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Bioengineering

Mouse Model of Pressure Ulcers After Spinal Cord Injury

Published: March 9th, 2019

DOI:

10.3791/58188

1Department of Biomedical Engineering, Rutgers University, 2Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Shriners Hospitals for Children, 3Department of Surgery, Yale School of Medicine, Yale University

Here, we describe a simple method to induce clinically relevant skin pressure ulcers (PUs) in a mouse model of spinal cord injury (SCI). This model can be used in pre-clinical studies to screen for different therapeutics for healing PUs in SCI patients.

Pressure ulcers (PUs) are common debilitating complications of traumatic spinal cord injury (SCI) and tend to occur in soft tissues around bony prominences. There is, however, little known about the impact of SCI on skin wound healing in the context of animal models in controlled experimental settings. In this study, a simple, non-invasive, reproducible and clinically relevant mouse model of PUs in the context of complete SCI is presented. Adult male mice (Balb/c, 10 weeks old) were shaved and depilated. Post-depilation (24 h), mice were subjected to laminectomy followed by complete spinal cord transection (T9-T10 vertebrae). Immediately after, a skin fold on the back of the mice was lifted and sandwiched between two magnetic discs held in place for next 12 h, thus creating an ischemic area that developed into a PU over the following days. The wounded areas demonstrated tissue edema and epidermal disappearance by day 3 post-magnet application. PUs spontaneously developed and healed. Healing was, however, slower in the SCI mice compared to control non-SCI mice when the wound was created below the level of SCI. Conversely, no difference in healing was seen between SCI and control non-SCI mice when the wound was created above the level of SCI. This model is a potentially useful tool to study the dynamics of skin PU development and healing after SCI, as well as to test therapeutic approaches that may help heal such wounds.

Pressure ulcers (PUs) are major secondary complications of traumatic SCI1. PUs are localized injuries to the skin and/or underlying tissues that usually occur over bony prominences where body weight is concentrated while the patient is sitting or lying1. The skin, fat, and muscle are exposed to this constant pressure that leads to the development of localized ischemia, tissue inflammation, mechanical damage, and necrosis2,3.

The development of PUs is affected by several local factors, including the magnitude of pressure and shear, load....

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All animal handling and surgical procedures were performed in accordance with a protocol approved by the Rutgers University Institutional Animal Care and Use Committee. Mice were fed standard diet and water ad libitum.

1. Preparation of Surgical and Non-surgical Instruments

  1. Sterilize the surgical and non-surgical instruments in an autoclave. 
  2. Clean the surgical operating table with 70% ethanol and warm a heating pad to 37 °C.
  3. Place the heating pad on t.......

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This protocol creates a PU in the setting of complete SCI. Briefly (as illustrated in Figure 1), all mice with or without complete SCI tolerated the magnets very well, which remained in their original position for the full 12 h (Figures 1c, 1d, 1f, 1h). All the mice developed two circular wounds separated by a bridge of normal tissue (Figure 1e, 1g, 1i). The initial wounding response was similar in mice without S.......

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The protocol in this study describes a novel experimental model of PUs to evaluate the impact of SCI on wound healing. The skin PUs were induced via a 12 h application of two 12 mm diameter disc magnets on a dorsal skin fold, either set above or below the SCI site. Data show that SCI slows down skin wound healing in mice. Importantly, these observations were specifically made in skin wounds below the innervation level of the SCI, as wounds made above the SCI level, and thus that remained innervated, were largely unaffect.......

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This work was partially supported by the New Jersey Commission on Spinal Cord Research (CSCR15IRG010), the U.S. Department of Defense (SC160029), and the Yale Department of Surgery Ohse Research Grant Program. We thank Sean O' Leary from the W.M. Keck Center for Collaborative Neuroscience, Rutgers for technical assistance.

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Name Company Catalog Number Comments
Magnets Master Magnetcs, Inc., Castle Rock, CO CD14C 3800 G Magnetic force
Mice standard diet PMI Nutrition International, Brentwood, MO Standard Food Pellet
Isoflurane HENRY SCHEIN Animal Health  SKU 029405
ImageJ NIH, Bethesda, MD Image Analysis Software
BETADINE Surgical Scrub HENRY SCHEIN Animal Health 
Ophthalmic Ointment  HENRY SCHEIN Animal Health  SKU 008897
NAIR-Hair Remover Lotion Church & Dwight Co., Inc. Princeton, NJ
ELOXIJECT (meloxicam) Injection HENRY SCHEIN Animal Health  SKU 049755 5 mg/mL, 10 mL
Cefazolin Sodium HENRY SCHEIN Animal Health  SKU 054846 1 g, 10 mL bottle
Buprenorphine-SR  ZooPharm, Windsor, CO - -
0.9% Sodium Chloride Injection USP BRAUN, Irvine, CA S8004-5384
10% Neutral Buffered Formalin  VWR, Radnor, PA 16004-130
BALB/C Male Mouse Charles River Lab., Wilmington, MA 28
Sterile Cotton Tipped Applicator Puritan, Guilford, ME SKU#: 25-806
Michel Suture Clips Fine Science Tools (USA) Inc., Foster City, CA 12040-01
Surgical Suture, U.S.P. Henry Schein Animal Health  101-2636

  1. Rappl, L. M. Physiological changes in tissues denervated by spinal cord injury tissues and possible effects on wound healing. International Wound Journal. 5 (3), 435-444 (2008).
  2. Salcido, R., Popescu, A., Ahn, C. Animal models in pressure ulcer research. The Journal of Spinal Cord Medicine. 30 (2), 107-116 (2007).
  3. Mak, A. F., Zhang, M., Tam, E. W. Biomechanics of pressure ulcer in body tissues interacting with external forces during locomotion. Annual Review of Biomedical Engineering. 12, 29-53 (2010).
  4. National Pressure Ulcer Advisory Panel. . Prevention and Treatment of Pressure Ulcers: Clinical Practice Guideline. , (2014).
  5. Marin, J., Nixon, J., Gorecki, C. A systematic review of risk factors for the development and recurrence of pressure ulcers in people with spinal cord injuries. Spinal Cord. 51 (7), 522-527 (2013).
  6. Krause, J. S. Skin sores after spinal cord injury: relationship to life adjustment. Spinal Cord. 36 (1), 51-56 (1998).
  7. Redelings, M. D., Lee, N. E., Sorvillo, F. Pressure ulcers: more lethal than we thought?. Advances in Skin & Wound. 18 (7), 367-372 (2005).
  8. Kruger, E. A., Pires, M., Ngann, Y., Sterling, M., Rubayi, S. Comprehensive management of pressure ulcers in spinal cord injury: current concept and future trends. The Journal of Spinal Cord Medicine. 36 (6), 572-585 (2013).
  9. Lala, D., Dumont, F. S., Leblond, J., Houghton, P. E., Noreau, L. Impact of pressure ulcers on individuals living with a spinal cord injury. Archives of Physical Medicine and Rehabilitation. 95 (15), 2312-2319 (2014).
  10. Li, C., DiPiro, N. D., Krause, J. A latent structural equation model of risk behaviors and pressure ulcer outcomes among people with spinal cord injury. Spinal Cord. 55 (6), 553-558 (2017).
  11. Kumar, S., Yarmush, M. L., Berthiaume, F. Impact of complete spinal cord injury on neovascularization and tissue granulation in mouse model of skin pressure ulcers. Journal of Neurotrauma. 34 (13), A72-A73 (2017).
  12. Kumar, S., Yarmush, M. L., Dash, B. C., Hsia, H. C., Berthiaume, F. Impact of complete spinal cord injury on healing of skin ulcers in mouse models. Journal of Neurotrauma. 35 (6), 815-824 (2018).
  13. Basso, D. M., Fisher, L. C., Anderson, A. J., Jakeman, L. B., McTigue, D. M., Popovich, P. G. Basso Mouse Scale for locomotion detects differences in recovery after spinal cord injury in five common mouse strains. Journal of Neurotrauma. 23 (5), 635-659 (2006).
  14. Leary, S., et al. . AVMA Guidelines for the Euthanasia of Animals. , (2013).
  15. Stadler, I., Zhang, R. Y., Oskoui, P., Whittaker, M. S., Lanzafame, R. J. Development of a simple, noninvasive, clinically relevant model of pressure ulcers in the mouse. Journal of Investigative Surgery. 17 (4), 221-227 (2004).
  16. Peirce, S. M., Skalak, T. C., Rodeheaver, G. T. Ischemia-reperfusion injury in chronic pressure ulcer formation: a skin model in the rat. Wound Repair and Regeneration. 8 (1), 68-76 (2000).
  17. Wong, V. W., Sorkin, M., Glotzbach, J. P., Longaker, M. T., Gurtner, G. C. Surgical approaches to create murine models of human wound healing. Journal of Biomedicine and Biotechnology. 2011, 969618-969625 (2011).

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