Safe hydrogel delivery requires stiffness-matching with host tissues to avoid iatrogenic damage and reduce inflammatory reactions. Hydrogel-encapsulated cell delivery is a promising combinatorial approach to spinal cord injury therapy, but a lack of in vivo clinical spinal cord injury stiffness measurements is a barrier to their use in clinics. We demonstrate that ultrasound elastography – a non-invasive, clinically established tool – can be used to measure spinal cord stiffness intraoperatively in canines with spontaneous spinal cord injury. In line with recent experimental reports, our data show that injured spinal cord has lower stiffness than uninjured cord. We show that the stiffness of hydrogels encapsulating a clinically relevant transplant population (olfactory ensheathing cells) can also be measured by ultrasound elastography, enabling synthesis of hydrogels with comparable stiffness to canine spinal cord injury. We therefore demonstrate proof-of-principle of a novel approach to stiffness-matching hydrogel-olfactory ensheathing cell implants to ‘real-life’ spinal cord injury values; an approach applicable to multiple biomaterial implants for regenerative therapies.

安全的水凝胶递送需要与宿主组织的刚度匹配，以避免医源性损害并减少炎症反应。水凝胶封装的细胞递送是脊髓损伤治疗的有前途的组合方法，但缺乏体内临床脊髓损伤刚度测量是其在临床中使用的障碍。我们证明了超声弹性成像技术（一种非侵入性，临床上公认的工具）可用于在患有自发性脊髓损伤的犬中术中测量脊髓刚度。与最近的实验报告一致，我们的数据显示受伤的脊髓比未受伤的脊髓具有更低的刚度。我们显示封装临床相关移植人群（嗅鞘细胞）的水凝胶的硬度也可以通过超声弹性成像法进行测量，从而能够合成具有与犬脊髓损伤相当的硬度的水凝胶。因此，我们证明了一种刚度匹配水凝胶-嗅觉鞘细胞植入物到“现实生活”脊髓损伤值的新方法的原理证明；