Synthesis of linear dendritic copolymers of poly (ethylene glycol) – poly (citric acid) and their application for encapsulation of nanogold nanoparticles

Dendrimers and hyperbranched polymers are a relatively new class of materials with unique molecular architectures and dimensions in comparison to traditional linear polymers [1]. These new class of macromolecules are able to load and transport small molecules such as nanoparticles and drugs. [2] Dendrimers are routinely synthesized as tuneable nanostructures that may be designed and regulated as a function of their size, shape, surface chemistry and interior void space. The internal cavity of dendritic macromolecules could be used for entrapment of guest molecules to afford host– guest systems. Dendritic polymers can be used as potential careears of nanoparticles and drug-delivery agents in at least two ways: firstly, the molecules can be physically entrapped inside the dendritic structure; secondly, the molecules can be covalently attached onto surface or other functionalities to afford dendrimer– drug conjugates [3]. Both poly (ethylene glycol) and citric acid are biocompatible compounds, water soluble and non-immunogenic; hence, they are good candidates for application as drug delivery systems. In this work, we report synthesis of novel conjugation of these two compounds, a linear- dendritic copolymer and its application for encapsulation of gust molecules such as nanogold nanoparticles