Disinfection of maxillofacial silicone elastomer using a novel antimicrobial agent: recombinant human beta-defensin-3

Maxillofacial silicone elastomer, when used as a prosthesis, is in contact with wound surfaces and mucosa, and tends to be contaminated with microorganisms from a patient's saliva and blood. The aim of the study was to evaluate the efficacy of human beta-defensin-3 (HBD3) on the reduction of two resistant bacteria species from the surface of maxillofacial silicone elastomer. HBD3 cDNA was amplified from total RNA, which had been extracted from human gingival epithelium by means of reverse-transcription polymerase chain reaction (RT-PCR). Following this, the cDNA fragments were recombined in a prokaryotic expression vector. The constructed expression vectors pET-32a/HBD3 were transformed into Escherichia coli to obtain recombinant protein. After protein purification and refolding, the product was verified in classic antimicrobial experiments against Staphylococcus aureus and Candida albicans. Specimens made of silicone elastomer A-2186, which had been contaminated with S. aureus or C. albicans, were immersed in rHBD3 or 5.25% sodium hypochlorite (a positive control) for 5 min, 10 min, 30 min, or 60 min. The active recombinant HBD3 obtained in the current study eliminated the S. aureus and C. albicans microorganism from the surface of the maxillofacial elastomer after a 30-min immersion. There was no statistically significant difference between the rHBD3 group and the sodium hypochlorite 5.25% group. In conclusion, rHBD3 exhibits antibacterial activity against oral pathogenic strains that adhere to maxillofacial elastomer, and may, thus, contribute to the prevention of infections caused by S. aureus and C. albicans.