Highly substituted dextran alkyl carbonates were synthesized applying different acylating agents. The influence of the reaction media and the alkyl chain length on the reaction efficiency was systematically studied. Moreover, fluoroformates were successfully adapted as highly efficient and easy to handle reagents for the synthesis of dextran alkyl carbonates. The products obtained were clearly described by means of NMR- and IR spectroscopy. The dextran esters form spherical nanoparticles of a size below 300 nm that might be applied for delivery of therapeutic- or imaging agents. (C) 2010 Elsevier Ltd. All rights reserved.