title: Tuning the architecture of three-dimensional collagen hydrogels by physiological macromolecular crowding.
abstract: Macromolecular crowding is an optimal physiological feature in intracellular and extracellular spaces, and results from a variety of macromolecules occupying space and contributing to a fractional volume occupancy. Here, we show that soft collagen hydrogels assembled in nature-inspired crowded conditions feature enhanced biophysical properties. We demonstrate that crowding tunes the rate of collagen nucleation and fiber growth, affecting fiber diameter and organization. Adjustments of crowding levels during collagen assembly tune the gel pore size, protein permeability, transparency and resistance to enzymatic degradation. Furthermore, gels assembled in crowded conditions are twice as resistant to mechanical stress as the controls, inducing a 70% boost of proliferation of stem cells cultured on tuned hydrogels. Emulating the crowdedness of interstitial fluids therefore represents a way to optimize the properties of soft collagen gels, with promising applications in soft biomaterials design.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore; NUS Tissue Engineering Programme, National University of Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Dewavrin
authors.affiliation: Impact Mechanics Laboratory, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Singapore; A∗STAR Institute of Microelectronics, Singapore.
authors.forename: Nader
authors.initials: N
authors.lastname: Hamzavi
authors.affiliation: Impact Mechanics Laboratory, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Singapore.
authors.forename: V P W
authors.initials: VP
authors.lastname: Shim
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore; NUS Tissue Engineering Programme, National University of Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. Electronic address: bierm@nus.edu.sg.
authors.forename: Michael
authors.initials: M
authors.lastname: Raghunath
mesh_terms: D002478:Cells, Cultured; D024042:Collagen Type I / Q000737:chemistry*; D020100:Hydrogels; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D016062:Porosity
chemical_list: D024042:Collagen Type I; D020100:Hydrogels
keywords: Biomaterial; Excluded-volume effect; Fibrillogenesis; Hydrogel