Dynamic Bioreactor Culture for Infiltration of Bone Mesenchymal Stem Cells within Electrospun Nanofibrous Scaffolds for Annulus Fibrosus Repair.

Shuang Wang,Jian‐Kun Wen,Xiao‐Jian Ye,Yun‐Fei He,Lei Yu,Jun Ma

doi:10.1111/os.12615

Abstract

ObjectiveTo compare the ability of three culture strategies of static culture, intermittent centrifugal culture and dynamic bioreactor culture in promoting the infiltration of bone marrow mesenchymal stem cells (BMSCs) throughout electrospun nanoporous aligned nanoyarn scaffold (AYS).MethodsAYS was constructed by the method of conjugated electrospinning, using the blended solution of poly (L‐lactide‐co‐caprolactone) (P (LLA‐CL)) and gelatin. Then the bone marrow mesenchymal stem cells (BMSCs) were transplanted on the scaffolds. Culture the scaffold‐cells using three methods of static culture, intermittent centrifugal culture and dynamic bioreactor culture. After 7 and 14 days in culture, the infiltration depth of the cells were observed and measured by hematoxylin and eosin (HE) or 4′, 6‐diamidino‐2‐phenylindole (DAPI) staining.ResultIn the current study, on the 7th day, the BMSCs in the scaffolds of static culture group, intermittent centrifugal culture group, and dynamic bioreactor culture group infiltrated to an average depth of 11.88 ± 1.82 μm, 21.17 ± 13.17 μm, and 26.27 ± 7.42 μm, respectively. There were differences between the bioreactor culture group with the static culture group and the intermittent centrifugal culture group. On the time point of 14 days, the depth of infiltration of BMSCs in dynamic bioreactor culture was the most (115.13 ± 25.44 μm, P < 0.05), and the infiltration of the cells in the intermittent centrifugal culture group was 42.53 ± 13.07 μm, deeper than that of the static culture group (24.53 ± 6.06, P < 0.05).ConclusionDynamic bioreactor culture may be a preferred method for tissue engineering approaches involving scaffolds with a low porosity, such as those needed for repair of the annulus fibrosus (AF).

Highlights

Discectomy is a common surgical treatment for patients with intervertebral disc herniation (IDH), and it can relieve symptoms caused by compression of nerve roots by the protruding disc, including pain, numbness, and muscle weakness
Morphology of Aligned Nanoyarn Scaffold and Bone Mesenchymal Stem Cells Cultured on the Scaffold Observed by Scanning electron microscope (SEM) before planting the cells, AYS were mainly constructed by the aligned nanoyarns and nanofibers were distributed among them
Adhesion and Proliferation of Bone Mesenchymal Stem Cells on Aligned Nanoyarn Scaffold At the first day, the optical density (OD) values of different groups were similar, which indicating that the cells of different groups have adhered to the surfaces of the scaffolds with nearly the same ability

Summary

Introduction

Discectomy is a common surgical treatment for patients with intervertebral disc herniation (IDH), and it can relieve symptoms caused by compression of nerve roots by the protruding disc, including pain, numbness, and muscle weakness. Because the AF functions to encase the nucleus pulposus and to maintain pressurization of the intervertebral disc (IVD), degeneration of the IVD will be accelerated[1] if the AF is not repaired and herniation of the disc may recur[2,3,4]. Several strategies have been developed for repair of the AF, such as suturing the AF directly[5] or filling the gap with an appropriate material such as collagen gel[6]. These methods can restore the integrity of the AF, at least partially, but they cannot restore the pressurization of the IVD, and the ability of the IVD to resist a loaded force remains

Methods

Results

Conclusion