The aim of this in vitro experimental study was to design a novel, polyvinyl alcohol(PVA)-basedpolymericscaffold that permits the controlled release of insulin-likegrowthfactor1(IGF-1)/bonemorphogenetic protein-2(BMP-2) following intervertebral disc administration.
The drug delivery system was composed of two different solutions that formed a scaffold within seconds after coming into contact with each other. We performed swelling,pH,temperature tests and analysis of the controlled release of growth factors from this system.The release kinetics of the growth factors was determined through enzyme linked immunosorbent assay(ELISA). Cell proliferation and viability was monitored with microscopy and analyzed using an MTT assay and acridine orange/propidium iodide(AO/PI) staining. Chondroadherin(CHAD), hypoxiainduciblefactor-1alpha(HIF-1α),collagentypeII(COL2A1) gene expressions were determined with quantitative real-timepolymerasechainreaction(qRT-PCR) analysis to show the effects of IGF-1/BMP-2 administration on annulus fibrosus cell(AFC)/nucleus pulposus cell(NPC) cultures.
The scaffold allowed for the controlled release of IGF-1 and BMP-2 in different time intervals. It was observed that as the application time increased, the number of cells and the degree of extracellular matrix development increased in AFC/NPC cultures. AO/PI staining and an MTT analysis showed that cells retained their specific morphology and continued to proliferate. It was observed that HIF-1α and CHAD expression increased in a time-dependent manner, and there wasn't any COL2A1 expression in the AFC/NPC cultures.
The designed scaffold may be used as an alternative method for intervertebral disc administration of growth factors after further in vivo studies. We believe that such prototype scaffolds may be an innovative technology in targeted drug therapies after reconstructive neurosurgeries.