Pt O-Bound Polymers

The platinum-containing copolymers were 5-15-fold less toxic than cisplatin in vivo. After IV administration, the blood clearance of the copolymers was slower (ti/2 10 h) than that of cisplatin itself (t,/2 5 min). The platinum- containing copolymers showed a 60-fold increase in Pt accumulation in the B16F10 tumor tissue in comparison to cisplatin itself. 

Such studies illustrate the potential for administrating larger dosages of platinum but that the anticancer activity of polymers is complex. 

Numerous related compormds have been synthesized and used in place of the dichloride. These include the dibromo, oxalato, malonato, dinitrato, sulfato, mono, and bis(D-glucuronato) Pt(II) compormds. A number of these compounds were found to inhibit L1210 mouse leukemia cells the oxalato, malonato, dinitrato, and mono(D-glucuronato) Pt(II) compormds were most effective.  

A related early study of dichloro, oxalate, malonate, methyhnalonate, and the uracil complex also showed antitumor activity. They investigated the cis, d-trans, 

Such studies spurred on investigations involving tran5-l,2-diaminocyclo-hexane Pt(II) complexes including a number of polymeric materials. 

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A tetraanionic porphyrin with four p-sulfonatophenyl substituents on the methine bridges (PTS) binds to cationic polyvinylpyrrolidone (PVP) with an equilibrium constant of 1.4 x 10 M . As with all other me o-tetraphenyl derivatives, there is no sign of porphyrin-porphyrin interaction in the UV/VIS spectrum. Light-scattering measurements of the polymer at optimum ratios of PVP to PTS showed, however, that only one porphyrin per four PVP was bound, although the binding constant was extremely high. ... 

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