Medical Devices : Drug delivery

UW–Madison researchers have developed a new microfluidic device that allows efficient, minimally invasive delivery of drugs within a tumor, sparing patients from the unnecessary drug toxicity of full and indeterminate chemotherapy regimens.

With nothing more than a hypodermic needle, researchers and clinicians are able to administer small implantable devices containing concentrations of chemotherapeutic compounds to the primary tumor. Each device remains anchored and stable by deploying small barbs upon implantation. Specific drugs or drug combinations can be delivered to different areas of the tumor. Surgical removal of the tumor with the devices in place enables assessment of drug efficacy on affected cells.

UW–Madison researchers have developed a new composite of tannin and chitosan.  The biodegradable and biocompatible composite can be formed into hydrogel films, 3-D foams, biogels, nanoparticles or liposome coatings for a variety of therapeutic applications.

This material combines the advantages of chitosan, which has blood-clotting and antimicrobial properties, with those of tannins, which have antibacterial, antifungal, antioxidant and wound healing properties.  As compared to chitosan alone, the composite has improved stability, higher drug loading capacity, better drug release properties, improved cell uptake, greater porosity, improved tensile strength and increased thermal stability.  In addition, this composite is non-cytotoxic in vitro.

UW–Madison researchers have developed a liquid-drug delivery device to autonomously and painlessly release pharmaceuticals through a bladder and microneedle system. The device consists of a bladder of a thick, rigid plastic along with a thin barrier film that is designed to have a microneedle fastened into its rigid side for drug delivery. A valve arrangement controls the flow of the drug solution from the chamber enclosed by the thin film and rigid plastic to the microneedle. The drug will be dispensed when the thin barrier film is displaced by a pressure source.

Advantages over traditional syringe-based systems include advanced functionalities such as custom delivery profiles, multiple-drug delivery and drug reconstitution. The system also has the potential to allow self-administration with minimal training, ultimately designed for ease-of-use to accommodate the general population. Furthermore, the device is simple to utilize and inexpensive to manufacture.

UW-Madison researchers have developed a simple and inexpensive method of mass producing biodegradable structures for tissue engineering and drug delivery applications. The method starts with a composite blend of a salt, a water-soluble polymer and a biodegradable polymer. A foaming agent and/or supercritical fluid may be added to the composite, which is injected into a mold to form components with complex geometries. After molding, the salt and water-soluble polymer are removed to result in a low density, biodegradable structure.