Fabrication of freestanding alginate microfibers and microstructures for tissue engineering applications.
Natural biopolymers such as alginate have become important materials for a variety of biotechnology applications including drug delivery, cell encapsulation and tissue engineering. This expanding use has spurred the development of new approaches to engineer these materials at the nano- and microscales to better control cell interactions. Here we describe a method to fabricate freestanding alginate-based microfibers and microstructures with tunable geometries down to approximately 3 µm. To do this, a polydimethylsiloxane stamp is used to micromold alginate or alginate-fibrin blends onto a sacrificial layer of thermally-sensitive poly(N-isopropylacrylamide) (PIPAAm). A warm calcium chloride solution is then used to crosslink the alginate and, upon cooling below the lower critical solution temperature (~32 °C), the PIPAAm layer dissolves and releases the alginate or alginate-fibrin as freestanding microfibers and microstructures. Proof-of-concept experiments demonstrate that C2C12 myoblasts seeded onto the alginate-fibrin microfibers polarize along the fiber length forming interconnected cell strands. Thus, we have developed the ability to engineer alginate-based microstructured materials that can selectively bind cells and direct cellular assembly.
Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15219, USA.
John M
JM
Szymanski
Adam W
AW
Feinberg
D000464:Alginates / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D001704:Biopolymers / Q000737:chemistry; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D005337:Fibrin / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry / Q000494:pharmacology; D006603:Hexuronic Acids / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
D000464:Alginates; D001672:Biocompatible Materials; D001704:Biopolymers; D004129:Dimethylpolysiloxanes; D006603:Hexuronic Acids; C013830:baysilon; D020723:Glucuronic Acid; D005337:Fibrin