Emulsion-Induced Polymersomes for Water-Soluble Drug Encapsulation and Sustained Release

The effectiveness of water-soluble drug delivery is limited by low carrying capacity, undesirable load leakage. The research aim is to develop emulsion-induced polymersomes capable of encapsulation and sustained release of water-soluble drugs. We systematically altered the composition of each polymer and tested each sample for carrying capacity and stability, and controlled release trend. The hypothesis was that a more soluble molecule would increase carrying capacity due to the ease of forming of aqueous pockets, and have higher stability due to a smaller repellent force between the hydrophilic drug and the polymer shell. The oil based polymers used were HPG-PPG-HPG and PPG-HPG-PPH at different levels of H branching, and thus solubility.

The tests performed on the emulsion induced polymersomes of varying branching were a 24 hour stability test in vitro, and a 36 hour release test for release in vitro. We also examined these particles through a microscope and NMR, comparing the results to predictions made through software to confirm the structure was as intended.

We found that hyperbranched polymers did have higher load capacity and stability as compared to molecules with smaller branching, most likely due to the high hydrophilicity, which prevented collapse and allowed larger pockets of the aqueous payload to form more easily inside the shell.