This work was supported by the National Natural Science Foundation of China, Nos. 82102314 (to ZSJ), and 32170977 (to HSL) and Natural Science Foundation of Guangdong Province, Nos. 2022A1515010438 (to ZSJ) and 2022A1515012306 (to HSL). This study was supported by the Clinical Frontier Technology Program of the First Affiliated Hospital of Jinan University, China, Nos. JNU1AF- CFTP- 2022- a01206 (to HSL). This study was supported by Guangzhou Science and Technology Plan Project, Nos. 202201020018 (to HSL), 2023A04J1284 (to ZSJ) and 2023A03J1024 (to HSL).

The studies involving animals were reviewed and approved by the Ethics Committee of Jinan University.
1. Anesthetization of animals and T10 spinal laminectomy
<ol>
	<li>Use 8 weeks-old female young adult C57/6J mice for this study. Anesthetize the mice by intraperitoneal injection of ketamine (100 mg/kg) and&#160;diazepam&#160;(5 mg/kg). Check for successful anesthetization indicated by loss of pain reflex. Apply vet ointment on eyes to prevent dryness under anesthesia.</li>...

A Spinal Cord Injury Contusion Device for Accurate Mouse Models

<ol>
	<li>Venkatesh, K., Ghosh, S. K., Mullick, M., Manivasagam, G., Sen, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+injury:+pathophysiology,+treatment+strategies,+associated+challenges,+and+future+implications.">Spinal cord injury: pathophysiology, treatment strategies, associated challenges, and future implications.</a> Cell and Tissue Research. 377 (2), 125-151 (2019).</li><li>Chiu, C. W., Cheng, H., Hsieh, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contusion+Spinal+Cord+Injury+Rat+Model.">Contusion Spinal Cord Injury Rat Model.</a> Bio Protocol. 7 (12), e2337 (2017).</li><li>Thygesen, M. M., Guldb&#230;k-Svensson, F., Rasmussen, M. M., Lauridsen, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contusion+Spinal+Cord+Injury+via+a+Microsurgical+Laminectomy+in+the+Regenerative+Axolotl.">Contusion Spinal Cord Injury via a Microsurgical Laminectomy in the Regenerative Axolotl.</a> Journal of Visualized Experiments. (152), 60337 (2019).</li><li>Anderson, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+controlled+pneumatic+technique+for+experimental+spinal+cord+contusion.">A controlled pneumatic technique for experimental spinal cord contusion.</a> Journal of Neuroscience Methods. 6 (4), 327-333 (1982).</li><li>Allen, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SURGERY+OF+EXPERIMENTAL+LESION+OF+SPINAL+CORD+EQUIVALENT+TO+CRUSH+INJURY+OF+FRACTURE+DISLOCATION+OF+SPINAL+COLUMN:+A+PRELIMINARY+REPORT.">SURGERY OF EXPERIMENTAL LESION OF SPINAL CORD EQUIVALENT TO CRUSH INJURY OF FRACTURE DISLOCATION OF SPINAL COLUMN: A PRELIMINARY REPORT.</a> Journal of the American Medical Association. LVII (11), 878-880 (1911).</li><li>Cheriyan, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+injury+models:+a+review.">Spinal cord injury models: a review.</a> Spinal Cord. 52 (8), 588-595 (2014).</li><li>Yan, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+modified+impactor+for+establishing+a+graded+contusion+spinal+cord+injury+model+in+rats.">A modified impactor for establishing a graded contusion spinal cord injury model in rats.</a> Annals of Translational Medicine. 10 (8), 436 (2022).</li><li>Gruner, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+monitored+contusion+model+of+spinal+cord+injury+in+the+rat.">A monitored contusion model of spinal cord injury in the rat.</a> Journal of Neurotrauma. 9 (2), 123-126 (1992).</li><li>Ghnenis, A. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+the+Cardiometabolic+Disorders+after+Spinal+Cord+Injury+in+Mice.">Evaluation of the Cardiometabolic Disorders after Spinal Cord Injury in Mice.</a> Biology (Basel). 11 (4), 495 (2022).</li><li>Scheff, S. W., Rabchevsky, A. G., Fugaccia, I., Main, J. A., Lumpp, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+modeling+of+spinal+cord+injury:+characterization+of+a+force-defined+injury+device.">Experimental modeling of spinal cord injury: characterization of a force-defined injury device.</a> Journal of Neurotrauma. 20 (2), 179-193 (2003).</li><li>Hong, Y. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+stimulation+improves+inflammatory+resolution,+neuroprotection,+and+functional+recovery+after+spinal+cord+injury.">Ultrasound stimulation improves inflammatory resolution, neuroprotection, and functional recovery after spinal cord injury.</a> Scientific Reports. 12 (1), 3636 (2022).</li><li>Noyes, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electromechanical+impactor+for+producing+experimental+spinal+cord+injury+in+animals.">Electromechanical impactor for producing experimental spinal cord injury in animals.</a> Medical &amp; Biological Engineering &amp; Computing. 25 (3), 335-340 (1987).</li><li>Stokes, B. T., Noyes, D. H., Behrmann, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+electromechanical+spinal+injury+technique+with+dynamic+sensitivity.">An electromechanical spinal injury technique with dynamic sensitivity.</a> Journal of Neurotrauma. 9 (3), 187-195 (1992).</li><li>Pearse, D. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histopathological+and+behavioral+characterization+of+a+novel+cervical+spinal+cord+displacement+contusion+injury+in+the+rat.">Histopathological and behavioral characterization of a novel cervical spinal cord displacement contusion injury in the rat.</a> Journal of Neurotrauma. 22 (6), 680-702 (2005).</li><li>Wu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Tissue+Displacement-based+Contusive+Spinal+Cord+Injury+Model+in+Mice.">A Tissue Displacement-based Contusive Spinal Cord Injury Model in Mice.</a> Journal of Visualized Experiments. (124), 54988 (2017).</li><li>Forgione, N., Chamankhah, M., Fehlings, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Mouse+Model+of+Bilateral+Cervical+Contusion-Compression+Spinal+Cord+Injury.">A Mouse Model of Bilateral Cervical Contusion-Compression Spinal Cord Injury.</a> Journal of Neurotrauma. 34 (6), 1227-1239 (2017).</li><li>Ji, Z. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+bioactive+iridium+metal-complex+alleviates+spinal+cord+injury+via+ROS+scavenging+and+inflammation+reduction.">Highly bioactive iridium metal-complex alleviates spinal cord injury via ROS scavenging and inflammation reduction.</a> Biomaterials. 284, 121481 (2022).</li><li>Chen, C., Qiao, X., Liu, W., Fekete, C., Reinhardt, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+spinal+cord+injury+in+China:+A+systematic+review+of+the+chinese+and+english+literature.">Epidemiology of spinal cord injury in China: A systematic review of the chinese and english literature.</a> Spinal Cord. 60 (12), 1050-1061 (2022).</li><li>Flack, J. A., Sharma, K. D., Xie, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delving+into+the+recent+advancements+of+spinal+cord+injury+treatment:+a+review+of+recent+progress.">Delving into the recent advancements of spinal cord injury treatment: a review of recent progress.</a> Neural Regeneration Research. 17 (2), 283-291 (2022).</li><li>Khuyagbaatar, B., Kim, K., Kim, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conversion+Equation+between+the+Drop+Height+in+the+New+York+University+Impactor+and+the+Impact+Force+in+the+Infinite+Horizon+Impactor+in+the+Contusion+Spinal+Cord+Injury+Model.">Conversion Equation between the Drop Height in the New York University Impactor and the Impact Force in the Infinite Horizon Impactor in the Contusion Spinal Cord Injury Model.</a> Journal of Neurotrauma. 32 (24), 1987-1993 (2015).</li><li>Alizadeh, A., Dyck, S. M., Karimi-Abdolrezaee, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Traumatic+Spinal+Cord+Injury:+An+Overview+of+Pathophysiology,+Models+and+Acute+Injury+Mechanisms.">Traumatic Spinal Cord Injury: An Overview of Pathophysiology, Models and Acute Injury Mechanisms.</a> Frontiers in Neurology. 10, 282 (2019).</li><li>Bilgen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+device+for+experimental+modeling+of+central+nervous+system+injuries.">A new device for experimental modeling of central nervous system injuries.</a> Neurorehabilitation and Neural Repair. 19 (3), 219-226 (2005).</li><li>Khan, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GSNOR+and+ALDH2+alleviate+traumatic+spinal+cord+injury.">GSNOR and ALDH2 alleviate traumatic spinal cord injury.</a> Brain Research. 1758, 147335 (2021).</li></ol>

Spinal cord injury can lead to sensory and motor deficits, which can result in severe physical and mental impairments. In China, incidences of spinal cord injuries in different provinces vary from 14.6 to 60.6 per million18. The increase in the prevalence of SCI will put more pressure on the healthcare system. Currently, there are limited effective treatment option for spinal cord injury, injuries because its pathomechanisms and repair processes are yet to be fully understood19</...

Spinal cord injury usually results in permanent spinal cord dysfunction below the injured segment. It is mostly caused by objects striking the spine and hyperextension of the spine, such as traffic accidents and falls1. Due to the limited availability of effective treatment options for spinal cord injury, elucidation of the pathogenesis of spinal cord injuries using animal models will be informative for the development of appropriate treatment approaches. The contusion model of spinal cord injury caused by impact on the spinal cord results in the development of animal models with similar pathologies to most clinical spinal cord injury cases2,3. Therefore, it is important to produce accurate, reproducible, and convenient animal models for spinal cord injury contusion.
Since Allen&#39;s invention of the first animal model of spinal cord injury in 1911, there have been major advances in the development of instruments for establishing spinal cord injury animal models4,5. Based on injury mechanisms, spinal cord injury models are classified as contusion, compression, distraction, dislocation, transection, or chemical6. Among them, the contusion models, which use external forces to displace and injure the spinal cord, are closest to the clinical etiology of most spinal cord injury patients. Therefore, the contusion model has been used by many investigators in spinal cord injury studies3,7. Various instruments are used to develop spinal cord injury contusion models. The New York University (NYU)-multicenter animal spinal cord injury studies (MASCIS) impactor produces spinal cord injury contusions by weight-drop device8. After several updated versions, the MASCIS impactor is widely used to develop spinal cord injury contusion animal models9. However, when the impact rod of MASCIS falls and hits the spinal cord, multiple injuries may occur, which affects the degree of injury in spinal cord injury models. Moreover, achieving mechanical precision to ensure the accuracy of the instrument and the repeatability of the manufacturing model is also challenging. The infinite horizon impactors cause contusions by controlling the force applied to the spinal cord rather than heavy drops10. It uses a computer connected to a sensor to directly measure the impact force between the impactor and the spinal cord. When the threshold is reached, the impactor is immediately retracted, thereby avoiding weight rebound and improving accuracy10,11. However, the use of this fine motor modality to inflict damage can result in inconsistent damage and functional deficits6. The Ohio State University (OSU) device compresses the dorsal surface of the spinal cord at a transient rate by an electromagnetic driver12,13. This device is similar to the infinite horizon impactors, as it uses short-distance compressions to cause spinal cord injuries. However, it has various limitations in that initial determination of the zero point will cause errors due to the presence of the cerebrospinal fluid6,14. In summary, there are many instruments that can be used to develop spinal cord injury contusion animal models, but they all have some limitations that lead to insufficient accuracy and reproducibility of animal models. Therefore, in order to more accurately, conveniently and reproducibly create mouse contusion models of spinal cord injury, an automated and intelligent spinal cord injury impactor is needed.
We present a novel spinal cord injury impactor, Guangzhou Jinan University smart spinal cord injury system (G smart SCI system; Figure 1), for producing spinal cord injury contusion models. The device uses a laser rangefinder as a positioning device, combined with an automated mobile platform to automate strikes according to set strike parameters, including strike speed, strike depth and dwell time. Automated operation reduces human factors and improves the accuracy as well as reproducibility of animal models.

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	<tbody>
		<tr>
			<td>0.01M PBS (powder, pH7.2-7.4)</td>
			<td>Solarbio Life Sciences</td>
			<td>P1010</td>
			<td></td>
		</tr>
		<tr>
			<td>2,2,2-Tribromoethanol</td>
			<td>Macklin</td>
			<td>75-80-9</td>
			<td></td>
		</tr>
		<tr>
			<td>4% paraformaldehyde tissue fixative</td>
			<td>Biosharp life science</td>
			<td>BL539A</td>
			<td></td>
		</tr>
		<tr>
			<td>Biomicroscope</td>
			<td>Leica</td>
			<td>LCC50 HD</td>
			<td></td>
		</tr>
		<tr>
			<td>CatWalk&#160;</td>
			<td>Noldus Information Technology</td>
			<td>CatWalk XT 9.1</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover glass</td>
			<td>CITOTEST Scientific</td>
			<td>10212432C</td>
			<td></td>
		</tr>
		<tr>
			<td>Embedding machine</td>
			<td>Changzhou Zhongwei Electronic Instrument</td>
			<td>BMJ-A</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol absolute</td>
			<td>DAMAO</td>
			<td>64-17-5</td>
			<td></td>
		</tr>
		<tr>
			<td>FootFaultScan</td>
			<td>Clever Sys Inc.</td>
			<td>-</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass slide</td>
			<td>CITOTEST Scientific</td>
			<td>80302-2104</td>
			<td></td>
		</tr>
		<tr>
			<td>Hematoxylin and Eosin Staining Kit</td>
			<td>Beyotime Biotechnology</td>
			<td>C0105S</td>
			<td></td>
		</tr>
		<tr>
			<td>micro-grinding drill&#160;</td>
			<td>FEIYUBIO</td>
			<td>19-7010</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse spinal fixator</td>
			<td>RWD Life Science</td>
			<td>68094</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraffin microtome</td>
			<td>Thermo</td>
			<td>shandon finesse 325</td>
			<td></td>
		</tr>
		<tr>
			<td>RotaRod for Mice</td>
			<td>Ugo Basile</td>
			<td>47600</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>KUY NICE</td>
			<td>SZM-7045</td>
			<td></td>
		</tr>
		<tr>
			<td>Tert-Amyl alcohol</td>
			<td>Macklin</td>
			<td>75-85-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylene</td>
			<td>China National Pharmaceutical</td>
			<td>#10023418</td>
			<td></td>
		</tr>
	</tbody>
</table>

automated impactor for contusive spinal cord injury model in mice

Spinal cord injury (SCI) due to traumatic injuries such as car accidents and falls is associated with permanent spinal cord dysfunction. Creation of contusion models of spinal cord injury by impacting the spinal cord results in similar pathologies to most spinal cord injuries in clinical practice. Accurate, reproducible, and convenient animal models of spinal cord injury are essential for studying spinal cord injury. We present a novel automated spinal cord injury contusion device for mice, the Guangzhou Jinan University smart spinal cord injury system, that can produce spinal cord injury contusion models with accuracy, reproducibility, and convenience. The system accurately produces models of varying degrees of spinal cord injury via laser distance sensors combined with an automated mobile platform and advanced software. We used this system to create three levels of spinal cord injury mice models, determined their Basso mouse scale (BMS) scores, and performed behavioral as well as staining assays to demonstrate its accuracy and reproducibility. We show each step of the development of the injury models using this device, forming a standardized procedure. This method produces reproducible spinal cord injury contusion mice models and reduces human manipulation factors via convenient handling procedures. The developed animal model is reliable for studying spinal cord injury mechanisms and associated treatment approaches.

Author Spotlight: Insight Into Innovations in Spinal Cord Injury Research

Automated Impactor for Contusive Spinal Cord Injury Model in Mice

My research scope includes the pathogenesis and the treatment methods of spinal cord injury. Our recent research has found that various biomaterials can promote the repair of spinal cord injury in mice through antioxidant stress. The development of biomaterial sensors, technologies, and the gene modification technology, as well as the optimization of spinal cord injury models are advancing our research field.Due to compress and incompletely understood mechanism of spinal cord injury, it is currently difficult to cure spinal cord injury using a single intervention. In the future, multiple intervention methods may be needed for research. We found that mental immediate compress can participate in the treatment and the repair of spinal cord injury in animals through antioxidant stress.

Laminectomy was performed on 24 female mice (8 weeks old) as described above. Mice in the sham group (n=6) were not subjected to spinal cord injury, while the rest of the mice, including 0.5 mm group (n=6), 0.8 mm group (n=6), and 1.1 mm group (n=6) were subjected to different depths of spinal cord impingement. The BMS scores were regularly recorded until 1 month postoperatively (Figure 4). There were significant differences in postoperative BMS scores of mice in different groups. After 1 mo...

Watch this Scientific Journal Video about Automated Impactor for Contusive Spinal Cord Injury Model in Mice at JoVE.com

Presented here is a novel automated spinal cord injury contusion device for mice, which can accurately produce spinal cord injury contusion models with varying degrees.

Spinal cord injury (SCI) due to traumatic injuries such as car accidents and falls is associated with permanent spinal cord dysfunction. Creation of ...

automated-impactor-for-contusive-spinal-cord-injury-model-in-mice