title: Influence of carboxyl group density on neuron cell attachment and differentiation behavior: gradient-guided neurite outgrowth.
abstract: A UV pre-irradiation step followed by a UV grafting step was used to graft poly(acrylic acid) (PAA) on polymeric substrates. These substrates were then used to investigate the influence of carboxyl groups (-COOH) on cell behavior. Both the attachment and differentiation behaviors of C17.2 cells showed a -COOH group density-dependent response. In order to achieve an even distribution of cells on a -COOH gradient surface for neuron differentiation studies, an Ar plasma post-treatment was applied to the PAA-grafted surfaces. It greatly improved the cell adhesion properties with little damage to -COOH groups. This allows uniform distributions of seeded cells even on substrates with -COOH gradients. A linear or stepped -COOH gradient was found to be capable of serving as a repelling cue to guide the outgrowth of neurites from C17.2 cells. Up to 3.7 times more cells developed neurites growing down the -COOH gradient than growing up it.
authors.affiliation: Institute of Materials Research and Engineering (IMRE), Micro and Nanosystems Cluster, 3 Research Link, Singapore 117602, Republic of Singapore.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Yuexia
authors.initials: Y
authors.lastname: Ma
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.forename: Peter M
authors.initials: PM
authors.lastname: Moran
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry; D002454:Cell Differentiation; D049109:Cell Proliferation; D048429:Cell Size; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D016501:Neurites / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D020099:Coated Materials, Biocompatible; D002245:Carbon Dioxide; C041069:carboxyl radical; C006903:carbopol 940