Antimicrobial green silver nanoparticles in bone grafts functionalization for biomedical applications

Abstract

In maxillofacial surgery and implantology clinical practice, infection processes are common during the healing and graft osseointegration. Microorganisms’ resistance to various antimicrobials has increased steadily through the widespread use of topical antibiotics, and new substances with antimicrobial properties are urgently necessary to avoid the infection processes in bone grafts. In the present study, bovine bone grafts (BG) for dental application were functionalized with silver nanoparticles (NPs) synthesized by the bioreduction technique using extracted (EEO) and commercial orange essential oil (CEO). The majoritarian compound identified in EEO and CEO was d-limonene, with a concentration up to 95%. The UV–Vis spectroscopy of NPs demonstrated the maximum absorbance peak around 400 nm and the average diameter obtained by transmission electron microscopy was 50 and 80 nm, respectively for NPs-EEO and NPs-CEO. The physicochemical stability of the NPs was studied for 60 days, at refrigerated temperature (6 ± 2 °C), and NPs-EEO presented better results of zeta potential, polydispersity index, and particle size during storage. The antioxidant activity was determined by the inhibition of DPPH and ABTS free radicals and by the Fe3+ reducing power (FRAP assay). NPs showed better results of antioxidant activity by DPPH and FRAP methods when compared to individualized essential oils. NPs and functionalized bone grafts showed greater antagonistic actions than individualized essential oils against the seven studied microorganisms. Therefore, it is possible to affirm the biological importance of the biosynthesized NPs for use as an antimicrobial agent in dental biomaterials, being a promising alternative to avoid the infection processes in bone grafts.