Linear ordered collagen scaffolds loaded with collagen-binding neurotrophin-3 promote axonal regeneration and partial functional recovery after complete spinal cord transection.
Neurotrophin-3 (NT3) is an important neurotrophic factor for spinal cord injury (SCI) repair. However, constant exchange of cerebrospinal fluid often decreases the effective dosage of NT3 at the targeted injury site. In the present study, a recombinant collagen-binding NT3 (CBD-NT3), consisting of a collagen-binding domain (CBD) and native NT3, was constructed. Linear rat-tail collagen (LRTC) was used as a physical carrier for CBD-NT3 to construct a LRTC/C3 system. The collagen-binding ability of CBD-NT3 was verified, and the bioactivity of CBD-NT3 was assayed with neurite outgrowth of dorsal root ganglia (DRG) explants and DRG cells in vitro. After complete spinal cord transection in rats, LRTC/CBD-NT3 or the LRTC/NT3 system was transplanted into the injury site. Hindlimb locomotion recovery was closely observed using the Basso-Beattie-Bresnahan (BBB) locomotor rating scale and the grid walk test. Significant improvement was observed in the LRTC/CBD-NT3 group. The results of regenerating nerve fiber and anterograde tracing of biotinylated dextran amine (BDA)-labeled corticospinal tract (CST) fibers demonstrated axonal regeneration of LRTC/CBD-NT3 in the injured spinal cord. Serotonin fiber regrowth also illustrated the effectiveness of LRTC/CBD-NT3. Thus, collagen-binding NT3 with LRTC may provide an effective method for treating SCI.
Fan
Juan
J
Department of Neurosurgery, Beijing Military General Hospital, Beijing, China.
Xiao
Zhifeng
Z
Zhang
Hongtian
H
Chen
Bing
B
Tang
Guoqiang
G
Hou
Xianglin
X
Ding
Wenyong
W
Wang
Bin
B
Zhang
Peng
P
Dai
Jianwu
J
Xu
Ruxiang
R
D000818:Animals; D001369:Axons / Q000473:pathology / Q000502:physiology*; D003094:Collagen / Q000378:metabolism*; D005260:Female; D006801:Humans; D045170:Matrix Attachment Regions / Q000502:physiology; D009416:Nerve Regeneration / Q000502:physiology*; D020933:Neurotrophin 3 / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology
D020933:Neurotrophin 3; D003094:Collagen