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Thiol functionalized polymethacrylic acid-based hydrogel microparticles for oral insulin delivery
S Sajeesh1, C Vauthier, C Gueutin
1Biosurface Technology Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India.
Acta Biomaterialia
|February 11, 2010
Summary
Thiol-functionalized hydrogel microparticles show promise for oral insulin delivery. These modified particles improved insulin absorption and reduced blood glucose levels in diabetic rats.
Area of Science:
- Biomaterials Science
- Drug Delivery Systems
- Nanotechnology
Background:
- Oral delivery of protein therapeutics like insulin is challenging due to enzymatic degradation and poor absorption.
- Hydrogel microparticles offer a potential platform for protecting and delivering sensitive biomolecules.
- Thiol functionalization can enhance mucoadhesion and improve transport across biological barriers.
Purpose of the Study:
- To develop and evaluate thiol-functionalized polymethacrylic acid-polyethylene glycol-chitosan (PCP) hydrogel microparticles for oral insulin delivery.
- To investigate the impact of thiol modification on particle properties, insulin loading, release, and stability.
- To assess the efficacy of these microparticles in enhancing insulin absorption and reducing blood glucose levels in a diabetic rat model.
Main Methods:
- Synthesis of thiol-functionalized Cys-PCP hydrogel microparticles by grafting cysteine.
- Characterization of swelling, insulin loading/release kinetics, and protease inhibition.
- In vitro insulin transport studies using Caco-2 cell monolayers and Ussing chamber.
- In vivo evaluation of blood glucose reduction in streptozotocin-induced diabetic rats.
Main Results:
- Thiolated Cys-PCP microparticles exhibited reduced swelling and lower insulin encapsulation efficiency compared to unmodified PCP.
- Both PCP and Cys-PCP microparticles demonstrated in vitro protease inhibition.
- Thiolation enhanced insulin absorption across Caco-2 cells, though less effectively in excised rat intestinal tissue.
- Insulin-loaded functionalized microparticles elicited a more significant pharmacological response in diabetic rats.
Conclusions:
- Thiolation of PCP hydrogel microparticles is a promising strategy for improving oral protein and peptide delivery.
- The functionalized microparticles demonstrate potential for enhancing insulin bioavailability and therapeutic efficacy.
- Further research may optimize thiolation strategies for improved oral bioavailability of protein drugs.
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