Effect of Molecular Mass and Degree of Deacetylation of Chitosan on Adsorption of Streptococcus sobrinus 6715 to Saliva Treated Hydroxyapatite.

Abstract

We evaluated the influence of molecular mass and degree of deacetylation of chitosan on the adsorption of Streptococcus sobrinus 6715 to saliva-treated hydroxyapatite (S-HA) by measuring the optical density of the bacterial cell suspensions released from saliva-treated hydroxyapatite. Twenty-five chitosan samples with different molecular masses (0.8-6 kDa) and degrees of deacetylation (10-95%) were prepared for the study. We found that the inhibition of adsorption of S. sobrinus 6715 to S-HA correlated positively with the molecular mass of chitosan (R‫)678.0ס‬ and that the optimal degree of deacetylation was 50-60% for maximum inhibition of bacterial binding to S-HA. We also examined the effect of chitosan on zeta potentials of the oral bacteria and their surface hydrophobicities. It was observed that chitosan reduced the magnitude of the zeta potential and surface hydrophobicities of the oral bacteria. Thus, the results demonstrated that chitosan with a molecular mass of 5-6 kDa and a degree of deacetylation of 50-60% might have the potential to act as an effective anti-plaque agent because of its polycationic properties.

Influence of a chitosan on oral bacterial adhesion and growth in vitro

“…The positive charge of chitosan‐treated pellicles explains the decreased viability of S. sanguinis attached to saliva‐coated enamel treated with chitosan (8). The increased hydrophobicity of salivary pellicles after chitosan adsorption explains the reduced adhesion of Streptococcus sobrinus to saliva‐coated hydroxyapatite disks, which was minimal for chitosans with a molecular weight of 5–6 kDa and a degree of acetylation of 50–60% (10). Also in vivo , low‐molecular‐weight chitosans inhibited the initial adhesion of oral bacteria to human tooth surfaces at a level comparable to that of a 50 mg l −1 (50 p.p.m.)…”

Biodegradable polymers for dental tissue engineering and regeneration

“…In fact, the polycationic nature of CS, with active amino and hydroxyl functional groups, permits good adhesion to salivary pellicles and creates positive charges that interact with microbial cell surfaces provoking loss of microbial cell barrier function [410]. Sano et al demonstrated the effect of increased hydrophobicity of salivary pellicles after CS adsorption and the obtained reduced adhesion of Streptococcus sobrinus to saliva coated HA disks [411]. They also found that low molecular weight CS inhibits the initial adhesion of oral bacteria to human tooth surfaces at a level comparable to that of a 50 ppm chlorhexidine solution [412].…”

Drug Carrier Systems Using Chitosan for Non Parenteral Routes

“…The formulation of chitosan with a drug may alter the pharmacokinetic and biodistribution profiles, and for pharmaceutical applications it is necessary to take in account the route of administration, its concentration, contact time and cell types that enter in contact with chitosan or chitosan complexes [58][59][60][61][62][63]. In Table 4 are listed some biological and toxicological properties of chitosan in several biological systems [64][65][66][67][68][69][70][71][72][73][74][75].…”