Comparison of polymethylmethacrylate (PMMA), native calcium sulfate, and high porous calcium sulfate beads as gentamicin carriers and osteoblast attachment

Abstract

Calcium sulfate, a bioresorbable material, has been used as a bone substitute material and antibiotic vehicle. The increasing porosity of calcium sulfate beads might improve drug delivery capacity as well as enhance the antibiotic elution property. High porous calcium sulfate (HPCS) beads were fabricated using a salt leaching technique as a new bead type for antibiotic delivery system. Gentamicin-based antibiotic beads were conducted by impregnating gentamicin (3.8% w/w) with polymethylmethacrylate (PMMA), or coating of PMMA, native calcium sulfate (NCS), and HPCS with gentamicin solution. Physical properties, microstructure, and gentamicin elution from gentamicin-impregnated PMMA (GI-PMMA), gentamicincoated PMMA (G-PMMA), gentamicin-coated NCS (G-NCS), and gentamicin-coated HPCS (G-HPCS) were compared. The osteoblast attachment revealed that PMMA, NCS, and HPCS beads were not toxic to h-OBs after co-incubation for sevendays. Furthermore, more h-OBs attachment appeared in HPCS beads compared to PMMA and NCS beads after co-culture for 7 days. Eluted gentamicin from G-NCS and G-HPCS beads were greater than those from GI-PMMA and G-PMMA beads during the experimental period. All types of beads were able to elute gentamicin for 10 days except G-PMMA, which released gentamicin only for four days. The highest to lowest total concentrations of eluted gentamicin were from G-NCS, G-HPCS,G-PMMA, and GI-PMMA, respectively. These results suggested that the HPCS beads improved local antibiotic delivery and improved h-OBs attachment.

Keywords

• porosity
• salt leaching
• elution
• osteoblast