Synthesis and characterization of polyamide metallodendrimers and their anti-bacterial and anti-tumor activities

Pt(II) and Pd(II) complexes with aromatic amine terminated first generation (G(1)) and second generation (G(2)) polyamide dendrimers [PAD-(NH2) (n) ] (n = 6 for G(1) and 12 for G(2)) were synthesized. All the synthesized dendrimers and metallodenrimers were characterized by elemental and spectral analysis. These novel dendrimers and their metallodendrimers (metal complexes of dendrimers) were screened for their anti-bacterial activity against Bacillus subtilis and Staphylococcus aureus (Gram positive) and Escherichia coli and Salmonella typhi (Gram negative) using agar disk diffusion method. The cytotoxicity assay of the dendrimers and metallodendrimers has been performed against MFC-7 cell lines using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Anti-bacterial evaluation indicates that the second generation dendrimer exhibit stronger biological activity against all the pathogenic bacterial strains in comparison to the first generation dendrimers. PdG(2) exhibited lowest value of MIC 70 mu g/ml against E. coli, while MIC value of PtG(2) was 78 mu g/ml. PdG(2) and PtG(2) show lowest anti-bacterial activity against S. typhi with 102 and 110 mu g/ml (MIC value), respectively. In general, the metallodendrimers showed lower cytotoxicity than cisplatin (standard drug) and Pt(II) containing metallodendrimers were found to be more efficient in the induction of MFC-7 death than Pd(II) containing metallodendrimers.