Development of a Novel Rat Model of Chronic Wound Using Magnetic Feature for Regenerative Medicine Applications

Background and Aim: Chronic wound development is a result ofdelayed wound healing process. Briefly, the wound progression into thechronicity is associated with the prolonged and excessive inflammatoryresponse and the myriad of factors including poor circulation, vascularinsufficiency, diabetes, aging, malnutrition and even local factors suchas bacterial infection and pressure. Developing the proper animalmodel would be an advancement to understand how chronic wounddevelops in humans. Finally, this provides the therapeutic field for furtherinvestigation in chronic wound treatment.Methods: Mature rats were purchased and the animal experimentswere conducted in accordance with the guideline approved by theInstitutional Animal Use and Care Committee of Shahrekord Universityof Medical Sciences. After anesthetizing the rats by ketamine (75-100mg/kg) and xylazine (10 mg/kg); they were shaved and disinfected with75% ethanol. A surgical incision was made on the back of the rat and onesterilized stainless-steel ring with a magnetic feature was implanted inthe depth of the skin. Next, the wound was closed by suturing and properwound dressing. Afterward, the wound was faced with a magnet every 8hours and each time for 20 minutes to prevent the normal wound healingprocess. After 21 days, under the anesthetic condition, the ring wasremoved and the wound was analyzed by applying hematoxylin & eosin(H&E) staining. The non-healing status of the wound and its elevated levelof inflammation should be seen. After confirming the chronic woundcreation, this model can be used for regenerative medicine applicationsResults: After 21 days, the wound had become chronic and the woundhad produced exudates which contained biofilm. The histologicalexaminations showed that the granulation tissue does not exist and theepidermis does not develop to close the wound. Therefore, these resultsindicate that chronic wound has been developed in rats.Conclusion: Considering the psychological, physiological, financialand social effects of chronic wounds for both government and affectedpatients, there is a huge need to have a proper model of a chronicwound. In addition, it will contribute to the understanding of howwounds become chronic and how they can be treated efficiently. In thisregard, we introduced a novel method for developing a rat model ofthe chronic wound within 21 days and at a lower cost for regenerative medicine applications

Keywords:

Wound healing , Chronic wound , Inflammation