May 22 2007
Drug delivery systems have progressed from the teaspoon to time-release capsules to drug-eluting stents. Nanotechnology promises yet another advance by delivering therapeutic agents at desired rates exactly where needed in the body. In a paper presented at the NSTI Nanotech 2007 Conference, researchers at the University of California, San Francisco demonstrate how they have created nanotubes from biocompatible metal oxides that can hold therapeutic proteins or drugs and deliver these agents in a highly-controlled manner.
The fabrication strategies developed by the authors is flexible in terms of controlling the diameter and length scales of the tubes. By changing these physical parameters of nanotubes, they could precisely control the dosage and deliver drugs at physiological rates for desired duration of time. In the case of orthopedic implants with nanotubes on the implant surfaces, drugs such as antibiotics can be loaded in the tubes and released right at the site of implantation. This method, which targets the drug where it is needed, can avoid the side effects due to high dosages normally given to patients. Further, in cases where a very long treatment regimen is needed, such as in growth factor therapy, nanotubes may provide superior performance.
According to Ketul C. Popat, "When a person has an orthopedic implant surgery, they normally will have to take antibiotics and growth factors either orally or by injection. There are several side effects associated with taking drugs this way which can be very painful for the patient. However, by placing the drugs on to the surface of these implants, we can deliver them right where they are needed and can avoid larger doses and side effects. The nanostructured coating on the implant surface helps the drug to maintain its bioavailability as well as deliver the drugs at physiological rates for a desired duration of time."