August 01, 2018
Scientists at Drexel University are making progress in the development of a new capsule that can durably transport medicine through the bloodstream to target physical ailments intravenously.
In tests and experiments supported by the National Science Foundation, a research team with Drexel's College of Engineering successfully proved the efficacy of a unique polymer described as a crystalsome. The tightly sealed drug delivery capsule, created in a lab in 2016, appears capable of outlasting the artificial nanoparticle packaging currently in wide use.
“Delivery vessels have traditionally been designed to avoid recognition by the immune system by mimicking naturally occurring materials in the body, such as cells or liposomes,” Christopher Li, a materials science professor, said in a university news release. “But the problem with the previously reported artificial carriers is that they’re not always durable enough to get to the far reaches of the body.”
Because the body is designed to target and eliminate foreign objects, the challenge of intravenous drug delivery becomes a matter of encasing medicine in a material that can remain camouflaged long enough to reach the intended target.
The crystalsome nanocapsules developed at Drexel are comprised of poly-L-lactide acid, which makes up the spherical casing, and poly-ethylene glycol to form a whisker-like surface defense against the body's immune systems.
“Crystalsomes structurally mimic the classical liposome and polymersomes used for drug delivery, yet mechanically they are more robust thanks to their single crystal-like shell,” Li continued.
Li and assistant materials science professor Hao Cheng recently published their experimental findings in the journal Nature Communications, producing promising data on the durability of their block copolymer crystalsomes.
Test results found that the crystalsomes have a 24-hour half-life and can last in the bloodstream for up to 96 hours.
“Crystalsomes are closely sealed so that medication will not be released until it reaches the target sites," Li said. "Thus medication can be delivered in higher doses, as desired, to afflictions in the body, without causing severe side-effects associated with the early release of the medicine. And a more direct intravenous delivery means that treatments are likely to be more effective.”
Researchers believe the findings could signal a new generation of long-circulating nano materials for drug delivery and gene therapy.
The study, available for review here, was also supported by the Pennsylvania Department of Health.