Free radical polymerization biologically active polymers

Monomers (XI) and (Xll) polymerize readily under free radical conditions to yield uncrosslinked polymers (31-36) The polymer from (Xlb) was found to inhibit P388 leukemia in mice but it was uncertain whether this was due to activity of the polymer or to a slow release of 5-fluorouracll since this polymer (and monomer) do slowly hydrolyze in an aqueous medium (34). Monomers (IX), (X), (XIII), (XIV) and (XV) also polymerize but no biological data have been reported. 

The vinyl derivatives of uracil and adenine have been studied more extensively than the other monomers. While 1-vinyluracil was found to undergo cyclopolymerization in some initial studies (32), subsequent research was able to prepare linear polymers which were water soluble (33,34). The 9-vinyladenine monomer readily polymerized on free radical initiation to yield water soluble polymers (22,35,36). The solution properties of these systems have been studied and they form complexes with each other in a manner similar to naturally occurring nucleic acids (20,21). These polymers do exhibit some biological activity including the inhibition of murine leukemia virus (37,38) and E. coli RNA polymerase (39). 

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