Untersuchungen zur Wirkung von Glucuronsäure auf die Hydroxylapatitbildung in und an Kollagen I - Templaten
Final Report Abstract
Developing new biopolymer-based materials with bio-identical properties is a significant challenge in modem science. One interesting route to this goal involves the biomineralization of collagen, a pre-structured and widely available protein, into a material with interesting properties. A prerequisite for biomineralization is the ability of cations (e.g. calcium) to bind to the protein and to result in concert with appropriate anions (e.g. phosphate) in composite material with e.g. bone-like properties. In order to increase the number of binding sites it is necessary to modify the protein prior to mineralization. Because numerous proteins known to initiate mineralization possess acidic species, we have modified the neutral electrical surface of collagen by carboxymethylation using glucuronic acid. For this glucuronic acid was used, due to its main functional groups, a carbonyl and a carboxyl, to derivatize positively charged protein-bound amino groups into negatively charged carboxyl groups. Our experiments showed for the first time, that N^-carboxymethyllysine is the major product of the in vitro non-enzymatic glycation reaction between collagen and glucuronic acid. We hypothesized that the function of blomimetically carboxymethylated collagen is to increase the local concentration of corresponding ions so that a critical nucleus of ions can be formed, leading to the formation of the mineral. Thus, the self organization of HAP nanocrystals on and within collagen fibrils was intensified by carboxymethylation.
Publications
- Principles of Demineralization: Modem Strategies for the isolation of Organic Frameworks. Part H. Decalcification, in: Micron
Hermarm Ehrlich, Petros G. Koutsoukos, Konstantinos D. Demadis, Oleg S. Pokrovsky
(See online at https://doi.org/10.1016/j.micron.2008.06.004) - Principles of Demineralization: Modern Strategies for the Isolation of Organic Frameworks. Part I. Common Definitions and History, in: Micron
Hermann Ehrlich, Petros G. Koutsoukos, Konstantinos D. Demadis, Oleg S. Pokrovsky
(See online at https://doi.org/10.1016/j.micron.2008.02.004)
