Bioprinted 3D calcium phosphate scaffolds with gentamicin releasing capability

Abstract

We investigated the suitability of 3D printed calcium phosphate scaffolds as drug carriers. The 3D powder printing process utilized α-tricalcium phosphate (α-TCP) as a solid phase and deionized water with 2.5% disodium hydrogen phosphate as a setting accelerator. The antibiotic gentamicin sulfate was incorporated by mixing it into α-TCP powder before printing. Two different concentrations of gentamicin (3 wt%, 7 wt%) were used to study the correlation between drug release kinetics and gentamicin content in the scaffolds. The scaffolds were hardened at 100% humidity. The synthesized scaffolds were characterized in terms of morphology, composition, mechanical strength, in vitro bioactivity and drug release kinetics. X-ray diffraction (XRD) analysis revealed that the α-TCP converted into calcium deficient hydroxyapatite (CDHA) during the printing process. Scanning electron microscopy (SEM) showed the typical needle-like structure of CDHA. Gentamicin release was investigated for a period of two weeks with an initial burst release. The produced scaffolds formed calcium enriched apatite crystals on their surface after three days of incubation in simulated body fluid.