Enhancement of osteoblastic differentiation in alginate gel beads with bioactive octacalcium phosphate particles. (14th December 2015)

• Record Type: Journal Article
• Authors: Endo, Kosei; Anada, Takahisa; Yamada, Masumi; Seki, Minoru; Sasaki, Keiichi; Suzuki, Osamu
• Is Part Of: Biomedical materials. Volume 10:Number 6(2015:Dec.)
• Publication Date: 2015-12-14
• Subjects: octacalcium phosphate -- alginate -- beads -- osteoblasts -- cell delivery; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1088/1748-6041/10/6/065019
• Languages: English
• ISSNs: 1748-6041

Abstract

Abstract: The present study investigated whether alginate (Alg) hydrogel microbeads have a role in maintaining mouse bone marrow stromal ST-2 cells and release the cells after being stimulated by synthetic octacalcium phosphate (OCP), which is a mineral crystal capable of stimulating osteoblastic differentiation during a conversion process to hydroxyapatite (HA). The ST-2 cell suspension in the alginate solution, which contained various concentrations of OCP granules with diameters less than 53 μ m, was extruded drop-wise into a stirred gelation solution containing BaCl2 using an encapsulator with nitrogen gas stream. The Alg-microbeads (Alg/OCP · ST-2 microbeads) that were generated, which had a diameter of approximately 400 μ m, were incubated for up to 14 d and then assessed for osteoblastic differentiation. Alg-microbeads with cells were also incubated to identify the possible conversion from OCP to HA. Osteoblast differentiation markers in ST-2 cells, alkaline phosphatase (ALP) and collagen type I, were up-regulated in the presence of higher amounts of OCP. X-ray diffraction analysis and Fourier transform infrared spectroscopy confirmed that the OCP tended to convert to HA over time, suggesting that the OCP in Alg-microbeads interacts three-dimensionally with ST-2 cells and stimulates its osteoblastic differentiation. The release of ST-2 cells from the microbeads was also estimated. ST-2 cells were identified outside of the microbeads, although the cell number tended to decrease with increasing OCP. These results suggest that Alg/OCP microbeads could be used as a vehicle to activate osteoblastic cells and deliver them to sites where bone regeneration is needed.