Synthesis and performance of hydroxyapatite- β-cyclodextrin composite microspheres

Abstract

Hydroxyapatite (HA) is a widely used drug loading material, and combining HA with related materials to form drug loaded microspheres can effectively alleviate the phenomenon of drug burst release. For this purpose, the synthesis was involved using sodium dodecyl sulfonate (SDS) and proline (Pro) as templates through a hydrothermal precipitation method to create calcium carbonate microspheres. Subsequently, these microspheres were combined with β-cyclodextrin via ion exchange in a hydrothermal process to create a cavity structure. The effects of varying synthesis conditions on the microsphere morphology were investigated. The results showed that when the content of cyclodextrin was 20%-30% and the hydrothermal reaction time was 6 h, HA-β-CD composite microspheres had well-defined morphology and good dispersion. Characterization using X-ray diffraction, scanning electron microscope, UV-Vis spectrophotometer confirmed the uniform particle size distribution (6.4-13.9 μm) and presence of cavity structures in the HA-β-CD microspheres. Drug loading studies using curcumin as a model drug demonstrated that HA-β-CD microspheres achieved enhanced the drug loading capacity (5.03% ± 0.37%) and encapsulation efficiency (37.67% ± 1.37%) when β-cyclodextrin content was optimized at 30%. Vitro drug release tests indicated sustained release behavior, effectively mitigating burst release observed in traditional HA microspheres, thereby prolonging the drug efficacy. At the same time, the formation mechanism and cytotoxicity of drug loaded microspheres were analyzed and explored. The results showed that HA-β-CD drug loaded composite microspheres were formed through the encapsulation of HA, β-CD, and drugs, which can achieve delayed drug release and significantly improve the sustained release performance of drug loaded microspheres. Moreover, the test results showed that HA-β-CD composite microspheres have almost no toxicity to cell proliferation. HA-β-CD composite microspheres address limitations of drug-loaded pure HA microspheres such as rapid drug release, low drug loading, short duration of action, highlighting their significant medical value and application potential.

Keywords

• biomedical materials
• composite microspheres
• hydroxyapatite (ha)
• β-cyclodextrin (β-cd)
• template method
• drug loading performance
• curcumin