Using NGF heparin-poloxamer thermosensitive hydrogels to enhance the nerve regeneration for spinal cord injury. (1st January 2016)

• Record Type: Journal Article
• Authors: Zhao, Ying-Zheng; Jiang, Xi; Xiao, Jian; Lin, Qian; Yu, Wen-Ze; Tian, Fu-Rong; Mao, Kai-Li; Yang, Wei; Wong, Ho Lun; Lu, Cui-Tao
• Is Part Of: Acta biomaterialia. Volume 29(2015)
• Page Start: 71
• Page End: 80
• Publication Date: 2016-01-01
• Subjects: SCI spinal cord injury -- NGF nerve growth factor -- ER endoplasmic reticulum -- HP heparin-poloxamer -- NGF–HP nerve growth factor–heparin poloxamer -- BBB Basso, Beattie, and Bresnahan -- BDA biotinylated dextran amine -- GFAP glial fibrillary acidic protein; Spinal cord injury -- Nerve growth factor (NGF) -- Thermosensitive hydrogel -- Nerve regeneration -- Controlled release; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1016/j.actbio.2015.10.014
• Languages: English
• ISSNs: 1742-7061

Abstract

Graphical abstract: Abstract: Objective: Nerve growth factor (NGF) has potential in spinal cord injury (SCI) therapy, but limited by the poor physicochemical stability and low ability to cross the blood spinal cord barrier. Novel heparin-poloxamer (HP) thermo-sensitive hydrogel was constructed to enhance the NGF regeneration on SCI. Method: NGF–HP thermo-sensitive hydrogel was prepared and related characteristics including gelation temperature, rheological behavior and micromorphology were measured. Local NGF delivery to the injured spinal cord was achieved by in situ injection in the injured space. The cellular uptake of NGF–HP hydrogel was evaluated with PC12 cells in vitro . Pathologic characteristics and neuron regeneration effects on the SCI rats were studied to evaluate the enhanced therapy of NGF–HP hydrogel. Endoplasmic reticulum (ER) stress-induced apoptosis was analyzed to explore the related mechanism in SCI regeneration. Results: NGF–HP hydrogel showed good morphology and stable bioactivity of NGF in vitro . NGF–HP hydrogel combined treatment significantly enhanced the efficiency of NGF cellular uptake ( P < 0.05) without obvious cytotoxicity. Significant improvements in both neuron functions and tissue morphology on the SCI rats were observed in NGF–HP hydrogel group. Compared with free HP hydrogel and NGF treatment groups, NGF–HP hydrogel group showed significant inhibition on the formation of glial scars in the extreme crushed rat SCI model. The neuroprotective effects of NGF–HP were related to the inhibition of chronic ER stress-induced apoptosis. Conclusions: HP hydrogel combined with orthotopic injection technique might be an effective method to deliver NGF into the injured site, which will provide an effective strategy for SCI regeneration. Statement of significance: Spinal cord injury (SCI) is a devastating condition that can lead to sudden loss of sensory and autonomic function. Current treatment includes decompression surgery, injury stabilization, secondary complications prevention and rehabilitation. However, neurological recovery is limited. Nerve growth factor (NGF) has potential in SCI therapy, but limited by the poor physicochemical stability and low ability to cross the blood spinal cord barrier. Hydrogels have good affinity and compatibility to biological tissue. In this study, we developed a novel heparin-poloxamer (HP) thermo-sensitive hydrogel to enhance the spinal cord regeneration of NGF. From SCI rat experiment, HP hydrogel combined with orthotopic injection technique showed best neuroprotective effects among experimental groups. This novel combined technique will provide an effective strategy for SCI regeneration.