Effect of hyaluronic acid (HA) in a HA/PLGA scaffold on annulus fibrosus regeneration: In vivo tests: In vivo tests

Intervertebral disc (IVD) degeneration is an age-related process that affects the biomechanical properties of the spine and is assumed to be one of the principal causes of low back pain. Poly(lactide-co-glycolide) (PLGA) and hyaluronic acid (HA) have been widely used as biocompatible scaffold materials for tissue regeneration. In the present study, we fabricated a microporous PLGA scaffold by the salt-leaching method and HA-loaded PLGA scaffolds by the penetrating method. As the porosity of PLGA and PLGA/HA is 90.7% and 96.5%, respectively, PLGA/HA scaffold has the higher porosity. However, the pore size of PLGA (240.7±14.0 μm) is the larger than HA/PLGA (212.0±12.5 μm), and cells from the annulus fibrosus (AF) were seeded into the scaffolds. For the in vivo study, the PLGA and HA/PLGA scaffolds were implanted in four-week-old nude mice. All scaffolds were characterized using a scanning electron microscope (SEM), and the amounts of glycosaminoglycan (GAG) and collagen in the scaffolds were determined by a spectrophotometer. Histological evaluation indicated the higher level of AF cell proliferation in the HA/PLGA scaffold than in PLGA scaffolds alone. In addition, AF cells showed the stronger production of GAG and collagen in HA/PLGA. Our results indicate that the HA/PLGA scaffold might be useful for intervertebral disc regeneration. [Figure not available: see fulltext.]