IADR Abstract Archives
Microbial and Osteoblast Responses to Copper-Containing Titanium Implant Material
Objectives: Dental implants are susceptible to failure due to bacterial infection, leading to poor osteo-integration. The aim of this study was to characterise the antimicrobial and osteogenic responses with a titanium alloy containing 5% Cu or titanium alone at the molecular level.
Methods: Expression of Cu-sensing transcriptional repressor (csoR), superoxide dismutase (sod) and heat shock protein (Hsp) genes were measured using qPCR in Streptococcus oralis. Global RNA expression profiles of the dental implant pathogens S. oralis, A. naeslundii and Neisseria mucosa were explored via RNA-seq. Expression of Cu transporter and pro-osteogenic genes were examined using immunoblotting and qPCR in MG-63 osteoblast-like cells.
Results: In the presence of Cu, significant microbial and osteoblast responses were observed as follows: 1. Expression of csoR, sod and Hsp from S. oralis was enhanced. 2. A. naeslundii transcripts for DNA-recombinase, DUF350 domain containing membrane protein and a HTH ArsR-Type transcriptional repressor involved in stress response to heavy metal ions were differentially expressed. 3. Immunoblotting of the osteoblast cell line revealed that CTR1 (Cu influx transporter), ATP7B (Cu excretion), ATOX1 (intermediate Cu transporter) and LOX (Cu dependent lysyl oxidase) proteins were upregulated. 4. Increased transcription of the pro-osteogenic genes RUNX2, ALP, ON, BMP2, BMP4 and the Cu transporting genes was observed.
Conclusions: Copper-containing titanium was shown not only to be detrimental to dental implant pathogens but also offers potentially beneficial osteogenic properties.
Methods: Expression of Cu-sensing transcriptional repressor (csoR), superoxide dismutase (sod) and heat shock protein (Hsp) genes were measured using qPCR in Streptococcus oralis. Global RNA expression profiles of the dental implant pathogens S. oralis, A. naeslundii and Neisseria mucosa were explored via RNA-seq. Expression of Cu transporter and pro-osteogenic genes were examined using immunoblotting and qPCR in MG-63 osteoblast-like cells.
Results: In the presence of Cu, significant microbial and osteoblast responses were observed as follows: 1. Expression of csoR, sod and Hsp from S. oralis was enhanced. 2. A. naeslundii transcripts for DNA-recombinase, DUF350 domain containing membrane protein and a HTH ArsR-Type transcriptional repressor involved in stress response to heavy metal ions were differentially expressed. 3. Immunoblotting of the osteoblast cell line revealed that CTR1 (Cu influx transporter), ATP7B (Cu excretion), ATOX1 (intermediate Cu transporter) and LOX (Cu dependent lysyl oxidase) proteins were upregulated. 4. Increased transcription of the pro-osteogenic genes RUNX2, ALP, ON, BMP2, BMP4 and the Cu transporting genes was observed.
Conclusions: Copper-containing titanium was shown not only to be detrimental to dental implant pathogens but also offers potentially beneficial osteogenic properties.