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Dendritic polymers are highly branched, with three-dimensional spherical structures. They have the internal cavity, which can be used for drug embedding, and a large number of functional groups in the outer, which can be used to bind a variety of drugs and other functional groups. So, they are considered to be ideal drug carriers. Dendritic polymers mainly include hyperbranched polymer and dendrimers, The dendrimers with narrow PDI, about 1.0, have uniform pharmic properties. But the synthesis of the dendrimer is very difficult and the purification is not easy. In contrast, the synthesis of hyperbranched polymer is much easier, but its molecular weight distribution is relatively broad. So far, many studies have mainly carried out on the several traditional dendritic polymers. Therefore, study on the novel dendritic polymers and their drug delivery to get better medical treatment is very necessary.In this paper, we synthesized two novel dendritic polymers. A polyester hyperbranched polymer was firstly prepared from 1,4-dithiothreitol and glyceryl triacrylate. For comparison, a novel polester dendrimer, with the core of (2,3-di-O-methacrylated-6-methacrylated)-CD, was also synthesized using the asymmetric monomers of 2-methacryloyloxyethyl acrylate (MAEA) and cysteamine (CA). Polymer drug conjugates were obtained by connecting polyethylene glycol (PEG) and anti-cancer drugs onto the two dendritic polymers through the covalent bonds. And the in vitro drug release behavior and cytotoxicity of these conjugates were studied.The results indicated that these dendritic polymers were biodegradable, and their conjugates with anticancer drug form monomolecular micelles in water. These micelles can easily enter into the cancer cells in a short time, and target the cytoplasm in the cells Moreover, these conjugates with high drug loading can kill the cancer cell at low dose.
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