Modification, characterization, analysis and life-science application of polymers: Polypropylene

Official URL: http://risc01.sabanciuniv.edu/record=b1076536 (Table of Contents)

Three stepwise chemical approaches were developed to transform commercially available isotactic polypropylene tubes into specialty' plastics for application in the life sciences: Oxidation. Ordinary polypropylene surfaces were oxidatively transformed inlo highsurface plastics bearing reactive surface groups by reaction with aqueous persulfate. Attcnuated-Total-Refiectance (ATR) infrared spcctroscopic analysis indicated that ketone, carboxylic acid and hydroxyl groups were afforded within the plastic. Surface analyses using optical microscopy revealed the formation of macroscopic parallel cracks. More importantly, scanning electron microscopy indicated the reacted material had developed a mesoscopic topology remarkably similar in appearance to microvilli. Protein immobilization experiments conducted using (luorescently labeled albumin served to quantify the performance of oxidized surfaces. Facile detection by visual observation under OV light disclosed that adsorbed protein was released during sequential washings of the tubes in high salt, low salt and detergent solutions. TEOS deposition. Hydrolysis products of tetraethoxysilane were cured onto oxidized, high-surface polypropylenes, affording tubes coated with prc-glass layers on the walls. ATR infrared spcctroscopic analyses verified the glass-like end product. These modified surfaces possessed the appropriate physico-chemical trails to reversibly bind mRNA, thus establishing the concept of a tube-mediated approach to purify mRKA out of total RNA. Protein could also be reversibly bound to the surface Triaminopropylsilane deposition. Oxidized surfaces were transformed using Ihe hydrolysis products of trimethoxysilylpropyldiethylenetriaminc to afford functional surfaces bearing surface-pendent amino groups. ATR infrared spectroscopy revealed that the network formed by triaminopropylsilyl moieties described a thin coating upon the surface. Ninhydrin coiorimctric analyses indicated that the surface amino group loading per unit frontal area had increased by an order of magnitude in comparison to commercially animated surfaces. As in the case of the TEOS tubes, the amino-modified tubes adsorbed protein reversibly. The amino moieties were subsequently transformed with glutaraldehyde solutions to afford surface-bound aldehyde functional groups. This time, immobilization studies using fluorescent albumin indicated that protein retention was remarkably resistant to washings with high salt, low salt and detergent solutions. In comparison to the aldehyde surfaces, native surfaces did not retain protein to any significant degree, and oxidized. TEOS, and triaminopropylsilylatcd surfaces showed merit in applications based upon a reversible association. Protein binding and retention was markedly influenced by mesoscale topology in the absence of covalent surfaceprotein interactions.