Antimicrobial peptide-loaded liquid crystalline precursor bioadhesive system for the prevention of dental caries.

BACKGROUND

Anticaries agents must interfere with the adhesion of and its proliferation in dental biofilm, without causing host toxicity and bacterial resistance. Natural substances, including cationic antimicrobial peptides (CAMPs) and their fragments, such as β-defensin-3 peptide fragment (D1-23), have been widely studied. However, the chemical and physical stability of CAMPs may be compromised by external factors, such as temperature and pH, reducing the period of antimicrobial activity.

METHODS

To overcome the aforementioned disadvantage, this study developed and character-ized a drug delivery system and evaluated the cytotoxicity and effect against biofilm of a D1-23-loaded bioadhesive liquid crystalline system (LCS). LCS was composed of oleic acid, polyoxypropylene-(5)-polyoxyethylene-(20)-cetyl alcohol, Carbopol 974P and Carbopol 971P. LCS was analyzed by polarized light microscopy (PLM), rheology (viscoelasticity and flow properties) and in vitro bioadhesion. The viability of epithelial cells was evaluated. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against were determined for D1-23 for further evaluation of the effect against biofilm after 4 and 24 h of exposure to treatments.

RESULTS

PLM, rheology, and in vitro bioadhesion tests showed that both viscosity and bioadhesion of LCS increased after it was diluted with artificial saliva. D1-23-loaded LCS system presented better activity against biofilm after 24 h when compared to 4 h of treatment, showing a cumulative effect. Neither LCS nor D1-23-loaded LCS presented toxicity on human epithelial cells.

CONCLUSION

D1-23-loaded LCS is a promising drug delivery system for the prevention of dental caries.