Nano-Engineering of Smart Drug Delivery Particles at Boston University

Accuracy of measurement of nanoparticles is a fundamental requirement for research involving smart particles for drug delivery.

Professor Mark Grinstaff and members of his group in the Departments of Biomedical Engineering and Chemistry at Boston University, have been researching the use of ‘expansile’ nanoparticles and hydrophilic triggers for targeted drug delivery. Specifically, new nanoparticle compositions are being developed that are pH responsive, which swell and release their contents once inside cancer cells.
Nanoparticles have been prepared using mini-emulsion polymerization chemistry, combining high-energy emulsification and free radical photopolymerization of an acrylate monomer. The effect of varying pH solutions on the size of these smart particles is then measured, by comparing particle-by-particle size and concentration details of the mixture at each pH level. Accurate measurement of particles both before and after the pH change is a crucial aspect in assessing the physical properties, reaction kinetics and drug efficacy.
Izon’s qNano is being used by the research group to measure various parameters (size, surface charge and concentration) of the synthesized nanoparticles before, during and after each phase change at varying pH conditions. Earlier measurements obtained using DLS did not provide the degree of accuracy and reliability required, and Izon’s nanopore technology is now being used to provide particle-by-particle measurement for a much higher degree of detail and precision.
Investigation into the flexibility and deformability of the particles is a further aspect enabled by Izon’s qNano by gating of the smart particles with the tunable nanopore.

Further reading:
Aaron H. Colby , Yolonda L. Colson and Mark W. Grinstaff (2013) “Microscopy and tunable resistive pulse sensing characterization of the swelling of pH-responsive, polymeric expansile nanoparticles” Nanoscale, Advance Article DOI: 10.1039/C3NR00114H
AP Griset, J Walpole, R Liu, A Gaffey, YL Colson, and MW. Grinstaff. (2009) “Expansile Nanoparticles: Synthesis, Characterization, and In vivo Efficacy of an Acid-Responsive Polymeric Drug Delivery System.” Journal of the American Chemical Society, 131, 2469-2471