Hydroxyapatite From the Skull of Tuna (Thunnus obesus) Head Combined With Chitosan to Restore Locomotive Function After Spinal Cord Injury

Hydroxyapatite is an important fish bone calcium in tuna head, which is widely used to repair of bone defect. Chitosan is a degradable basic polysaccharide with good biocompatibility and bone guiding, which can achieve targeted delivery to the injured spinal cord after spinal cord injury (SCI). This study aimed to evaluate the beneficial effects of chitosan combined hydroxyapatite (chitosan-hydroxyapatite) nanoparticles on SCI. The result revealed the chitosan-hydroxyapatite particles were successfully constructed and the stability of particles was maintained at low temperature. Moreover, we found chitosan-hydroxyapatite administration could improve SCI, while chitosan alone treatment resulted in no significant increase of the Basso Beattie Bresnahan (BBB) scores compared with the control group. In addition, chitosan-hydroxyapatite particles also significantly reduced the lesion cavity volume and improved the dispersed structure, indicating it could promote the recovery of tissue function of SCI rats. This study explored the effects of chitosan-hydroxyapatite nanoparticles on the location and function of spinal cord injury, provided experimental evidence for further research on its application in spinal cord repair, and helped improve the efficient use of tuna heads.