title: The mechanisms of fibroblast-mediated compaction of collagen gels and the mechanical niche around individual fibroblasts.
abstract: Fibroblast-mediated compaction of collagen gels attracts extensive attention in studies of wound healing, cellular fate processes, and regenerative medicine. However, the underlying mechanism and the cellular mechanical niche still remain obscure. This study examines the mechanical behaviour of collagen fibrils during the process of compaction from an alternative perspective on the primary mechanical interaction, providing a new viewpoint on the behaviour of populated fibroblasts. We classify the collagen fibrils into three types - bent, stretched, and adherent - and deduce the respective equations governing the mechanical behaviour of each type; in particular, from a putative principle based on the stationary state of the instantaneous Hamiltonian of the mechanotransduction system, we originally quantify the stretching force exerted on each stretched fibrils. Via careful verification of a structural elementary model based on this classification, we demonstrate a clear physical picture of the compaction process, quantitatively elucidate the panorama of the micro mechanical niche and reveal an intrinsic biphasic relationship between cellular traction force and matrix elasticity. Our results also infer the underlying mechanism of tensional homoeostasis and stress shielding of fibroblasts. With this study, and sequel investigations on the putative principle proposed herein, we anticipate a refocus of the research on cellular mechanobiology, in vitro and in vivo.
authors: Graduate School of Science and Engineering, Yamagata University, Japan. Electronic address: zhgfeng@yz.yamagata-u.ac.jp.
authors: Zhonggang
authors: Z
authors: Feng
authors: Graduate School of Science and Engineering, Yamagata University, Japan.
authors: Yusuke
authors: Y
authors: Wagatsuma
authors: Graduate School of Science and Engineering, Yamagata University, Japan.
authors: Masato
authors: M
authors: Kikuchi
authors: Graduate School of Science and Engineering, Yamagata University, Japan.
authors: Tadashi
authors: T
authors: Kosawada
authors: Graduate School of Medical Science, Yamagata University, Japan.
authors: Takao
authors: T
authors: Nakamura
authors: Graduate School of Medical Science, Yamagata University, Japan.
authors: Daisuke
authors: D
authors: Sato
authors: Department of Anatomy and Structural Science, Yamagata University, Japan.
authors: Nobuyuki
authors: N
authors: Shirasawa
authors: Electronic Systems Engineering, Malaysia-Japan International Institute of Technology, Malaysia.
authors: Tatsuo
authors: T
authors: Kitajima
authors: Integrative Bioscience and Biomedical Engineering, Graduate School of Waseda University, Japan.
authors: Mitsuo
authors: M
authors: Umezu
mesh_terms: D000818:Animals; D002138:Calibration; D002448:Cell Adhesion; D019070:Cell Lineage; D003094:Collagen / Q000737:chemistry*; D004548:Elasticity; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D005782:Gels / Q000737:chemistry; D006706:Homeostasis; D009336:Necrosis; D051381:Rats; D017208:Rats, Wistar; D044968:Regenerative Medicine; D013314:Stress, Mechanical; D014945:Wound Healing
chemical_list: D005782:Gels; D003094:Collagen
keywords: Cell culture; Collagen; Fibroblast; Hydrogel; Modelling