Hong Research Group
Using our basic understanding of nano-bio interactions we have prepared engineered polymeric nanoparticles combining advantageous properties of multiple systems. Micelles self-assembled from linear and dendritic amiphilic copolymers represent a promising class of nanocarriers. We have developed dendron-based micelles consisting of a hydrophobic, biodegradable poly(ε-caprolactone) core, a hyperbranched generation 3 polyester dendrimer, and a poly(ethylene glycol) outer layer. Owing to the hyperbranched dendron structure, our micelles demonstrated enhanced thermodynamic stability, a high degree of surface PEG coverage, and are able to maintain ligand-mediated cell targeting in the presence of serum proteins. The dendron micelles further allow for control over the surface distribution of targeting ligands.
We have developed a multiscale, hybrid nanoparticle delivery system consisting of smaller PAMAM dendrimers (<10 nm) encapsulated within a larger poly(lactide)-b-poly(ethylene glycol) shell (150 nm). Whereas the larger outer PEG coating allows for increased circulation time and tumor accumulation due to the enhanced permeability and retention effect, the encapsulated smaller dendrimers exhibit improved tumor penetration capabilities. Folate-targeted dendrimers encapsulated within hybrid NPs displayed significantly enhanced tumor accumulation compared to their free counterparts. These findings demonstrate the potential for using hybrid approaches to take advantage of multiple drug delivery systems.
