"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 development."
Targeted drug delivery systems release their drug from the moment they enter the body. The microsyringes, however, while releasing material continuously, do so only from the tiny hole in their surface and not from the other 95 percent of the sphere's surface. This will concentrate the drug at the target and reduce the amount of toxins circulating in the body.
"These particles are delivery vessels to which you can add whatever you want when you need it," says Jerri. "Drugs can be either solid -- incorporated when the capsules are made -- or liquid -- filled later. Chemicals that target the diseased cells can be attached in a variety of ways."
To serve as viable, flexible drug delivery systems, these microcapsules should be off the shelf and not completely tailor made for each application. The researchers tested the robustness of the microsyringes by dehydrating and then reconstituting them. Their ability to withstand long periods dried out and then successfully rehydrate is important both for shelf life and because that is the way that liquid medications will be inserted in the microcapsules as needed.
To ensure that the spheres refill, the researchers used a solution containing fluorescent dyes. The filling and emptying of the microcapsules are controlled by the acidity of the liquid in which the tiny beads float. Successful rehydration and filling suggest that these microsyringes could be manufactured and stored until needed. They could then be filled with the appropriate drug and have the proper targeting agent attached to treat specific diseases and patients.
"The masking process used to manufacture these microcapsules is relatively inexpensive, current technology and is scalable," says Velegol. "This means they could be mass produced."
A'ndrea Elyse Messer | EurekAlert!
Small but versatile; key players in the marine nitrogen cycle can utilize cyanate and urea
10.12.2018 | Max-Planck-Institut für Marine Mikrobiologie
Carnegie Mellon researchers probe hydrogen bonds using new technique
10.12.2018 | Carnegie Mellon University
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals
Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.
Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.
Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...
Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.
The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.
10.12.2018 | Event News
06.12.2018 | Event News
03.12.2018 | Event News
10.12.2018 | Life Sciences
10.12.2018 | Physics and Astronomy
10.12.2018 | Life Sciences