Korean scientists design magnetically controlled capsule to deliver drugs for gastrointestinal cancer
Korean scientists have designed a magnetically controlled wireless capsule that can efficiently and non-invasively deliver treatment drugs to patients who have gastrointestinal cancer.
Korean scientists have designed a magnetically controlled wireless capsule that can efficiently and non-invasively deliver treatment drugs to patients who have gastrointestinal cancer.
The tiny capsule can precisely deliver three patches of the anti-cancer drug doxorubicin to lesion locations in the gastrointestinal tract.
The new design has advantages over other systems because magnetic nanoparticles in the capsule can be externally manipulated to reach their specific target in the body. The new device also makes use of an adhesive hydrogel derived from mussels to attach the drug patch to the destination site and hold it there in the wet, mucosal environment of the intestine.
A team of scientists from the Robotics Engineering Department at Daegu Gyeongbuk Institute of Technology and the Division of Gastroenterology at Yonsei University College of Medicine describe the patch and capsule in the Wiley Online journal Advanced Intelligent Systems, Jan. 19.
Improved delivery system
The authors summarize the new capsule's attributes: "The proposed mucoadhesive patch has the following features. (1) It can be actively delivered to multiple target lesion sites using a magnetically actuated capsule. (2) It is fabricated using a mussel-inspired hydrogel that demonstrates biocompatibility, biodegradability, and improved adhesion to wet gastrointestinal tract surfaces. (3) It can perform a hyperthermia treatment and a controlled drug release at the desired time through a temperature rise using an AMF [alternating magnetic field] as an external stimulus."
The researchers then explain the fabrication of the capsule and their experiments to demonstrate how it works.
The capsule contains the patch delivery assembly with three patches and a cover that opens and closes, so that the patches are protected as the capsule moves. Each patch is layered with polyvinyl alcohol, chitosan-catechol, magnetic particles, and the drug doxorubicin. The polyvinyl alcohol layer keeps each patch separate.
Chitosan-catechol is the biodegradable mixture of a polysaccaride and the "mussel-inspired"-adhesive protein.
When the capsule reaches its target site in the gastrointestinal tract, guided by external magnets, it delivers the patch, which sticks to the spot. Then an external alternating magnetic field is applied to the patch, which heats up the patch's magnetic nanoparticles. These in turn heat the drug, releasing it to kill cancer cells.
The researchers carried out a variety of experiments to determine that each part of the capsule performed as planned. The delivery system was also tested on a pig small intestine. The experiments verified the capsule's successful performance as a concept, and the authors will now work on improvements for moving the capsule around the curved, narrow sections of digestive organs, especially if food is being digested. They also suggest adding an imaging camera to determine the capsule position or radio-frequency identification.
Short videos of the capsule at work can be found here.
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Jihun Lee et al., "Drug-Loaded Mucoadhesive Patch with Active Delivery and Controlled Releasing Ability," Advanced Intelligence Systems, Jan. 19, 2022.
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