Blocking of Amines on PAMAM Dendrimers

The number of amine groups on dendrimers of medium to large size (G-3 and above) often is many more than what is required to prepare a conjugate. Since amines can become protonated 

Reactions with succinic anhydride or acetic anhydride to block dendrimer amines can be done in aqueous or methanolic solution. If organic solvent is used for the reaction, then it is typical to include triethylamine as a proton acceptor, which helps drive the reaction. Such reactions, however, can t be done to dendrimer amines once a protein containing amines also has been conjugated, as the protein too will get modified. 

Dissolve the amine-dendrimer to be modified in methanol at a concentration of lOmg/ml (all operations are done in a fume hood). 

The reaction is continued for 24 hours in the fume hood with mixing. 

Dialyze the modified dendrimer against PBS buffer and then water to remove excess reactants. 

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