We’re never at a loss for toothpaste choices, but we may see the addition of “With Nanotechnology!” advertised on the tubes in the future. Researchers from the University of Rochester and University of Pennsylvania have designed drug-releasing nanoparticles to protect the teeth from bacterial damage and decay.
The particles are engineered with a positively-charged outer segment to bind to negatively-charged sites on plaque biofilms and tooth enamel, effectively anchoring the particles in place. The particles’ cores are hydrophobic and loaded with farnesol, a hydrophobic antibacterial drug. The cores release the drug more quickly in acidic environments – perfect for when cariogenic bacteria begin to take over the teeth and form biofilms, which can drop locally to pH of 4.5-5.5.
They showed that head-to-head in a topical application, the drug-loaded nanoparticles were four times more powerful in destroying the bugs (Streptococcus mutans, in this study) than the free drug alone. They attributed this fact to the ability of the nanoparticles to adhere and deliver the drug in a controlled-release fashion, targeting sites of bacterial growth (biofilms) to deliver higher concentrations locally. Additionally, laboratory models of teeth and decay showed that the particles were able to greatly reduce the mechanical stability of the biofilms, rendering them more brittle and breakable. In vivo trials showed reductions in both the number and severity of dental caries in rats treated twice daily with the farnesol-loaded nanoparticles. The free farnesol applications were less effective, and likely washed away in what we imagine to be copious amounts of rat saliva.
Given that the nanoparticles will inevitably be ingested after application to teeth, the researchers understand they’ll have to prove their safety before they can be introduced into the marketplace. For starters, will they attach to biofilms elsewhere along the GI tract, and damage the good bacteria in our bodies? Regardless, we can imagine the use of particles in things like toothpaste or mouthwash to keep our teeth free of dental caries and prevent a painful trip to the dentist’s office.
More at Science news: Plaque-busting nanoparticles could help fight tooth decay…