title: Fabrication of Density Gradients of Biodegradable Polymer Microparticles and Their Use in Guiding Neurite Outgrowth.
abstract: We report a new method for generating both continuous and discrete density gradients in microparticles of biodegradable polymers via an electrospray technique. The gradients were generated by spatially varying the deposition time of electrosprayed microparticles. The substrate coated with a density gradient of microparticles has varying surface roughness, offering a unique system for studying the effect of physical cues on neurite outgrowth from dorsal root ganglia. We obtained an optimal surface roughness for promoting neuron adhesion and neurite extension in vitro. Furthermore, this capability of approach was extended to generate a gradient of fluorescein isothiocyanate-labeled bovine serum albumin by encapsulating it in the polymer microparticles in situ during electrospray. Taken together, this new class of substrates with gradients of microparticle density can potentially be used in various biomedical applications such as neural tissue engineering.
authors.affiliation: Department of Biomedical Engineering, Washington University, St. Louis, MO 63130 (USA); School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (P. R. China).
authors.forename: Xiaoran
authors.initials: X
authors.lastname: Li
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Macewan
authors.forename: Jingwei
authors.initials: J
authors.lastname: Xie
authors.forename: Daku
authors.initials: D
authors.lastname: Siewe
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yuan
authors.forename: Younan
authors.initials: Y
authors.lastname: Xia