title: Nanostructured Brownian surfaces prepared through two-photon polymerization: investigation of stem cell response.
abstract: Nondeterministic phenomena are at the base of plenty of biological processes that comprise physiological signaling, cellular communications, and biological architectures. Among them, natural surface topographies are often characterized by "chaotic" features that are not trivial to be recreated in vitro. Recently, some methods have been proposed to resemble the hierarchical organization of the extracellular microenvironment, through the chemical preparation of randomly rough and self-affine fractal surfaces. Notwithstanding, this approach does not allow the fractal dimension to be modulated at a desired value, being moreover the self-affinity maintained just for one decade of spatial frequencies. Here, we propose the replication of in silico generated Brownian surfaces through a two-photon polymerization technique. As a result of the direct laser writing of the desired patterns, we were able to obtain highly reproducible self-affine (in a range of two spatial frequency decades) structures characterized by the desired predetermined Hurst exponents. Rat mesenchymal stem cells were moreover cultured on the obtained substrates, highlighting interesting phenomena concerning cell adhesion, cytoskeleton conformation, and actin polymerization, strictly depending on the fractal dimension of the surfaces.
authors.affiliation: Center for Micro-BioRobotics, Istituto Italiano di Tecnologia , Viale Rinaldo Piaggio 34, 56025 Pontedera, Pisa, Italy.
authors.forename: Attilio
authors.initials: A
authors.lastname: Marino
authors.forename: Andrea
authors.initials: A
authors.lastname: Desii
authors.forename: Mario
authors.initials: M
authors.lastname: Pellegrino
authors.forename: Monica
authors.initials: M
authors.lastname: Pellegrini
authors.forename: Carlo
authors.initials: C
authors.lastname: Filippeschi
authors.forename: Barbara
authors.initials: B
authors.lastname: Mazzolai
authors.forename: Virgilio
authors.initials: V
authors.lastname: Mattoli
authors.forename: Gianni
authors.initials: G
authors.lastname: Ciofani
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D049329:Nanostructures; D017785:Photons; D058105:Polymerization; D051381:Rats; D013499:Surface Properties
keywords: Brownian surfaces; bio/non-bio interfaces; cytoskeleton organization; mesenchymal stem cells; two-photon polymerization