Design, synthesis, and characterization of biodendritic polymers

Research concerning dendritic polymers continues to expand as further advances in synthetic methodology and characterization techniques translate to additional applications. Dendritic polymers composed of natural metabolites such as glycerol, succinic acid, myristic acid, glycine, and cholesterol are synthesized, functionalized, and evaluated as new medical materials. The design and synthesis of p&barbelow;oly(glycerol-s&barbelow;uccinic a&barbelow;cid) (PGLSA) dendrimers and dendrons are discussed, including comparing and contrasting the convergent versus the divergent methodologies for preparing such macromolecules. Specifically, the high yielding convergent synthesis of PGLSA dendrimers and dendrons is presented that facilitates the preparation of particularly interesting and complex polymers. For example, amphiphilic surface-block dendrimers which display aqueous self-assembly properties are described. Such amphiphilic dendrimers can preferentially solubilize hydrophibic molecules within spontaneously formed supramolecular aggregates in aqueous solution and may be useful for drug delivery applications. Photocrosslinkable dendritic macromolecules are prepared possessing methacrylate groups at the dendritic periphery. These polymers form three-dimensional hydrogels when irradiated with light and have desirable physical properties for wound sealing procedures. Additionally, quaternized amines are incorporated into amphiphilic surface-block dendrimers and these macromolecules display DNA binding capabilities. Such molecules are of interest for gene transfection applications. A cholesterol derivative is described which displays unique physical properties such as thermal transition temperature and critical aggregation concentration. Finally, layered dendrimers are designed and prepared that have distinct 1H NMR chemical shifts in different generations. These dendrimers encapsulate Reichardt's dye and provide new insight into dendritic host/guest interactions. Overall, the family of dendritic PGLSA polymers presented provide methods of manipulating many key physical properties necessary for the development of new and improved patient treatments. Furthermore, the synthetic methods described herein can be utilized to prepare an entire host of functionalized macromolecules with degrees of precision highly unusual for macromolecular systems.