activity and hematological effects. The antimicrobial tests yielded promising results for both the green chitosan nanoparticles and the CuO composite when tested using two bacterial strains and two fungal strains. Moreover, the results showed that using a similar concentration of both green-based chitosan samples resulted in a slightly larger inhibition zone and a lower minimum inhibition concentration (MIC) for the copper oxide chitosan composite compared to the chitosan nanoparticles for all microorganisms included in the test. The mean count of blood components (RBCs and platelets), clotting time, and cholesterol levels in three different blood samples were used to indicate the hematological activity of both greenly synthesized nanoparticles. The results verified a slight reduction in blood component count after the addition of green chitosan nanoparticles, but the chitosan copper oxide composite did not have a noticeable effect on the three blood samples. The chitosan nanoparticles were able to cause a considerable reduction in clotting time and cholesterol levels for all blood samples, thus acting as procoagulants. However, the mixing of CuO with chitosan nanoparticles prolonged the rate of clotting in blood samples from hypercholesteremic individuals, and thus, the mixture acted as an anticoagulant agent.

Sustainable nanotechnology requires synthesis approaches that are environmentally benign while maintaining high efficiency, yield, and functionality. Plant-mediated synthesis combined with advanced heating techniques offers a promising route to achieve these goals. Phyto-copper oxide nanoparticles (Phy-CuO-NPs) were synthesized using Psidium guajava leaf extract under different pH conditions via two approaches: conventional heating (Series A) and microwave-assisted synthesis (Series B). The influence of pH and heating mode on nanoparticle formation was systematically evaluated. The synthesized nanoparticles were characterized using physicochemical and morphological techniques, and their antibacterial activity was assessed against Staphylococcus aureus and Pseudomonas aeruginosa. Microwave-assisted synthesis significantly altered pH-dependent nucleation pathways, resulting in nanoparticles with enhanced crystallinity, more uniform morphology, higher copper content, and improved colloidal stability, particularly under alkaline conditions. Series B nanoparticles showed a 34% increase in maximum yield (up to 80 mg/g) while achieving a 92% reduction in energy consumption compared to the conventional method. Antibacterial assays revealed strong inhibitory activity against both tested strains, with greater efficacy against Gram-negative bacteria. The improved antibacterial performance is attributed to the bio-capped nature of the nanoparticles, which facilitates cellular entry and promotes intracellular copper ion release, leading predominantly to reactive oxygen species generation rather than direct ionic toxicity. This study highlights the synergistic role of microwave irradiation and pH control in enhancing both sustainability and functionality.

Understanding the stability of metal–ligand complexes is essential for advancing applications in environmental, industrial, and biomedical chemistry; however, titanium coordination systems remain underexplored, particularly with organic ligands of chelating properties. This study aims to evaluate and compare the stability constants of titanium ( iv ) complexes with propanoic acid and citric acid to better understand their coordination behavior. A multi-method computational approach was employed, integrating point-wise calculation, half-integral, linear plot, and least-squares methods to enhance the accuracy and reproducibility of proton–ligand dissociation constants (p K _a ) and metal–ligand formation constants (log K ). The titanium–propanoate complexes showed moderate stability (log K ₂ = 4.7564, log K ₃ = 4.1015), influenced by steric and electronic factors, while the titanium–citrate complex exhibited a higher binding affinity (log K ₁ = 7.8351), indicating strong chelation capacity. The consistency across all computational and graphical methods validates the reliability of the findings. These insights provide a dependable framework for evaluating titanium-based coordination compounds and may guide future research into their potential applications in environmental and biomedical fields.