The repairing effect of natural killer cell-derived exosome on hypertrophic scars in rabbit ears
LI Ruoran
YUE Danxia
REN Fangli
YANG Rongya
Abstract：Objective To investigate the repair effect of natural killer(NK)cell-derived exosomes on rabbit ear hypertrophic scars,with the aim of providing a novel therapeutic approach for hypertrophic scar management.Method NK cells were isolated from peripheral blood of healthy donors via density gradient centrifugation,and NK cell-derived exosomes were extracted.The safety of the prepared exosomes was confirmed in a mouse experiment.Six New Zealand white rabbits were divided into a blank control group(2 rabbits)and an exosome group(4 rabbits).Six circular incisions(1 cm in diameter)were made on the ventral side of both ears,followed by drug intervention at 28 days post-surgery.The blank control group received no treatment for natural healing,while the exosome group received local injection of PBS on the control side and NK cell exosomes(0.3 mL per injection,1×109 particles)on the experimental side,once weekly for 8 consecutive weeks.Macroscopic changes in hypertrophic scars were observed,and wound tissues were harvested on day 56 for Hematoxylin-Eosin(HE)staining to evaluate histopathological characteristics.Scar color,thickness,and Hypertrophic Index(HI)were recorded weekly post-surgery.Result HE staining-based safety assessment in mice showed normal structures in the colon,heart,kidney,liver,spleen,and lung,without inflammatory infiltration,necrosis,or fibrotic lesions.After 8 weeks of exosome treatment,rabbit ear scars exhibited color approximation to normal skin and soft texture.Histopathological results(HE staining)indicated exosomes treatment significantly accelerated epidermal regeneration,more ordered dermal collagen fiber arrangement,and blurred boundaries between scars and surrounding normal skin.The scar thickness in the experimental side of the exosome group were significantly lower than the blank control group(P<0.05),and HI was significantly lower than that on the control side of the exosome group(P<0.05).Conclusion NK cell-derived exosomes demonstrate dual effects in promoting physiological repair and inhibiting hypertrophic scar formation.The rabbit ear scar model study reveals the potential of NK cell exosomes as a local therapeutic agent,offering novel insights for the treatment of hypertrophic scars.
Keywords：Killer cellnaturalExosomesScarsRepairAnimalexperimentRabbit
Publication Date：2025-06-10
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 183-189 )