Electrospun nanoyarn scaffold and its application in tissue engineering

doi:10.1016/j.matlet.2012.08.141

Materials Letters

Volume 89, 15 December 2012, Pages 146-149

https://doi.org/10.1016/j.matlet.2012.08.141 Get rights and content

Abstract

Silk fibroin (SF)/Poly(L-lactide-co-caprolactone) P(LLA-CL) nanoyarn scaffolds were prepared by dynamic liquid electrospinning. The scaffold morphology was observed by scanning electron microscopy (SEM) and mechanical properties of the scaffold were examined. L929 mouse fibroblasts were cultured on the nanoyarn scaffolds. Cell morphology, infiltration and proliferation on the scaffolds were investigated by SEM, hematoxylin-eosin (H&E) staining and methylthiazol tetrazolium (MTT) assay, respectively. The results indicated that cells showed an organized morphology along the nanoyarns and considerable infiltration into the nanoyarn scaffolds. It was also observed that the nanoyarn scaffold significantly facilitated cell proliferation. Therefore, this work provides a promising approach to fabricate scaffolds for tissue engineering applications.

Highlights

► We prepared a novel nanoyarn scaffold using electrospinning. ► The scaffold has excellent surface properties and porous structures. ► L929 cells show an oriented growth pattern and improved cell infiltration on the nanoyarn scaffold.

Introduction

Recent approaches using electrospun scaffolds for tissue repair demonstrate the superiority of electrospinning in the fabrication of engineered scaffolds for tissue engineering applications [1]. Electrospun scaffolds have been widely investigated as substitutes for bone [2], cartilage [3] and tendon [4] regeneration. However, some limitations appeared in the applications due to the layer-by-layer process of electrospinning [5]. One of the problems encountered in the use of electrospun scaffolds is the limited infiltration of cells [6]. This is attributed to the smaller pore size of electrospun scaffold compared with that of cell diameter.

Many efforts have been addressed to improve pore size of the electrospun scaffolds so as to facilitate cell infiltration into electrospun scaffolds. One of the efforts relates to the optimizing of scaffold structures. For example, selecting of special materials for the scaffold fabrication was described to be a desirable approach to improve cell infiltration [7]. In this approach, water-soluble poly(ethylene oxide) (PEO) polymer was served as sacrificial fibers and leached out from nanofiber scaffolds to improve pore size. Leong et al. [8] reported a cryogenic electrospinning technique which utilized ice crystals as porogens to create larger pores within nanofiber scaffolds. Bryan et al. [5] designed a novel collection system for electrospinning to prepare cotton-like, uncompressed scaffold, which supported significantly enhanced cell in-growth penetration. However, the improved cell infiltration attained by those approaches inevitably compromise scaffold integrity or mechanical properties.

This study aims to fabricate a novel nanoyarn scaffold and evaluate its applications in tissue engineering. Electrospun SF/P(LLA-CL) nanofibers were deposited in a water vortex and bonded into nanoyarns and then collected by a rotating mandrel. The nanoyarn made up by nanofibers might have improved surface properties and porous structure. The nanoyarn scaffolds, composed of aligned nanoyarns, were seeded with mouse fibroblasts. The results showed that the nanoyarn scaffolds supported significantly accelerated proliferation, organized morphology and improved infiltration of cells compared with that of the random-oriented nanofibrous scaffolds.

Section snippets

Experimental

Materials: P(LLA-CL) (Mw=300 kDa; LA:CL=75:25) was obtained from Nara Medical University, Japan. Bombyx mori silkworm cocoons were kindly given by Jiaxing Silk Co. Ltd. (Jiaxing, China). L929 cells were obtained from institute of biochemistry and cell biology (Chinese Academy of Sciences, China). All reagents and medium for cell culture and seeding were purchased from Invitrogen.

Scaffold fabrication: Regenerative silk fibroin was prepared as our previously used method [9]. SF and P(LLA-CL) were

Results and discussion

The nanoyarn scaffold was prepared using a dynamic liquid electrospinning (Fig. 1). It is the vortex in water that twists electrospun nanofibers into nanoyarns. When the nanofibers arrive at the water surface, they flow with the whirly water in the vortex and form nanoyarns which are collected by the rotating mandrel. The obtained scaffold (Fig. 2A), made up of aligned nanoyarns (∼20 μm), shows a porous structure with large pores (20–50 μm in diameter) and grooves on the surface. However, the

Conclusion

We have developed a novel nanoyarn scaffold by dynamic liquid electrospinning. The scaffold has excellent surface properties and porous structures. L929 cells show an oriented growth pattern and enhanced cell infiltration on the nanoyarn scaffold. This scaffold is beneficial for cell growth and may be served as tendon or cartilage substitutes in tissue engineering applications. Further studies will be focused on its implantation into animal models for the investigation of biocompatibility in

Acknowledgments

This work is supported by the National Nature Science Foundation of China (31070871).

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Electrospun nanoyarn scaffold and its application in tissue engineering

Abstract

Highlights

Introduction

Section snippets

Experimental

Results and discussion

Conclusion

Acknowledgments

Mater Lett

Adv Drug Delivery Rev

Acta Biomater

Biomaterials

Biomaterials

Biomaterials