Tiny capsules deliver( A tiny particle syringe composed of ...),Health

A tiny particle syringe composed of polymer layers and nanoparticles may provide drug delivery that targets diseased cells without harming the rest of the body, according to a team of chemical engineers. This delivery system could be robust and flexible enough to deliver a variety of substances.

"People probably fear the effects of some treatments more than they fear the disease they treat," says Huda A. Jerri, graduate student, chemical engineering. "The drugs are poison. Treatment is a matter of dosage so that it kills the cancer and not the patient. Targeted treatment becomes very important."

Newer approaches to drug delivery include particles that find specific cells, latch on and release their drugs. Another approach allows the cells to engulf the particles, taking them into the cell and releasing the drug. However, the requirements for these delivery systems are complicated and challenging to implement.

The Penn State researchers' approach produces a more universal delivery system, a tiny spherical container averaging less than 5 microns or the diameter of the smallest pollen grains.

The spheres are formed around solid microparticles that are either the drug to be delivered or a substance that can be removed later leaving a hollow sphere for liquid drugs. They reported their results online in Soft Matter.

Alternating positive and negative layers of material form the microcapsules. The capsules are created while attached to a flat surface so the section of the sphere touching the surface is not coated, leaving about 5 percent of the surface as an escape area for the drugs. The microcapsule, excluding the exit hole, is then covered in a slippery, non-stick barrier coating.

"These are not the first microcapsules for drug delivery developed, but a previous attempt had surfaces that stuck together and clumped," says Velegol. "We also designed the tiny hole in the sphere for controlled delivery and that is a new develo
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