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Scale‐dependent fiber kinematics of elastomeric electrospun scaffolds for soft tissue engineering
Author(s) -
Stella John A.,
Wagner William R.,
Sacks Michael S.
Publication year - 2009
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.32593
Subject(s) - materials science , mandrel , microscale chemistry , tortuosity , composite material , fiber , elastomer , scaffold , soft robotics , deformation (meteorology) , ultimate tensile strength , biomedical engineering , porosity , computer science , actuator , medicine , mathematics education , mathematics , artificial intelligence
Electrospun poly(ester urethane)urea (PEUU) scaffolds contain complex multiscale hierarchical structures that work simultaneously to produce unique macrolevel mechanical behaviors. In this study, we focused on quantifying key multiscale scaffold structural features to elucidate the mechanisms by which these scaffolds function to emulate native tissue tensile behavior. Fiber alignment was modulated via increasing rotational velocity of the collecting mandrel, and the resultant specimens were imaged using SEM under controlled biaxial strain. From the SEM images, fiber splay, tortuosity, and diameter were quantified in the unstrained and deformed configurations. Results indicated that not only fiber alignment increased with mandrel velocity but also, paradoxically, tortuosity increased concurrently with mandrel velocity and was highly correlated with fiber orientation. At microlevel scales (1–10 μm), local scaffold deformation behavior was observed to be highly heterogeneous, while increasing the scale resulted in an increasingly homogenous strain field. From our comprehensive measurements, we determined that the transition scale from heterogenous to homogeneous‐like behavior to be ∼1 mm. Moreover, while electrospun PEUU scaffolds exhibit complex deformations at the microscale, the larger scale structural features of the fibrous network allow them to behave as long‐fiber composites that deform in an affine‐like manner. This study underscores the importance of understanding the structure–function relationships in elastomeric fibrous scaffolds, and in particular allowed us to link microscale deformations with mechanisms that allow them to successfully simulate soft tissue mechanical behavior. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010