Improving the protective effects of aFGF for peripheral nerve injury repair using sulfated chitooligosaccharides

Yanmei Liu; Fenglin Yu; Beibei Zhang; Meng Zhou; Yu Bei; Yifan Zhang; Jianzhong Tang; Yan Yang; Yadong Huang; Qi Xiang; Yueping Zhao; Qian Liang; Yang Liu

doi:10.1016/j.ajps.2018.09.007

Improving the protective effects of aFGF for peripheral nerve injury repair using sulfated chitooligosaccharides

Asian J Pharm Sci. 2019 Sep;14(5):511-520. doi: 10.1016/j.ajps.2018.09.007. Epub 2018 Nov 1.

Authors

Yanmei Liu¹, Fenglin Yu¹, Beibei Zhang², Meng Zhou³, Yu Bei³, Yifan Zhang¹, Jianzhong Tang¹, Yan Yang¹, Yadong Huang^{1

3}, Qi Xiang^{1

3}, Yueping Zhao⁴, Qian Liang⁴, Yang Liu⁴

Affiliations

¹ Institute of Biomedicine and Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou 510632, China.
² Department of Pharmacy, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
³ College of Pharmacy, Jinan University, Guangzhou 510632, China.
⁴ Department of Stomatology, Jinan University Medical College, Guangzhou 510632, China.

Abstract

Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor (aFGF) promotes the growth and survival of neurons and is a possible treatment for peripheral nerve injury. Yet, the actual therapeutic utility of aFGF is limited by its short half-life and instability in vivo. In the present study, we prepared sulfated chitooligosaccharides (SCOS), which have heparin-like properties, to improve the bioactivity of aFGF. We investigated the protective effects of SCOS with or without aFGF on RSC96 cells exposed to Na₂S₂O₄ hypoxia/reoxygenation injury. Cell viability was measured by MTT assay and cytotoxicity induced by Na₂S₂O₄ was assessed by lactate dehydrogenase (LDH) release into the culture medium. Pretreatment with aFGF and SCOS dramatically decreased LDH release after injury compared to pretreatment with aFGF or SCOS alone. We subsequently prepared an aFGF/SCOS thermo-sensitive hydrogel with poloxamer and examined its effects in vivo. Paw withdrawal thresholds and thermal withdrawal latencies were measured in rats with sciatic nerve injury. Local injection of the aFGF/SCOS hydrogels (aFGF: 40, 80 µg/kg) increased the efficiency of sciatic nerve repair compared to aFGF (80 µg/kg) hydrogel alone. Especially aFGF/SCOS thermo-sensitive hydrogel decreased paw withdrawal thresholds from 117.75 ± 8.38 (g, 4 d) to 65.74 ± 3.39 (g, 10 d), but aFGF alone group were 140.58 ± 27.54 (g, 4 d) to 89.12 ± 5.60 (g, 10 d) (aFGF dose was 80 µg/kg, P < 0.05, n = 8). The thermal withdrawal latencies decreased from 11.61 ± 2.26 (s, 4 d) to 2.37 ±0.67 (s, 10 d). However, aFGF alone group were from 17.69 ± 1.47 (s, 4 d) to 4.65 ± 1.73 (s, 10 d) (P < 0.05, n = 8). Furthermore, the aFGF/SCOS hydrogels also exhibited good biocompatibility in mice. In summary, SCOS improved the protective effects of aFGF in RSC96 cells injured with Na₂S₂O₄ and increased the efficiency of nerve repair and recovery of function in rats with sciatic nerve injury. These findings pave an avenue for the development of novel prophylactic and therapeutic strategies for peripheral nerve injury.

Keywords: Acidic fibroblast growth factor; Neuroprotection; Peripheral nerve injury; RSC96 cells; Sulfated chitooligosaccharides.