Magnetically Guided Nanocarriers Deliver Drug to Tumor Cells

University of Buffalo (UB, Buffalo, NY, www.buffalo.edu) researchers have developed a drugdelivery system that uses an external magnetic field to guidedrug-filled nanocarriers to cultured tumor cells. The nanocarriers weredeveloped from polymeric micelles, which are nanosized,water-dispersible clusters of polymeric molecules.

The research team encapsulated the photodynamic therapy (PDT) drug and iron oxide nanoparticles inside the nanocarriers, allowingmagnetophoretic-controlled delivery of the PDT drug once the magneticfield is applied.

Confocal microscopy confirmed the results of in vitro studies that demonstratedthe ability of this system to direct the nanocarriers to concentratemore precisely on tumor cells, thereby reducing theaccumulation of drug in normal tissues and increasing the cellularuptake of PDT drugs.

Although the research team demonstrated this system on PDT drugs, thetechnique could also facilitate gene therapy delivery, chemotherapy,and other treatments into cells, said Paras Prasad, PhD, executivedirector of UB's Institute for Lasers, Photonics, and Biophotonics in auniversity press release. "Because the nanocarriers proved to besignificantly stable and because they retained the PDT drugs, we areoptimistic that they will be able to deliver a wide range of therapiesto tumors or other disease sites in the body without any significantloss in the circulatory system or in normal tissues," he said.

PDT exploits the propensity of tumors to retain higher concentrationsof photosensitive drugs than normal tissues. These drugs generate toxicmolecules that destroy cancer cells once the drug is exposed to light."The magnetically guided drug delivery would allow for the use of lowerconcentrations of the drug to deliver a therapeutic dose, thussignificantly reducing the amount of PDT drug that accumulates innormal tissue," said Prasad.

Studies to demonstrate the effectiveness of the new deliverymethod in animal models are currently underway.