Precision 3D printed meniscus scaffolds to facilitate hMSCs proliferation and chondrogenic differentiation for tissue regeneration

Xingyu Deng,Yikai Wang,Fangqian Wang,Wei Zhang,Xin Tang,Jie Zhang,Peng Wang,Xiaohua Yu,Zhenzhen Li,Fang Geng,Shurong Hou,Xiabin Chen,Na Zheng

doi:10.1186/s12951-021-01141-7

Abstract

BackgroundThe poor regenerative capability and structural complexity make the reconstruction of meniscus particularly challenging in clinic. 3D printing of polymer scaffolds holds the promise of precisely constructing complex tissue architecture, however the resultant scaffolds usually lack of sufficient bioactivity to effectively generate new tissue.ResultsHerein, 3D printing-based strategy via the cryo-printing technology was employed to fabricate customized polyurethane (PU) porous scaffolds that mimic native meniscus. In order to enhance scaffold bioactivity for human mesenchymal stem cells (hMSCs) culture, scaffold surface modification through the physical absorption of collagen I and fibronectin (FN) were investigated by cell live/dead staining and cell viability assays. The results indicated that coating with fibronectin outperformed coating with collagen I in promoting multiple-aspect stem cell functions, and fibronectin favors long-term culture required for chondrogenesis on scaffolds. In situ chondrogenic differentiation of hMSCs resulted in a time-dependent upregulation of SOX9 and extracellular matrix (ECM) assessed by qRT-PCR analysis, and enhanced deposition of collagen II and aggrecan confirmed by immunostaining and western blot analysis. Gene expression data also revealed 3D porous scaffolds coupled with surface functionalization greatly facilitated chondrogenesis of hMSCs. In addition, the subcutaneous implantation of 3D porous PU scaffolds on SD rats did not induce local inflammation and integrated well with surrounding tissues, suggesting good in vivo biocompatibility.ConclusionsOverall, this study presents an approach to fabricate biocompatible meniscus constructs that not only recapitulate the architecture and mechanical property of native meniscus, but also have desired bioactivity for hMSCs culture and cartilage regeneration. The generated 3D meniscus-mimicking scaffolds incorporated with hMSCs offer great promise in tissue engineering strategies for meniscus regeneration.Graphical

Highlights

The poor regenerative capability and structural complexity make the reconstruction of meniscus challenging in clinic. 3D printing of polymer scaffolds holds the promise of precisely constructing complex tissue architecture, the resultant scaffolds usually lack of sufficient bioactivity to effectively generate new tissue
Our results demonstrates the fabricated biocompatible porous meniscus-like scaffolds greatly promote human mesenchymal stem cells (hMSCs) growth and chondrogenic differentiation, and are suitable for cartilage regeneration and meniscus tissue engineering
The mechanical property of scaffolds with 25% porosity (0.25 mm diameter in average) was very close to that of the goat meniscus, which has been reported to be close to human meniscus [2, 44]

Summary

Introduction

The poor regenerative capability and structural complexity make the reconstruction of meniscus challenging in clinic. 3D printing of polymer scaffolds holds the promise of precisely constructing complex tissue architecture, the resultant scaffolds usually lack of sufficient bioactivity to effectively generate new tissue. The poor regenerative capability and structural complexity make the reconstruction of meniscus challenging in clinic. Meniscus injury primarily resulted from physical trauma or degenerative process, has become one of the most prevalent and challenging diseases of the knee joint [3, 4]. Some meniscus tears can be surgically repaired, but treatments for central tears or large injuries are very limited. The well-established treatment option is meniscal allograft transplant, i.e., to replace the damaged meniscus with a meniscus from a cadaver donor, but the clinical outcome is not satisfactory [7, 8]. Development of customized biocompatible alternatives to recapitulate native tissue complexity is of great clinical significance for meniscus engineering

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