title: Photocrosslinked nanocomposite hydrogels from PEG and silica nanospheres: structural, mechanical and cell adhesion characteristics.
abstract: Photopolymerized hydrogels are extensively investigated for various tissue engineering applications, primarily due to their ability to form hydrogels in a minimally invasive manner. Although photocrosslinkable hydrogels provide necessary biological and chemical characteristics to mimic cellular microenvironments, they often lack sufficient mechanical properties. Recently, nanocomposite approaches have demonstrated potential to overcome these deficits by reinforcing the hydrogel network with. In this study, we investigate some physical, chemical, and biological properties of photocrosslinked poly(ethylene glycol) (PEG)-silica hydrogels. The addition of silica nanospheres significantly suppresses the hydration degree of the PEG hydrogels, indicating surface interactions between the silica nanospheres and the polymer chains. No significant change in hydrogel microstructure or average pore size due to the addition of silica nanospheres was observed. However, addition of silica nanospheres significantly increases both the mechanical strength and the toughness of the hydrogel networks. The biological properties of these nanocomposite hydrogels were evaluated by seeding fibroblast cells on the hydrogel surface. While the PEG hydrogels showed minimum cell adhesion, spreading and proliferation, the addition of silica nanospheres enhanced initial cell adhesion, promoted cell spreading and increased the metabolic activity of the cells. Overall, results indicate that the addition of silica nanospheres improves the mechanical stiffness and cell adhesion properties of PEG hydrogels and can be used for biomedical applications that required controlled cell adhesion.
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-2032, USA. agaharwa@purdue.edu
authors.forename: Akhilesh K
authors.initials: AK
authors.lastname: Gaharwar
authors.forename: Christian
authors.initials: C
authors.lastname: Rivera
authors.forename: Chia-Jung
authors.initials: CJ
authors.lastname: Wu
authors.forename: Burke K
authors.initials: BK
authors.lastname: Chan
authors.forename: Gudrun
authors.initials: G
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D019245:Compressive Strength / Q000187:drug effects / Q000528:radiation effects; D003432:Cross-Linking Reagents / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D020100:Hydrogels / Q000494:pharmacology*; D007700:Kinetics; D008027:Light; D055595:Mechanical Phenomena / Q000187:drug effects* / Q000528:radiation effects; D051379:Mice; D041681:NIH 3T3 Cells; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000494:pharmacology*; D012822:Silicon Dioxide / Q000494:pharmacology*; D013718:Tensile Strength / Q000187:drug effects / Q000528:radiation effects; D014867:Water
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D014867:Water; D011092:Polyethylene Glycols; D012822:Silicon Dioxide
keywords: Mechanical properties; Nanocomposite; Photocrosslinked hydrogels; Silica nanospheres