Spinal cord injury (SCI) causes histological alterations which in turn affects functional activity. Studies have demonstrated that dental pulp-derived stem cells conditioned medium has beneficial effects on the nervous system. Besides, collagen hydrogel acts as a drug releasing system in SCI investigations.

This research aimed to evaluate effects of dental pulp-derived stem cells conditioned medium loaded in collagen hydrogel in SCI.

After culturing of Stem cells from human exfoliated deciduous teeth (SHEDs), SHED-conditioned medium (SHED-CM) was harvested and concentrated. Collagen hydrogel containing SHED-CM was prepared. The rats were divided into five groups receiving laminectomy, compressive SCI with or without intraspinal injection of biomaterials (SHED-CM and collagen hydrogel with or without SHED-CM). After 6 weeks, histological parameters were estimated using stereological methods.

The total volume of preserved white matter and gray matter (p < 0.05) as well as the total number of neurons and oligodendrocytes in the rats received SHED-CM loaded in collagen hydrogel were significantly higher, and also lesion volume and lesion length were significantly lower (p < 0.05) compared to those of the other injured groups.

In conclusion, intraspinal administration of SHED-CM loaded in collagen hydrogel leads to neuroprotection, proposing a cell-free therapeutic approach in SCI.

脊髓损伤 (SCI) 会导致组织学改变，进而影响功能活动。研究表明，牙髓干细胞条件培养基对神经系统有益。此外，胶原水凝胶在 SCI 研究中充当药物释放系统。

本研究旨在评估载有胶原水凝胶的牙髓干细胞条件培养基对 SCI 的影响。

从人类脱落的乳牙 (SHED) 培养干细胞后，收获并浓缩 SHED 条件培养基 (SHED-CM)。制备了含有 SHED-CM 的胶原蛋白水凝胶。将大鼠分为五组，分别接受椎板切除术、压缩性 SCI，有或没有椎管内注射生物材料（SHED-CM 和胶原水凝胶，有或没有 SHED-CM）。6 周后，使用立体学方法估计组织学参数。

胶原蛋白水凝胶负载SHED-CM的大鼠保留的白质和灰质的总体积（p <0.05）以及神经元和少突胶质细胞的总数显着增加，并且病变体积和病变长度显着降低(p < 0.05) 与其他受伤组相比。

总之，加载在胶原水凝胶中的 SHED-CM 的椎管内给药导致神经保护，提出了一种无细胞治疗 SCI 的方法。