Platinum-containing polymers

Tumoral cell lines were tested in the usual manner. The cell lines were trypsinized, cells suspended and counted, then diluted to 10 and plated onto Corning 1 ml well plates. The plates were incubated overnight in a 00% humidity carbon dioxide incubator and the next day the Dulbecco s Modified Eagle Medium (DMEM) sucked off and substituted with DMEM containing various microgram quantities of the platinum-containing polymer. Inhibition was tested for by both visual observation and employing trypan blue (an exclusion stain). 

The variety of platinum-containing compoimds that exhibit reasonable inhibition of cancer cell lines is large as indicated by the preceding discussion. The structures for potentially useful platinum-containing polymers should also be variable. 

A major effort at utilizing the platinum-containing polymer itself as a drug is the mainchain incorporation of platinum based on the de novo synthesis of the polymer structure from specified monomers, as no presynthesis of carrier polymer is required. The preparative approach is exemplified by the polymerization of tetra-chloroplatinate(II) dianion with diamines and other nitrogen-containing compounds. 

Wang synthesized a munber of similar platinum-containing polymers derived from ring-opened DIVEMA (46). Along with the 1,2-cyclohexanediamine platinum compound, other complexes of cis-PtL2Cl2 and cis-PtL2l2 were studied. These include compounds where L = NH3, isopropylamine, aziridine, and L2 = 2,2 -bipyridine, 1,3-propanediamine, and o-phenylenediamine. 

These acid groups are subsequently reacted with a platinum-containing moiety such as /rani-1,2-diaminocyclohexane platinum(ll) salt, forming the following platinum-containing polymer ... 

The polymeric nature may inhibit premature drug deactivation. Thus, cisplatin (structure 19.20), the most widely used anticancer drug, is converted into numerous inactive, but more toxic, platinum-containing compounds before it arrives at the targeted cancer cells. Placement of the active platinum-containing moiety into a polymer (structure 19.21) decreases this tendency to hydrolyze into these unwanted cisplatin compounds because of the greater hydrophobic character of the polymeric drug. 

Palladium(II)- and platinum(II)-containing polymers assembled by diisocyanide ligands are generally not luminescent.37 Because photoinduced labili-zation of the ligand in M C=N—R systems is possible, absence of luminescence can occur when this photochemical process happens, and consequently the light energy is wasted. As a result, luminescence is often not observed at room temperature in solution for such coordination polymers. Occasionally, only weak emissions at low temperature in the solid state can be detected. 

The use of Pt-acetylides containing phosphine ligands was extended further by the Schanze group in 2006 [84, 85], In one contribution, they incorporated platinum-acetylide polymers into photovoltaic devices which demonstrate good device efficiency. Transient absorption studies provide definitive evidence for photoinduced electron transfer from the Pt-acetylide to PCBM by the temporal evolution of the TA spectrum, observing the formation of the PCBM radical anion at 1,050 nm. The same system was eventually demonstrated to operate as a bulk heterojunction photovoltaic device [84],... 

Figure 188 PL and EL spectra of light-emitting diodes of the platinum-containing monomer and polymer at 290 K. The triplet emission is denoted by Ti and the singlet emission by Si. The percentual numbers provide the fraction of the numbers of singlet and triplet emitted photons with respect to the totally emitted photons (the larger numbers of Si and smaller numbers for Ti characterize the PL spectra). Reprinted by permission from Ref. 614. Copyright 2001 Macmillan Publishers, Ltd. [http //www.nature.com/].

In spite of the presence of metal-carbon o-bonds and carbon-carbon triple bonds in the backbone, the metal-poly-yne polymers are fairly stable to air in the solid state and show considerably good thermal stability (Table 6). The platinum-containing... 

Tanase et al. described the synthesis of platinum-containing organometallic rigid-rod polymers 29.75 These polymers were prepared by reacting [Pt3(p,-dpmp)2(XylNC)2](PF6)2 with... 

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