R&D Digest: The monthly review of new technologies and medical device innovations.
Porous microspheres are loaded with drugs in both the walls and lumens of the beads. The beads are absorbed by the body over a controlled period of time.
By precisely targeting cancerous cells, a drug-delivery device could dramatically improve a cancer patient's quality of life. The goal is to reduce the side effects of chemotherapy and to prevent the deaths that may result from high drug doses. Researchers anticipate that the technology will be a more-direct and -controlled way of killing cancer cells. The current method involves injecting a chemotherapy drug into a patient's vein so that it is transported around the body.
“The objective of our work is to develop a novel multidrug-delivery vehicle, based on biodegradable microfibers and microspheres, that is capable of providing extended and controlled release to a targeted site,” says Semali Perera, group leader and senior lecturer of chemical and biochemical engineering at the University of Bath (Bath, UK).
The technology, called Fibrasorb, is “a flexible, fully resorbable device that can be formulated as beads, fibers, or mesh, or a tubular system connected via a line to an external port for easy alteration of a drug regimen,” says Perera. Biodegradable and compatible with body tissue, the device is soaked in a chemotherapy drug before being implanted into a cancerous site in the body. Perera says that beads could also be injected as a microsuspension into the abdominal cavity of a patient suffering from ovarian cancer.
A tubular device can be assembled from fibers shown here at different angles. The liquid drug is loaded into the lumen. If extended controlled release is required, drug-loaded microbeads can also be used.
The device size would depend on the type of solid tumor. Researchers have been producing drug-filled microfibers ranging from 40 to 200 µm using a biodegradable polymer. This carefully tailored fiber system would allow doctors to control the drug dose required for the patient over an extended period. The drug is integrated into the walls and lumen of the device. The combination enables the drug to be released over a large surface area, according to Perera. It also allows a slow, consistent, and precise drug release through the fiber walls as the fiber degrades. By accurately targeting the drug and controlling the dosage, Fibrasorb lessen some chemotherapy side effects. And it could help induce patients who may otherwise resist chemotherapy treatment.
The next move will be to optimize the design of the tubular device to make it easier to modify a patient's drug regimen. The researchers are also working with another university department on the sterility of the fibers to ensure that bacteria can't destroy or erode them.
The researchers are now conducting the second phase of preclinical work, but Perera says they need a funding partner to support their current work and the clinical trials. The initial trials, which could begin in a few years, will be conducted on patients with ovarian cancer.
A patent application has been filed. The university is also closely collaborating with the oncology team at the Royal United Hospital in Bath to develop the devices.