Project Details
Projekt
Cross-linking and decoration of polysialic acid
Applicant
Professor Dr. Andreas Kirschning
Subject Area
Biological and Biomimetic Chemistry
Organic Molecular Chemistry - Synthesis and Characterisation
Organic Molecular Chemistry - Synthesis and Characterisation
Term
from 2004 to 2012
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5471076
The chemical modification of polysialic acid is a central part of the whole proposal. The aim of this work package is to provide modified polysialic acid with adapted solubility and improved mechanical properties as well as materials which can be more easily engineered to crafted products in WP3. Three approaches are followed to meet these targets: organic derivatization of polysialic acid (polymer-analogous reactions), organic derivatization of monomers, followed by chemoenzymatic polymerization and mineralization to yield organic-inorganic composite materials. The chemical modification of polysialic acid and the differentiation of the hydroxy groups will be possible using the well-known and reliable toolbox of carbohydrate chemistry which will of course have to be adapted. Among the planned transformations are: O-alkylation, modification of the carboxyl function, esterification of the free hydroxy groups and selective derivatization of the primary OH-group at C-9. At this stage, also phosphate, phosphonate and sulphate groups shall be introduced in order to facilitate the following mineralization. The chemoenzymatic approach starts with well-known sialic acid derivatives and uses the enzymes CMP-sialic acid synthetase and polysialyltransferase (polyST) to directly access modified polysialic acids; in the course of this work the substrate specificities of these enzymes will be studied. Unmodified and derivatized polysialic acids as well as crafted pieces obtained from WP3 will be mineralized with biocompatible inorganic materials such as silica, calcium carbonate and calcium phosphate.
DFG Programme
Research Units
