Development of Nanoparticle Encapsulation for Targeted Drug Delivery

Polymer nanoparticles are commonly used in the research lab as a method to controllably release a drug. However, the high surface to volume ratio of the nanoparticles results in the drug release commonly taking place over the course of 24 to 48 h. For longer term delivery, other methods need to be developed. We have developed a method to create injectable hydrogels filled with polymer nanoparticles. The hydrogel acts as a barrier to slow down diffusion of the drug from the nanoparticles effectively extending release of the drug.

Polylactide-co-glycolide polymer nanoparticles loaded with a model drug were prepared by impingement jets mixing and removal of the solvent using an ultrafiltration stir cell. Sucrose was added to the aqueous nanoparticle solution and the mixture was freeze dried to produce polymer nanoparticle powder. The nanoparticles were loaded into an injectable hydrogel formulation to modulate the controlled release of a model drug. The drug release kinetics of the polymer nanoparticle/hydrogel composite were evaluated in vitro to determine the effect of adding a mass transfer barrier on the rate of drug release from polymer nanoparticles. The use of a hydrogel effectively increased the drug release time from 2 d to 12 d.