Fabrication and Characterization of Chitosan-Loaded Biomimetic Apatite Beads with Their Antimicrobial Activity

In this study, biomimetic apatite/chitosan (AP-CS) composite was prepared and characterized. The apatite powder, prepared by wet precipitation with a Ca/P molar ratio of 1.46 ± 0.02, was added to a solution containing different percentages of CS (10, 20, and 30wt.%). The resulting mixture was extruded in a basic solution to induce precipitation of the AP-CS composite in the spherical form beads, and then washed and dried at 37 and 105 °C. The prepared samples were characterized by Fourier transform infrared, X-ray diffraction, scanning, and transmission electron microscopy techniques. The total water content, beads’ hardness, and CS release in an acidic medium were investigated. The result shows that the as-prepared pure powder is an apatitic structure with nanocrystal sizes (5 to 40 nm) composed of Ca²⁺, HPO₄²⁻, and water. The as-prepared composites have relatively homogeneous spherical shapes with millimeter size and roughened surfaces. The shrinkage diameter of the beads and the water mass loss increase with the increase of the CS content. The AP-30%CS composite, dried at 37 °C, has the highest water content (84.72%) and the highest crushing strength (4.25 Kg.f). Dissolution tests showed that the CS was not degraded in the buffer solution. The structural integrity of the beads and the release concentration of CS were maintained over a long time. Antimicrobial activity tests confirm that the composite beads have significant antibacterial and excellent antifungal activities. The developed product has the potential to be applied as a bone substitute and can be used in drug delivery systems.