@article {19173, title = {Self-Assembled Hydrogel Fiber Bundles from Oppositely Charged Polyelectrolytes Mimic Micro-/Nanoscale Hierarchy of Collagen}, journal = {Adv. Funct. Mater.}, year = {2017}, month = {2017-08-16 00:00:00}, abstract = {

Fiber bundles are present in many tissues throughout the body. In most cases,
collagen subunits spontaneously self-assemble into a fibrilar structure that
provides ductility to bone and constitutes the basis of muscle contraction.
Translating these natural architectural features into a biomimetic scaffold still
remains a great challenge. Here, a simple strategy is proposed to engineer
biomimetic fiber bundles that replicate the self-assembly and hierarchy of
natural collagen fibers. The electrostatic interaction of methacrylated gellan
gum with a countercharged chitosan polymer leads to the complexation of the
polyelectrolytes. When directed through a polydimethylsiloxane channel, the
polyelectrolytes form a hierarchical fibrous hydrogel demonstrating nanoscale
periodic light/dark bands similar to D-periodic bands in native collagen and
align parallel fibrils at microscale. Importantly, collagen-mimicking hydrogel
fibers exhibit robust mechanical properties (MPa scale) at a single fiber bundle
level and enable encapsulation of cells inside the fibers under cell-friendly mild
conditions. Presence of carboxyl- (in gellan gum) or amino- (in chitosan) functionalities
further enables controlled peptide functionalization such as Arginylglycylaspartic
acid (RGD) for biochemical mimicry (cell adhesion sites) of native
collagen. This biomimetic-aligned fibrous hydrogel system can potentially be
used as a scaffold for tissue engineering as well as a drug/gene delivery vehicle.

}, keywords = {bottom-up self-assembly, chitosan and gellan gum, collagen mimicking, hierarchical hydrogel fibers, Polyelectrolyte Complexes}, issn = {1616-3028}, doi = {10.1002/adfm.201606273}, url = {http://onlinelibrary.wiley.com/doi/10.1002/adfm.201606273/full}, author = {Sant, S. and Coutinho, D. F. and Gaharwar, A. K. and Neves, N. M. and Reis, R. L. and Gomes, M. E. and Khademhosseini, A.} }