Controlled Release Tissue Engineering Scaffolds Delivering Chondroitinase ABC Repair In The Injury Of Spinal Hemisection

Objective:To prepare an effective and biodegradable tissue with controlled release engineering scaffold for ChABC, which can release drug slowly and steadily with low nerve stimulation and promote functional recovery and regeneration of the hemisected spinal cord.Methods:(1) ChABC-loaded PPC and CS scaffold for tissue engineering was preparated by electrospinning, analysising the parameters of stent diameter, drug loading rate, encapsulation efficiency, and then to observe the drug releasing rate,drug inactivation rate of tissue engineering scaffolds and the degradating rate of the scaffold with phosphate buffer solution (PBS).(2) Adult female Wistar rats were randomly selected with a number of70, which were randomly divided into ChABC sustained release tissue engineering scaffolds treatment group (group A) and tissue engineering scaffolds in treatment group (group B), respectively implanted the ChABC sustained release tissue engineering scaffolds and tissue engineering scaffolds in T10spinal cord hemisection injury on the right side area (3) Scoring BBB movement function score in rat spinal cord injury surgery preoperative and postoperative1day,3days,7days,14days,21days and28days line (4) GAP-43immunohistochemical staining was performed in groups in postoperative1week,2weeks,3weeks and4weeks, analysis of NF-200and GFAP double standard fluorescence staining was earned on postoperative4weeks.Results:(1) ChABC sustained release tissue engineering scaffolds in the PPC of8%mass concentration, the voltage of10-15kv,the distance of15-20cm can be spun into fiber with diameter of about3micron smooth, pure PPC fiber. uniform diameter, chitosan microsphere is smooth, PPC, blended with chitosan spun stent after a beaded sample structure, it can slowly release active ChABC, after12days stents degradation of weightlessness rate is about7%.(2) The right posterior limbs of rats are paralysis after SCI, and begining to recover after5days, restoring more apparent at2weeks to3weeks.The change is not significant among the4weeks, there is no significant difference between preoperative and postoperative1day,1day,3days,1week,2weeks in BBB movement function score, but BBB movement function score of group A is higher than group B in3weeks and4weeks postoperatively.(P<0.05).(3) General observation of the spinal cord specimens,there is less scarring in group A than group B in postoperative3weeks, under GFAP and NF-200double labeling immunofluorescencer, empty area of the spinal cord injury group A was significantly less than in group B in postoperative4weeks (4) GAP-43immunohistochemical staining:after1week,2weeks,3weeks and4weeks, the positive expression of spinal cord hemisection injury area in group A was higher than in group B,2,3weeks compared to1,4weeks werer more apparently; postoperative four weeks NF200and GFAP double labeling:NF-200A expression of the damage zone of the spinal hemisection cephalic in group A was significantly more than group B, the newborn axon grow into the cavity; GFAP expression of the damage zone of the spinal hemisection cephalic in group A was significantly more than group B. no new axons grow and break through the glial scar..Conclusions:(1) Electro spinning method has been applied successfully to prepare ChABC PPC and CS tissue engineering scaffolds, it has the advantages of stable drug release, the local application was no nerve stimulation and it is biodegradable.(2) The ChABC sustained release tissue engineering scaffolds can promote nerve repair,the regeneration of axons, and recovery of motor function in rats with spinal cord hemisection injury.