Effects of simvastatin-loaded PLGA microspheres on treatment of rats with intervertebral disk degeneration and on 6-K-PGF1α and HIF-1α

Effects of simvastatin-loaded PLGA sustained release microspheres on the treatment of rats with intervertebral disk degeneration (IVDD) and on 6-keto-prostaglandin F1α (6-K-PGF1α) and hypoxia inducible factor-1α (HIF-1α) were investigated. Eighty female rats were selected and randomized into a model group (modeled for IVDD), a treatment group (modeled and treated with simvastatin-loaded PLGA sustained release microspheres), a sham operation group (only operated without excision), and a control group (not treated) (n=20 each). After modeling, 6-K-PGF1α and HIF-1α in the peripheral blood of the rats were, respectively, detected before simvastatin injection (T0), at 2 weeks (T1) and 4 weeks (T2) after simvastatin injection. The bone mineral density (BMD) of L(5) and L(6) was detected by X-ray. The trabecular thickness, number, and separation of the vertebral body were detected. Changes in the sagittal T2-weighted signal of intervertebral disc nucleus pulposus were detected by MRI. There were no differences between the control and sham operation groups in the indices (P>0.050). Compared with those in the model group during the treatment, BMD, 6-K-PGF1α, HIF-1α, and trabecular number in the treatment group significantly increased (P<0.050), while the trabecular separation significantly decreased (P<0.050). The sagittal T2-weighted MRI signal in the model group was the lowest between the four groups (P<0.050). Simvastatin-loaded PLGA sustained release microspheres can improve the BMD of the vertebral body and increase the contents of 6-K-PGF1α and HIF-1α in the treatment of rats with IVDD, so they are important for the clinical treatment of the disease.