Thermosensitive and biocompatible amphiphilic poly(organophosphazenes) and preparation method thereof

A method of preparing poly(organophosphazenes) represented by Formula 1, comprising the steps of:

• (1) reacting poly(ethylene glycol) represented by Formula 4 with poly(dichlorophosphazene) represented by Formula 3;
• and
• (2) reacting the product obtained in step (1) with an oligopeptide ester represented by Formula 6 or its acid salt;
• wherein R is a methyl or ethyl group;
• R′ is selected from the group consisting of CH2CH(CH3)2, CH2C6H5, CH(CH3)CH2CH3 and CH3;
• R″ is selected from the group consisting of CH2COOR, CH2CH2COOR, CH2CH(CH3)2, CH2C6H5, CH(CH3)CH2CH3 and CH3;
• R′″ is a group selected from the group consisting of CH2COOR, CH2CH2COOR and H,
• wherein R is the same as defined above;
• n is a number between from 30 to 100;
• x is a number selected from the integers of 3, 4, 7, 12 and 16;
• y is a number between from 0.5 to 1.5;
• a equals to 1;
• b and c equal to 0 or 1.