TY - JOUR

T1 - Into the groove

T2 - instructive conductive silk films with topological guidance cues

AU - Hardy, John

AU - Khaing, Zin

AU - Xin, Shangjing

AU - Tien, Lee

AU - Ghezzi, Chiara

AU - Mouser, David

AU - Sukhavasi, Rushi C.

AU - Preda, Rucsanda

AU - Gil, Eun

AU - Kaplan, David L.

AU - Schmidt, Christine E

N1 - This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Biomaterials Science, Polymer Edition on 28/09/2015, available online: http://wwww.tandfonline.com/10.1080/09205063.2015.1090181

PY - 2015/11

Y1 - 2015/11

N2 - Instructive biomaterials capable of controlling the behaviour of the cells are particularly interesting scaffolds for tissue engineering and regenerative medicine. Novel biomaterials are particularly important in societies with rapidly aging populations, where demand for organ/tissue donations is greater than their supply. Herein we describe the preparation of electrically conductive silk film-based nerve tissue scaffolds that are manufactured using all aqueous processing. Aqueous solutions of Bombyx mori silk were cast on flexible polydimethylsiloxane substrates with micrometer-scale grooves on their surfaces, allowed to dry, and annealed to impart β-sheets to the silk which assures that the materials are stable for further processing in water. The silk films were rendered conductive by generating an interpenetrating network of polypyrrole and polystyrenesulfonate in the silk matrix. Films were incubated in an aqueous solution of pyrrole (monomer), polystyrenesulfonate (dopant) and iron chloride (initiator), after which they were thoroughly washed to remove low molecular weight components (monomers, initiators, and oligomers) and dried, yielding conductive films with sheet resistances of 124 ± 23 kΩ square-1. The micrometer-scale grooves that are present on the surface of the films are analogous to the natural topography in the extracellular matrix of various tissues (bone, muscle, nerve, skin) to which cells respond. Dorsal Root Gangions (DRGs) adhere to the films and the grooves in the surface of the films instruct the aligned growth of processes extending from the DRGs. Such materials potentially enable the electrical stimulation of cells cultured on them, and future in vitro studies will focus on understanding the interplay between electrical and topographical cues on the behaviour of cells cultured on them.

AB - Instructive biomaterials capable of controlling the behaviour of the cells are particularly interesting scaffolds for tissue engineering and regenerative medicine. Novel biomaterials are particularly important in societies with rapidly aging populations, where demand for organ/tissue donations is greater than their supply. Herein we describe the preparation of electrically conductive silk film-based nerve tissue scaffolds that are manufactured using all aqueous processing. Aqueous solutions of Bombyx mori silk were cast on flexible polydimethylsiloxane substrates with micrometer-scale grooves on their surfaces, allowed to dry, and annealed to impart β-sheets to the silk which assures that the materials are stable for further processing in water. The silk films were rendered conductive by generating an interpenetrating network of polypyrrole and polystyrenesulfonate in the silk matrix. Films were incubated in an aqueous solution of pyrrole (monomer), polystyrenesulfonate (dopant) and iron chloride (initiator), after which they were thoroughly washed to remove low molecular weight components (monomers, initiators, and oligomers) and dried, yielding conductive films with sheet resistances of 124 ± 23 kΩ square-1. The micrometer-scale grooves that are present on the surface of the films are analogous to the natural topography in the extracellular matrix of various tissues (bone, muscle, nerve, skin) to which cells respond. Dorsal Root Gangions (DRGs) adhere to the films and the grooves in the surface of the films instruct the aligned growth of processes extending from the DRGs. Such materials potentially enable the electrical stimulation of cells cultured on them, and future in vitro studies will focus on understanding the interplay between electrical and topographical cues on the behaviour of cells cultured on them.

KW - silk

KW - biomaterial

KW - tissue engineering

KW - nerve guide

U2 - 10.1080/09205063.2015.1090181

DO - 10.1080/09205063.2015.1090181

M3 - Journal article

VL - 26

SP - 1327

EP - 1342

JO - Journal of Biomaterials Science, Polymer Edition

JF - Journal of Biomaterials Science, Polymer Edition

SN - 0920-5063

IS - 17

ER -