Novel cisplatin-type platinum complexes and their cytotoxic activity

Preparation and evaluation of a novel liposomal formulation of cisplatin

A novel liposomal formulation of cisplatin (L-CDDP) was synthesized and characterized. The L-CDDP was formed by conjugating CDDP to the carboxyl of oleic acid incorporated into empty liposomes. Particle size (155.4±16.1nm) and zeta potential (-50.92±1.19mV) of the L-CDDP were determined. In addition, pharmacokinetic properties and antitumor activity in vitro and in vivo were evaluated. Pharmacokinetic study demonstrated that L-CDDP had markedly prolonged circulation time relative to the free drug. Furthermore, L-CDDP showed significantly enhanced in vitro cytotoxicity in comparison to free CDDP. A549-engrafted mice treated with L-CDDP had a higher survival rate compared to those treated with free CDDP. Finally, A549-engrafted mice treated with L-CDDP showed no significant loss of body weight, whereas free CDDP treatment at the same dose caused significant loss of body weight. These results suggest further evaluation of the in vivo antitumor efficacy of the novel L-CDDP formulation is warranted.

In vitro biological evaluation of platinum(II) complexes with 1-(methoxy substituted benzyl) azetidine-3,3-dicarboxylato ligands

A number of platinum(II) complexes with ammine or 1R,2R-diaminocyclohexane as carrier ligands and 1-(methoxy-substituted benzyl) azetidine-3,3-dicarboxylate as leaving groups were synthesized and spectrally characterized. Biological evaluation in vitro showed that some of compounds showed positive antitumor activity. In particular, complex 3a, (1R,2R-diaminocyclohexane)[1-(3-methoxylbenzyl) azetidine-3,3-dicarboxylato)-O,O'] platinum(II), possessed a potent antitumor effect comparable to cisplatin and/or oxaliplatin, and very low toxicity in vivo. Preliminary antitumor mechanism of 3a has been investigated by cell apoptosis assays compared with cisplatin and oxaliplatin.

Synthesis, characterization and cytotoxicity of diam(m)-ineplatinum(II) complexes containing beta-phenylisosuccinate ligand

Four diam(m)ineplatinum(II) complexes containing beta-phenylisosuccinate as the leaving groups were prepared, characterized, and evaluated for their cytotoxicity against A549/ATCC human lung cancer cell line and SGC-7901 human gastric cancer cell line. One of the complexes, (trans-1R,2R-diaminocyclohexane)-beta-phenylisosuccinatoplatinum(II) 4, was much more active than cisplatin and carboplatin.

In vitro cytotoxicity study on platinum (II) complexes with epoxysuccinates as leaving groups

A series of novel cisplatin-type platinum complexes were designed, characteristic of epoxysuccinates as leaving groups. The pertinent compounds were prepared and characterized by IR, (1)H NMR, and ESI-MS spectra with elementary analyses. The in vitro cytotoxic activities of compounds toward SPC-A1 human lung adenocarcinoma cell line and BGC823 human stomach adenocarcinoma cell line were determined. Biological tests have confirmed that complexes containing 4R,5R-DMID [abbreviation of (4R,5R)-4,5-bis (aminomethyl)-2-isopropyl-1,3-dioxolane] as carrier ligands have greater cytotoxicity toward tumor cells than the corresponding compounds with other carrier ligands. Most platinum complexes with trans-epoxysuccinates usually have higher cytotoxicity than those with cis-epoxysuccinates. Complex 4a shows the most effective among those tested platinum complexes in both cell lines, and its cytotoxicity approached that of cisplatin.

Synthesis and in vitro cytotoxicity of novel lipophilic (diamine)platinum(II) complexes of salicylate derivatives

Novel lipophilic (diamine)platinum(II) complexes of salicylate derivatives as the leaving groups were synthesized and characterized by elemental analysis, FAB(+)-MS, FT-IR, and (1)H NMR spectroscopy. Most of the resulting platinum complexes had high solubility in organic solvents such as ethanol, acetone, and ether, and had right partition coefficient suited to be encapsulated in liposomes. The pertinent complexes were evaluated for their in vitro cytotoxicity against A549 human lung carcinoma and SGC-7901 human gastric carcinoma cell lines. They showed better cytotoxic activity than carboplatin and oxaliplatin.