Characterization of electrospun nanocomposite scaffolds and biocompatibility with adipose-derived human mesenchymal stem cells

Seth D McCullen^1,2, Derrick R Stevens³, Wesley A Roberts³, Laura I Clarke³, Susan H Bernacki¹, Russell E Gorga², Elizabeth G Loboa¹

¹Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA; ²Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC, USA; ³Department of Physics, North Carolina State University, Raleigh, NC, USA

Abstract: Electrospun nanocomposite scaffolds were fabricated by encapsulating multi-walled carbon nanotubes (MWNT) in poly (lactic acid) (PLA) nanofibers. Scanning electron microscopy (SEM) confirmed the fabrication of nanofibers, and transmission electron microscopy identified the alignment and dispersion of MWNT along the axis of the fibers. Tensile testing showed an increase in the tensile modulus for a MWNT loading of 0.25 wt% compared with electrospun nanofibrous mats without MWNT reinforcement. Conductivity measurements indicated that the confined geometry of the fibrous system requires only minute doping to obtain significant enhancements at 0.32 wt%. Adipose-derived human mesenchymal stem cells (hMSCs) were seeded on electrospun scaffolds containing 1 wt% MWNT and 0 wt% MWNT, to determine the efficacy of the scaffolds for cell growth, and the effect of MWNT on hMSC viability and proliferation over two weeks in culture. Staining for live and dead cells and DNA quantification indicated that the hMSCs were alive and proliferating through day 14. SEM images of hMSCs at 14 days showed morphological differences, with hMSCs on PLA well spread and hMSCs on PLA with 1% MWNT closely packed and longitudinally aligned.

Keywords: adipose-derived human mesenchymal stem cells, multi-walled carbon nanotubes, bone tissue engineering, poly (lactic acid), electrospinning, nanocomposites