Invited: Long Collagen Fibers as a New Biomaterial for Tissue Engineering

There is a growing need to engineer soft tissue substitutes in controlled structure and cellular organization. Matching the extracellular fiber and cellular orientation of the native tissue can accelerate the integration and functionality of the tissue in-vivo.
For instance, blood vessels, intervertebral disk, tendons, ligaments, neural tissues all have defined collagen fiber orientation and cell organization which determines their function. This research introduces a new biomaterial based on collagen fibers extracted from corals (Sarcophyton). The collagen fibers are cm`s long and they maintain their natural conformation and hyperelastic mechanical behavior. The collagen fibers were wrapped around rectangular frames to create aligned arrays in controlled fiber
orientation and density. Fibroblast cells were seeded on the collagen fibers and monitored over time using quantitative metrics including growth rates and cell orientation. Cells cultured on the fibers adhered and spread along and in between the fibers, and showed increased viability over time for more than 28 days. Moreover, cells orientation was found to follow that of the collagen fibers for the entire duration of the experiment. We also demonstrate the possibility to integrate a supporting hydrogel
(PEG-DA) to the collagen fibers and the cultured cells, that can serve as a glue to create a more stable integrated bio-composites at various mechanical properties.
Our study shows that coral collagen fibers in combination with a supporting hydrogel can support biological growth in pre-defined orientation over a long time in culture (>28 days). Therefore, it is an attractive scaffold to support construction of various engineered-tissues according to their native morphology.