BMP-2 Modified Electrospun Scaffold for Acetabular Labral Reconstruction Promotes Collagen Fiber Regeneration in a Porcine Model

Abstract

Background: Acetabular labral tear is one of the contributing factors to early hip osteoarthritis. Patients with symptomatic labral tears may require surgical treatment, and labral reconstruction is indicated in cases of irreparable tears. Purpose: The purpose of the study was to construct the bone morphogenic protein 2 (BMP-2) electrospun scaffold for acetabular labral reconstruction and analyze the composition of the labrum and the influence of collagen fiber distribution in regenerated tissue on the biomechanical properties of labrum. Study Design: Controlled laboratory study. Methods: Eighteen mature male miniature pigs were selected for labral reconstruction in vivo. The animals were divided into 3 groups, including the autologous tendon group (T group), dopamine/polylactic acid–polyethylene glycol (PELA) electrospun group (DP group), and dopamine/PELA electrospun/BMP-2 group (DPB group), and the native labra were used as the control group. The microstructure of the reconstructed labrum was analyzed by scanning electron microscopy. Histologic and immunohistochemistry sections were used to evaluate the composition and structure of reconstructed labrum. The related gene expression was tested via quantitative reverse transcriptase–polymerase chain reaction test. The compressive and tensile properties of tissues were evaluated using the elasticity test device. Results: Hematoxylin and eosin staining showed that the DP group and the T group were mainly composed of fibroblasts. The alignment of fibers was irregular. In the DPB group, the reconstructed tissues were composed of fibroblasts and chondrocytes, with parallel fibers and denser structure. The native labrum was composed of a large number of fibroblasts, which were arranged orderly and parallel, and there was almost no vascular proliferation. Under scanning electron microscopy, the reconstructed tissue of the DBP group was more similar to the native labral structure, forming a denser, clear-layered collagen fibrous structure, while the fiber alignment of the DP and T groups was irregular. The contents of type I, II, and III collagen ( COL1, COL2, and COL3, respectively) were upregulated in labrum reconstructed with the DPB scaffold, while the gene expressions did not increase in the DP and T groups. The tensile and compressive properties of the implants in the DPB group were significantly enhanced. Conclusion: BMP-2 modified electrospun scaffold promotes collagen regeneration and osteogenic differentiation and is associated with better biomechanical performance of the reconstructed labrum. Clinical Relevance: This study demonstrated that BMP-2 modified electrospun scaffold could induce the regeneration of collagen and osteogenic differentiation and provide better biomechanical performance in labral reconstruction. This scaffold could be used in clinical practice after further improvement.

Ultrasound-Controlled Delivery of Growth Factor-Loaded Cerasomes Combined with Polycaprolactone Scaffolds Seeded with Bone Marrow Mesenchymal Stem Cells for Biomimetic Tendon-to-Bone Interface Engineering

“…Ultrasonication was then used to enhance the release of DOX using the thermal effects of ultrasound. The accumulative amount of released DOX was determined by measuring its fluorescence. , …”

“…The accumulative amount of released DOX was determined by measuring its fluorescence. 36,37 Preparation and Characterization of PCL Scaffolds. PCL, with a molecular weight averaging at 80,000 g/mol, was melted in a hightemperature cartridge at 150 °C for 40 min.…”

Can the Acetabular Labrum Be Reconstructed With a Meniscal Allograft? An In Vivo Pig Model

“…The acetabular labrum in pigs comprises avascular tissue that displays properties similar to fibrocartilage and can simulate mechanical stimulation of the labrum and allografts in vivo, similar to the human acetabular labrum [29,34]. Twelve 6-month-old skeletally mature male Bama miniature experimental pigs weighing 25 to 30 kg were subjected to bilateral labral surgery.…”

“…A prior investigation demonstrated that the acetabular labrum in pigs comprises avascular tissue with fibrocartilage-like characteristics similar to the human acetabular labrum [29]. Additionally, a Bama miniature pig model can promote mechanical stimulation in vivo and was considered as an ideal animal model [34].…”