New Nanoparticle System Achieves Nearly 10% Oral Bioavailability for Peptide Drug Exenatide | Research

The takeaway

Biomimetic chylomicron-like nanoparticles achieved 9.67% oral bioavailability for exenatide in diabetic rats by mimicking natural fat absorption pathways.

9.67% oral bioavailability
Achieved by mimicking natural chylomicron fat absorption pathway — remarkably high for an oral peptide drug

What the researchers found

Core-shell nanoparticles mimicking chylomicrons achieved 9.67% pharmacological bioavailability for oral exenatide, with 5.6-fold increased intestinal permeability and persistent hypoglycemic effects in type 2 diabetic rats.

Why it matters

Most peptide drugs require injection because they can't survive the GI tract. An oral delivery system achieving ~10% bioavailability could eliminate the need for daily or weekly injections of GLP-1 drugs, dramatically improving patient compliance.

How the study worked

In vitro characterization of HA-DOG/EAZ nanoparticles (enzymatic stability, mucosal penetration, intestinal permeability), followed by in vivo pharmacokinetic and pharmacodynamic studies in type 2 diabetic rats.

What this study cannot tell us

Only tested in rats; human GI conditions differ significantly. 9.67% bioavailability, while impressive for oral peptides, still means over 90% of the drug is lost. Manufacturing scalability not addressed. Long-term safety of the nanoparticle system unknown.

How to read the evidence

Preclinical study with thorough in vitro characterization and in vivo validation in diabetic rats. Promising but requires human translation.

When this study was published

Published in 2025, representing cutting-edge peptide oral delivery technology.

The bigger picture

Oral peptide delivery is one of the biggest challenges in drug development. This biomimetic approach that hijacks the body's natural fat absorption pathway represents a creative strategy that could be applied to many peptide and protein drugs beyond exenatide.

Questions still open

Can this chylomicron-mimicking approach achieve similar bioavailability in humans?
Could the same delivery platform work for other GLP-1 drugs like semaglutide or tirzepatide?
What is the long-term safety profile of repeated oral HA-DOG nanoparticle administration?

Common questions

Why can't you just swallow most peptide drugs?

Peptide drugs are proteins that get broken down by stomach acid and digestive enzymes before they can be absorbed. This study's nanoparticle system protects the peptide and helps it cross the intestinal barrier by mimicking how the body naturally absorbs fats.

What does 9.67% bioavailability mean and is it good?

It means about 10% of the oral dose reaches the bloodstream in active form. While that sounds low, most oral peptide attempts achieve less than 1%. For comparison, oral semaglutide (Rybelsus) has about 1% bioavailability, so 9.67% is a significant improvement.

Read the original research

Design of biomimetic chylomicrons based on 1,3-diolein grafted hyaluronic acid to drive biomacromolecules across the intestinal mucosal barrier.

Journal of controlled release : official journal of the Controlled Release Society, 390, 114504

View on PubMed ↗Publisher’s paper ↗

Citation

Cui, Shuman; An, Yalin; Cui, Zhixiang; Liu, Shiyun; Li, Hongfang; Wen, Xiangce; Guan, Jian; Mao, Shirui; Yi, Han; Zhang, Xin. (2026). Design of biomimetic chylomicrons based on 1,3-diolein grafted hyaluronic acid to drive biomacromolecules across the intestinal mucosal barrier.. Journal of controlled release : official journal of the Controlled Release Society, 390, 114504. https://doi.org/10.1016/j.jconrel.2025.114504