Microfluidic alignment of collagen fibers for in vitro cell culture

Abstract

Three dimensional gels of aligned collagen fibers were patterned in vitro using microfluidic channels. Collagen fiber orientation plays an important role in cell signaling for many tissues in vivo, but alignment has been difficult to realize in vitro. For microfluidic collagen fiber alignment, collagen solution was allowed to polymerize inside polydimethyl siloxane (PDMS) channels ranging from 10-400 microm in width. Collagen fiber orientation increased with smaller channel width, averaging 12+/-6 degrees from parallel for channels between 10 and 100 microm in width. In these channels 20-40% of the fibers were within 5 degrees of the channel axis. Bovine aortic endothelial cells expressing GFP-tubulin were cultured on aligned collagen substrate and found to stretch in the direction of the fibers. The use of artificially aligned collagen gels could be applied to the study of cell movement, signaling, growth, and differentiation.

Electromechanical properties of dried tendon and isoelectrically focused collagen hydrogels

“…In addition, comparing the electromechanical properties of natural collagenous tissues and engineered collagenous constructs could help understand the biological significance of piezoelectricity in collagen. Numerous approaches to assemble fibrillar collagen structures have been implemented, including hydrodynamic flow in the presence of potassium [11,12], magnetic field alignment [13], dip-pen lithography [14], chemical nanopatterning [15], microfluidics [16], and atomic force microscopy (AFM) manipulation [17]. Recent attempts to align collagen by electrochemical processes have demonstrated successful alignment of anisotropically-oriented collagen monomers [9,18].…”

Correlating Mechanical Properties with Aggregation Processes in Electrochemically Fabricated Collagen Membranes

“…1,8,[10][11][12][13] An alternative class of approaches for providing high orientational order and packing density involves manipulating the electrochemical environment and microscopic 2D collagen membranes by a similar process, 15 while othershave made collagen bundles in the presence of electric fields 3,16 .…”

Collagen: Applications of a Natural Polymer in Regenerative Medicine

“…Without mimicking this alignment found in tissues, it is not possible to build a biomimetic tissue. Methods used in vitro to control alignment of collagen type I include magnetic alignment, interstitial directional fluid flow to control alignment and flow of collagen solution through microfluidic chambers during gelation (Elsdale and Bard 1972;Girton et al 1999;Guo and Kaufman 2007;Lee et al 2006;Ng and Swartz 2003;Ng and Swartz 2006). Elsdale and Bard were amongst the first groups able to align collagen.…”