title: Planar and tubular patterning of micro and nano-topographies on poly(vinyl alcohol) hydrogel for improved endothelial cell responses.
abstract: Poly(vinyl alcohol) hydrogel (PVA) is a widely used material for biomedical devices, yet there is a need to enhance its biological functionality for in vitro and in vivo vascular application. Significance of surface topography in modulating cellular behaviour is increasingly evident. However, hydrogel patterning remains challenging. Using a casting method, planar PVA were patterned with micro-sized features. To achieve higher patterning resolution, nanoimprint lithography with high pressure and temperature was used. In vitro experiment showed enhanced human endothelial cell (EC) density and adhesion on patterned PVA. Additional chemical modification via nitrogen gas plasma on patterned PVA further improved EC density and adhesion. Only EC monolayer grown on plasma modified PVA with 2 μm gratings and 1.8 μm concave lens exhibited expression of vascular endothelial cadherin, indicating EC functionality. Patterning of the luminal surface of tubular hydrogels is not widely explored. The study presents the first method for simultaneous tubular molding and luminal surface patterning of hydrogel. PVA graft with 2 μm gratings showed patency and endothelialization, while unpatterned grafts were occluded after 20 days in rat aorta. The reproducible, high yield and high-fidelity methods enable planar and tubular patterning of PVA and other hydrogels to be used for biomedical applications.
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore; Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Marie F A
authors.initials: MFA
authors.lastname: Cutiongco
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore; Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore.
authors.forename: Seok Hong
authors.initials: SH
authors.lastname: Goh
authors.affiliation: INSERM, U1148, Laboratory for Vascular Translational Science, Paris, France.
authors.forename: Rachida
authors.initials: R
authors.lastname: Aid-Launais
authors.affiliation: INSERM, U1148, Laboratory for Vascular Translational Science, Paris, France; INSERM, U791, Center for OstesArticular and Dental Tissue Engineering, Nantes, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Le Visage
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore; Engineering Product Development Cluster, Singapore University of Technology and Design, Singapore. Electronic address: hongyee_low@sutd.edu.sg.
authors.forename: Hong Yee
authors.initials: HY
authors.lastname: Low
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore; Mechanobiology Institute, National University of Singapore, Singapore; Department of Surgery, National University of Singapore, Singapore; Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. Electronic address: eyim@uwaterloo.ca.
authors.forename: Evelyn K F
authors.initials: EKF
authors.lastname: Yim
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D020007:Implants, Experimental; D008297:Male; D054802:Molecular Imprinting; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D056951:Photoelectron Spectroscopy; D058626:Plasma Gases / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000494:pharmacology*; D011327:Printing; D017208:Rats, Wistar; D013499:Surface Properties
chemical_list: D058626:Plasma Gases; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011142:Polyvinyl Alcohol
keywords: Endothelialisation; Luminal patterning; Surface modification; Surface topography; Three-dimensional; Vascular grafts