Conjugated Bio-Polymer Anchored Surfaces to Mitigate Stain and Bacterial Colonization for Oral Hygiene Application

Due to health and environmental hazards, there is an increased desire to rely on sustainable resources that are biocompatible, biodegradable, and safe for human administration. Herein, the present study explores bioconjugate efficacy as a potential anti-stain and green antibacterial additive in toothpaste formulation using GRAS (generally regarded as safe) and Food and Drug Administration (FDA)-approved ingredients. In this study, a series of conjugated polymers were synthesized using sodium alginate and alendronic acid and are labeled as SA-ALN amide and SA-ALN ester. Spectroscopic techniques thoroughly characterized the synthesized conjugated polymers. These synthesized polymers were adsorbed onto hydroxyapatite (HAP, a tooth model) to evaluate its practical application as anti-stain and reduce bacterial attachment. The adsorption of the conjugate polymers on the HAP surface was confirmed by Raman spectra and Fourier transform infrared spectroscopy (FTIR). The anti-stain test revealed significant whitening benefits for coated hydroxyapatite (HAP) tiles over uncoated tiles. The antibacterial activity of conjugated polymers toward E. coli (Gram-negative) and S. mutans (Gram-positive, bacteria responsible for tooth decay) strain showed 2.5 log reduction and 1.5 log reduction, respectively. Among the conjugated polymers, the SA-ALN-ester showed slightly higher antibacterial activity against E. coli as well as S. mutans strain relative to the SA-ALN amide product due to the presence of a free amine group in the former. Further, we carried out the in vitro cytotoxicity test of the conjugated polymers using gingival fibroblasts and pre-osteoblasts and the study demonstrated that the synthesized conjugates are cytocompatible in nature. Thus, this study revealed that the proposed work might provide insights into sustainable oral hygiene.