Nanoparticles of chitosan conjugated to organo-ruthenium complexes

Abstract

The synthesis of nanoparticles of conjugates of caffeic acid-modified chitosan with ruthenium arene complexes is described. The chemical structure and physical properties of the nanoparticles were characterised by electronic absorption spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), ¹H NMR spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and circular dichroism (CD) analysis. The multi-spectral results revealed that caffeic acid is covalently bound to chitosan and chelates to {Ru(p-cymene)Cl}⁺. The DLS studies indicated that the Ru–caffeic acid modified chitosan nanoparticles are well-defined and of nanometre size. Such well-defined nanocomposites of chitosan and metal complexes might find a range of applications, for example in drug delivery.

Yanqing Wang from Yancheng Teachers University, People's Republic of China is developing a research programme in the exciting area of medicinal inorganic chemistry, and in particular the design of nanoparticles for the delivery of metal anticancer complexes. He was awarded a research fellowship from the Jiangsu Overseas Research & Training Program for University Prominent Young & Middle-aged Teachers and President to spend the year from February 2014 to February 2015 in the laboratory of Peter Sadler at the University of Warwick, UK. There he carried out research in bioinorganic chemistry on topics related to the design and synthesis of nanoparticle conjugates of natural polymers with organo-ruthenium complexes. He synthesised nanocomposites of caffeic acid-modified chitosan linked to ruthenium arene complexes. Chitosan is deacetylated chitin, found in the exoskeleton of crustaceans and cell walls of fungi. Such well-defined nanocomposites of chitosan and metal complexes might find a range of applications, for example in drug delivery.