title: Growth factor and matrix molecules preserve cell function on thermally responsive culture surfaces.
abstract: Thermally-responsive culture surfaces were designed using copolymers of N-isopropylacrylamide, 4-(aminomethyl)styrene, and acrylic acid. These surfaces contained functional amine and carboxyl groups, which allowed biomolecules to be grafted by amide formation. Epidermal growth factor (EGF), and extracellular matrix (ECM) molecules (collagen type IV, and chondroitin sulfate) were investigated, as surface-grafted biomolecules, for their ability to stimulate cell attachment, proliferation, and function by signaling only from the basal side of cultured cells. Surface analysis of biomolecule-grafted porous inserts showed covalent binding of biomolecules to either amine or carboxyl groups. Multiple attachment to amine and/or carboxyl groups served as cross-linking points that made the polymer hydrogel permanently adherent to the culture surface. Immunofluorescence microscopy techniques gave positive identification of grafted biomolecules. Grafting of EGF improved cell proliferation versus that on nongrafted controls, or controls grafted only with ECM molecules. ECM grafting induced cell attachment on attachment-resistant surfaces. Analysis of trans-epithelial resistance, fluid transport, and polarized g-glutamyl transpeptidase activity indicated that simultaneous grafting of both EGF and ECM produced better polarized cell function than nongrafted controls, or controls grafted with only one type of biomolecule. Covalent grafting of biomolecules did not interfere with cells ability to detach from thermally responsive surfaces upon temperature decrease.
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.
authors.forename: H
authors.initials: H
authors.lastname: von Recum
authors.forename: A
authors.initials: A
authors.lastname: Kikuchi
authors.forename: M
authors.initials: M
authors.lastname: Yamato
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai
authors.forename: T
authors.initials: T
authors.lastname: Okano
authors.forename: S W
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000577:Amides; D000818:Animals; D001672:Biocompatible Materials; D002448:Cell Adhesion / Q000187:drug effects; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000187:drug effects; D016764:Cell Polarity / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D002809:Chondroitin Sulfates / Q000494:pharmacology; D003094:Collagen / Q000494:pharmacology*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D016326:Extracellular Matrix Proteins / Q000494:pharmacology; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D011093:Polyethylene Terephthalates; D011108:Polymers; D015398:Signal Transduction / Q000187:drug effects; D013499:Surface Properties; D013696:Temperature; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D000577:Amides; D001672:Biocompatible Materials; D016326:Extracellular Matrix Proteins; D011093:Polyethylene Terephthalates; D011108:Polymers; D004815:Epidermal Growth Factor; D002809:Chondroitin Sulfates; D003094:Collagen; D005723:gamma-Glutamyltransferase