ABSTRACT
The extracellular matrix plays a crucial role in the growth of human neural stem cells (hNSCs) by forming a stem cell niche, bothin vitroandin vivo. The demand for defined synthetic substrates has been increasing recently in stem cell research, reflecting the requirements for precise functions and safety concerns in potential clinical approaches. In this study, we tested the adhesion and expansion of one of the most representative hNSC lines, the ReNcell VM Human Neural Progenitor Cell Line, in a pure-synthesized short peptide-basedin vitroniche using a previously established integrin-binding peptide array. Spontaneous cell differentiation was then induced using two differentin vitroapproaches to further confirm the multipotent features of cells treated with the peptides. Twelve different integrin-binding peptides were capable of supporting hNSC adhesion and expansion at varied proliferation rates. In the ReNcell medium-based differentiation approach, cells detached in almost all peptide-based groups, except integrinα5ß1 binding peptide. In an altered differentiation process induced by retinoic acid containing neural differentiation medium, cell adhesion was retained in all 12 peptide groups. These peptides also appeared to have varied effects on the differentiation potential of hNSCs towards neurons and astrocytes. Our findings provide abundant options for the development ofin vitroneural stem cell niches and will help develop promising tools for disease modeling and future stem cell therapies for neurological diseases.
Subject(s)
Cell Adhesion , Cell Differentiation , Cell Proliferation , Integrins , Neural Stem Cells , Peptides , Humans , Neural Stem Cells/cytology , Neural Stem Cells/metabolism , Cell Differentiation/drug effects , Cell Adhesion/drug effects , Peptides/chemistry , Peptides/pharmacology , Integrins/metabolism , Cell Proliferation/drug effects , Cell Line , Extracellular Matrix/metabolism , Neurons/metabolism , Neurons/cytology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Tretinoin/pharmacology , Surface Properties , Astrocytes/metabolism , Astrocytes/cytologyABSTRACT
Silica and hybrid organic-inorganic films, ca. 100-200 nm thick, can be grown on glassy carbon electrodes through reactions initiated by electrogenerated hydroxide or hydronium ions in water under reductive and oxidative conditions, respectively. A variety of different alkoxysilanes (tetramethoxysilane and organoalkoxysilanes) and supporting electrolytes were used to evaluate whether film formation takes place on glassy carbon electrodes. The results of the study indicate that the acid-base properties of the supporting electrolyte are an important factor in determining whether film formation will take place. For cathodic electrodeposition, thin films can be formed using supporting electrolytes that are close to neutral, such as KCl, KNO3, and NaClO4. For anodic electrodeposition, thin films can be formed using supporting electrolytes that are acidic, such as, KH2PO4, HNO3, H2SO4, etc. The acidity/basicity effects of the electrolytes arise in part from the strong dependence of the hydrolysis and condensation rates of the silicon alkoxide precursors on pH.
