Peptide ormosils as cellular substrates

Abstract

Peptide-functionalized thin films exhibit significant potential for integration into implantable devices and cell-based technologies. A new type of neuroactive peptide-modified silica was developed using sol-gel reaction chemistry to produce thin films from four different peptide silane precursors. Peptide silanes containing binding sequences from laminin (YIGSR and KDI), fibronectin (RGD), and EGF repeats from laminin and tenascin (NID) were produced using standard solid-state FMOC peptide synthesis conditions and the covalent attachment of 39-(aminopropyl)trimethoxysilane (APTMS), using carbonyldiimadazole (CDI) as a linking molecule. Precursor formation was confirmed with MALDI-MS. Thin films were produced by dip-coating using the peptide precursors combined with hydrolyzed tetramethoxysilane. Atomic force microscopy indicated that the surface topography was not affected by low concentrations of peptide precursor (0.0025 mol%), but higher concentrations of peptide precursor (0.01 mol%) resulted in features that were 50-75 nm in height. The height features observed were consistent in size with previously determined topographical morphology supportive of neuronal cell lines. The surfaces were biologically active and modulated the phenotype of the embryonic carcinoma stem cell line, P19. Combinations of the peptide silanes resulted in altered cell types after retinoic acid treatment. More neurons were observed on RGD/YIGSR and RGD/YIGSR/NID surfaces compared to tetramethoxysilane (TMOS) controls. More supporting cells were observed compared to collagen coated tissue culture plates. In addition, neurites were significantly longer on the peptide ormosils compared to controls. This work demonstrates a novel method for producing biologically active peptide ormosils using peptide-modified precursors.

A self-referencing glutamate biosensor for measuring real time neuronal glutamate flux

“…After retinoic acid treatment, differentiated cells were plated at a density of 4 × 10 4 cells/cm 2 on UV treated culture dishes coated with 0.5 mg/mL rat tail collagen (BD Biosciences, Franklin Lakes, NJ), and allowed to mature for 10-14 days. Under these conditions, approximately 16% of the cells are neurons and 7% are astrocytes (Jedlicka et al, 2007). Differentiated P19 cells respond to electrical stimulation by release of both Glu and GABA (Jedlicka et al, 2009).…”

Thin-film silica sol–gel coatings for neural microelectrodes

“…The potential therapeutic applications that depend on stable chronic recording from the cortex make the mitigation of the reactive tissue response a pressing issue. Silica sol-gels provide an excellent substrate for interaction with neuronal tissue (Jedlicka et al, , 2007a, and thus the ability to successfully coat silicon-based electrodes with this material provides a promising avenue for averting the reactive tissue response.…”

“…The films have a thickness of approximately 100 nm. These ultra-porous sol-gel thin films have been shown to be excellent substrates for neuronal growth (Jedlicka et al, , 2007a. Jedlicka et al demonstrated that thin films derived from tetramethoxysilane (TMOS)-based sol-gels encourage adhesion of neuronal cells and differentiation of PC12 cells and pluripotent embryonic carcinoma cells into a neuronal phenotype with enhanced neurite outgrowth (Jedlicka et al, 2005(Jedlicka et al, , 2007a.…”

“…These ultra-porous sol-gel thin films have been shown to be excellent substrates for neuronal growth (Jedlicka et al, , 2007a. Jedlicka et al demonstrated that thin films derived from tetramethoxysilane (TMOS)-based sol-gels encourage adhesion of neuronal cells and differentiation of PC12 cells and pluripotent embryonic carcinoma cells into a neuronal phenotype with enhanced neurite outgrowth (Jedlicka et al, 2005(Jedlicka et al, , 2007a. In addition, the application of a TMOS sol-gel coating to microelectrodes may improve biocompatibility by facilitating surface modifications by anchoring biomolecules to the precursor silanes (Jedlicka et al, 2007a,b), which are used in preparation of the gels, or through the controlled release of drugs encapsulated in the porous material (Radin et al, 2005;Radin and Ducheyne, 2007;Santos et al, 1999).…”

Silica Entrapment of Biofilms in Membrane Bioreactors for Water Regeneration

“…Silica based sol-gel glasses possess materials properties that make them appealing substrates for the encapsulation of pharmaceutical agents (Kortesuo, Ahola et al 2000;Koehler, Zhao et al 2008), enzymes (Bhatia, Brinker et al 2000;Luckarift, Spain et al 2004), and proteins (Ellerby, Nishida et al 1992;Jedlicka, Little et al 2007). The interconnected mesopourous amorphous glass network that forms due to the polycondensation of silicic acid molecules stabilizes sensitive biomolecules (Eggers and Valentine 2001), provides a large area for surface/solution interactions (Yang and Zhu 2005), and allows for the controlled release of entrapped agents (Roveri, Morpurgo et al 2005).…”