Low molecular weight chitosan ch

Levofloxacin hydrochloride (LVF, C₁₈H₂₀FN₃O₄, MW 397.8), low molecular weight chitosan (CH; (C₁₂H₂₄N₂O₉)_n; 75–85% deacetylated; MW, 50.000–190.000 Da based on viscosity; viscosity: 20–300 cps, 1% solution in 1% acetic acid), sodium tripolyphosphate (TPP), trehalose, and lysozyme (EC 3.2.1.17) were purchased from Sigma-Aldrich Chemie^® (St. Louis, MO, USA). Sulfobutyl-ether-β-cyclodextrin (SBE-β-CD, CAPTISOL^®, average MW 2162, seven is the average degree of sulfobutyl substitution) was a free sample given by CyDex Pharmaceutical (Lenexa, KS, USA). Double-distilled water filtered through 0.22 μm Millipore^® GSWP filters (Bedford, MA, USA) was used throughout the study. All other products and reagents were of analytical grade.

Low molecular weight chitosan (CH) (89% deacetylated, 50–190 kDa) and chitosan oligosaccharide (COS) (5000 kDa) were purchased from Sigma-Aldrich (448869 and 523,682 St. Louis, USA). Intermediate Restorative Material (IRM) Ivory Standard Package (Dentsply, York, USA) was used as Zinc oxide-eugenol (ZOE) material. Zinc oxide powder was mixed with COS and CH powder respectively in a ratio of 20 wt% before the addition of eugenol (250 μl/g powder), and mixed to achieve a mouldable paste. The amount of chitosan incorporated was chosen based on previous results from incorporation in methacrylate based composite and bonding materials [30 (link)]. The material was left to set overnight in a moist environment at 37 °C.