Gold Particle Stabilization by Cape Aloe Active Components

Biosynthesis of metallic nanoparticles is reported in literature as clean, non toxic and environmentally acceptable route, using different plant extracts [1, 2], bacteria, yeast or fungi [3, 4]. In this context we wondered whether during nanoparticle biosynthesis could exist any specific metal-plant active component adduct. For this purpose, we have chosen to use two active components extracted from the Cape Aloe plant, Aloin A and Aloesin in the stabilization of gold and silver nanoparticles. Varying the reaction conditions, temperature, reaction time and reducing agents stabile, water soluble particles of different size and shape have been prepared. Gold particles have been fully characterized using UV-vis, ATR-FTIR and 1H and HR-MAS NMR spectroscopies and TEM. In particular, the interaction of these compounds with the gold particle surface has been investigated by spectroscopic techniques in solution and in solid state, as well. In solution, gold particles resulted stabilized by coordination of glucose OH moieties present in both molecules investigated, while in the solid state, π electronic interaction plays an additional important role in gold stabilization. Since Cape Aloe plant has been investigated as a potential anticancer agent [5], we have studied the cellular uptake of these hybrid materials into macrophage and HeLa cells, using Confocal and Fluorescence microscopy. The uptake into macrophage cells is an important result, since macrophage cells play an important role in the tumour angiogenesis [6]. Aloin A and Aloesin coated gold particles represent novel bioactive nano-carriers able to carry active principles into the cell and propose these particles as potential anticancer nano-vehicles and anticancer agents. References: 1. Shankar, S. S., Rai, A., Ankamwar, B., Sigh, A., Ahmad, A. and Sastry, M. (2004) Nature Mater. 3, 482–488. 2. Rai, A., Singh, A., Ahmad, A. and Sastry, M. (2006) Langmuir 22, 736–741. 3. Mohanpuria, P., Rana, N. K. and Yadav, S. K. (2008) J. Nanopart. Res. 10, 507–517. 4. Sastry, M., Ahmad, A., Khan, M. I. and Kumar, R. (2003) Curr. Sci. 85, 162–170. 5. Pecere, T., Gazzola, M. V., Mucignat, C., Parolin, C., Vecchia, F. D., Cavaggioni, A., Basso, G., Diaspro, A., Salvato, B., Carli, M. and Palù, G. (2000) Cancer Res. 60, 2800–2804. 6. Whitworth, P. W., Pak, C. C., Esgro, J., Kleinerman, E. S. and Fidler, I. J. (1989) Cancer Met. Rev. 8, 319–351.