In Vitro/In Vivo Evaluation of Sustained Release of Glucagon-Like Peptide-1 (GLP-1) from Nanocomposite Hydrogel to Induce Angiogenesis

Abstract

Background: Glucagon-like peptide-1 (GLP-1) is a proglucagon hormone with cardioprotective effects and angiogenic ability. Results: Chitosan nanoparticles (65nm) possess the ability to encapsulate 65±4.1% of the GLP-1 used for the formulation of nanoparticles. Freeze-dried gels containing these particles released 40% of the total loaded GLP-1 during 192 hours. Field emission scanning electron microscopy was done to observe the morphology of particles both alone or when embedded into a gel. Results of in vivo studies and histological images showed that following the gradual release of GLP-1, new vessels formed into and around gels implanted into the back of rats. Through Drabkin assay, it was observed that the concentration of hemoglobin in the samples containing GLP-1 loading were similar to samples with VEGF loading, while a significant difference exists between hemoglobin concentration in sponges with or without GLP-1 release (P<0.05). Conclusion: Sustained release of GLP-1 induced new vessel formation in a subcutaneous in vivo model of angiogenesis. This system has the potential to induce angiogenesis in myocardial infarction situations.