Electrosprayed Hydroxyapatite on Polymer Nanofibers to Differentiate Mesenchymal Stem Cells to Osteogenesis

Abstract

Electrospraying of hydroxyapatite (HA) nanoparticles onto the surface of polymer nanofibers provides a potentially novel substrate for the adhesion, proliferation and differentiation of mesenchymal stem cells (MSCs) into bone tissue regeneration. HA nanoparticles (4%) were electrosprayed on the surface of electrospun polycaprolactone (PCL) nanofibers (420 ± 15 nm) for bone tissue engineering. PCL/HA nanofibers were comparatively characterized with PCL/Collagen (275 ± 56 nm) nanofibers by FT-IR analysis to confirm the presence of HA. Fabricated PCL/HA and PCL/Collagen nanofibers and TCP (control) were used for the differentiation of equine MSC into osteogenic lineages in the presence of DMEM/F12 medium supplemented with β-glycerophosphate, ascorbic acid and dexamethasone. Cell proliferation and differentiation into an osteogenic lineage was evaluated by MTS assay, SEM observation, ALP activity, ARS staining, quantification of mineral deposition and expression of osteocalcin. Proliferation of MSCs increased significantly (P ⩽ 0.05) up to 12% in PCL/Collagen (day 15) compared to PCL/HA nanofibrous substrate. ALP activity was increased 20% in PCL/HA by day 10 confirming the direction of osteogenic lineage from MSCs differentiation. PCL/HA stimulated an increased mineral secretion up to 26% by day 15 on ARS staining compared to PCL/Collagen nanofibers and showing cuboidal morphology by expressing osteocalcin. These results confirmed that the specifically fabricated PCL/HA composite nanofibrous substrate enhanced the differentiation of MSCs into osteogenesis.

Keywords:

• Electrospraying
• electrospinning
• hydroxyapatite
• polycaprolactone
• mesenchymal stem cells
• ALP activity
• mineralization

Acknowledgements

This study was supported by NRF-Technion (R-398-001-065-592), NUSNNI, Faculty of Engineering, National University of Singapore and StemLife Sdn Bhd, 50450 Kuala Lumpur, Malaysia.