Autologous platelet-rich plasma in combination with tendon stem cells to treat tendinopathy in a rabbit model: histomorphological changes of the tendon tissue and matrix metalloproteinase 1 expression / 中国组织工程研究

ABSTRACT

BACKGROUND:The research and application of platelet-rich plasma in tissue regeneration and restoration have always been an issue of concern in the medicine and bioengineering fields.OBJECTIVE:To analyze the effects of platelet-rich plasma in combination with tendon stem cells on histomorphology change and matrix metalloproteinase 1 expression of the tendon tissues in a rabbit model of Achilles tendinopathy.METHODS:Forty New Zealand white rabbits were randomly divided into model group (n=32) and blank control group (n=8).In the model group,the animals were injected about 2 cm distant to the attachment point of the left calcaneus with prostaglandin E2 (once a week,for totally 4 weeks) to make the animal model of tendinopathy.The rabbits in the blank control group were injected the equal amount of normal saline.After 4 weeks,model rabbits were randomly divided into four subgroupscombination group,tendon stem cell group,platelet-rich plasma group and model control group,with eight rabbits in each group.Platelet-rich plasma and tendon stem cells,alone or in combination,and normal saline were injected into the corresponding group,twice with an interval of 3 weeks.At 6 weeks after injection,the tendon tissue was collected and stained for histological examination and detection of matrix metalloproteinasa 1 expression.RESULTS AND CONCLUSION:(1) Hematoxylin-eosin stainingthe tendon fibers in the combinationgroup were intact and arranged orderly;in the tendon stem cell group,the tendon fibers were almost arranged orderly despite some fractured fibers;in the platelet-rich plasma group,fiber breakage and loose fiber structure were observed;in the model control group,there were no intact tendon fibers,with the presence of inflammatory cell filtration.(2) Masson stainingThe tendon fibers in the combination group had slight wave-shaped changes but the fibers were not cut off;in the tendon stem cell group,the tendon fibers were slightly in disorder,but with the intact structure,and obvious inflammatory cell filtration was observed;in the platelet-rich plasma group,fiber breakage,reduced collagen fibers and inflammatory cell filtration were obviously observed;in the model control group,there were no intact tendon fibers,and inflammatory cell filtration was clearly visible.(3) The expression of matrix metalloproteinase 1Compared with the blank control group,the expression of matrix metalloproteinase 1 was significantly higher in the other groups except the combination group (P ＜ 0.05).There was no significant difference in the expression of matrix metalloproteinase 1 between the combination group and blank control group (P ＞ 0.05).To conclude,the combination of platelet-rich plasma and tendon stem cells can inhibit the vicious cycle of degeneration of collagen and extracellular matrix,reduce the expression of matrix metalloproteinase 1 in tenocytes,and delay inflammation responses and degeneration due to tendinopathy.