Study provides proof-of-concept for the oral delivery of nanoparticles.
It is known that oral administration is a preferred method of drug delivery, and that formulation into nanoparticles can improve drug stability in the harsh gastrointestinal (GI) tract environment. However, diverse conditions in the GI tract, including varied pH, extensive mucus structure, numerous cell types, and various physiological functions are a barrier to effective oral delivery of nanoparticles. Now, a study from researchers at University of Utah Health modifies nanoparticles to improve their uptake in the gastrointestinal tract. The team state their proof-of-concept technology using nanoparticles could offer a new approach for oral medications. The study is published online in the journal ACS Nano.
Previous studies show that nanomedicine is a burgeoning field of medicine which delivers tiny particles, or nanoparticles, to carry drugs to treat a variety of conditions, including cancer. However, commonly nanoparticles have to be injected into the bloodstream due to the fact they aren’t absorbed well orally. The current study provides a proof-of-concept for a nanoparticle oral delivery system and propose pathways for oral nanoparticle absorption from the GI.
The current study modifies the surface of the nanoparticles with glycocholic acid, a bile acid that helps the body absorb fat in the small intestine; to monitor the nanoparticle movement, the researchers affixed a red fluorescence tag on the treated particles and watched as they circulated through the body. Results show that the glycocholic acid acts like a cloak, allowing the nanoparticle to slip incognito through the lining of the small intestine. Data findings show that the coating helps the nanoparticles bind to proteins which let them move into the gut lymphatic system where it can access the bloodstream.
Results show that when the team fed the modified nanoparticles to rats, approximately 47% of the particles made it into the blood, as opposed to the 7% seen for nanoparticles lacking bile acids. Data findings show that bile acids on the nanoparticles interact with a bile acid transporter found on the surface of enterocytes, which may help the nanoparticles move through the cells and into the circulation. The lab note that it takes about one to ten hours for the nanoparticles to appear in the bloodstream.
The team surmise their study proposes a pathway for oral nanoparticle absorption via the GI lymphatic system, utilising apical bile acid transporter-mediated cellular uptake. For the future, the researchers state that this work is still at the preliminary stages and more work is needed to move the results from animal studies to clinical trials.
Source: University of Utah Health