Antibacterial Performance of Stephania pierrei-Functionalized Hydroxyapatite Nanoparticles Synthesized Using Basella alba Mucilage as a Template

This study investigates the physicochemical properties and antibacterial activity of hydroxyapatite (HA) nanoparticles synthesized using Basella alba mucilage (BAM) as a natural template and coated with Stephania pierrei (S. pierrei) extract. HA composites were prepared via the sol-gel method with varying BAM concentrations (0–25 wt%) to optimize material properties. S. pierrei tuber and leaf extracts were then incorporated, forming functionalized S. pierrei/BAM-HA materials. Characterization via X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and N₂ adsorption/desorption confirmed the formation of biphasic calcium phosphate structures with enhanced surface area and reduced particle sizes. The 5 wt% BAM composite exhibited the highest surface area (17.59 m²/g) and smallest particle size (6.57 nm). Antibacterial activity was evaluated against Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus, and Bacillus subtilis using the agar well diffusion method. The S. pierrei/BAM-HA composites showed selective antibacterial effects, particularly against Pseudomonas aeruginosa and Bacillus cereus. Notably, 4.0S. pierrei-L/BAM-HA exhibited the strongest activity against Bacillus cereus (MIC and MBC: 4 mg/mL). This research highlights the potential of S. pierrei/BAM-HA composites as antibacterial coatings for implants and bone tissue engineering, while suggesting that further modifications may be needed to enhance antifungal properties.