Thermoresponsive sol–gel containing probiotic’s cell free supernatant for dental caries prophylaxis

BACKGROUND: Lactobacillus rhamnosus SD11 is a probiotic derived from the human oral cavity and has potential being used for dental prophylaxis. The cell free supernatant (CFS) of L. rhamnosus SD11 has good antimicrobial and antioxidant effects. AIM: This study aimed to incorporate CFS of the probiotic into thermoresponsive copolymers to create a sol–gel formulation. METHODS: The sol–gel formulation was developed using Poloxamer 407 as the main polymer, which was mixed with natural polymers such as gellan gum, sodium alginate, and xyloglucan in different proportions. The sol–gel formulations were characterized based on their physicochemical parameters such as appearance, pH, viscosity, flow-ability in low temperature, antioxidant and antibacterial activity. An in vitro release study was performed using Franz’s diffusion cell and the stability was determined under freeze-thaw cycle conditions. RESULTS: The combination of 15% w/v of poloxamer 407 with 0.5% w/v of sodium alginate was the best sol–gel formulation to deliver the CFS of the probiotic. CONCLUSION: This study was successful in creating a sol–gel formulation using a thermoresponsive copolymer, that could efficiently deliver CFS of the probiotic L. rhamnosus SD11. [Figure: see text]