Decreased fibroblast and increased osteoblast adhesion on nanostructured NaOH-etched PLGA scaffolds

Lester L Smith¹, Paul J Niziolek², Karen M Haberstroh^1,3, Eric A Nauman^1,4,5, Thomas J Webster^1,3

¹Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indianapolis, IN, USA; ²Indiana University School of Medicine, Indianapolis, IN, USA; ³Division of Engineering, Brown University, Providence, RI, USA, ⁴School of Mechanical Engineering, Purdue University, West Lafayette, Indianapolis, IN, USA; ⁵Department of Basic Medical Sciences, Purdue University, West Lafayette, Indianapolis, IN, USA

Abstract: To facilitate locomotion and support the body, the skeleton relies on the transmission of forces between muscles and bones through complex junctions called entheses. The varying mechanical and biological properties of the enthesis make healing this avascular tissue difficult; hence the need for an engineered alternative. Cells in situ interact with their environment on the nano-scale which suggests that engineered approaches to enthesis regeneration should include such biologically-inspired nano-scale surface features. The present in vitro study investigated the effects of etching poly-lactic-co-glycolic acid (PLGA) scaffolds to produce nano-topography on the adhesion of fibroblasts and osteoblasts, two integral enthesis cell types. Nano-topography was produced on PLGA by etching the scaffolds in NaOH. Results showed that etching PLGA with NaOH to create nano-scale surface features decreased fibroblast adhesion while it increased osteoblast adhesion; criteria critical for the spatial control of osteoblast and fibroblast adhesion for a successful enthesis tissue engineering material. Thus, the results of this study showed for the first time collective evidence that PLGA can be either treated with NaOH or not on ends of an enthesis tissue engineering construct to spatially increase osteoblast and fibroblast adhesion, respectively.

Keywords: nano-topography, enthesis, tissue engineering, scaffold, porosity