Three-dimensional bioprinting collagen/silk fibroin scaffold combined with neural stem cells promotes nerve regeneration after spinal cord injury.

Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord. Indeed, cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration. This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord. This scaffold allows cell growth in vitro and in vivo. To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury. Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed), spinal cord injury (transection injury of T10 spinal cord without any transplantation), 3D-CF (3D scaffold was transplanted into the local injured cavity), and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity. Neuroelectrophysiology, imaging, hematoxylin-eosin staining, argentaffin staining, immunofluorescence staining, and western blot assay were performed. Apart from the sham group, neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups. Moreover, latency of the 3D-CF + NSCs group was significantly reduced, while the amplitude was significantly increased in motor evoked potential tests. The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group. Moreover, regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups. These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord. This study was approved by the Institutional Animal Care and Use Committee of People's Armed Police Force Medical Center in 2017 (approval No. 2017-0007.2).

Neurological functional evaluation based on accurate motions in big animals with traumatic brain injury.

An accurate and effective neurological evaluation is indispensable in the treatment and rehabilitation of traumatic brain injury. However, most of the existing evaluation methods in basic research and clinical practice are not objective or intuitive for assessing the neurological function of big animals, and are also difficult to use to qualify the extent of damage and recovery. In the present study, we established a big animal model of traumatic brain injury by impacting the cortical motor region of beagles. At 2 weeks after successful modeling, we detected neurological deficiencies in the animal model using a series of techniques, including three-dimensional motion capture, electromyogram and ground reaction force. These novel technologies may play an increasingly important role in the field of traumatic brain injury diagnosis and rehabilitation in the future. The experimental protocol was approved by the Animal Care and Use Committee of Logistics University of People's Armed Police Force (approval No. 2017-0006.2).

Multiplanar and combined distraction osteogenesis for three-dimensional and functional reconstruction of unilateral large maxillary defects.

We have developed a new way of three-dimensional and functional reconstruction of unilateral large maxillary defects by multiplanar and combined distraction osteogenesis of the zygoma, maxillary alveolar process, and hard palate. In the first procedure we started the internal curvilinear distraction osteogenesis of the left zygoma in one patient who had had a left maxillectomy to rebuild midfacial bony support. In the second procedure, the internal curvilinear distraction osteogenesis of the maxillary anterior alveolar process and straight distraction osteogenesis of the right hard palate were used to restore the posterior alveolar process and left palate. In the third procedure, the distracted zygoma and alveolar process were connected by a small local bone graft. The important lost maxillary bony architecture was re-established three-dimensionally and resulted in a natural facial appearance, normal speech and swallowing, and good foundation for chewing. This may be the first example of three-dimensional and functional reconstruction of unilateral large maxillary defects that did not require bone grafts from other anatomical areas.

Evaluation of a new semiburied curvilinear distraction device in dogs.

We developed a semiburied, curvilinear distraction device for use in osteogenesis in the reconstruction of maxillofacial defects. The device was tested in two dogs, which had segmental defects made in the maxilla and zygoma. The residual zygoma was distracted with the device. The bony transport discs were distracted about 12mm around an arc, and the new bone formed well in the distracted gap. The semiburied curvilinear distraction device has proved to be reliable for internal curvilinear distraction. Its clinical applicability needs to be studied further.

[Application of multislice helical computed tomography in maxillofacial distraction osteogenesis].

OBJECTIVE: To develop the method and investigate the value of the application of multislice helical computed tomography (CT) in the maxillofacial distraction osteogenesis. METHODS: Twelve cases of maxillofacial distraction osteogenesis (3 in zygoma, 2 in maxilla, and 7 in mandible) were scanned by the multislice helical CT, then the reconstruction of three dimensional and fault image and the relative measurement were carried out to study the effect of distraction and osteogenesis. RESULTS: The three dimensional image provided clear and high resolution stereoscopic view that the effect of distraction osteogenesis could be evaluated easily and exactly. The fault image could be set up in private computer by Mimics and the measurements, such as distance, thickness and density, could be performed as expected. The effect of 12 cases was satisfied, and the average distracted distance was 16.73 mm. CONCLUSION: Basing on multislice helical CT scanning, the high resolution image reconstruction and relative measurement data could be obtained which could meet the need of clear and direct observation. Its application in the maxillofacial distraction osteogenesis is expecting and promising.

[Segmental reconstruction of maxillary defects by arced distraction osteogenesis of zygoma].

OBJECTIVE: To study the possibility of segmental maxillary regeneration by arced distraction osteogenesis of zygoma. METHODS: The distraction of zygoma with the internal arced devices was performed in 2 dogs to simulate the reconstruction of maxillary defect. The zygoma was distracted about 12 mm, and the process of new bone formation was studied by histology and scanning electron microscopy. RESULTS: The transport disk was distracted about 12 mm around the arc. After 8 weeks of consolidation, the density of new bone was close to that of normal bone. CONCLUSIONS: The segmental maxillary regeneration by arced distraction osteogenesis of zygoma is possible.

[Applied anatomy study related to implants in the temporal bone region].

OBJECTIVE: To study the bone anatomic structure of the temporal bone region and provide reference in implant surgery in this region. METHODS: Manual quantitative measurements of the bone structure were performed in 73 skull specimens (38 from male and 35 from female). RESULTS: In the area of 8:00-11:00 (right ear) and 16-22 mm from center of the external auditory canal in the temporal bone region, the minimum bone thickness is as follows: 11:00: 6.77 mm in male, 5.18 mm in female; 10:00: 8.60 mm in male, 6.77 mm in female; 9:00: 9.85 mm in male, 7.30 mm in female; 8:00: 14.50 mm in male, 10.80 mm in female. CONCLUSION: (1) In the temporal bone region, the area of 8:00-11:00 (right ear) and 16-22 mm from center of the external auditory canal offers sufficient bone for implants. The length of implants should be as follows: 11:00: 4-5 mm in male, 3-4 mm in female; 10:00: 4-7 mm in male, 4-5 mm in female; 9:00: 4-8 mm in male, 4-6 mm in female; 8:00: 4-12 mm in male, 4-8 mm in female. (2) Towards the external auditory canal and from 12:00 to 11:00, 10:00 to 8:00, the bone became thicker, so, if no ample bone is available in the initial site, the location should be shifted anti-clockwise in right side (clockwise in left side) and closer to the external auditory canal. (3) The differences between male and female are statistically significant in the temporal bone region, so they should be treated distinguishingly during the clinical practices.