A novel artificial saliva enriched with CaneCPI-5 for irradiated head and neck cancer (HNC) patients: in vitro antimicrobial and anticaries effect

Abstract

Objectives: This study assessed the antimicrobial and anticaries potential of artificial saliva formulations containing CaneCPI-5, either alone or combined with fluoride and xylitol, designed for irradiated head and neck cancer (HNC) patients with hyposalivation. The impact of the combined formulation on microbial composition was also evaluated. Methods: Saliva from five irradiated HNC patients was mixed with McBain medium to form biofilms on irradiated bovine enamel specimens (70 Gy; n = 168). Treatments were applied for 1 min before biofilm formation and then once daily for 5 days: artificial saliva (AS) base with 0.1% hydroxyethyl cellulose, 0.1% sodium benzoate, and 0.3% mint flavor, either alone, with 0.1 mg/mL CaneCPI-5 (AS+Cane), or with 0.1 mg/mL CaneCPI-5, 1500 ppm fluoride, and 10% xylitol (AS+Cane+F+Xyl, ASF). Controls included PBS (negative), 0.12% chlorhexidine (CHX, positive), and BioXtra (R) (BXT, commercial). Biofilm metabolic activity, bacterial viability, CFU counts, enamel demineralization, and microbial community composition were assessed. Results: AS+Cane+F+Xyl significantly reduced live biovolume, CFU counts, and mineral loss (Delta Z and R Delta Z) compared with PBS (p < 0.001), with efficacy comparable or superior to BXT and CHX. AS+Cane also showed significant effects but with lower efficacy. ASF preserved overall microbial diversity while selectively enriching ASVs annotated as Streptococcus parasanguinis. Conclusions: CaneCPI-5 formulations, particularly combined with fluoride and xylitol, exhibit considerable antimicrobial and enamel-protective effects while maintaining microbial diversity in this in vitro model. Clinical Significance: Cost-effective artificial saliva enriched with CaneCPI-5 represents a promising translational strategy for caries prevention in vulnerable populations, especially those undergoing radiotherapy for HNC.