3D-printedβ-TCP scaffolds coated with palmarosa essential oil: antibacterial and cytotoxicity studies

The use of natural antibacterial agents in bone tissue engineering has gained attention as an alternative to conventional antibiotics, particularly in response to the growing challenge of bacterial resistance. In this study,β-tricalcium phosphate (β-TCP) scaffolds were fabricated via direct ink writing and coated with palmarosa essential oil (PEO), which was extracted from the medicinal plantCymbopogon martinii, known for its high geraniol content and antifungal, antibacterial, antiviral, and antioxidant properties. The scaffolds were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), andin vitrobiological assays. SEM images confirmed the structural fidelity and porous architecture of the scaffolds, while FTIR spectra indicated the presence of PEO-associated functional groups. Dissolution studies revealed a marked release within the first 24 h, and kinetic fitting indicated that the release profile was best described by a first-order model. Antibacterial tests demonstrated effective inhibition againstS. aureusandEscherichia coli, and cell viability assays using MG-63 cells indicated good cytocompatibility. The novelty of this work lies in coating 3D-printedβ-TCP scaffolds with PEO, a combination not previously reported, offering a sustainable, antibiotic-free strategy for localized antibacterial activity. These findings highlight the potential of PEO-coatedβ-TCP scaffolds as multifunctional biomaterials for infection-prone bone repair applications.