The effect of BMP-2 in DBP sponge for annulus fibrosus regeneration

Demineralized bone particle(DBP) that affects to cell proliferation and differentiation has been used as biomaterials. In this study, we evaluated 3-dimensional DBP sponge and Collagen sponge on proliferation and phenotype maintenance of annulus fibrosus cells. DBP sponge were prepared by freeze-drying method after addition 2 wt% DBP solution. sponge was crosslinked with 1-ethyl-(3-3-dimethyl aminopropyl) carbodiimide hydrochloride(EDC) solution with 50 mM concentration for 24 hrs and lyophilized. We seeded cells in DBP sponge and Collagen sponge. Cellular viability and proliferation were assayed by 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium-bromide(MTT) test. DBP sponge and Collagen sponge were characterized by scanning electron microscopy(SEM). Reverse transcription polymerase chain reaction(RT-PCR) was assessed to measure mRNA expression for type I collagen, type II collagen, aggrecan and osteonectin and glycosaminoglycan(GAG) quantity from annulus fibrosus cells in sponges. In MTT assay result, DBP sponges were higher cell viability. In SEM observation, we observed that DBP sponge has uniform porosity. In addition, annulus fibrosus stronly expressed their specific mRNA. and produced well sGAG in DBP sponge. This result indicates that DBP sponge is useful for intervertebral disc regeneration.