Objective To review the basic researches and the cl inical appl ication of the nano-neural tissue engineering materials, especially the electrically conductive carbon nanotubes (CNT). Methods The l iterature concerning the basic and cl inical researches of the conductive materials of nano-neural tissue engineering, especially the electrically conductive CNT were reviewed. Results The researches of conductive materials of nano-neural tissue engineering have made some progress, the electrically conductive CNT can not only promote Schwan cells’ adhension, migration, and prol iferation, but also mimic the function of electric conductivity of neural myel in and enhance neurite growth and regeneration. So the electrically conductive CNT make great sense in stimulating and directing the growth of neurite and the regeneration of axons. Conclusion Because of these unique properties, the electrically conductive CNT have great advantages in peripheral nerve repair and function reconstruction, and are promising to provide a novel method for cl inical peri pheral nerve repair and function reconstruction after injury.
Objective To investigate the feasibility of Drawtex hydroconductive dressing in treatment of early implantation-associated infection and soft tissue defect after internal fixation of tibial fracture. Methods Thirty-six New Zealand rabbits were used to prepare the model of early implantation-associated infection after internal fixation of tibial fracture, and randomly divided into 3 groups (n=12) . The infected wounds were covered with Drawtex hydroconductive dressing (group A), chitosan solution gauze (group B), and normal saline gauze (group C), respectively. The dressing was changed every 2 days. X-ray films were performed at 1, 14, and 21 days. The gross observation, microbiological evaluation, and histological observation were done at 21 days. Results There was no significant difference in the wound grading according to the Jamesʾ grading criteria between groups at 21 days (χ2=3.713, P=0.156). X-ray films showed no bone destruction in all groups at 1 day; and there was no significant difference in radiographic scores between groups (P>0.05). At 14 days, the mild osteolysis was observed in group B; the radiographic score was significantly lower in groups A and C than in group B (P<0.05), but there was no significant difference between groups A and C (P>0.05). At 21 days, the osteolysis and osteomyelitis were observed in groups B and C; the radiographic score was significantly lower in group A than in groups B and C (P<0.05), but there was no significant difference between groups B and C (P>0.05). Also, the microorganism in bone tissue of group A was less than that of groups B and C (P<0.05); and the difference between group B and group C was not significant (P>0.05). Histological observation showed the mild inflammatory cell infiltration in group A and many inflammatory cells in groups B and C. The Smeltzer histological score was significant lower in group A than in groups B and C (P<0.05); and there was no significant difference between groups B and C (P>0.05). Conclusion Drawtex hydroconductive dressing can be used for the implantation-associated infection after tibial fracture internal fixation. And the effectiveness of Drawtex hydroconductive dressing is better than that of chitosan solution gauze and normal saline gauze.
ObjectiveTo explore the preparation method, physical and chemical properties, and biocompatibility of a conductive composite scaffold based on polypyrrole/silk fibroin (PPy/SF) fiber with " shell-core” structure, and to provide a preliminary research basis for the application in the field of tissue engineered neuroscience.Methods The conductive fibers with " shell-core” structure were prepared by three-dimensional printing combined with in-situ polymerization. PPy/SF fiber-based conductive composite scaffolds were formed by electrospinning. In addition, core-free PPy conductive fibers and SF electrospinning fibers were prepared. The stability, biomechanics, electrical conductivity, degradation performance, and biological activity of each material were tested to analyze the comprehensive properties of fiber-based conductive composite scaffolds.ResultsCompared with pure core-free PPy conductive fibers and SF electrospinning fibers, the PPy/SF fiber-based conductive composite scaffolds with " shell-core” structure could better maintain the stability performance, enhance the mechanical stretchability of the composite scaffolds, maintain long-term electrical activity, and improve the anti-degradation performance. At the same time, PPy/SF conductive composite scaffolds were suitable for NIH3T3 cells attachment, conducive to cell proliferation, and had good biological activity.ConclusionPPy/SF fiber-based conductive composite scaffolds meet the needs of conductivity, stability, and biological activity of artificial nerve grafts, and provide a new idea for the development of a new generation of high-performance and multi-functional composite materials.