Cell Integration with Electrospun PMMA Nanofibers, Microfibers, Ribbons, and Films: A Microscopy Study.

Daniel P. Ura,Piotr K. Szewczyk,Urszula Stachewicz,Joanna E. Karbowniczek,Sara Metwally,Mateusz Kopyściański

doi:10.3390/bioengineering6020041

Abstract

Tissue engineering requires properly selected geometry and surface properties of the scaffold, to promote in vitro tissue growth. In this study, we obtained three types of electrospun poly(methyl methacrylate) (PMMA) scaffolds—nanofibers, microfibers, and ribbons, as well as spin-coated films. Their morphology was imaged by scanning electron microscopy (SEM) and characterized by average surface roughness and water contact angle. PMMA films had a smooth surface with roughness, Ra below 0.3 µm and hydrophilic properties, whereas for the fibers and the ribbons, we observed increased hydrophobicity, with higher surface roughness and fiber diameter. For microfibers, we obtained the highest roughness of 7 µm, therefore, the contact angle was 140°. All PMMA samples were used for the in vitro cell culture study, to verify the cells integration with various designs of scaffolds. The detailed microscopy study revealed that higher surface roughness enhanced cells’ attachment and their filopodia length. The 3D structure of PMMA microfibers with an average fiber diameter above 3.5 µm, exhibited the most favorable geometry for cells’ ingrowth, whereas, for other structures we observed cells growth only on the surface. The study showed that electrospinning of various scaffolds geometry is able to control cells development that can be adjusted according to the tissue needs in the regeneration processes.

Highlights

Tissues are the functional basic units in the body, built of cells surrounded by the extracellular matrix (ECM)
The roughness of the electrospun mats was related to their average fiber diameter, typically, a larger diameter corresponded to a higher roughness [38]
The increase of roughness was responsible for the increase of the contact angle, up to 140◦ for microfibers, see Figure 3, showing a very high hydrophobicity of poly(methyl methacrylate) (PMMA) microfibers

Summary

Introduction

Tissues are the functional basic units in the body, built of cells surrounded by the extracellular matrix (ECM). To grow tissues in the laboratory conditions, a supportive structure in the form of a scaffold must be provided. Interactions of cells with the designed scaffolds are the key to a proper tissue development and regeneration processes [1]. The matrix, or scaffold, does support the cells and helps in the cells’ signaling pathways. Understanding how individual cells respond and interact with their surroundings allows the development of scaffold geometry to enhance the processes of tissue regeneration [2]. Cells need to first develop a suitable morphology and physical features, such as filopodia, in the in vitro conditions [3]. Cells reorganize by interactions with material properties, such as topography [4], mechanical strength [5], and surface potential [6,7,8]

Methods

Results

Conclusion