Objective To investigate the role of composite graphene-protein hydrogels in repairing spinal cord injury (SCI) and promoting neural regeneration in rats. MethodsA composite graphene-protein hydrogel was prepared using the radical copolymerization method. Its physical properties, including adhesion, were evaluated through shear testing, and cytotoxicity was assessed using the MTT assay. Twenty-four adult female Sprague-Dawley rats were randomly divided into four groups: sham surgery, injury, hydrogel, and hydrogel+graphene groups (6 rats per group). The sham surgery group only exposed the T10 spinal cord tissue. The other three groups underwent laminectomy combined with spinal cord tissue block resection to establish a T10 SCI model. Post-modeling, the hydrogel group and the hydrogel+graphene group received implants of the protein hydrogel and composite graphene-protein hydrogels, respectively, at the injury defect site. The injury group received no additional implant treatment. Postoperative survival rates were monitored across groups. Hindlimb motor function recovery was assessed weekly via Basso-Beattie-Bresnahan (BBB) scores during the 12-week postoperative period. At 12 weeks, motor-evoked potentials were measured to assess neurophysiological function. T10 spinal cord tissue was harvested for histopathological examination via HE staining, followed by immunofluorescence staining for glial fibrillary acidic protein (GFAP), Laminin, and 5-hydroxytryptamine (5-HT) immunofluorescence staining to observe glial scar formation and axonal regeneration at the injury site. ResultsShear testing and MTT assays demonstrated that the composite graphene-protein hydrogels exhibited excellent underwater adhesion and biocompatibility. All rats in each group survived until the end of the experiment. During 12-week postoperative period, the BBB scores in the hydrogel and hydrogel+graphene groups showed a sustained upward trend over time (P<0.05). At 12 weeks after operation, BBB scores were significantly higher in the hydrogel and hydrogel+graphene groups than in the injury group, in the hydrogel+graphene group than in the hydrogel group, showing significant differences between groups (P<0.05). Neurophysiological testing revealed that the motor evoked potential amplitude in the hydrogel+graphene group was significantly higher than that in the injury group and the hydrogel group (P<0.05), with no significant difference compared to the sham surgery group (P>0.05). HE staining revealed that the hydrogel+graphene group exhibited spinal cord morphology most similar to the sham surgery group, with significantly restored tissue structural integrity and minimal vacuolation and inflammatory cell infiltration. Quantitative immunofluorescence analysis revealed that the relative fluorescence intensity of GFAP and Laminin in the injury group was significantly higher than that in the other groups (P<0.05). The relative fluorescence intensity of GFAP and Laminin in the hydrogel+graphene group was significantly lower than that in the hydrogel group (P<0.05). The relative fluorescence intensity of 5-HT in the injury group was significantly lower than that in the other groups (P<0.05). The relative fluorescence intensity of 5-HT in the hydrogel+graphene group was significantly higher than that in the hydrogel group (P<0.05), with no significant difference compared to the sham surgery group (P>0.05). ConclusionThe composite graphene-protein hydrogels effectively repairs SCI in rats by significantly inhibiting glial scar formation at the injury site, promoting 5-HT-positive axonal regeneration, and improving post-injury neurophysiological function and hindlimb motor recovery. It represents a spinal cord repair material with potential clinical application value.
Abstract： Objective To investigate the effect of preoperative oral carbohydrate （CHO） administration on perioperative risks of patients with surgical thoracic oncology，and provide evidence for establishing new scientific preoperative fasting strategy.Methods?In this prospective study， from July to September 2010，32 out of 65 enrolled patients with surgical thoracic oncology in Department 1 of Thoracic Surgery，Cancer Hospital of Peking University， were randomly allocated to preoperative experiment group （fasting overnight and oral 12.5% dextrose 400 ml administration 2 h before anesthesia induction） or control group （fasting overnight and water deprivation from midnight）. Clinical data were collected including subjective evaluation of thirst and hunger measured by visual analogue scale （VAS）， blood glucose level（BGL），serum insulin level， homeostasis model assessment insulin resistance（HOMA-IR），postoperative length of hospital stay （LOS） and complications.Results?Sixteen patients were enrolled in each group. VAS scores of thirst and hunger of the preoperative experiment group at 1 h before anesthesia induction were significantly lower than those of the control group（24 vs. 49，24 vs. 62 ，P=0.000）. BGL（8.59±0.43 mmol/L vs. 5.59±0.43 mmol/L， P=0.000）， serum insulin level （24.33±1.80 mIU/ ml vs. 16.28±1.80 mIU/ml， P=0.004）and HOMA-IR（9.23±0.77 vs. 4.03±0.77，P=0.000）of the preoperative experiment group before anesthesia induction were significantly higher than those of the control group，and these three variables of the preoperative experiment group returned to baseline level soon after surgery. There was no statistical difference in postoperative LOS and complication rate between the two groups （P＞0.05）.Conclusion?Preoperative oral CHO treatment is safe for non-diabetic patients with surgical thoracic oncology， can alleviate their subjective discomfort，decrease insulin resistance， and ameliorate their perioperative stress and metabolism.