RESUMO
Abstract Purpose: To evaluate the effect of transforming growth factor β1 (TGF-β1) on tendon-to-bone reconstruction of rotator cuff tears. Methods: Seventy-two rat supraspinatus tendons were transected and reconstructed in situ. At 8 and 16 weeks, specimens of three groups; that is control, L-dose (low dose), and H-dose (high dose) were harvested and underwent a biomechanical test to evaluate the maximum load and stiffness values. Histology sections of the tendon-to-bone interface were identified by hematoxylin-eosin or Masson trichrome stain. Collagen type III was observed by picric acid sirius red staining under polarized light. The level of insulin-like growth factor 1 (IGF-1) and vascular endothelial growth factor (VEGF) was measured by the enzyme-linked immunosorbent assay (ELISA) method. Results: Collagen type III of the H-dose group had a significant difference in histology structure compared with the L-dose group (P<0.05). The maximum load and stiffness decreased significantly in the control group compared with the values of the L-dose and H-dose groups. The stiffness among the three groups differed significantly at the same postoperative time (P<0.05). Interestingly, progressive reestablishment of collagen type III affected tendon-to-bone healing significantly in the later stages. Conclusion: The H-dose was associated with an increased collagen type III morphology stimulated by TGF-β1.
Assuntos
Animais , Masculino , Ratos , Traumatismos dos Tendões/tratamento farmacológico , Cicatrização/fisiologia , Manguito Rotador/cirurgia , Fatores de Crescimento do Endotélio Vascular/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Lesões do Manguito Rotador/cirurgia , Traumatismos dos Tendões/metabolismo , Resistência à Tração/fisiologia , Cicatrização/efeitos dos fármacos , Fenômenos Biomecânicos , Ensaio de Imunoadsorção Enzimática , Manguito Rotador/metabolismo , Ratos Sprague-Dawley , Colágeno Tipo III/metabolismo , Modelos Animais de Doenças , Elasticidade/fisiologia , Fator de Crescimento Transformador beta1/farmacologia , Força Muscular/fisiologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Lesões do Manguito Rotador/metabolismoRESUMO
<p><b>OBJECTIVE</b>To prepare a rabbit meniscus acellular matrix scaffold and explore the histomorphological and biomechanical properties of the scaffold.</p><p><b>METHODS</b>Rabbit meniscuses were collected and acellularized using a modified eight-step detergent process with hydrogen peroxide, distilled water, Triton X-100, and sodium deoxycholate. Its color and texture were observed. Histomorphological assessment was performed using routine hematoxylin-eosin stain, toluidine blue stain, Saffron stain, Hoechst-33258 stain, and immunohistochemical staining of collagen I. The ultrastructure of the specimens was observed with inverted phase contrast microscopy. Transient recovery rate of deformation, maximal recovery rate of deformation, and maximal compressive strength were tested to determine the biomechanical properties of the scaffold.</p><p><b>RESULTS</b>The processed meniscus was milk-white in color with loose structure. It histologically appeared cell-free, stained positively for collagen I, and had abundant micropores according to phase-contrast microscopy. The transient recovery rate of deformation was (76.65∓4.61)%, the maximal recovery rate of deformation was 100%, and the maximal compressive strength was (4.51∓0.69) N when the specimens were compressed 40%.</p><p><b>CONCLUSIONS</b>The rabbit meniscus acellular matrix scaffold, with numerous micropores, is easy to be recovered from deformation and suitable for the adhesiveness and growth of breeding cells. This scaffold can be used as an ideal implant for future tissue engineering of the meniscus.</p>