FORMATION OF DNA COMPLEXES WITH DIBLOCK COPOLYMERS OF POLY(N-(2-HYDROXYPROPYL)METHACRYLAMIDE) AND POLYCATIONS

The self-assembly of calf thymus DNA with diblock copolymers of poly(N -(2-hydroxypropyl)methacrylamide) (HPMA) and polycations (PC) with ami no or quaternary ammonium groups in their side chains was tested by st atic and dynamic light scattering methods in aqueous 0.15 M NaCl. We h ave observed formation of well defined clusters of single DNA interpol yelectrolyte complexes with hydrodynamic radii of about 300 nm. Long-t erm size stability of clusters has been found to be a function of chem ical structure of PC and of diblock copolymer composition. The most st able clusters were obtained by DNA association with diblock copolymers consisting of a poly(HPMA) block (A) and polycation block (B) with qu aternary ammonium groups in their side chains, with molecular weight o f A block higher than that of B. In the opposite case, lower molecular weight of A block, slow aggregation of SIPEC clusters was observed. T he micelle-like structure was proposed for these clusters. (C) 1998 El sevier Science Limited.