Protein-imprinted polysiloxane scaffolds

Abstract

Molecular imprinting is a technique used to create specific recognition sites on the surface of materials. Although widely developed for chromatographic separation of small molecules, this approach has not been adequately investigated for biomaterial applications. Thus, the objective of these experiments was to explore the potential of molecular imprinting for creating biomaterials that preferentially bind specific proteins. Macroporous polysiloxane (silica) scaffolds were imprinted with either lysozyme or RNase A using sol-gel processing. The quantity of surface-accessible protein, which was related to the number of potential binding sites, was varied by changing the amount of protein loaded into the sol. Up to 62% of loaded protein was accessible. The amount of protein per unit surface area ranged from 0.3μg m −2 for low loading of RNase to 152μg m −2 for high loading of lysozyme. Protein-imprinted scaffolds were then evaluated for their ability to preferentially recognize the template biomolecule when incubated in mixtures containing both the imprinted protein and a competitor protein of comparable size (approximately 14 kD). In solutions containing a single protein, up to 3.6 times more template bound compared with the competitor. Furthermore, in solutions containing equal amounts of both molecules, the porous scaffolds bound up to three times more template than the competitor protein, which is a level of preferential binding similar to values reported in the molecular imprinting literature for both organic and inorganic materials.

Protein binding to peptide-imprinted porous silica scaffolds

“…Results from the lysozyme-imprinted scaffold experiments showed good preferential binding, which confirmed our previous findings [14]. The template protein bound significantly more to the silica scaffolds than did the competitor under both noncompetitive (1:0 and 0:1) and competitive (1:1) conditions.…”

“…Because of its potential for greater stability, silica was used for the present studies [14]. During polycondensation to form the polysiloxane network, amino groups on the functional monomer APS are able to interact with the template (protein or peptide).…”

“…Vortex mixing the sol created bubbles that were retained in the gel and therefore gave the scaffolds a macroporous structure. As reported previously, scaffolds were about 40% porous with an average pore size of about 6 µm [14]. Blank scaffolds were made without the addition of protein.…”

“…Fabrication of the silica scaffolds began with a two step sol-gel process [14]. Tetraethoxysilane (TEOS; Fluka, Milwaukee, WI) as a cross-linking agent, 0.1M hydrochloric acid (HCl) as a catalyst, absolute ethanol as a co-solvent, and distilled water as another other co-solvent were mixed with γ-aminopropyltriethoxysilane (APS; Sigma, St. Louis, MO) as the functional monomer and sodium dodecyl sulfate (SDS) as a foaming agent.…”

Al2O3 coated with 3-n-propyl-1-azonia-4-azabicyclo[2.2.2]octane silsesquioxane chloride and its use for immobilization of cobalt(II) tetrasulfonated phthalocyanine in oxalic acid electrooxidation

“…[1][2][3][4][5][6] The preparation of hybrid materials with functionalized internal surface by a sol-gel processing technique can be easily achieved by cohydrolysis and polycondensation of tetraethylorthosilicate and an organotrialkoxysilane RSi(OR') 3 . Thus, 3-chloropropyltrimethoxysilane as the organosilane precursor has been already used in the preparation of 3-chloropropylsilsesquioxane, in which the chloropropyl group reacts with pyridine, leading to the formation of 3-n-propylpyridiniumsilsesquioxane chloride polymer.…”