Drug Delivery and Translational Research

, Volume 8, Issue 3, pp 857–862 | Cite as

Sustained exenatide delivery via intracapsular microspheres for improved survival and function of microencapsulated porcine islets

  • Benjamin Lew
  • In-Yong Kim
  • Hyungsoo ChoiEmail author
  • Kyekyoon (Kevin) KimEmail author
Short Communication


The ability of glucagon-like peptide-1 analogs to enhance glucose-dependent insulin secretion and to inhibit β cell apoptosis could be of potential benefit for islet transplantation. In this study, we investigated the effect of sustained local delivery of exenatide, a synthetic exendin-4, on the in vitro viability and function of encapsulated porcine islets. Prior to encapsulation, we fabricated exenatide-loaded poly(latic-co-glycolic acid) microspheres, and investigated their release behavior with different initial drug-loading amounts. Exenatide-loaded microspheres, exhibiting a sustained release over 21 days, were subsequently chosen and co-encapsulated with porcine islets in alginate microcapsules. During the 21-day period, the islets co-encapsulated with the exenatide-loaded microspheres exhibited improved survival and glucose-stimulated insulin secretion, compared to those without. This suggested that the intracapsular sustained delivery of exenatide via microspheres could be a promising strategy for improving survival and function of microencapsulated porcine islets for islet xenotransplantation.


Porcine islets Exenatide Microspheres Microcapsules Islet encapsulation Islet xenotransplantation 



This work was carried out in part in the Frederick Seitz Materials Research Laboratory Central Facilities and Beckman Institute for Advanced Science and Technology, University of Illinois.


Financial support for this work was partially provided by the Research Board and Kim-Fund of the University of Illinois.

Compliance with ethical standards

All institutional and national guidelines for the care and use of laboratory animals were followed.

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Controlled Release Society 2018

Authors and Affiliations

  1. 1.Department of Electrical and Computer EngineeringUniversity of IllinoisUrbanaUSA
  2. 2.Department of Biotechnology, College of Life Sciences and BiotechnologyKorea UniversitySeoulSouth Korea
  3. 3.Micro and Nanotechnology LaboratoryUniversity of IllinoisUrbanaUSA
  4. 4.Department of BioengineeringUniversity of IllinoisUrbanaUSA
  5. 5.Department of Materials Science and EngineeringUniversity of IllinoisUrbanaUSA

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