Injectable gellan/gelatin microspheres for the treatment of heart failure

Injectable scaffolds are receiving a great interest as strategies to repair the infarcted myocardium. The aim of this work was the preparation and characterization of injectable microspheres for myocardial tissue engineering. Gellan/gelatin microspheres were prepared by a single water-in oil emulsion, using phosphatidylcholine as surfactant. The obtained particles underwent morphological, physicochemical and functional investigation. Loading with IGF-1 was then performed by adsorption. Loaded and unloaded particles, in combination with rat cardiac progenitor cells, were injected after cryoinjury on the rat heart. The morphological analysis showed a spherical shape and microporous surface. The infrared analysis confirmed the presence of interactions among the functional groups of the two biopolymers. Injectability through a narrow needle was verified. Preliminary in vivo tests, performed by three intramyocardial injections of cell loaded microspheres in a rat model of myocardial injury, documented that progenitor cells homed to the damaged myocardium and IGF-1 functionalization increased their engraftment. The results obtained showed adequate morphological, physicochemical, functional and biological properties for application as injectable scaffold for myocardial repair. This work was supported by the European Commission FP7 Programme, grant 214539.