中国神经再生研究(英文版) ›› 2021, Vol. 16 ›› Issue (5): 871-877.doi: 10.4103/1673-5374.297786

• 原著:周围神经损伤修复保护与再生 • 上一篇    下一篇

矿物质包被微粒持续生长因子递送促进周围神经损伤后功能的恢复

  

  • 出版日期:2021-05-15 发布日期:2020-12-29

Functional recovery after peripheral nerve injury via sustained growth factor delivery from mineral-coated microparticles

Daniel J. Hellenbrand1, 2, Clayton L. Haldeman1, Jae-Sung Lee2, 3, Angela G. Gableman1, Elena K. Dai1, Stephen D. Ortmann1, Jerrod C. Gotchy1, Kierra K. Miller1, Adrianna M. Doucas1, Nicole C. Nowak1, William L. Murphy2, 3, Amgad S. Hanna1, *#br#   

  1. 1 Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA;  2 Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA;  3 Department of Orthopedics and Rehabilitation University of Wisconsin Madison, WI, USA
  • Online:2021-05-15 Published:2020-12-29
  • Contact: Amgad S. Hanna, MD, hanna@neurosurgery.wisc.edu.

摘要:

自体神经移植作为治疗周围神经长段神经缺损的金标准,移植后的受损神经功能恢复效果也不尽人意。已有研究将复合生长因子的神经移植物用于周围神经缺损的修复,且取得了一些令人鼓舞的结果,但是这些生长因子在 持续释放方式和作用时间方面尚存在一些不足。理想的药物递送载体需在足够的时间内,使轴突在整个神经移植物上生长。实验假设矿物质包被微粒(MCM)(4.2 mM碳酸氢盐涂层)将以持续释放的方式稳定释放具有生物活性的胶质细胞源性神经营养因子(GDNF)和神经生长因子(NGF),旨在通过测试矿物质包被微粒在10 mm坐骨神经移植物远端释放生长因子,诱导神经移植物轴突生长和恢复后肢功能的能力验证该假设。实验发现,体外生理条件下,矿物质包被微粒释放神经生长因子和胶质细胞源性神经营养因子持续3d,然后持续释放至少22d。与未复合生长因子的同种异体神经移植物治疗的大鼠相比, 矿物质包被微粒在坐骨神经移植物的远端释放神经生长因子和胶质细胞源性神经营养因子可促进更多髓鞘轴突延伸至移植物的远端,大鼠的后肢功能也从术后7-12周显示出明显的改善。总之,矿物质包被微粒持续释放具有生物活性的神经生长因子和胶质细胞源性神经营养因子可明显促进神经移植物轴突的生长,改善周围神经缺损大鼠的后肢功能。动物实验于2017年10月6日获威斯康星大学麦迪逊分校动物护理和使用委员会(ACUC,协议编号M5958)批准。

https://orcid.org/0000-0002-5062-5952 (Amgad S. Hanna)

Abstract: The gold standard for treating peripheral nerve injuries that have large nerve gaps where the nerves cannot be directly sutured back together because it creates tension on the nerve, is to incorporate an autologous nerve graft. However, even with the incorporation of a nerve graft, generally patients only regain a small portion of function in limbs affected by the injury. Although, there has been some promising results using growth factors to induce more axon growth through the nerve graft, many of these previous therapies are limited in their ability to release growth factors in a sustained manner and tailor them to a desired time frame. The ideal drug delivery platform would deliver growth factors at therapeutic levels for enough time to grow axons the entire length of the nerve graft. We hypothesized that mineral coated microparticles (MCMs) would bind, stabilize and release biologically active glial cell-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in a sustained manner. Therefore, the objective of this study was to test the ability of MCMs releasing growth factors at the distal end of a 10 mm sciatic nerve graft, to induce axon growth through the nerve graft and restore hind limb function. After sciatic nerve grafting in Lewis rats, the hind limb function was tested weekly by measuring the angle of the ankle at toe lift-off while walking down a track. Twelve weeks after grafting, the grafts were harvested and myelinated axons were analyzed proximal to the graft, in the center of the graft, and distal to the graft. Under physiological conditions in vitro, the MCMs delivered a burst release of NGF and GDNF for 3 days followed by a sustained release for at least 22 days. In vivo, MCMs releasing NGF and GDNF at the distal end of sciatic nerve grafts resulted in significantly more myelinated axons extending distal to the graft when compared to rats that received nerve grafts without growth factor treatment. The rats with nerve grafts incorporated with MCMs releasing NGF and GDNF also showed significant improvement in hind limb function starting at 7 weeks postoperatively and continuing through 12 weeks postoperatively when compared to rats that received nerve grafts without growth factor treatment. In conclusion, MCMs released biologically active NGF and GDNF in a sustained manner, which significantly enhanced axon growth resulting in a significant improvement of hind limb function in rats. The animal experiments were approved by University of Wisconsin-Madison Animal Care and Use Committee (ACUC, protocol# M5958) on January 3, 2018.

Key words: autografts, axon growth, drug delivery, glial cell-derived neurotrophic factor, growth factors, mineral coatings, nerve grafting, nerve growth factor