Drug Developers PRINT Disease-Specific Nanoparticles

A recent publication described a new technology that allows production of nanoparticles with well-defined sizes, shapes, and surface charges that have great potential as highly specific transporters of chemotherapeutic agents.

Investigators at the University of North Carolina (Chapel Hill, NC, USA) developed the technique, which is known as PRINT (Particle Replication in Non-wetting Templates). Details of the interaction between PRINT particles and HeLa cells was reported in the August 12, 2008, online edition of the journal the Proceedings of the [U.S.] National Academy of Sciences (PNAS). A key finding was that long, rod-shaped particles were internalized by cells approximately four times faster than lower aspect ratio particles, and traveled significantly further into the cells as well.

Unlike other particle fabrication techniques, PRINT is described by its inventors as being delicate and general enough to be compatible with a variety of important next-generation cancer therapeutic, detection, and imaging agents, including various cargos (e.g. DNA, proteins, chemotherapy drugs, biosensor dyes, radio-markers, contrast agents); targeting ligands (e.g. antibodies, cell targeting peptides); and functional matrix materials (e.g. bioabsorbable polymers, stimuli responsive matrices, etc.).

PRINT particles are presently being designed to reach new understandings and therapies in cancer prevention, diagnosis, and treatment. Early detection via targeted delivery of the imaging agent goes hand in hand with these new directions. Cellular targeting can be accomplished by attaching cell-specific ligands to the surface of the PRINT particle. Potential cell-specific ligands include the integrin receptor peptide (GRGDSP), melanocyte stimulating hormone, vasoactive intestinal peptide, anti-Her2 mouse antibodies, cell-penetrating peptides, and a variety of vitamins.

Once targeted with a cell specific ligand, the PRINT particle can be delivered and imaged at the desired site. In this respect, PRINT particles promise great potential, since it is possible to utilize the ability to specifically target, be shape and size-specific, possess tunable matrixes, as well as the ability to incorporate imaging contrast agents.

"This would mean that we could deliver lower dosages of drugs to specific cells and tissues in the body and actually be more effective in treating the cancer,” said senior author Dr. Joseph DeSimone, professor of chemistry at the University of North Carolina.

Liquidia Technologies (Durham, NC, USA) has an exclusive license to the PRINT technology and the company is developing engineered nanoparticles for delivery of nucleic acids and small molecule therapeutics. Neal Fowler, CEO of Liquidia Technologies said, "We are delighted to contribute to the important work that Professor DeSimone and his students are undertaking in the field of nanomedicine. This work answers key questions about the role of particle shape and size that industry leaders have been asking for some time.”

Related Links:
University of North Carolina
Liquidia Technologies