Fabrication and properties of alginate/calcium phosphate hybrid beads: A comparative study

Abstract

BACKGROUND: Microbeads for bone repair have been widely studied because they can be conveniently used in clinical applications. OBJECTIVE: This study concerns the preparation, physical properties and in vitro characterisation of different types of alginate/calcium phosphate (CaP) ceramic microbeads, which were designed for use as drug delivery systems and bone-regeneration matrices. METHODS: Hybrid microbeads were successfully prepared from sodium alginate and various CaP, namely 𝛼-tricalcium phosphate, 𝛽-tricalcium phosphate and hydroxyapatite using the liquid droplet method. RESULTS: Porosity, swelling properties and in vitro degradation of the microbeads in the aqueous environment were significantly changed by the added CaP. The compressive strength of the blocks fabricated from the beads was around 120 MPa irrespective of the type of CaP. The initial release rate of the model drug methylene blue was suppressed by the addition of CaP. CONCLUSION: The alginate-CaP composite beads hold promising potential as an encapsulation carrier of drugs and component of bone substitutes.