Effect of platelet rich plasma associated or not to suture on severe muscle injury repair of rats

Author(s)

Thiago Alves Garcia

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2019-07-15

Examining board members

William Dias Belangero; Bruno Livani; Mario Jefferson Quirino Louzada

• Advisor: Jose Carlos Silva Camargo Filho; William Dias Belangero

Abstract

Introduction: Muscle injuries are divided in mild, moderate and severe, corresponding to the quantity of rupture muscle fibers. The standard treatment for the severe injuries is the suture of the edges of the ruptured muscle. The local application of Plaque Rich Plasma (PRP) has been considered an alternative treatment because it promotes the release of growth factors that would stimulate angiogenesis, chemotaxis and synthesis of new muscle fibers. Objective: To analyze the effects of PRP, associated or not to suture, on regeneration and mechanical properties of muscle tissue in the acute period of a muscle injury. Method: Seventy-five rats were distributed in five groups: control (C), control lesion (CL), lesion and suture (LS), lesion and PRP (LP), lesion, suture and PRP (LSP). A transverse section was produced with the use of scalpel in the lateral portion of the gastrocnemius muscle. Twenty-four hours after the muscle injury was applied in the LP and LSP groups, the PRP produced with the blood of the C group. The animals were euthanized on the seventh day after injury. Seven animals had muscles undergoing mechanical testing, while others had frozen muscle tissue for histological analysis of inflammation, muscle collagen and oxidative stress by means of Raman espectroscopy. Gaussian distribution tests followed by parametric and nonparametric tests were used for statistical differentiation of the groups, with a significance of 5%. Results: It was found that type I and III of collagen had a higher quantity in groups LP and LSP, compared to groups C and CL, moreover the LP group had greater amount of collagen type I than the LS group. The LP group had a mean of Maximum Load obtained by mechanical testing, higher than the CL group, and similar to the C group. The histological analysis showed a chronic inflammatory process in all the injured groups, and greater intensity in the LP and LSP groups. The oxidative stress seen by the ratio of the NADH/NAD molecules, showed a higher stress in the LS and LSP groups, compared to the C group. Conclusion: The application of the isolated PRP increased the collagen, maximum strength supported and intensified the inflammation, while suture decreased muscle stiffness and increased oxidative stress observed in muscle. The PRP was effective in reducing the maximum force loss caused by the injury, while the muscular suture did not have a beneficial effect (AU)

• FAPESP's process: 17/06930-0 - Treatment analysis of muscle injury by the association of suture and platelet rich plasma
• Grantee: Thiago Alves Garcia
• Support Opportunities: Scholarships in Brazil - Master