SYNTHESIS, CHARACTERIZATION, ANTIBACTERIAL PROPERTIES, AND CYTOTOXICITY OF TERBIUM-DOPED HYDROXYAPATITE CRYSTALS FOR BIOMEDICAL APPLICATIONS

Background: Hydroxyapatite (HAp) is widely recognized for its biocompatibility, osteoconductivity, and similarity
to natural bone mineral. However, its limited antimicrobial properties and mechanical stability restrict its broader
biomedical applications. Recent advances in rare earth element doping, such as with terbium (Tb), have shown
potential to enhance these properties by introducing antimicrobial and bioactive functionalities.
Aim:This study aims to synthesize, characterize, and evaluate the biocompatibility and antimicrobial properties of
terbium-doped hydroxyapatite (Tb-HAp) nanoparticles for potential biomedical applications.
Materials and Methods:Tb-HAp nanoparticles were synthesized using a co-precipitation method, maintaining a
Tb/(Tb + Ca) ratio of up to 10%. The nanoparticles were characterized using FTIR spectroscopy, SEM imaging, and
EDS analysis. Biocompatibility was assessed using the MTT cytotoxicity assay, while antimicrobial activity was
evaluated against S. aureus, S. mutans, and P.gingivalis using the agar well diffusion method.
Results:FTIR confirmed successful incorporation of Tb into the HAp matrix without altering its structural integrity.
SEM analysis revealed a rough, porous morphology favorable for cell attachment and osseointegration. The MTT
assay indicated higher cell viability for Tb-HAp than undoped HAp, demonstrating improved biocompatibility.
Antimicrobial testing showed larger inhibition zones for Tb-HAp against all tested microorganisms compared to
undoped HAp and standard antibiotics, highlighting its enhanced antibacterial efficacy.
Conclusion:The incorporation of terbium into hydroxyapatite significantly improves its antimicrobial and
biocompatible properties, making it a promising candidate for applications in dental and orthopedic implants, tissue
engineering, and infection-resistant coatings. Further studies are warranted to evaluate long-term stability, systemic
effects, and scalability for clinical translation.