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 James? 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.
ObjectiveTo review the application and research progress of the electroactivity graphene-based materials (GBMs) in the field of bone defect repair. Methods The recent domestic and international literature was extensively reviewed to systematically summarize the electroactive performance of GBMs in bone repair composite materials. The unique advantages of GBMs in material preparation, multi-functionalization, and application were discussed, along with their contributions and clinical translation challenges in bone tissue engineering. ResultsBone defect repair remains a major global clinical challenge. Utilizing electroactive biomaterials to mimic the endogenous bioelectric microenvironment is a frontier strategy to accelerate bone regeneration. With outstanding electrical conductivity and physicochemical properties, GBMs exhibit great potential in constructing electroactive bone repair materials. The introduction of GBMs into conductive scaffolds or self-powered piezoelectric systems not only builds a continuous conductive network to promote electrical signal transduction and osteogenic differentiation, but also exerts broad-spectrum antibacterial effects via physical cutting and induced oxidative stress. Furthermore, GBMs promote the M2 polarization of macrophages, achieving a multi-effect synergy of antimicrobial and immunomodulatory functions within a single material system. Extensive animal experiments have verified that GBMs can significantly accelerate new bone formation and interfacial integration in complex or even infected microenvironments. Moreover, the biocompatibility and degradation performance of GBMs are highly dependent on their concentration, size, and oxidation degree. The cytotoxicity induced by high concentrations, the batch-to-batch heterogeneity of materials, and the long-term retention of large-sized residues in vivo remain the primary challenges at present. Conclusion Electroactivity GBMs materials provide an innovative, efficient, and multifunctional synergistic solution for bone repair. Future research should focus on the standardization of electrical stimulation parameters, overcoming the physicochemical heterogeneity of the materials, and systematically evaluating their long-term in vivo biosafety and degradation kinetics to accelerate their clinical translation.