Study of recovery effectiveness in blunt trauma rat treated by basic fibroblast growth factor-coated magnetic nanoparticles

To study the effects of basic fibroblast growth factor (bFGF)-coated magnetic nanoparticles on the recovery in rat skeletal muscles after acute contusion. Recombinant bFGF-coated magnetic nanoparticles were produced by immunochemical coupling techniques. The acute skeletal muscle contusion was produced by heavy objects dropping devices. Subcutaneous injection or blank control were performed respectively with each group and targeted and focused at the injured site with the guidance of external magnetic fields. The muscles were sampled at day 2, 10, 17, 24 and 30 respectively after contusion, and then the muscle contractive strength and relaxation were measured and calculated. The expression of MHC-II b mRNA in rat gastrocnemius was investigated by real-time PCR assay. Magnetically nanocrystallized bFGF could significantly increase the muscle contractive strength at day 17 and day 24 in gastrocnemius after contusion. From day 2 after contusion, magnetically nanocrystallized bFGF could restore the muscle relaxation back close to the normal level. Compared with the direct injection bFGF group, BFGF-coated group more significantly increased the muscle contractive strength at day 17 (P <;0.05). BFGF-coated group was significantly different from other four groups in the expression of MHC-II b mRNA at day 2-10 after contusion (P <;0.05). Magnetically nanocrystallized bFGF could significantly enhance the contractive strength, promote the expression of MHC-II b mRNA, restore the muscle relaxation and improve more effectively the healing of injured muscles in rat acute skeletal muscle contusion.