Langmuir-Blodgett (LB) films of poly (5-(2-(4-((4-hexylphenyl)azo)phenoxy)ethyl) L-glutamate) (P2) and poly (5-(6-(4-((4-hexylphenyl)azo)phenoxy)hexyl) L-glutamate) (P6) polymers with a stiff backbone and flexible side chains ("hairy rods"), have been investigated at different steps of the photoisomerization and annealing process by means of X-ray reflection and U V-vis spectroscopy. From the absorption spectra the amount of aggregated chromophores was estimated using a peak-fitting procedure. The original LB structure, which is characterized by deformed "hairy rods" arranged in bilayers, is destroyed upon photoisomerization or annealing. The side chains relax to a more symmetrical distribution around the main chain helix. Furthermore the aggregation of the chromophores as well as their orientation in respect to the main chain helix is changed. The changes are more pronounced upon irradiation and depend on the length of the spacer used to tether the chromophores to the polymer backbone.

Stamm, M. (1997). Grafting of polypeptides on solid substrates by initiation of N-carboxyanhydride polymerization by aminoterminated self-assembled monolayers. Langmuir, 13(4), 723-728. DOI: 10.1021/la960467g Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Volker Erb and Manfred StammMax-Plank-Institut fü r Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany Received May 13, 1996. In Final Form: December 9, 1996 A series of mixed self-assembled monolayers of functionalized (Br(CH2)11SiCl3) and unfunctionalized (CH3(CH2)10SiCl3) alkyltrichlorosilanes of different compositions have been prepared on bulk silicon substrates. By in situ modification of these monolayers the bromo end groups were transformed to amino end groups as shown by X-ray photoelectron spectroscopy measurements. The change of hydrophilicity was monitored by water contact angle measurements, showing the expected decrease of contact angles with increase amino group content on the surface. These substrates were used to initiate Ncarboxyanhydrides in dioxane to yield R-helical polypeptides grafted from the surface. The thicknesses of the obtained polymer layers were measured with ellipsometry and X-ray reflectometry. Fourier transform infrared measurements confirm that the grafted polymers are in the R-helical conformation.

Polyamines mimicking substances which occur naturally in biosilicas have been synthesized and show an accelerating effect on silica condensation, which depends on the chemical nature, the architecture (linear or branched), and the degree of polymerization.

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A simple method for the functionalization of a common implant material (Ti6Al4V) with biodegradable, drug loaded chitosan-tripolyphosphate (CS-TPP) nanoparticles is developed in order to enhance the osseointegration of endoprostheses after revision operations. The chitosan used has a tailored degree of acetylation which allows for a fast biodegradation by lysozyme. The degradability of chitosan is proven via viscometry. Characteristics and degradation of nanoparticles formed with TPP are analyzed using dynamic light scattering. The particle degradation via lysozyme displays a decrease in particle diameter of 40% after 4 days. Drug loading and release is investigated for the nanoparticles with bone morphogenetic protein 2 (BMP-2), using ELISA and the BRE luciferase test for quantification and bioactivity evaluation. Furthermore, nanoparticle coatings on titanium substrates are created via spray-coating and analyzed by ellipsometry, scanning electron microscopy and X-ray photoelectron spectroscopy. Drug loaded nanoparticle coatings with biologically active BMP-2 are obtained in vitro within this work. Additionally, an in vivo study in mice indicates the dose dependent induction of ectopic bone growth through CS-TPP-BMP-2 nanoparticles. These results show that biodegradable CS-TPP coatings can be utilized to present biologically active BMP-2 on common implant materials like Ti6Al4V.