Polarised hydroxyapatite- sodium alginate composite as an antibacterial filler matrix

Bone-substituted composite material based on bioceramics and polymer has enhanced their biological performance with dynamic properties such as bioactivity, biocompatibility, osseointegration, and mechanical stability, which can be used in a controlled drug delivery system for avoiding infections as well as pain. Here in this study, we developed a new approach for inducing antibacterial and osteogenic responses on biomaterial substrates via surface polarisation. The hydroxyapatite- sodium alginate composite was negatively polarised using a corona poling setup and characterised using X-ray diffraction analysis. The thermally stimulated depolarization current study showed a maximum current of 4.74 nA/cm², observed at a temperature of 480 °C. The wettability of the specimen was measured using contact angle measurements, which demonstrated that the polarised composite specimen exhibited higher water retention ability. The bacterial cell viability test was measured using the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay, which revealed poor bacterial growth on polarised specimens as compared to their unpolarised counterparts. In addition, the osteogenic MG63 cell proliferation showed increased gene expression on polarised specimens. These findings showed that polarising hydroxyapatite- sodium alginate composite could be an excellent option to be used as an antibacterial bone filler matrix for faster healing as it showed both antibacterial and osteogenic activity.