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Creating homogenous strain distribution within 3D cell‐encapsulated constructs using a simple and cost‐effective uniaxial tensile bioreactor: Design and validation study
Author(s) -
Subramanian Gayathri,
Elsaadany Mostafa,
Bialorucki Callan,
YildirimAyan Eda
Publication year - 2017
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.26304
Subject(s) - bioreactor , ultimate tensile strength , materials science , uniaxial tension , biomedical engineering , strain (injury) , composite material , chemistry , anatomy , engineering , medicine , organic chemistry
ABSTRACT Mechanical loading bioreactors capable of applying uniaxial tensile strains are emerging to be a valuable tool to investigate physiologically relevant cellular signaling pathways and biochemical expression. In this study, we have introduced a simple and cost‐effective uniaxial tensile strain bioreactor for the application of precise and homogenous uniaxial strains to 3D cell‐encapsulated collagen constructs at physiological loading strains (0–12%) and frequencies (0.01–1 Hz). The bioreactor employs silicone‐based loading chambers specifically designed to stretch constructs without direct gripping to minimize stress concentration at the ends of the construct and preserve its integrity. The loading chambers are driven by a versatile stepper motor ball‐screw actuation system to produce stretching of the constructs. Mechanical characterization of the bioreactor performed through Finite Element Analysis demonstrated that the constructs experienced predominantly uniaxial tensile strain in the longitudinal direction. The strains produced were found to be homogenous over a 15 × 4 × 2 mm region of the construct equivalent to around 60% of the effective region of characterization. The strain values were also shown to be consistent and reproducible during cyclic loading regimes. Biological characterization confirmed the ability of the bioreactor to promote cell viability, proliferation, and matrix organization of cell‐encapsulated collagen constructs. This easy‐to‐use uniaxial tensile strain bioreactor can be employed for studying morphological, structural, and functional responses of cell‐embedded matrix systems in response to physiological loading of musculoskeletal tissues. It also holds promise for tissue‐engineered strategies that involve delivery of mechanically stimulated cells at the site of injury through a biological carrier to develop a clinically useful therapy for tissue healing. Biotechnol. Bioeng. 2017;114: 1878–1887. © 2017 Wiley Periodicals, Inc.